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AnatomyPNS — Transcript

by Dr. Naveen Jalota, M.D. · 12,564 words · 1,871 segments · language en · Watch on YouTube

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0:00hello there let's talk peripheral
0:03nervous system today so peripheral
0:05nervous system yeah here we'll see if
0:07you follow the note-taker it's the best
0:09way to go through if you're using the
0:11book it jumps around chapters 14 15 17
0:13and so forth so let's talk peripheral
0:16nervous system now when we talk
0:18peripheral nervous system you've seen
0:20we've gone through and we've already
0:21talked about this division and we've
0:22mentioned this division is going to be
0:24made up of everything outside of the
0:26central nervous system and when we say
0:28everything outside of the central
0:29nervous system we looked at what the
0:31central nervous system itself is made up
0:33of and the central nervous system itself
0:35is made up of the brain in the spinal
0:36cord excuse me so everything outside of
0:40the brain in the spinal cord now is
0:42going to be mainly made up of the nerves
0:43so here when we go through and we talk
0:45peripheral nervous system we're talking
0:47all neural structures outside the brain
0:50and the spinal cord that is now the
0:54sensory receptors your peripheral nerves
1:00your peripheral nerves and also their
1:05associated ganglia and their associated
1:08ganglia but we talked about ganglia
1:12we've mentioned the term ganglia you
1:14should all be familiar with the term
1:15ganglia now and also the efferent motor
1:19endings and the efferent motor endings
1:22so when we talk receptors let's talk
1:26first sensory receptors make a first
1:29component here that when we talk sensory
1:30receptors sensory receptors we'll see
1:33are going to be a cell that's going to
1:39be specialized to respond to stimuli so
1:46cells that are going to be responsible
1:50or specialized to responding to stimuli
1:56now what's a stimuli a stimuli is going
1:59to be a change in the environment excuse
2:03me it'll be a change in the environment
2:05that's what a stimuli is
2:12so here now when we go through and we
2:14talk sensory receptors their function
2:17now is to get stimulated their function
2:20is to get stimulated then in turn
2:24trigger nerve impulses then in turn
2:30trigger nerve impulses along the
2:33afferent along the afferent pns fibers
2:46which are going to be coursing towards
2:49the CNS which are coursing towards the
2:53CNS now when we go through and we talk
3:04receptors I want you to know we have
3:06various types of receptors and these
3:08receptors they are going to be
3:11classified a few different ways first
3:14we'll go through and we'll look at you
3:17know one type of classification that
3:19will move to the next and we'll move to
3:20the third now when we look at the
3:21classifications you'll see
3:23classification here of the receptors is
3:26going to be done by three basically
3:28methods no there's three ways these
3:31receptors are classified so first here
3:33you'll see receptors are going to be
3:34classified according to the type of
3:36stimulus that they're going to detect
3:38first we'll see they're going to be
3:40classified according to the type of
3:42stimulus that they detect so stimulus
3:45type they're classified by second our
3:49receptors are going to be classified by
3:51their body location by their location on
3:55the body by their location and third
4:01then by their structural complexity
4:02third then by their structural
4:04complexity we'll look at the receptors
4:06structure and we'll talk about that so
4:11let's go through and let's talk first
4:13there's classification according to the
4:15type of stimulus that the receptors will
4:18detect now when we go through and we
4:20classify our receptors according to the
4:22type of stimulus that they will detect
4:24we'll see here they
4:26going to be named according to the
4:29activating stimulus they will be named
4:32according to the activating stimulus so
4:35here the first classification of
4:37receptors that we'll have are going to
4:38be Meccano receptors now when we talk
4:41about Meccano receptors Meccano
4:44receptors are receptors that respond to
4:47mechanical forces they respond to
4:51mechanical forces they respond to
4:53mechanical forces and we talk mechanical
4:55forces these are going to be forces such
4:58as touch pressure vibration and stretch
5:13so those are mechanoreceptors they
5:16respond to those types of stimuli then
5:20we have thermal receptors when we talk
5:22thermo receptors thermo receptors
5:23they're going to be sensitive to
5:26temperature changes they are sensitive
5:29to temperature changes so they detect
5:35changes in temperature so the name kind
5:39of there is giving it away as well you
5:41can see thermo and same thing with
5:42Meccano now as well and then photo
5:45receptors the third type photo receptors
5:48now photo receptors they are receptors
5:50such as those found in the retina such
5:53as those found making up the retina and
5:56photo receptors you guessed it they're
6:01going to respond to light stimuli very
6:04good they respond to light stimuli then
6:11here the fourth classification are going
6:13to be chemo receptors now when we talk
6:15about chemo receptors chemo receptors
6:16are receptors that are going to detect
6:18changes in relation to our basically
6:26taste buds and our sense of smell so
6:29when we go through we talk chemo
6:30receptors they respond to chemicals in
6:33solutions they respond to chemicals in
6:37solutions
6:38so molecules again that are smelled or
6:40tasted and also if we have changes in
6:47the blood or interstitial fluid as well
6:50chemoreceptors are going to be
6:51responsible for detecting those changes
6:53so respond to chemicals and solutions
6:58and the fifth type then will be the
7:02nociceptors nociceptors nam we talked
7:04nociceptors nociceptors are gonna
7:06respond to damaging stimuli that results
7:10in pain they respond to damaging stimuli
7:14that result in pain for example searing
7:20heat extreme cold excessive pressure
7:30candy v'n inflammatory chemicals they're
7:34all interpreted as painful now these
7:39signals these signals here they also
7:41stimulate these signals are also going
7:44to stimulate subtypes of thermoreceptors
7:48Meccano receptors and even chemo
7:51receptors so nociceptors
7:58next then you have this classification
8:00according to the location in the body
8:03now when we go through we talk about the
8:05location in the location according to
8:09the body here we're going to see we've
8:10got three main classifications here
8:13first we're going to have X Tarot's
8:16scepters first we have what we call
8:18external receptors next then we're going
8:24to have after X taro receptors we have
8:28them our entero receptors our inteiro
8:31receptors and then third our proprio
8:34receptors as we can see here so x
8:36sterile four in Tarot and proprio so
8:40we've gone through classes by stimulus
8:46okay here now we're
8:48looking at location in the body so here
8:53we've got now first Xterra receptors now
8:56our Xterra receptors are going to be
8:57sensitive to stimuli that's arising
9:00outside the body they are sensitive to
9:03stimuli that's found arising from the
9:05outside of the body and the name again
9:07that the prefix there in the name is
9:10helping to kind of give that away also
9:11we could see here too so stimuli arising
9:17outside the body or also near or at the
9:24body surface so outside the body and
9:30near or at the body surface and this
9:34will include this will include your
9:37receptors for touch it'll include your
9:40receptors for pressure pain and
9:44temperature receptors in the skin and
9:48most of your special senses they'll get
9:50classified here in this category of
9:52Xterra receptors next and we have our
9:58inteiro receptors our inteiro receptors
10:01now when we talk about entero receptors
10:04will see our in terror receptors they're
10:07also known as our visceral receptors
10:11also known as our visceral receptors
10:16visceral receptors visceral because
10:19we're going to see now when we talk they
10:21respond to stimuli that's going to be
10:23arising within the body they respond to
10:27stimuli that's going to be arising
10:28within the body such as from internal
10:33viscera such as from our internal
10:36viscera and our blood vessels so again
10:41the prefix there is helping you out you
10:43got to use that to advantage next and we
10:48have our third classification of
10:51receptors according to the location in
10:55the in relation to the location of the
10:58body we have here now proprio receptors
11:00now our probe
11:02receptors they're gonna respond to
11:04internal stimuli they respond to
11:08internal stimuli now this internal
11:09stimuli is gonna arise it all arise in
11:11skeletal muscle from our tendons from
11:18our joints from our ligaments and from
11:26the connective tissue that's covering
11:29our bone and muscle and you should know
11:33the names of both of those hey we talked
11:35bone outside right around around that
11:42prefix we've discussed is very good
11:46peri-peri now pertaining to bone then we
11:50have peri ostium all right connective
11:54tissue in relation to muscle very good
11:58very good
11:59epi my seal can't be my seal that be my
12:05cm not happy mycelium epimysium epi my s
12:14I um if you remember we talked about how
12:20that happen my cm is basically this
12:21fashio and it blends in with other
12:24fashio and it's going to be extending
12:27sometimes beyond the muscle to help form
12:29the tendon right and that's in one type
12:32of attachment and then we had another
12:33type of attachment so it gets all into
12:35that but just from again talking about
12:38that layer out there so next then let's
12:42move through and let's talk
12:44classification according to the
12:46receptors structure let's talk according
12:48to receptors structure so when we talk
12:50according to receptor structure here
12:53we're going to see we have a couple of
12:54major classifications now here first
12:57we're going to see we have what we call
12:59simple receptors and then what we have
13:01what we're gonna refer to then as you'll
13:04see basically our more complex receptors
13:09there we'll talk about then next so
13:11first let's talk our simple receptors
13:13now when we talk simple
13:15scepters simple receptors are going to
13:18be modified dendritic endings they are
13:22modified dendritic endings of sensory
13:26neurons of sensory neurons so modified
13:29dendritic endings of sensory neurons and
13:36they're gonna be found throughout the
13:37body they're going to be found
13:39throughout the body and they monitor
13:42they monitor most types of general
13:45sensory information
13:47these simple receptors do now when we
13:52talk simple receptors will see these
13:54simple receptors themselves now are
13:58going to get further sub classified into
14:02onion capsulated dendritic endings and
14:07encapsulated dendritic endings so here
14:09we can see we've got first our onion
14:12capsulated nerve endings and then we're
14:15gonna go to the encapsulated nerve
14:17endings as you can see on the next slide
14:19so going back to the onion capsule and
14:21in dendritic endings the first type that
14:24we have here are going to be our free
14:26nerve endings our free nerve endings now
14:30when we talk about our free nerve
14:32endings we'll see when we talk about our
14:35free nerve endings we're going to see
14:37their present nearly everywhere in the
14:39body they're found present nearly
14:41everywhere in the body they're
14:44particularly abundant in epithelia and
14:48connective tissue they are particularly
14:51abundant in epithelia and in connective
14:55tissue so here we can see a nice image
14:58depicting to us our first type of
15:02uninflated dendritic ending which we
15:05said is a free nerve endings so here we
15:07can see one image depicting those free
15:09nerve endings again they are going to be
15:11of they're of sensory neurons their
15:16present nearly everywhere in the body
15:18they're particularly abundant we said in
15:20epithelia and in connective tissue now
15:24we'll see most sensory fibers
15:29sensory fibers are unmyelinated and
15:36their distal endings will end or they're
15:41going to have these little nob like
15:43swellings and their distal endings are
15:46going to have these nob like swellings
15:51so again those are going to be our free
15:54nerve endings our free nerve endings are
15:58going to include warm receptors called
16:00receptors and even nociceptors the
16:05second type of uninflated dendritic
16:08ending you'll be responsible for knowing
16:09about are going to be your tactile discs
16:13or your Merkel discs your tactile discs
16:18or your Merkel discs which we can see
16:21right inside of here now when we talk
16:24about these tactile discs or Merkel or
16:27Merkel discs these are free nerve
16:31endings that are associated with disk
16:37shaped epidermal cells so again these
16:42are free nerve endings so we can see
16:44that right inside of here that are going
16:46to be associated with enlarged disc
16:50shaped epidermal cells and eye bells
16:54should have already been ringing off
16:55we've talked about these before we we
16:58talked about these before and we talked
17:00about them before in relation to skin
17:03they're going to be found in a specific
17:06layer there as well we described they're
17:08found in the stratum basalt lay the
17:09deepest layer of the epidermis now when
17:13we talk about these merkel discs these
17:15Merkel discs they're going to function
17:17as light touch receptors and pressure
17:23receptors so they sense light touch and
17:26pressure
17:32so again tactile or Merkel disks so it's
17:38a free nerve endings associated with a
17:39cell we've again I've said that before
17:42already now it not just now but in again
17:46chapters before next we have our hair
17:50follicle receptors now we talk here
17:51follicle receptors here we can
17:53appreciate our hair follicle receptors
17:55when we talk hair follicle receptors
17:57they are free nerve endings that wrap
18:00again we've talked about these before as
18:02well there are free nerve endings that
18:04wrap basket like I've described to you
18:06guys before they wrap basket like around
18:10hair follicles and I also told you
18:13before that they are light touch
18:14receptors they are light touch receptors
18:17that are going to be responsible for
18:19detecting the bending of hairs they're
18:22responsible for detecting the bending of
18:26hairs mosquitoes flies they come and
18:34they sit on the hair and this is gonna
18:36basically then activate those receptors
18:39and letting us be aware of having
18:41something there so movement in relation
18:45to hair so hair receptors or peri treat
18:52you'll endings also known as so next and
18:59we'll move from our onion capsulated
19:01nerve endings right true then our
19:05encapsulated attorney encapsulate
19:07generate candida nerve endings now this
19:09is that second sub classification that i
19:10mentioned here in in relation to
19:12structural complexity so here then we
19:15can see now when we talk about our
19:17encapsulated dendritic endings now
19:20encapsulated in region and then capsule
19:23a dendritic and exists is telling a lot
19:25of information there just the term
19:26itself know the name itself now these
19:29encapsulated dendritic endings they're
19:31going to consist of one or more fiber
19:34they're gonna consist of one or more
19:36fiber terminal of sensory neurons right
19:40one or more fiber terminal of these
19:44sensory neurons
19:46that are enclosed that are going to be
19:49enclosed in a connective tissue capsule
19:53that are going to be enclosed in a
19:55connective tissue capsule now when we
20:02talk about our encapsulated dendritic
20:04endings you'll see most of our
20:05encapsulated dendritic endings are types
20:08of mechanoreceptors they're gonna be
20:10types of mechanoreceptors and majority
20:18of our receptors are going to be simple
20:20receptors they fall under this
20:23classification here of simple receptors
20:26now when we talk our encapsulated
20:30dendritic endings our encapsulated
20:31reading endings are going to include now
20:34number one we've got what we refer to as
20:36meissner's corpuscles or tactile
20:39corpuscles so you can see that right
20:41inside of here okay and here we can see
20:44our tactile corpus closed very well now
20:48we talk about our tactile corpuscles or
20:50meissner's corpuscle these are small
20:52receptors they're going to be small
20:54receptors you can there are oval masses
20:57in dermal papillae they're basically
21:00these oval masses in our dermal papillae
21:04so small receptors in which a few
21:08spiraling sensory terminals you can see
21:13here in which a few spiraling sensory
21:17terminals are surrounded by Schwann
21:20cells they're surrounded by Schwann
21:24cells and then by a thin egg-shaped
21:29connective tissue capsule and then by a
21:33thin egg-shaped connective tissue
21:37capsule so again they're found beneath
21:42the epidermis we said in the dermal
21:44papillae numerous found in sensitive and
21:53hairless skin regions numerous
21:58quantities found in sensitive and
22:00hairless skin regions like the nipples
22:03like the fingertips and the soles of our
22:08feet
22:20so again they're going to serve as light
22:25touch receptors and texture perception
22:34so they're involved with light they're
22:37sensing light touch and texture
22:39perception next after meissner's
22:47corpuscle x' we're going to have than
22:48what we had referred to as our pacinian
22:51corpuscles our pacinian corpuscle or our
22:55lamellar corpuscles now when we talk
22:58pacinian corpuscles or lamellar
23:00corpuscles
23:01they're known as lamella lated
23:03corpuscles basically now here when we
23:06talk to lamellar corpuscles you'll see
23:08these lamellar corpuscles are going to
23:09be scattered deep in the dermis they are
23:12scattered deep in the dermis scattered
23:19deep in the dermis and in the
23:22subcutaneous tissue that's underlying
23:24the skin and in subcutaneous tissue that
23:28is underlying the skin these lamellar
23:39pacinian corpuscle you can refer to them
23:41as they are looking onion like you can
23:44see here they look onion like or a
23:47potato like kind of as well I guess you
23:49could say same thing as the bulbous
23:51corpuscles say they look onion like now
23:56these lamellar corpuscles they're going
23:58to sense deep pressure excuse me they're
24:04gonna sense deep pressure now they
24:06respond only when pressure is first
24:08applied they're gonna respond only when
24:11pressure is first applied so there
24:20you'll see also responsible for
24:22detecting stretch our tickle receptors
24:28my articles and vibrations and
24:31vibrations
24:33so deep pressure when this pressure is
24:35first applied so they're better for
24:37vibrations and then stretch and tickle
24:40as well these are the largest
24:47corpuscular receptors we're going to see
24:52so here coming back excuse me
24:55we can see now they're the largest
24:57corpuscular receptor now here we're
25:00going to see the dendrite is covered or
25:03surrounded by a capsule of like 60
25:08layers it's surrounded by a capsule like
25:1260 layers of collagen fibers and cells
25:16and you can see how that's quite thick
25:25next and we have what we refer to as our
25:28Ruffini endings or bulbous corpuscles
25:32our bulbous corpuscles or Ruffini
25:35endings now when we talk
25:37Ruffini endings our bulbous corpuscles
25:39they're gonna be found located you'll
25:41see in the dermis in subcutaneous tissue
25:49in the dermis in subcutaneous tissue and
25:55our joint capsules and our joint
25:59capsules they're a bit flat you'll see
26:04in structure so again our bulbous
26:07corpuscles so they contain receptor
26:16endings enclosed by a flattened capsule
26:21enclosed by a flattened capsule so hence
26:23the term flat here and these receptors
26:27they respond to deep and continuous
26:31pressure so they sense pressure deep and
26:33continuous pressure so more specifically
26:35speaking this stretch of skin so skin
26:40stretch and also
26:45movements and joint movement so our
26:51Ruffini endings are our bulbous
26:53corpuscles next and we have our end
26:57bulbs and bulbs are basically Kraus
27:02corpuscles now they're going to be
27:04similar to tactile corpuscles but not
27:07located in mucous membranes they're not
27:11located in mucous membranes okay so here
27:17we can see those end balls
27:22next and we have our muscle spindles our
27:27Golgi tendon organs and then joint
27:32kinesthetic receptors so here we're
27:36gonna look at muscle spindles muscle
27:37spindles they're going to be basically
27:39in relation to fusiform muscle here
27:42we're going to see and we're going to
27:46see now when we go through and we talk
27:55all right so muscle spindles and Golgi
28:04tendon organs and joint kinesthetic
28:05receptors again now when we talk muscle
28:07spindles muscle spindles are going to be
28:10found we'll see in relation to the
28:13perimysium they're gonna be found in
28:15relation to the perimysium
28:17and what they do is they're going to
28:19detect stretch they detect stretch and
28:22they initiate a reflex they detect
28:26stretch and they initiate a reflex here
28:29you can appreciate those muscle spindles
28:31now very nicely next time we have our
28:37Golgi tendon organs and we talk Golgi
28:40tendon organs they're leaf-like so the
28:42muscle spindles refuse deform like now
28:44here you know kind of like a fusiform
28:47when we talk to the shape of muscles and
28:49whatnot there as well here now we can
28:53see so they're going to be
28:59fusiform in shape next in here when we
29:01go to Golgi tendon organs now
29:04these go to tendon organs what they're
29:05going to do is they're going to sense
29:07stretch that's caused by muscle activity
29:09so they sense stretch that's going to be
29:12caused by muscle activity and then our
29:16joint kinesthetic receptors now will
29:18detect stretch then in relation to our
29:19joints in relation to our joints so
29:23these were again our simple receptors
29:26our simple receptors next and here we
29:28have what we call our complex receptors
29:31now we talk complex receptors we'll see
29:34our complex receptors they're going to
29:37be receptors for our special senses they
29:41are receptors for our special senses now
29:44these complex receptors are going to be
29:47receptors that are going to be housed
29:48they are going to be housed they will be
29:57housed in complex sense organs they will
30:01be housed in complex sense organs now
30:07when we talk about these complex
30:08receptors these complex receptors they
30:10are localized collections of cells they
30:13are localized collections of cells that
30:15are going to be associated with our
30:17special senses they are going to be
30:19associated with our special senses now
30:23when we talk special senses special
30:25senses are gonna include our special
30:26sense basically a sense for vision
30:28hearing my equilibrium smell and even
30:34taste and even taste now we jump to
30:41nerves and let's talk nerves now when we
30:45talk nerves here we can see a nice
30:47depiction of a nerve we've talked
30:49already about nerves and here we can see
30:52now when we go through we talk nerves
30:53there cord like organs we've got a nice
30:56view here as well they record like
30:59organs and they are a part of our
31:01peripheral nervous system right we've
31:03already established that and they are
31:05going to vary in size some are going to
31:08be thicker and some will be thinner some
31:11will be long
31:12some will be shorter so they will vary
31:15in size and they consist of parallel
31:18bundles of peripheral axons as we've
31:20described and these axons can be
31:23myelinated or unmyelinated here we can
31:25see examples of myelinated axons right
31:29inside of here and then here you can see
31:35both myelinated and unmyelinated fibers
31:40so both different types of fibers there
31:43now when we go through we talk nerves
31:45first component I'd like to talk to you
31:47about in relation to nerves is going to
31:49be the EPI nerium the EPI Nerium now
31:53when we talk about the EPI Miriam the
31:54epineurium is a tough fibrous sheath
31:57it's a tough fibrous sheath that
32:01encloses all the fascicles it encloses
32:05all the fascicles so here you can see a
32:08whole bunch of fascicles here's one
32:10fascicle your second fascicle third
32:12fascicle and here's the fourth fascicle
32:14so it encloses all these fascicles to
32:17help form a nerve to help form a
32:20complete nerve so that's the EPI nerium
32:23it's a tough fibrous sheath that
32:26encloses all the fascicles to form the
32:29actual nerve next in here you can see
32:33it's the nerve is made up of a whole
32:34bunch of fascicles so here we can see
32:36now we've got four different fascicles
32:38are being depicted here if we move back
32:40to this picture you can see one two
32:42three four five six seven eight
32:45different fascicles and again one has
32:47been basically removed from that nerve
32:49to give you the idea of that one
32:51fascicle same thing that's been occurred
32:54basically something that's taking place
32:55here as well now when we talk this one
32:58fascicle in relation to the fascicles we
33:00have what we call peri Nerium peri
33:02Nerium now peri Nerium is gonna be a
33:04coarser connective tissue it's a
33:06slightly coarser of a connective tissue
33:09and it's a it's again a coarser
33:11connective tissue wrapping and it's
33:13going to be found
33:14binding groups of fibers or binding
33:18groups of axons you can say there as
33:21well
33:21into bundles are into fascicles so when
33:24we talk again peri Miriam
33:26it's going to be found as a coarser
33:30connective tissue wrapping that binds
33:33groups of fibers or axons that binds
33:37groups of fibers or axons into bundles
33:39or in to fascicles so that's peri nerium
33:45next then here we move further in this
33:47is like muscle exact same thing as we
33:49did with muscle now here we move further
33:51in then we can see a whole bunch of
33:53axons now we'll pull one individual axon
33:56out of there when we talk axons you can
33:58see in relation to the axon you've got
34:00now endo Nerium endo Nerium when we talk
34:04endo Nerium and dhoni reham is a
34:06delicate layer of loose connective
34:09tissue it is a delicate layer of loose
34:12connective tissue that encloses the
34:16fibers it's a delicate layer of loose
34:19connective tissue that encloses the
34:21fibers that are associated I'm sorry it
34:25encloses the fibers and it's gonna
34:28enclose you can see the myelin that's
34:31associated with that fiber as well so it
34:37surrounds the axon along with the axon
34:40it encloses the myelin in there as well
34:41if that axon is a myelinated axon so
34:49that's how we refer to nerves as being
34:51bundles of axons so you can see that
34:54they're now very nicely along with that
34:56you've got a couple of blood vessels you
34:57can see there an artery being depicted
34:59in red and here we have our vein being
35:02depicted in blue and we'll learn more
35:03about them as we progress and you'll see
35:05what their functions are in relation to
35:08the body and not just a body but here in
35:10the nerves as well so let's move then
35:14let's talk about the general
35:16classification of our nerves now when we
35:18go through we generally classify our
35:20nerves here we're going to see some of
35:23our nerves are going to be classified as
35:26being sensory nerves as being basically
35:28a forint nerves and some will be
35:30classified as motor nerves and then some
35:34will be classified as mixed nerves there
35:36as well now when we go through we talk
35:39about our a prett v
35:40we've seen they're carrying sensory
35:42information this information is gonna be
35:43making its way towards the CNS it's
35:46gonna be making its way from the
35:48receptors towards the CNS a friend
35:51fibers efferent fibers are doing the
35:53opposite now they're carrying motor
35:55signals from the CNS to your effector
35:58organs we talked the effector organs
35:59we've mentioned effector organs are
36:01going to be your muscles and your glands
36:04now your somatic fibers they're going to
36:07innervate skin skeletal muscle bone and
36:09joints and then this little fibers
36:12obviously you can see blood vessels
36:14glands and then the viscera so we have
36:18general fibers and we have special
36:19fibers there you can see as well now
36:23here what this is taking us into now is
36:25going to be eventually the cranial
36:27nerves so when we talk sensory nerves
36:28they carry impulses towards the CNS
36:31afferent fibers are going to be carrying
36:33away then we talk mix nerves talk mix
36:36nerves
36:37both to CNS and away from CNS so right
36:40mix to and from and like I said that
36:47this is taking us to our cranial nerves
36:49this is taking us to our cranial nerves
36:52now when we talk cranial nerves cranial
36:54nerves we can see here we have 12 pairs
36:56here we're going to need to know them
36:59not only by name you can see they're
37:01also by Roman numeral number provided
37:04that for you there as well and also by
37:06normal Arabic numbers we use 1 through
37:0812 here we can appreciate all 12 pairs
37:13of cranial nerves in this view here what
37:17we'll do is we'll go through each of
37:18them one by one and check out each of
37:20them individually one by one another
37:23diagram depicting the same exact thing
37:25going through them here one by one line
37:28you to understand which one is where so
37:30you gotta use all your resources let's
37:35start here with them cranial nerve
37:36number 1 cranial nerve number 1 cranial
37:39nerve number 1 is going to be the
37:41olfactory nerve our olfactory nerve here
37:44you can see now they have basically you
37:48can they've highlighted optic nerve here
37:50they're trying to show two nerves in one
37:51but we're really focusing on this
37:53here the olfactory nerve so here you can
37:55see that nerve right inside of here
37:57medial to the optic nerve on both sides
38:00now when we go through and we talk this
38:03olfactory nerve let's move here to this
38:07view you can actually appreciate that
38:08nerve there in greater detail now here
38:12you can see now when we go through and
38:14we talk now when we go to and we talk
38:25olfactory nerve you can see the
38:27olfactory nerve is going to be found
38:30located seated on the cribriform plate
38:32it's found located seated on the
38:35cribriform plate of the ethmoid bone if
38:38you recall and then we had openings we
38:42have holes you should know the name of
38:43those openings there as well cuz we've
38:44discussed all of this before this is a
38:47kind of wind all of this on lines
38:49transition occurred and we've got the
38:51olfactory foramina the cribriform
38:52parameter there as well that are gonna
38:54allow you can see now these filaments to
38:55basically penetrate now when we talk
38:59about cranial nerve number one cranial
39:01nerve number one it's function now it's
39:03function is a sensory function its
39:05function is to carry smell impulses it
39:09carries smell impulses now and it's
39:13gonna be carrying these impulses
39:15obviously towards the central nervous
39:16system as we discussed so here we can
39:19appreciate the olfactory nerve the
39:22olfactory nerve has got a couple of
39:23divisions to it you can see here first
39:25is a tract that's why I taught you these
39:27terms before and here you can see is the
39:29olfactory bulb what we're gonna do is
39:31we're gonna look inside of this bulb and
39:32see why it's widened out here next in
39:38here we can move over to cranial nerve
39:40number two cranial nerve number two is
39:42the optic nerve cranial nerve number two
39:48is going to have some parts to it we're
39:50gonna go through we're going to check
39:51out first here we have what we call the
39:52optic chiasma and this is the crossover
39:56point and then here we can see the optic
39:59tracts basically bilaterally so
40:05we talked optic nerve cranial nerve
40:07number two cranial nerve number two is
40:09going to arise from the retina it will
40:13arise from the retina and you can see
40:15it's found located on the inferior
40:17aspect of that frontal lobe running
40:21towards then you can see here the
40:23pituitary gland and anterior to the
40:26pituitary gland is where you can see
40:27that crossover the optic chiasma and
40:30then you can see just lateral to it
40:33bilaterally the optic tract will then
40:36continue now cranial nerve number two
40:39cranial nerve number two is a sensory
40:42nerve and it's responsible main function
40:44here is going to be to carry vision
40:46impulses I'd like you to know about it's
40:48going to carry vision impulses and we're
40:53going to see in physio and physios we're
40:54gonna see how it will come into play you
40:57can actually actually go through and see
40:58that retina in greater detail we're
41:00gonna cover that in here and they're
41:02gonna have to actually know what each of
41:04these cells are doing in terms of
41:07physiology the electrical events that
41:09are taking place leading to the brain
41:12knowing basically what's happening
41:14interpreting these visual stimuli are
41:18using memory and using you know
41:20basically missed information that's been
41:22stored there and saying oh yeah I you
41:24know mr. John hi miss Jane and you know
41:29being able to recognize and knowing
41:30basically what you have there you don't
41:32walk in you know who are you after
41:34you've been in you know same classes
41:36same vicinity with somebody for 16 weeks
41:38okay so optic nerve carries vision
41:42impulses Kerry's vision impulses sensory
41:44nerve now you have to know also whether
41:46there's sensory or motor along with
41:47knowing the names created or of number
41:51three cranial nerve number three so we
41:53can move to then next cranial nerve
41:55number three here they're depicting to
41:57us three and four again some of these
41:58pictures they try to do too and in here
42:00what we'll do is we'll go to just the
42:01one so here we can see cranial nerve
42:03number three cranial nerve number three
42:05is the oculomotor nerve it's the ocular
42:08motor nerve it's motor in function motor
42:13function location you can see it's gonna
42:16make its way from the ventral mid
42:19right it makes its way from that ventral
42:21midbrain all the way over to that
42:26orbital cavity to help come in and
42:30innervate we can see extrinsic eye
42:33muscles to help come and innervate
42:36extrinsic eye muscles so motor in
42:40respect to function and we say motor its
42:43function is to provide motor innervation
42:46to certain eye muscles to certain eye
42:50muscles now which I muscles will see
42:53number one is going to be the inferior
42:56oblique eye muscle the inferior oblique
42:59eye muscle number two the superior
43:04rectus muscle the superior rectus muscle
43:10number three the inferior rectus muscle
43:15and then number four the medial rectus
43:21muscle
43:37next then here we've got cranial nerve
43:39number four cranial nerve number four is
43:42going to be the trochlear nerve so
43:44cranial nerve number three was the
43:45oculomotor nerve oculomotor trochlear
43:52nerve cranial nerve number four
43:53trochlear nerve cranial nerve number
43:56four is going to be found located
43:58arising from that ventral midbrain as
44:00well making its way over to the eye
44:04where it's going to provide motor
44:06innervation to the superior oblique
44:09muscle it will provide motor innervation
44:12to the superior oblique muscle next and
44:21we have cranial nerve number five
44:25cranial nerve number five here's number
44:28five being depicted along with five six
44:31here let's check out five and its
44:34entirety
44:36cranial nerve number five is going to be
44:40known as the trigeminal nerve this nerve
44:43does both motor and sensory this nerve
44:48cranial nerve number five is going to be
44:51found located at the ventral aspect of
44:53the pons making its way over to then you
44:57can see the face making its way over to
45:02the face it runs from this lateral
45:04aspect or it helps innervate them to
45:07face cranial nerve number five is going
45:10to have three major divisions to it
45:13first division is the ophthalmic
45:16division we can see here so here is the
45:19trigeminal nerve cranial nerve number
45:20five and here you can see we've got the
45:25ophthalmic division v1 or 5:1 right it's
45:29being depicted as and in the second
45:32division we can see here is the
45:34maxillary division v2 or 5/2 maxillary
45:38division and the number 3 here we've got
45:40the mandibular division 5 3 or v3
45:45mandibular division now
45:49when we go through when we talk
45:50trigeminal nerve trigeminal nerve is
45:52going to be providing major sensory
45:57innervation so it's a major sensory
45:59nerve of the face major sensory nerve of
46:02the face and it provides motor
46:06innervation to our chewing muscles so
46:11sensory innervation to the face and
46:13motor innervation to our chewing muscles
46:16and motor innervation to our chewing
46:18muscles cranial nerve number 6 then we
46:23have next cranial nerve number 6 now
46:27when we talk cranial nerve number 6
46:28cranial nerve number six is the abducens
46:30nerve the abducens nerve cranial nerve
46:33number six is going to be providing
46:35strictly motor innervation makes its way
46:38you can see from the inferior aspect of
46:41the palm so the superior aspect you can
46:43save the medulla oblongata over it to
46:46the eye go over to that orbital socket
46:48where it provides motor innervation and
46:51it provides motor innervation now you
46:54can see to the lateral rectus I muscle
47:00cranial nerve number you saw number for
47:03providing innervation cranial nerve
47:09number four we stopped providing
47:11innervation to the superior obliques of
47:12now here we've got number six providing
47:15innervation and it's providing
47:17innervation you can see to the lateral
47:18rectus muscle so this concludes all six
47:21extrinsic eye muscles cranial nerve
47:26number six abducens nerve let's move
47:29them to cranial nerve number seven
47:31cranial nerve number seven cranial nerve
47:33number seven now you can see is going to
47:37be known as the facial nerve it's a very
47:41major branch facial nerve this facial
47:43nerve does both motor and sensory the
47:46spatial nerve has five divisions to it
47:49it's got five divisions here you can
47:52appreciate all five divisions now you
47:54can see first we're going to have first
47:57we have the temporal branch you can hear
48:01the depicting it with the hand to give
48:02you are five and you can kind of a you
48:05know you can put that right inside of
48:08basically on this side here you can see
48:10okay or you can see same thing basically
48:13right inside here so all five branches
48:15you've got there
48:16so temporal zygomatic and and obviously
48:20you can you can kind of think of a
48:21temporal region zygomatic bones
48:23zygomatic buccal mandibular and I here
48:27you can see you that cervical so making
48:30its way all the way through this nerve
48:32by dividing into these five branches and
48:35those five branches are going to now
48:37you'll see be responsible for being the
48:40chief motor nerve to the muscles of the
48:43face to the muscles of the face and our
48:45facial expression muscles sensory it
48:49will provide sensory innervation to that
48:52taste buds of the anterior two-thirds of
48:55the tongue it will provide sensory
48:58innervation to the taste buds of the
49:00anterior two-thirds of the tongue and
49:03that branch more specifically speaking
49:06is going to be the chorda tympani the
49:11chorda tympani branch you have to be
49:14you'll be responsive or knowing about
49:18next time let's move to cranial nerve
49:20number eight when we talk cranial nerve
49:22number eight cranial nerve number eight
49:23you can see now is going to be the
49:27vestibulocochlear nerve so again two
49:29nerves being depicted let's look at the
49:30one let's stimulate cochlear nerve and
49:33we talk to vestibule cochlear nerve
49:34located you can see it's going to be
49:37making its way now from also that
49:42ventral medulla oblongata right inferior
49:46to the pond so all in that area there
49:48and here you can see now it's gonna be
49:51kind of moving a little bit more lateral
49:53now if we were to go back to this
49:54picture here in this original picture
49:55you can relate all of this to here okay
49:58so here you can see you've got six seven
50:01eight and then nine and then 10 and then
50:0411 and then here's gonna be 12 so you
50:06can see how they're all curving around
50:09so here then when we talk
50:11vestibulocochlear nerve it's got two
50:13parts to it so it's a
50:15mixed nerve it's gonna be fighting motor
50:17and sensory innervation motor it
50:19provides to the outer hair cells of the
50:22cochlea excuse me
50:24motor it's gonna provide to the outer
50:25hair cells of the cochlea sensory
50:30innervation it will provide sensory
50:31innervation to the vestibular apparatus
50:33it provides sensory and from a sensory
50:37innervation you can see here to the
50:40vestibular apparatus we talk vestibular
50:43apparatus the vestibular apparatus we'll
50:46see is going to be made up of the
50:48semicircular canals in the vestibule and
50:51also provide sensory innervation to that
50:52coach Leo as well cranial nerve number
50:57nine cranial nerve number nine
50:58glossopharyngeal nerve we talk cranial
51:01nerve number nine glossopharyngeal nerve
51:03glossopharyngeal nerve now you can see
51:05is going to be also providing a book
51:08motor and sensory it also again now
51:11location so you've got understand now
51:12from that again from this medulla
51:16oblongata you can see right inside of
51:17there making its way now to you can see
51:20basically that oral cavity and along
51:22with that making its way down into the
51:24throat area as well so when we talk
51:26glossopharyngeal glossopharyngeal tongue
51:29pharynx right it's all in that name so
51:31glossopharyngeal is gonna provide motor
51:33to some muscles of the tongue and the
51:36pharynx so provides motor innervation to
51:39some muscles of the tongue and the
51:41pharynx we can see that there very
51:42nicely and sensory innervation sensory
51:45to the taste buds of the posterior
51:49one-third of the tongue so taste to the
51:54posterior one-third of the tongue and
51:56the pharynx next and we've got cranial
52:03nerve number ten cranial nerve number 10
52:06is the vagus nerve and when we talk
52:09vagus nerve cranial nerve remember ten
52:11vagus nerve is going to be doing both
52:14motor and sensory and it supplies our
52:17visceral organs it supplies our visceral
52:21organs
52:28cranial nerve number 11 cranial nerve
52:32number 11 is the accessory nerve the
52:35accessory nerve is going to be you can
52:38see formed by spinal nerves it's formed
52:42by spinal nerves so spinal nerves are
52:44going to make their way up into that
52:47cranial cavity via this foramen we've
52:51talked about before in Fryman magnum and
52:53then they're going to you can see curve
52:55around come together with other fibers
52:57curve around and exit exiting that
53:01jugular foramen as that accessory nerve
53:05you can see so that accessory nerve then
53:07provides motor innervation to the
53:08sternocleidomastoid muscle and also to
53:11the trapezius muscle so motor
53:15innervation to the traps and the sternal
53:17and the sternocleidomastoid cranial
53:25nerve number 12 cranial nerve number 12
53:27is the hypoglossal nerve hypoglossal
53:31nerve is a motor nerve it's gonna
53:34provide motor to the muscles of the
53:38tongue so it's a tongue motor nerve
53:42basically you can think of provides
53:44innervation to the majority of the
53:47tongue muscles coming back to Kenya note
53:53number 10 it also provides sensory
53:56innervation relation to taste at the
53:57most dorsal aspect of basically that
54:01throat and epiglottis area and all the
54:03way deep and do that pharynx so taste
54:06you can see three different nerves that
54:08are gonna be involved there so all
54:14cranial nerves 12 pairs of cranial
54:16nerves come up with mnemonics easiest
54:19way to do that is by coming up with
54:20mnemonics a lot of students will use
54:24mnemonics for also the motor and sensory
54:26or you know the mixed component there as
54:30well next and we have our spinal nerves
54:34let's talk spinal nerves now when we go
54:37through we talk spinal nerves here
54:39Before we jump in there's a couple of
54:40nirodh
54:41diseases we want to mention there as
54:43well Alzheimer's and Parkinson's
54:45Parkinson's we've already gone through
54:46we've talked about and we've mentioned
54:48so you've got that down there as well so
54:50make sure you go through and understand
54:51the rest of this there and then here
54:53we've got Alzheimer's Alzheimer's I want
54:55you guys know basically what we're gonna
54:56have happen here is they're going to
54:58have atrophy of the gyri of the cerebral
55:00cortex and the hippocampus so we've
55:02talked about the functions of these
55:03areas there and that's why then you'll
55:04see memory loss right we talked about
55:07memory loss and it be found in certain
55:09areas and then also reduced attention
55:11span disorientation they you see there
55:13as well in these patients and now in
55:15their actual labs you can see in scans
55:18of the brain neurofibrillary tangles and
55:21then also see now plaques that start to
55:23accumulate so the one basically a couple
55:26of methods of diagnosing Alzheimer's
55:27disease and obviously that's not going
55:30to happen until you know you do not
55:32Topsy so that's unfortunate they're next
55:37in here you can appreciate basically
55:39what you're gonna see with Alzheimer's
55:40that atrophy of the chyron right we saw
55:43how they normally are nice and pulp
55:44plump you can see there and here you can
55:47see some of those tangles in the plaques
55:51spinal nerves then we talk spinal nerve
55:53spinal nerves we have 31 pairs of spinal
55:56nerves 31 pairs 31 pairs how do you
55:59remember this and they're all mixed
56:00nerves how do you remember this 31 pairs
56:03you have to go to get all the names down
56:04no no no no no they're gonna be numbered
56:06they won't be named so that'll be a
56:08little easy one way to remember 31
56:10flavors 31 flavors baskin-robbins right
56:13my one of my favorite places to go and
56:16eat ice cream it's one of the original
56:18places that have still been there I
56:21think about ice cream I wanna go there
56:23now I don't know if they're essential or
56:25not I think they're essential at a time
56:26like this I'm gonna call and find out so
56:29let's get this taken care of when we
56:30talk a spinal nerves 31 pairs they're
56:33gonna be named according to their point
56:35of issue from the spinal cord right
56:38we've gone through we've talked about
56:40the cervical vertebra so those are gonna
56:41be our land marks basically there and
56:43we're gonna see these nerves are gonna
56:44emerge either above or below the the
56:47vertebra from which they're going to be
56:48named so here when we go through we talk
56:50spinal nerves 31 pairs each have
56:53thousands of nerve
56:54so each of these nerves are gonna have
56:56thousands of nerve fibers and like I
56:58said they're gonna arise from the spinal
57:00cord and they're gonna supply all parts
57:02of the body they will supply all parts
57:04of the body except the head and some
57:07areas of the neck except for the head
57:09and some areas of the neck and like I
57:13said before all are going to be mixed
57:14nerves all are mixed nerds now when we
57:17go through we talk about these nerves
57:18these nerves are going to be named again
57:21according to the region they're going to
57:22be emerging from so here when we go
57:24through we classify them will classify
57:26them according to the region so first we
57:27have cervical nerves then we talked
57:30cervical nerves as you can see here we
57:31can see we're going to have eight pairs
57:33of cervical nerves they're going to be
57:35named c1 through c c1 through c8 the
57:40first seven the first seven are going to
57:44exit the intervertebral foramina
57:51superior to the vertebra for which they
57:54are named but c8 c8 is going to emerge
58:01inferior to the seventh vertebra next
58:11and we have our thoracic spinal nerves
58:13we talked thoracic spinal nerves 12
58:16pairs they're named
58:18t1 through t12 12 pairs of thoracic
58:23nerves t1 through t12 next we have our
58:29lumbar neurs lumbar nerves we have five
58:32pairs five pairs of lumbar nerves
58:35they're named l1 through l5 that's my
58:40dog snoring I know if you guys can see
58:44rusty rusty boy sorry to wake up
58:54l1 through l5 l1 through l5 lumbar
59:00nerves sacral nerves we have five pairs
59:04of sacral nerves and they're going to be
59:06named as one through s5 s1 through s5
59:10and then we have our coccygeal nerve one
59:15pair and the coccygeal nerve is written
59:18or it's known as the nerve C 0 or C 0 1
59:23it's a tiny coccygeal nerve a tiny Cox a
59:27tumor now let's talk about the general
59:32structure of these nerves and how
59:35they're emerging and what not so here
59:37let's go through and let's move over to
59:39this picture right inside of here this
59:43picture here depicts the same thing but
59:45without the division of that spinal
59:46nerve so here we can see now we've got
59:49these spinal nerves now these spinal
59:51nerves we've got first the nerve is made
59:54up from the dorsal root the dorsal root
59:57already talked about we said it's formed
59:59from the reutlitz so the rootlets come
1:00:00together to give rise to the root so
1:00:03here you can appreciate the dorsal roots
1:00:04the dorsal roots of the spinal nerves
1:00:06are going to contain sensory I told you
1:00:09fibers they're gonna contain sensory
1:00:11fibers or afferent fibers and these
1:00:13fibers are gonna arise from the various
1:00:16sensory neurons so these fibers arise
1:00:21from the sensory neurons in the dorsal
1:00:23root ganglia and then they're gonna
1:00:26conduct impulses from those peripheral
1:00:30receptors to a spinal cord now our
1:00:34ventral roots ventral roots they contain
1:00:38we said the in the other chapters one
1:00:40previous chapter they contain motor or
1:00:42efferent fibers don't contain motor or
1:00:45efferent fibers that are gonna arise
1:00:50from the ventral horn motor neurons that
1:00:53will arise from the ventral horn motor
1:00:58neurons and they're gonna extend to and
1:01:03they will extend to and they will
1:01:05innervate the skeletal
1:01:07you'll extend to and innervate skeletal
1:01:11muscles and then again you can
1:01:16appreciate all the rootlets I told you
1:01:17the rootlets will give rise to each of
1:01:18the roots then you have the dorsal Ram I
1:01:23now the dorsal Ram I here we can
1:01:26appreciate now the spinal nerve
1:01:27penetrates through the intervertebral
1:01:29foramina you can see it divides it'll
1:01:31split into two and here we've got first
1:01:34the dorsal Ramon's the dorsal ramus is
1:01:36the branch that's running posterior it's
1:01:39running towards the dorsal aspect hence
1:01:42the name dorsal ramus it's very short
1:01:45it's a small division it's a small
1:01:48division of the spinal nerve and it's
1:01:50found almost immediately after emerging
1:01:52from its parameter like the spinal
1:01:56nerves they're going to carry like the
1:02:01spinal nerves they're going to carry
1:02:05motor and sensory fibers it basically
1:02:12those rama are going to be you'll see
1:02:14all mixed next and we have the ventral
1:02:17rami ventral ramus is the more it's a
1:02:21more larger division running towards the
1:02:26anterior aspect running more ventral
1:02:29running more anterior necks and we have
1:02:36the Rama community contests the RAM eye
1:02:39community contests and the RAM eye
1:02:41community contests are going to join the
1:02:45various Ram I together they will help
1:02:48join the various Ram I together
1:02:56next is nerve plexuses nerve plexuses
1:03:00now we'll move backwards we can see here
1:03:03nerve plexuses they're going to be
1:03:05complicated interlacing x' they are
1:03:08complicated interlacing of the ventral
1:03:12ram i they're complicated interlacing x'
1:03:15of the ventral ram i of the spinal
1:03:18nerves will
1:03:21see except for t12 I'm sorry except for
1:03:23tea I'm sorry from t2 down to tweet t12
1:03:27okay so from t2 down to about t12
1:03:32all the ventral Ram I all the ventral
1:03:37Ram I do not form those plexus easier so
1:03:49we talked plexuses they're complicated
1:03:52interlacing of the ventral Ram I have
1:03:54the spinal nerves
1:03:56except for t2 to t12 these branches
1:04:01don't go off and form these complicated
1:04:04interlacing these plexus ease you see
1:04:06here you see that very well they're not
1:04:08forming these complicated interlacing
1:04:11these plexuses as you see lateral to the
1:04:17vertebral column in certain areas so all
1:04:23the ventral Ram I are gonna branch and
1:04:27then they're going to join one another
1:04:30and they join one another lateral to the
1:04:33vertebral column to form the plexuses to
1:04:37form these plexus ease so when you talk
1:04:40about the innervation of the back the
1:04:43innervation of the back is accomplished
1:04:45via the dorsal Ram I it'll be
1:04:49accomplished via the dorsal Ram I now
1:04:52the innervation of the back is gonna
1:04:53follow a nice neat segmented plan you'll
1:04:58see all the way through here we have a
1:05:00nice view that depicts that to you right
1:05:03inside of here
1:05:04same thing you're seeing right in there
1:05:07same thing you're seeing right inside of
1:05:09there and right inside of there
1:05:16appreciate it here better hear hear all
1:05:18those dorsal grab my posterior Ram way
1:05:22so the innervation of the back
1:05:24innervates in line with these nerves are
1:05:30gonna innervate in line with their point
1:05:31of emergence from that spinal cord from
1:05:34there
1:05:34point of emergence from the spinal cord
1:05:40now when we talk innovation of the
1:05:42thorax now we talk innovation of the
1:05:44thorax we can move right back to this
1:05:45picture here these intercostal nerves
1:05:48these intercostal nerves they're formed
1:05:51from the ventral rami of t2 down to t12
1:05:54even t1 is contributing a branch there
1:05:57as well so ventral rami of t1 will say
1:05:59to t12 these ventral rami are gonna
1:06:01course anteriorly deep to each rib deep
1:06:06to each rib in class I'll usually ask
1:06:09you guys what's the name of the
1:06:11structure that they pass through in
1:06:13relation to the rib we talked about when
1:06:15we talked ribs and usually one person
1:06:18will remember a costal groove costal
1:06:21groove I usually give like ten extra
1:06:22credit points because only one person
1:06:24maybe remembers but you gotta remember
1:06:27that there as well the costal groove so
1:06:29you'll see that intercostal nerve
1:06:30basically a whole bunch of blood vessels
1:06:32are all going to be passing right
1:06:34through that inferior aspect of that rib
1:06:37so if you don't know where that costal
1:06:38groove is I suggest you go back and you
1:06:40look at that costal groove because it's
1:06:42gonna be an important landmark when it
1:06:44comes to inserting tubes into the chest
1:06:46you want to go and you want to stay away
1:06:48from that so to avoid the nerve the
1:06:50artery and basically these connective
1:06:53tissue structures that you can have
1:06:54there what we do is we go to and we
1:06:58penetrate in the intercostal a region to
1:07:00the superior border of the rib below so
1:07:04we stay away from that inferior border
1:07:06of the rib above because that's where
1:07:08you're gonna see basically this
1:07:10these structures passing through so here
1:07:13now when we go through again highly
1:07:15trained individuals you know physicians
1:07:18are who are trained to do that type of
1:07:20stuff and you'll see that when you are
1:07:22rotating to the hospitals so here when
1:07:24we go through we talk then intercostal
1:07:26nerves these intercostal nerves they're
1:07:29gonna branch and they're gonna supply
1:07:30the intercostal muscles they're gonna
1:07:33supply the muscles and the skin of the
1:07:36anterior lateral thorax and abdomen and
1:07:40they will supply the muscle in the skin
1:07:42of the anterior lateral thorax and
1:07:44abdomen
1:07:48and we have our cervical plexus let's go
1:07:50through each of these plexus ease now
1:07:51so first plexus we have is the cervical
1:07:53plexus now we talk cervical plexus
1:07:54cervical plexus I'd like you to know is
1:07:56going to be found located deep in the
1:07:59neck it's located deep in the neck
1:08:01buried under the sternocleidomastoid
1:08:05deep in the neck
1:08:07buried under the sternocleidomastoid and
1:08:09it's going to be formed by the ventral
1:08:11Ram I of the first four cervical nerves
1:08:14it will be formed by the ventral rami of
1:08:18the first four cervical nerves is what
1:08:19they say they're now the single most
1:08:23important nerve for you guys at this
1:08:25level is going to be the phrenic nerve
1:08:27here now one important herb making its
1:08:30way from the cervical plexus is going to
1:08:31be there's obviously way more branches
1:08:33coming off from there you've seen even
1:08:35some making its way in helping to form
1:08:37that's this cranial nerve that we talked
1:08:39about so cervical plexus deep in the
1:08:42neck buried under the
1:08:43sternocleidomastoid and the most
1:08:45important nerve comes from you is the
1:08:46phrenic nerve phrenic nerve is going to
1:08:48be a nerve that's gonna be responsible
1:08:50for providing innervation to the
1:08:52diaphragm muscle to the diaphragm muscle
1:08:55if you recall the diaphragm muscle is
1:08:57going to be the big biggest muscle of
1:08:59inspiration the biggest muscle of
1:09:01breathing right it separates the
1:09:03abdominal cavity from the thoracic
1:09:05cavity talking cavities
1:09:07my daughter had a little assignment I
1:09:12gave her to do when she read a book on
1:09:16caterpillars and butterflies and she had
1:09:18to go and do the anatomy tell me all the
1:09:21anatomy and go through and draw the
1:09:22butterfly and label all the parts there
1:09:26so I mean you know you've got to be
1:09:27doing activities like that for yourself
1:09:29here as well you know when you're
1:09:31studying it's just all you know just
1:09:32methods of studying and that's what I
1:09:34thought of you know as an assignment to
1:09:35provide to her so she had to tell me the
1:09:37thorax the abdomen and 10a the head so
1:09:40she learned those basic parts there and
1:09:42so she knows the thorax and we
1:09:44orientated it to the human body and did
1:09:47head thorax abdomen and then obviously
1:09:50we don't have antennae so you know I
1:09:53told her we have nerves so I don't know
1:09:55that's kind of what you've got to do
1:09:57there as well so here when we talk
1:09:59phrenic nerve phrenic nerve was going to
1:10:01be providing innervation they
1:10:02to the diaphragm we talk hiccups my over
1:10:07excitation of that diaphragm because of
1:10:10this phrenic nerve so you've got that
1:10:13kind of in line there as well so make
1:10:15sure you've got that understood next n
1:10:18is the brachial plexus the brachial
1:10:19plexus so we move further down and here
1:10:22we move further down and here we talk
1:10:24brachial plexus breaker plexus now is
1:10:28going to be another plexus here so it's
1:10:30a very large plexus the breaker box very
1:10:32important plexus this brachial plexus is
1:10:34situated partly in the neck and partly
1:10:37in the axilla partly in the neck and
1:10:39partner in the axilla it's going to give
1:10:41rise to all the nerves it gives rise to
1:10:44all the nerves that supply the upper lip
1:10:45gives rise to all the nerves that supply
1:10:48the upper lip now one major branch we're
1:10:50going to have here so let's move
1:10:51directly to these plexus ease and let's
1:10:54look at these plexus ease now in greater
1:10:56detail so ganglia you got there again we
1:10:58looked at the picture from the last
1:10:59presentation as well so here we've got
1:11:02all the different spinal nerves we've
1:11:03been talking about we've been mentioning
1:11:04and here you can see the distribution
1:11:07very nice pictures we've seen this
1:11:10picture as well right penetrating into
1:11:12that subarachnoid space so here's the
1:11:17different plexus ease that we've been
1:11:18going through we've been talking about
1:11:19here is the cervical plexus you can see
1:11:22in greater detail here we have that
1:11:23phrenic nerve now I want to also mention
1:11:25you guys so let's jump back to this
1:11:27cervical plexus this phrenic nerve is
1:11:28gonna be formed from nerve roots c3 c4
1:11:31and c5
1:11:32so one way to remember see three four
1:11:34five keep the diaphragm alive low
1:11:36kidsong C three four five keep the
1:11:39diaphragm alive and it also helps you to
1:11:40remember not only what is forming the
1:11:42phrenic nerve but what also the phrenic
1:11:44nerve is going to intervene so diaphragm
1:11:45so three four five keep the diaphragm
1:11:48alive okay one way to remember again
1:11:52that $750,000 knowledge I described to
1:11:54you guys so here you can see then
1:11:56cervical plexus break your plexus next
1:12:02step so we talked brachial plexus break
1:12:04your plexus is going to be formed from
1:12:08branches ventral branches c5 did c8 m t1
1:12:11okay and here you can see often in
1:12:14certain individuals we have
1:12:15we talk anatomical variability right
1:12:17here you can see even some individuals
1:12:20see 42 c4 down in t2 as well so more
1:12:24commonly speaking right normal is we
1:12:26don't say normal here because what are
1:12:28we to say somebody with the brachial
1:12:30plexus c4 this t2 is not normal they you
1:12:33know so when we talk about this
1:12:35distribution more commonly we talk about
1:12:37c5 to t1 okay so here when we go through
1:12:40we talk then branches from the brachial
1:12:43plexus branch to the brink of plexus
1:12:44we're going to see are going to be very
1:12:47important branches now here we go
1:12:48through we talk about the brachial
1:12:49plexus the breaker box is such a big
1:12:50plexus here that it's going to get
1:12:52divided up its gonna get its parts will
1:12:54get divided up into roots trunks
1:12:56divisions and chords and then branches
1:13:01so roots trunks division cords and then
1:13:04the individual branches when we go
1:13:06through we talk each individual nerve
1:13:08branch so that's what we're gonna have
1:13:09there so roots trunks roots trunks
1:13:12divisions cords and branches so here you
1:13:17can see all of that they're very well
1:13:19roots trunks divisions cords and then
1:13:28each individual branch one way to
1:13:31remember that I have a mnemonic there as
1:13:33well a $150,000 knowledge a joke with
1:13:35you guys with Randy Travis drinks cold
1:13:42beers Randy Travis drinks cold beers
1:13:46another one I
1:13:48my cousin he took the same class at UCLA
1:13:51he told me one was that he used was
1:13:54really thirsty
1:13:56drink cold really thirsty drink cold
1:14:05beers really thirsty drink cold beer I
1:14:07think that's what is was I'm not
1:14:09promoting that I'd say really thirsty
1:14:13drink cold beverages water right best
1:14:16beverage alright so here when we go
1:14:19through them we will go to each of these
1:14:21different branches now let's talk first
1:14:23the axillary nerve axillary nerve is
1:14:26going to be a branch off of the
1:14:28posterior cord
1:14:29it's a branch off of the posterior cord
1:14:31and the axillary nerve so it's a branch
1:14:34off of the posterior cord and it runs
1:14:37posterior to the surgical neck
1:14:39it runs posterior to the surgical neck
1:14:42it innervates the deltoid muscle it
1:14:47innervates the deltoid muscle I told you
1:14:49guys momentum we're done you're gonna
1:14:51know not only maoi muscle origin
1:14:54insertion in action but you're also
1:14:56gonna know nav maoi and nav nerve artery
1:15:00and vein for each of the muscles I mean
1:15:02that's the right way to do it if you
1:15:03learn anatomy I feel that we you've
1:15:06covered everything in relation to each
1:15:08and every one of these muscles that's
1:15:09what I did when I went to med school
1:15:10after this it's much easier to get this
1:15:13information down so here now innervates
1:15:16a deltoid muscle innervates at ares
1:15:18minor muscle and it also innervates
1:15:31alright so here we could see the
1:15:34axillary nerve so we've talked about the
1:15:37muscles that will be providing
1:15:39innervation to and deltoid muscle we
1:15:42said the teres minor muscle we said you
1:15:45can see that here very nicely and also
1:15:48the skin and the joint capsule of the
1:15:50shoulder this muscle this nerve this
1:15:53nerve when we look at this nerve this
1:15:55nerve you can see it's a branch I told
1:15:56you off the posterior cord and I want
1:15:58you to know this nerve is gonna run
1:15:59you'll see posterior to the surgical
1:16:01neck it will run posterior to the
1:16:04surgical neck now when it runs posterior
1:16:07to the surgical neck surgical neck if
1:16:09you recall we talked about there as well
1:16:11in relation to a very important bone the
1:16:12humerus bone and so you can see there
1:16:15now when that surgical neck we described
1:16:17as being the most common fractured part
1:16:21so if now that becomes fractured now not
1:16:23only are we gonna be concerned about the
1:16:24fracture but also we're gonna be
1:16:25concerned about this nerve damage there
1:16:28as well so two components to say the
1:16:31least
1:16:31that we have to be worried about there
1:16:33next in here let's move down from the
1:16:35axillary nerve to the musculocutaneous
1:16:37nerve now here we can appreciate the
1:16:39musculocutaneous nerve in yellow the
1:16:41musculocutaneous nerve
1:16:43is going to be a major end branch of the
1:16:47lateral cord it is a major end branch of
1:16:51the lateral cord and you can see it
1:16:54courses inferiorly in the anterior arm
1:16:57it will course inferiorly in the
1:17:00anterior arm and it will supply motor
1:17:04fibers of the biceps muscles
1:17:07it will provide motor innervation so to
1:17:09supply motor fibers of the biceps and
1:17:11the brachialis and the brachialis distal
1:17:15to the elbow then distal to the elbow it
1:17:18provides cutaneous sensation to the
1:17:21lateral forearm I know if you can see
1:17:24that here but cutaneous sensation to the
1:17:25lateral forearm just right outside of
1:17:28here next and we have the median nerve
1:17:33we talk median nerve the median nerve is
1:17:36going to descend through the arm to the
1:17:39anterior forearm it will descend through
1:17:43the arm to the anterior forearm it
1:17:46branches to the skin and the flexor
1:17:49muscles so descends through the arm to
1:17:52the anterior forum where branches to the
1:17:55skin and the flexor muscles
1:17:58it will also innervate the five extend
1:18:02defied intrinsic muscles of the palm it
1:18:05will also innervate the five intrinsic
1:18:07muscles of the palm this median nerve is
1:18:11also responsible for intervening the
1:18:15pronator z' the muscles that are
1:18:17involved in pronation again versus
1:18:19supination in pronation so the pro
1:18:25Nader's it also innervates the muscles
1:18:27that are gonna help flex the wrist and
1:18:29the fingers helps to flex the wrist and
1:18:32the fingers and also the muscles that
1:18:36are gonna help oppose the thumb and it
1:18:38innervates the muscles that oppose the
1:18:40thumb now the median nerve I'd like you
1:18:45to know is involved in carpal tunnel
1:18:47syndrome in carpal tunnel syndrome okay
1:18:50this nerve is passing right through
1:18:53you'll see the retina Coulomb that's
1:18:55basically
1:18:56helping to divide this forum from the
1:18:59wrist and as it passes through its real
1:19:01superficial and so you see this nerve
1:19:03gets compressed leading to than this
1:19:05pain the patients are described in
1:19:07carpal tunnel syndrome wrist slashings
1:19:12in wrist lashings one method of suicide
1:19:16people will will use can also lead to
1:19:21damage of the of the nerves and this may
1:19:24not be always a hundred percent
1:19:26successful and so that they end up
1:19:28having then this nerve damage just
1:19:30medium nerve damage what they're trying
1:19:32to do is they're trying to get their
1:19:32main arteries the ulnar artery and the
1:19:35radial artery to basically bleed out and
1:19:39this nervous wasting professional
1:19:40compared to those arteries next and we
1:19:44have the older nerve now when we talk
1:19:46all nerves the all our nerve you can see
1:19:48branches off of the medial cord branches
1:19:50off to the medial cord and it descends
1:19:53along the medial aspect of the arm it
1:19:56descends along the medial aspect of the
1:19:59arm towards the elbow and at the elbow
1:20:04it swings behind the medial epicondyle
1:20:07at the elbow it will swing behind the
1:20:10medial epicondyle then it follows the
1:20:13ulna along that media forearm then it
1:20:16will follow the ulna along all not you
1:20:20LNA along the medial forearm funny bone
1:20:28we describe funny bone you guys went
1:20:30through all the different bones of the
1:20:31body I don't remember seeing any funny
1:20:32bone anywhere in the body so we talk
1:20:35funny bone what we're actually in
1:20:36reference to what we're actually
1:20:37referencing there is going to be you'll
1:20:40see the ulnar nerve I describe the ulnar
1:20:42nerve is passing behind that medial
1:20:43epicondyle so that's what you have there
1:20:45now what happens here is that we end up
1:20:47stimulating that right in here and then
1:20:50that is what we refer to as the funny
1:20:51bone
1:20:53next and we have our radial nerve the
1:20:56radial nerve is the largest branch the
1:21:00radial nerve is going to be the
1:21:02posterior cord continuation it's
1:21:04basically the inferior continuation of
1:21:06the posterior cord the radial nerve
1:21:09wrapped
1:21:09the radial groove and then it runs
1:21:13around ever it's gonna run anteriorly
1:21:16around the lateral epicondyle so it
1:21:19wraps around the radial groove runs
1:21:22around runs anteriorly around the
1:21:26lateral epicondyle and it's gonna divide
1:21:29into two branches and it'll divide then
1:21:32into two branches here you can see that
1:21:36here very nicely okay we can see that
1:21:42here very well so coming down and you
1:21:46can see it starts to divide will give
1:21:49off then you can see this branch coming
1:21:50down here and divide off and will give
1:21:52off basically two branches next then we
1:21:56have wrist drops wrist drops damage to
1:22:00this radial nerve will lead to a wrist
1:22:02drop okay
1:22:04also we refer to this as a Saturday
1:22:07night palsy okay over Friday night palsy
1:22:10it became known as then now it's like
1:22:11Thursday night palsy you go to the bar
1:22:14you have too many drinks and you knock
1:22:17out basically on the chair there when
1:22:20you knock out right and this chair is
1:22:22too tall but let's say the chair ended
1:22:24like right here at barstool they usually
1:22:25end right here towards the back and you
1:22:27put your basically axilla right over it
1:22:30and you knock out and what that does is
1:22:32it pushes it pushes up in here and it
1:22:35pushes up against this radial nerve and
1:22:37causing compression of the radial nerve
1:22:40to occur and leading to then even this
1:22:41wrist drop in patients sometimes as well
1:22:43crutches crutches that's why if you have
1:22:45to use crutches there they'll tell you
1:22:48you got to put extra padding on top of
1:22:49the crutches so when it does push up in
1:22:52the axillary region it doesn't compress
1:22:53that radial nerve and lead to then you
1:22:57know any other compression there in
1:22:59relation to the radial nerve next let's
1:23:01move down let's move down to the lumbar
1:23:03plexus so here's a nice depiction of
1:23:05this brachial plexus there as well in
1:23:08our cadavers when we dissect the
1:23:09cadavers we usually dissect out the
1:23:12brachial plexus as well and you're able
1:23:14to see this very complex it's just like
1:23:15this in the cadavers I mean it's so
1:23:17beautiful when you get to appreciate
1:23:18these things on the cadavers as well
1:23:23so same thing there okay
1:23:29next in here we can see lumbar plexus we
1:23:33talk lumbar plexus the lumbar plexus
1:23:34arises from spinal nerves l1 through l5
1:23:39nerve cell 1 through l4 it's located
1:23:44found lying within the psoas major
1:23:47muscle it's found located lying within
1:23:49the psoas major muscle one major nerve
1:23:54we have from here is the femoral nerve
1:23:55the femoral nerve the femoral nerve is
1:23:57the largest terminal nerve of this
1:23:59plexus and the femoral nerve you can see
1:24:03is going to provide innervation to the
1:24:06anterior aspect of the thigh it'll
1:24:09provide innervation to the anterior
1:24:10aspect of the thigh we also have here
1:24:13the obturator nerve the obturator nerve
1:24:16it enters the medial thigh it enters the
1:24:19medial thigh I don't know if you recall
1:24:21via the obturator foramen we saw the
1:24:24obturator foramen we saw was formed from
1:24:27these various bumps so it makes its way
1:24:31into the medial thigh via the obturator
1:24:33foramen and it's responsible for
1:24:35innervating the adductor muscles
1:24:37it'll be responsible for innovating the
1:24:39adductor muscles next and we have the
1:24:45sacral plexus so we'll move just
1:24:47inferior or caudal to this from femoral
1:24:52plexus lumbar plexus
1:24:54and here we can appreciate end the
1:24:57sacral plexus now we talk sacral plexus
1:24:59sacral plexus it arises from spinal
1:25:02nerves l4 through s4 it arises from
1:25:06spinal nerves l4 through s4 and we talk
1:25:10sacral plexus sacral plexus lies
1:25:12immediately caudal to the lumbar plexus
1:25:15it's found lying immediately caudal to
1:25:21our a lot more plexus now major nerve we
1:25:24have here is a sciatic nerve sciatic
1:25:27nerve is the largest branch it's the
1:25:29thickest and longest nerve we're going
1:25:31to see in the body and it supplies the
1:25:34entire lower
1:25:35it'll supply the entire lower limb
1:25:37except for the anterior medial thigh
1:25:41that we just talked about this sciatic
1:25:45nerve you can see is formed from the
1:25:47tibial nerve and the common fibular
1:25:48nerve these two nerves come together
1:25:50give rise to the sciatic nerve and the
1:25:52sciatic nerve then we can appreciate
1:25:54here it descends in through the
1:25:57posterior aspect of that thigh you can
1:26:00see there very nicely and here you can
1:26:02see all these other branches coming off
1:26:03as well and it makes its way down into
1:26:05that thigh and you can see here at the
1:26:07posterior aspect of that knee area all
1:26:11right right inside of here
1:26:13you can see we've got that popliteal
1:26:15region so right in the superior to that
1:26:19popliteal triangle we're gonna have form
1:26:22back here you can see it divides and
1:26:24then it divides into the common fibular
1:26:26and the tibial nerve so you can see it
1:26:30becomes the sciatic and then divides
1:26:34back to the branches now when we talk
1:26:37sciatic nerve okay you've got the tibial
1:26:39nerve first tibial nerve is gonna course
1:26:42posterior closest posterior to that knee
1:26:45joint courses posterior to that knee
1:26:49joint you can see here very nicely makes
1:26:54its way down into the leg to provide
1:26:57that innervation you can see in the leg
1:27:01now this tibial nerve you can see its
1:27:05branches making its way towards the
1:27:07front and all helping to provide
1:27:09innervation basically to these deep
1:27:12structures of that anterior aspect of
1:27:15that leg because when we talk common
1:27:16fibular common fibular nerve it's also
1:27:19known as a common peroneal also known as
1:27:22the common peroneal now we talked this
1:27:24fibular nerve you'll see this common
1:27:26peroneal nerve is going to descend from
1:27:29its origin and it wraps around the neck
1:27:31of the fibula you can see that they're
1:27:33very nicely
1:27:34it's common fibular okay tibial we said
1:27:37is gonna descend through common fibular
1:27:39is gonna wrap around the neck of the
1:27:42fibula that's an important landmark so
1:27:44it wraps around the neck of the fibula
1:27:45and it's gonna divide it we'll divide
1:27:47that into a super
1:27:49so in a deep branch it divides into
1:27:52superficial and deep branches and then
1:28:02here you can see the deep fibular making
1:28:09its way down and in the superficial will
1:28:12remain basically superficial next in
1:28:17here we can appreciate various other
1:28:19images depicting to us again the same
1:28:21exact thing but then also here we have
1:28:23our motor ending we have a neuromuscular
1:28:28Junction this neuromuscular Junction
1:28:30just like the name says narrow muscular
1:28:33we have a nerve and we have a muscle you
1:28:35got this in lab you're supposed to be
1:28:37looking at as well you're following
1:28:38along with the labs so this is the
1:28:40second part of lab we did the first part
1:28:42in the last class so here we have the
1:28:44second part so you're looking at these
1:28:46different slides there as well you want
1:28:48to be adding in a couple of slides every
1:28:50day as well this way you get all six
1:28:52lights taken care of there also so
1:28:53neuromuscular Junction this is where the
1:28:56terminals of the somatic this is where
1:28:59the terminals of the somatic motor
1:29:02fibers innervate voluntary muscles with
1:29:06effector cells innervate voluntary
1:29:11muscles with effector cells so here
1:29:15you've got the narrow component here's
1:29:18the muscular component we've already
1:29:19gone through we've talked about this
1:29:20you've seen this here is acetylcholine
1:29:22found within those vesicles the
1:29:25acetylcholine is a neurotransmitter
1:29:26that's going to be removed via
1:29:28exocytosis from this terminal and the
1:29:31terminal bouton and into the synaptic
1:29:34cleft from the synaptic cleft the space
1:29:36you have in between the two cells that
1:29:38synaptic cleft
1:29:39it'll diffuse through a little bind to
1:29:42receptors on that neuro on basically on
1:29:45that muscles sarcolemma so when it binds
1:29:49to the receptors on the muscle
1:29:50sarcolemma it's going to help trigger
1:29:52then action potentials or nerve impulses
1:29:55along this muscle allowing those
1:29:57impulses then to travel all the way down
1:30:00the sarcolemma
1:30:03then uh that's what we've got there and
1:30:07then you can go through and look at the
1:30:08innervation of cardiac muscle smooth
1:30:10muscle and glands you'll see that's
1:30:13autonomic innervation that's gonna be
1:30:14much simpler than the junctions that are
1:30:17formed between somatic fibers and our
1:30:19skeletal muscle fibers

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