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AnatomyGastrointestinalPart1 — Transcript

by Dr. Naveen Jalota, M.D. · 6,800 words · 991 segments · language en · Watch on YouTube

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0:00hello and welcome let's discuss
0:02gastrointestinal system let's start GI
0:05tract it's chapter 24 in this book so
0:10let's go through let's talk digestive
0:12tract digestive system gastrointestinal
0:14system whatever you want to call it
0:16there first let's go to let's talk let's
0:19mention some functions of the digestive
0:22system here we can see when we talk
0:24digestive system we'll go through the
0:26different components that make up the
0:27digestive system and we'll check it all
0:28out it's basically gonna run from the
0:30mouth all the way down to the anus and
0:32then we'll go to all the different parts
0:33and check all that stuff out so here
0:35when we go through we talk functions
0:36first thing I'd like you to know the
0:38digestive system is going to take in
0:40food it takes in food and it'll break
0:43this food down into nutrient molecules
0:46it will break it down into nutrient
0:49molecules then it'll absorb these
0:51nutrient molecules and it'll absorb
0:53those nutrients into the bloodstream
0:56once it's absorbed whatever needs to
0:59absorb whatever is left it will then rid
1:01the body of these indigestible remains
1:04so when we go through and we talk
1:07functions you can see all the main
1:09functions we've got them we're gonna go
1:11through each of these functions there
1:12one by one as well so then let's move
1:15from that slide over to this slide here
1:18it's the same slide as we have on the
1:20first page and it's just a little bit
1:22less info on there and we can see what
1:25we need to see in greater detail so here
1:28when we go through we talked about the
1:29components of the digestive system let's
1:31go through those first and then we'll go
1:32through each individual component will
1:33talk and check each one out one by one
1:35so here when we go through and we check
1:38them all out now here we've got first
1:40when we go to we talk the components
1:43we've got here so let's go through then
1:47and let's talk about let's check out all
1:49the various components of the digestive
1:52system so here when we go can we talk
1:54about the components now the digestive
1:55system here we'll see we'll go through
1:57and we'll basically classify them into a
2:00few different categories so here now we
2:05can see so when we go to the components
2:08again now here we could see we're going
2:11to start off with
2:13throwing these different components into
2:15two main categories we're going to have
2:17let's see here
2:19we're going to have what we call our
2:22elementary canal and then we will have
2:24what we call our accessory organs so
2:27here you can see alimentary canal it's
2:28basically from the mouth to the anus and
2:30when we talk alimentary canal also known
2:33as your GI tract like they're telling us
2:34also known as your GI tract so we talk
2:37alimentary canal I'd like you to know
2:39that the alimentary canal is going to be
2:41a continuous muscular tube it's a
2:46continuous muscular digestive tube you
2:50can even refer to it as that's going to
2:53wind through the body that winds through
2:58the body and you can see that they're
3:00very well now when we talk about this
3:03alimentary canal I'd like you to know
3:05the organs of the alimentary canal so
3:08when we go through we talk about the
3:09organs of the alimentary canal you'll
3:11see the organs of the alimentary canal
3:13now are going to include the mouths
3:15number one so we can start right at the
3:18top we've got the mouth
3:19number one right after the mouth the
3:21oral cavity we're going to appreciate
3:22the pharynx right after the pharynx then
3:25we have the esophagus the esophagus
3:28after the esophagus then will lead to
3:31the stomach here we've got the stomach
3:33and after the stomach then you can see
3:36we've got the small intestine small
3:38intestine comes around you can see it
3:41here very nicely and then the small
3:43intestine will lead us to the large
3:45intestine you can here we can see
3:49bringing us all the way down to then the
3:54anal canal and the anus ending basically
3:57there so that is your alimentary canal
3:59your GI tract now we can see this this
4:07elementary canal it extends for about 30
4:10feet it's about 30 feet long and just as
4:14you can see here and then we start to
4:16talk about all the different you can see
4:19there you've also got villi and
4:20microvilli and that all just increases
4:23the length that you have inside it there
4:24so again about 30 feet
4:27now when we go to when we talk accessory
4:30digestive organs now the second
4:31classification now these accessory
4:34digestive organs it'll include number
4:36one the teat it'll include the teeth and
4:39the tongue inside the mouth so the teeth
4:42of the tongue inside the mouth it'll
4:45include the gallbladder you can see as
4:48we continue down the liver and the
4:52pancreas so here we can see when we go
4:56through we talk teat tongue inside the
5:00mouth
5:01we've got these various glands here as
5:04well these are all going to be our
5:06salivary glands and then we've got other
5:09glands a liver and the pancreas and then
5:16last we have our gallbladder our blah
5:19blah so all accessory digestive organs
5:22accessory digestive organs now when we
5:25go do we talk about the digestive
5:26process we talk about the actual
5:28digestive process here you can see now
5:30moving back to this picture you know we
5:33can see the digestive functions
5:35basically these are the processes we can
5:36appreciate them then in greater detail
5:38here off of this slide so here we go do
5:41we talk about these digestive processes
5:42the first process that I'd like you to
5:44know about is going to be ingestion now
5:47when we talk about ingestion ingestion
5:48is talking about the process of taking
5:50food into the digestive tract talking
5:53about taking food into the digestive
5:54tract and this occurs usually via the
5:56mouth orally second process I'd like you
6:01to know about here is going to be
6:02propulsion propulsion now we talk
6:05propulsion propulsion is the process of
6:07moving food through the elementary canal
6:10it is the process of moving food through
6:13the alimentary canal and this process
6:16moves food through the alimentary canal
6:17by swallowing number one which is
6:21initiated voluntarily so by swallowing
6:25number one which is initiated
6:27voluntarily and then number two by
6:29peristalsis and also by peristalsis
6:32which is an involuntary event which is
6:36an involuntary event
6:40so swallowing and peristalsis some will
6:44consider segmentation you see your
6:47segmentation some will consider
6:49segmentation as also a type of
6:51propulsion it's a mechanical digestion
6:55and also type of propulsion so here
6:57we'll check out that we'll look at that
6:59we'll check that out before we finish
7:00here so next thing we have mechanical
7:02digestion now we talk mechanical
7:04digestion this process mechanical
7:06digestion is going to prepare food for
7:08chemical digestion mechanical digestion
7:13so mechanically digesting our food you
7:15could think of it prepares food for
7:17chemical digestion by enzymes now when
7:21we talk mechanical digestion we're
7:22talking chewy Cherney and segmentation
7:28chewy mixing food with saliva right by
7:32the tongue churning as we can see is
7:35gonna take place inside the stomach it's
7:36a powerful pulverization that's gonna
7:40happen to the food and that's gonna
7:42happen because the stomach you'll see as
7:44a third layer of muscle normally
7:47speaking we've seen how many layers of
7:49muscle very good very good to next time
7:59let's go through let's talk chemical
8:01digestion so we talk chemical digestion
8:03chemical digestion involves a whole
8:05bunch of catabolic steps when we talk
8:08chemical digestion here we'll see food
8:11molecules are broken down to their
8:13chemical building blocks they're gonna
8:16get broken down to their chemical
8:17building blocks thanks to enzymes thanks
8:21to enzymes so going back to mechanical
8:27digestion we talked to tournee
8:28chewing and the segmentation we have
8:30there as well right that's gonna happen
8:32inside the small intestine another type
8:34of mechanical digestion so when we
8:36talked segmentation you can peristalsis
8:39we've already talked about we said it's
8:40an alternating contraction and
8:41relaxation of the muscles which allows
8:44this forward movement of food now in
8:46segmentation what happens is this food
8:48is getting kind of broken down as it
8:51moves you can think of easiest
8:53to describe it as two steps forward one
8:55step back so when it moves two steps
8:58forward one step back two steps forward
9:01one step back two steps forward one step
9:04back two steps forward one step back
9:07here what's happening is number one
9:08we're having a propulsion the food is
9:10moving forward as we described number
9:12two what's gonna be happening is it's
9:13getting smeared along the walls and
9:16that's a type of mechanical digestion
9:18we're having take place there so that's
9:22all getting everything ready for
9:23chemical digestion so we talked chemical
9:24digestion food molecules are gonna be
9:26broken down to their chemical building
9:29blocks thanks to n signs I like to think
9:32of enzymes here in the digestive tract
9:34as biological scissors they're like
9:36biological scissors when they break down
9:39all categories of foodstuff they break
9:44down all categories of foodstuff next
9:48that we've got absorption let's talk
9:50about this food down next we can move
9:55into absorption absorption now is
9:56talking about the passage of these
9:57digested end products talking about the
10:01passage of these digestive end products
10:03from the lumen of the GI tract then into
10:05the bloodstream into the bloodstream so
10:09it's a process that the digested end
10:15products are gonna take when they move
10:16from the lumen of the GI tract through
10:18the mucosal cells and that will all
10:21happen thanks to active and passive
10:23transport which you learned from biology
10:25and they'll move into the blood of the
10:28lymph defecation then we have last
10:32defecation now is the process of
10:35elimination of indigestible remains
10:41indigestible substances from the body
10:45via the anus in the form of feces so
10:48removal of indigestible substances from
10:51the body via the anus in the form of
10:53feces next end let's move down to the
11:00peritoneum let's discuss the peritoneum
11:02now when we go through we talk about the
11:04peritoneum
11:05here we can see the peri
11:07tonyia is going to be basically a
11:11slippery serous membrane found in
11:15relation to the ventral body cavities
11:18now when we go through and we talk about
11:20this peritoneum the peritoneum is going
11:23to have two parts to it here we can go
11:26through you can see all the different
11:27peritoneal we're gonna go through we're
11:28gonna eventually talk about you're gonna
11:29have to know every single one of them
11:31here you can see various peri Tonia's
11:34same thing here okay here it gives us a
11:38basic idea so it's a slippery serous
11:41membrane that covers the ventral body
11:43cavities not only the organs but lines
11:45the cavities as well so here when we go
11:48through we talk we have first what we
11:50call the parietal peritoneum
11:53so we talked parietal peritoneum
11:56parietal peritoneum is going to be the
11:59peritoneum is going to be found lining
12:01the wall if you don't recall from the
12:03beginning of the semester so here we can
12:05see that parietal peritoneum lining the
12:08wall of the cavity now when we go
12:11through we talk parietal peritoneum it's
12:14going to be continuous as you can see in
12:16this picture as well it's gonna be
12:17continuous with the visceral peritoneum
12:19so this what you see right on top of the
12:21organ same thing we're showing here
12:26right on top of the organ so it's gonna
12:32be covering the external surface of most
12:33of your digestive organs next here we
12:37can appreciate mesentery now mesentery
12:40we see mesentery is a double layer of
12:43peritoneum it's a double layer of
12:45peritoneum you can think of it as a
12:47sheet of two serous membranes that are
12:52fused back to back either a fused back
12:56to back that extend to the jejunum the
13:01ileum or you can say to your digestive
13:03organs from the body wall
13:09what does this mesentery do number one
13:11the mesentery is going to help hold the
13:13organs it's gonna tether them to the
13:16back wall so you don't see the organs
13:18just fall right out
13:20you know if somebody was to stand up I
13:21mean
13:21there have a little bit of a play but
13:23they're not gonna just right fall right
13:25to the floor you know so next time we
13:29have not only are they going to be
13:32tethering the organs but they're also
13:33going to provide routes for blood
13:36vessels lymphatic vessels and nerves to
13:41reach the digestive viscera and the
13:45nerves to reach the digestive misra now
13:50when we go back and we look at the pride
13:52on the visceral peritoneum between the
13:53two we can appreciate the peritoneal
13:55cavity now when we talk about the
13:57peritoneal cavity the peritoneal cavity
14:00is going to be it's going to be found
14:04number one between the two peritoneum it
14:07is a slit like it's a slit like
14:11potential space it's a slit like
14:13potential space that contains fluid
14:20it'll contain fluid and it's going to
14:22help keep those organs from generating
14:27friction so let's move them to the back
14:32of the peritoneum let's talk about the
14:35retroperitoneal organs now when we talk
14:37about the retroperitoneal organs Retro
14:39taking it back right retro night at the
14:42club taking it back to the 70s 80s right
14:45yeah don't say 90s okay
14:47it's not that old so 70s and 80s you can
14:51think of retro retroperitoneal
14:53organs so organs behind the peritoneum
14:57so retro peritoneum organs organs
14:59located behind the peritoneum and their
15:02organs that adhere to the dorsal
15:05abdominal wall their organs that adhere
15:08to the dorsal abdominal wall and they
15:11lie posterior to the peritoneum and they
15:14lie posterior to the peritoneum
15:20retroperitoneal organs
15:28let's go to the histology let's check
15:30out the histology and then in relation
15:31to the digest in motion to the digestive
15:33tract now when we go through we talk
15:35about the histology here we're going to
15:38go through the various layers that you
15:41can see here and we'll go through
15:43basically each the histology of each of
15:45the different organs as we go through
15:46them also so here we can see number one
15:49we've got the mucosa
15:51we've got mucosa and we talk mucosa
15:54mucosa is going to be making up the
15:57inner most layer we can see here so we
16:00talked to me Costa you can see the
16:01mucosa right inside of here
16:03now the mucosa is going to be made up of
16:06a few different parts the first part
16:08here that you have to know about is
16:09going to be the epithelium you can
16:11appreciate the epithelium right inside
16:13of here this epithelium now is going to
16:16vary as you move from place to place
16:18within that alimentary canal right this
16:21epithelium
16:22it's a moist epithelium that lines the
16:26alimentary canal from the mouth all the
16:28way to the anus and you should know
16:29every single region and what type of
16:31epithelia that it has there because
16:33we've already gone through them this
16:34isn't the first time you're checking
16:35them out we've talked the oral cavity we
16:37talked esophagus we've talked stomach
16:39and we're basically going all the way
16:40through typically it's a simple columnar
16:48that's rich with mucous secreting cells
16:51that's just typically speaking like I
16:53said we're gonna go through each every
16:54each and every component you'll have to
16:57know them from every single one of those
16:58elementary canal components so next year
17:02then we can appreciate just beneath that
17:04mucosa just beneath that mucosal
17:07epithelium we've got lamina propria so
17:10right inside of here this is all lamina
17:13propria the lamina propria we see here
17:16it underlines the epithelium and the
17:17lamina propria it's a loose areolar
17:21connective tissue it is a loose areolar
17:24connective tissue continuing to move
17:29even deeper now we can appreciate the
17:35third layer so here you can see it's a
17:37nice scant layer of muscle a Riceville
17:40thin layer of muscle what
17:42muscle cardiac right
17:45no smooth muscle smooth muscles when we
17:48talk smooth muscle you can appreciate
17:50this muscularis mucosae the muscularis
17:54mucosae is external to the lamina
17:57propria and what it is is it's a scant
17:59layer like a set of smooth muscle cells
18:01and they're responsible for producing
18:04local movements they will produce local
18:07movements next let's move to the
18:12submucosa then we look to the submucosa
18:16the submucosa it's going to be found now
18:18external to the mucosa see here you've
18:23got that mucosa we move out well here we
18:27can appreciate sub mucosa submucosa now
18:32sub b cosa is areolar connective tissue
18:34it is areolar connective tissue and it
18:37contains you can see here a rich blood
18:40supply
18:41it's areolar connective tissue that
18:44contains a rich supply of blood vessels
18:46and lymphatic vessels you can see the
18:51nerve fibers in there as well and also
18:54we can appreciate it here lymphoid
18:56follicles here's some glands here's some
19:04lymphoid tissue the follicles would look
19:07similar to those organs there but in
19:10this deeper layer so next time from the
19:14submucosa we're gonna be able to
19:15appreciate the muscularis externa the
19:19muscularis externa then we talk about
19:21the muscularis externa it's going to be
19:23surrounding the submucosa it will be
19:26found surrounding the submucosa
19:27and this is the layer that's responsible
19:31for segmentation and peristalsis this is
19:35the layer that's responsible for
19:36segmentation and peristalsis here you
19:39can see this layer is made up of a layer
19:41of circular smooth muscle cells and a
19:44layer of longitudinal smooth muscle
19:46cells then we've got the serosa
19:50we talked to serosa it's a protective
19:52outer most layer the protective
19:56outermost layer of intraperitoneal
19:57organs is basically the visceral
19:59peritoneum now here in relation to it
20:04the serosa we can appreciate connective
20:07tissue we talk connective tissue
20:08connective tissue is going to be areolar
20:10connective tissue and it's going to be
20:12covered with mesothelium so epithelium
20:18you can see here is going to be
20:20mesothelium and we all know what that is
20:23now let's move then to another layer we
20:28can see out here and that's gonna be in
20:30only certain organs this is the
20:31adventitia now we talk adventitia it's
20:34in the esophagus we'll see is where it's
20:37gonna be found so in the esophagus what
20:39happens is the serosa is replaced by
20:41adventitious so in place of serosa there
20:44we have what we call adventitia and what
20:47it is it's ordinary fibrous connective
20:49tissue that's gonna help bind the
20:51esophagus to surrounding structures it
20:54helps to bind the fibrous connective
20:56tissue of that masaf eglise to the
21:01surrounding structures
21:03so let's cool let's go through the
21:05various organs let's start off by
21:06talking about the mouth so here you see
21:09the same exact thing so here we can see
21:15the mouth when we talk mouth we'll go to
21:16the mouth and we'll go to the Associated
21:17organs here as well when we talk about
21:19the mouth I want you to know that the
21:20mouth is a mucosa lined cavity it is a
21:24mucosa lined cavity we also refer to the
21:27mouth as the oral cavity and the
21:30function now of the mount is that it's
21:33going to start ingestion so we talk
21:35ingestion ingestion is going to happen
21:38here also it begins the propulsive
21:40process of swallowing that's number two
21:45number three it's gonna help with the
21:48chemical digestion it's involved with a
21:51little bit of chemical digestion you
21:56have salivary amylase which is gonna
21:59help break down starchy foods and you
22:00have lingual lipase which will break
22:03down fatty foods lingual lipase
22:09lipase not chase la Li pas e ASE so
22:21anyways here let's move down let's talk
22:22boundaries n we talk boundaries of the
22:25oral cavity of the mouth you can see
22:27here you've got the lips located
22:28anteriorly you're going to have then the
22:31cheeks laterally and then we'll have the
22:34palate superiorly and then we've got the
22:37tongue down here inferior ly so this is
22:40your oral cavities boundaries first
22:47you've got the oral orifice the opening
22:48into the oral cavity that's the oral
22:50orifice then here we can appreciate the
22:53lips let's move over from that picture
22:55over to this picture here here we've got
22:57the lips then and we talk about the lips
22:59the lips are basically formed from the
23:02orbicularis Oris if you recall and you
23:04have a red margin on the lips as well
23:06that red margin is going to be the
23:08reddened area where a person applies
23:11lipstick or lands of kiss next time we
23:17have our cheeks our cheeks and we talk
23:19about the cheeks the cheeks again you
23:21should know the muscles that you have
23:22there as well we've discussed those in
23:23the beginning your busan aiders next to
23:27here you can appreciate the vestibule
23:29now we go through and we talked about
23:31the vestibule now we'll see the
23:33vestibule is going to be alright so as
23:37we were mentioning here we can
23:38appreciate the vestibule so we go
23:41through we talked vestibule the
23:42vestibule is going to be space or a
23:46chamber you can think of it's the
23:49chamber the space that's bounded
23:51externally by the lips as you can see
23:54right inside of here and then the gums
23:58on the inside the gingiva on the other
24:00side so it's bounded externally by the
24:02lips by the gingiva internally and the
24:06cheeks so the you can think of lips and
24:09the cheeks here on the outside and we've
24:12got the gingiva on the inside and the
24:14space in between the two right is going
24:17to be the vestibule or the chamber in
24:18between the two you can think of next
24:21then is the palate let's just
24:22pal eight in greater detail we talked to
24:24Pilate Pilate we've talked and we've got
24:26two different parts so recall hard and
24:28soft palate and go through those
24:29components as we've talked about before
24:31the hard palate is underlined by the
24:34Palatine bone and the polishing process
24:36of the maxilla bone as well and it's
24:39going to help form this rigid surface on
24:42to which food is going to be forced
24:45during chewing next on the soft palate
24:50you can see at the dorsal aspect and the
24:52soft palate is a mobile fold it's formed
24:56mostly of skeletal muscle and it rises
25:00reflexively it rises reflexively to
25:03close off the nasal pharynx when we
25:05swallow to help close off the nasal
25:08pharynx when we swallow you can also
25:12appreciate here then the uvula
25:14now the uvula is a pendular structure
25:17it's a pendulous structure finger-like
25:19structure you can think of as well and
25:21it projects downward it projects
25:24downward from the free edge of the soft
25:27palate that's the uvula and they usually
25:31along with the soft palate are gonna
25:32help to block off the entrance into the
25:34nasal pharynx next then we've got our
25:38palate of lhasa arches the palate of
25:41glosses our palette of colossal arches
25:42are going to be appreciated here very
25:43nicely here we can appreciate the
25:44palatal glossa larches everything is in
25:47the name and then here we can see
25:50palatov pharyngeal palate Oh pharyngeal
25:53arches dorsal to the palatal glassy
25:57arches next time we've got the tongue so
26:00we talk tongue tongue is going to be
26:02found occupying the floor of the mount
26:04that occupies the floor of the mount
26:06fills the oral cavity when the mouth is
26:10closed it fills the oral cavity when the
26:12mouth is closed and the function we tuck
26:15functions a function of the tongue is to
26:17grip and constantly reposition food it's
26:21to grip and constantly reposition food
26:24between the teeth number two it mixes
26:30food with saliva it mixes food with
26:33saliva and number three it's involved
26:35with taste right we talked about that
26:36one
26:36talked about the special senses now when
26:40we go through we talk muscles we talk
26:41muscles muscles we have various types we
26:44have first intrinsic muscles intrinsic
26:46muscles are going to be confined in the
26:49tongue they are confined in the tongue
26:52and they are not attached to bone
26:55intrinsic muscles and in the extrinsic
26:58muscles the extrinsic muscles they're
27:01going to extend to the tongue they will
27:04extend to the tongue and they're gonna
27:07extend to the tongue from their points
27:10of origin on bones of the skull or the
27:15soft palate we have seen and we've
27:21talked about the papillae you have in
27:22relation to the tongue we've talked
27:24about fungiform foliate and
27:25circumvallate papillae so let's talk
27:27then the filiform papillae now we talk
27:30filiform papillae the filiform papillae
27:33are going to give the tongues surface
27:36our roughness they'll give the tongue
27:39surface or roughness and this roughness
27:42is going to aid it's going to aid in
27:46licking semi-solid foods it will aid in
27:50licking semi solid foods and these
27:54papillae are also going to provide
27:57friction they also provide friction for
28:00manipulating food in our mouths and
28:04these papillae are the smallest and the
28:07most numerous papillae that we'll have
28:09when we talk about papillae so the
28:14salivary glands let's move to now when
28:17we go through we talk salivary glands
28:18you've got a couple of really good
28:20images depicting to us and both of those
28:25images depicting to us the glands so
28:29when we go do we talk about glands
28:30salivary glands is what we're talking
28:32about now the function of the glands is
28:33going to be to secrete saliva so their
28:36job is to secrete saliva then what is
28:38saliva do for us now saliva is going to
28:41number one clean them out number two
28:43it's going to dissolve food chemicals
28:46for taste when we talked about that
28:49the the Salida is gonna be required
28:51there number three helps to moisten food
28:55the saliva does and the number 4 you can
28:58see food is going to contain enzymes
29:00sorry the saliva is gonna contain
29:02enzymes that are gonna break down foods
29:04so saliva is gonna contain enzymes that
29:06will break down foods and I mentioned to
29:09you so salivary amylase and lingual
29:13lipase lingual lipase lipase gets picks
29:24up light to pace alright so let's go
29:28through let's talk then in your
29:29intrinsic salivary glands and we talked
29:32about your intrinsic salivary glands
29:34these are going to be also known as your
29:36buccal glands your buccal glands now
29:42when we go to we talk intrinsic salivary
29:43glands are very small and they're gonna
29:46be scattered throughout the oral
29:47cavities mucosa they're small and
29:51they're scattered throughout the oral
29:53cavity mucosa then we have our extrinsic
29:59salivary glands we can appreciate here
30:00very nicely these extrinsic salivary
30:03glands are going to be responsible
30:04producing for producing most of the
30:06saliva and these extrinsic salivary
30:12glands are gonna be found lying outside
30:13of the oral cavity they're found lying
30:17outside the oral cavity and they empty
30:20their secretions into the oral cavity so
30:22they're lying outside the oral cavity
30:23emptying their secretions into it first
30:26one you can see the product lend found
30:29as a pair okay parotid gland we talk
30:32parotid gland product gland is going to
30:34be large it will be large and it's going
30:39to contain and we'll see so when we talk
30:43these extrinsic salivary glands are
30:45gonna be found as pairs so first pair
30:48here we'll talk about is going to be the
30:49parotid glands the parotid glands you
30:51can see here very nicely so here you can
30:53see one and the other one is going to be
30:54found the exact same way on the other
30:56side excuse me just anterior to the ear
31:00I'll describe to you guys here so here
31:02when we go through my
31:03then when we go through we see first
31:05we've got the product land the product
31:06gland is going to be as we can see a
31:08very large gland and it's been lying
31:10anterior to the ear lying anterior to
31:14the ear and we talk about the product
31:17land you'll see it's found more
31:19specifically speaking in between the
31:20Meseta in between them a cedar muscle in
31:24the skin so in between the Messina
31:25muscle in the skin you can usually feel
31:27that gland here now when you eat
31:29something sour sometimes you'll see they
31:31get going and they start secreting
31:33secretions and here you can see when
31:35they secrete their secretions when they
31:37secrete their secretions you can see
31:39here those secretions are going to be
31:40emptied right there you can see next to
31:45then the molars so here we can see so
31:53here we can see its duct here you've got
31:56it's called Stenson's duct maybe
31:59sencence Stenson's duct basically making
32:01its way down and it's emptying we said
32:03that the molars more specifically
32:04speaking it's gonna be the second molar
32:06it'll empty right at the second molar
32:09next time we're gonna be able to
32:11appreciate the pair of submandibular
32:12glands now submandibular gland the name
32:15is telling you a lot they're their
32:16walnut-sized glands and they're gonna be
32:18found lying along the medial aspect of
32:20the mandibular body lying along the
32:22medial aspect of the mandibular body
32:25next sublingual glands also again found
32:29as a pair small lying anterior now to
32:31the man submandibular glands lying
32:34anterior to submandibular glands under
32:36the tongue and these glands now you can
32:39see they're all going to open both these
32:40glands are gonna open via 10 to 12 ducts
32:43so all these ducts are going to come in
32:45and these ducts they're going to
32:48basically open from 10 to 12 ducts into
32:51the floor of the mouth remember of
32:54leaking it's absolutely disgusting
32:58basically the person is spitting you
33:01know out in a controlled fashion from
33:03underneath their tongue and they're able
33:05to allow those secretions to make their
33:08way out it's disgusting when people
33:10actually do that on to people like I
33:12said that's spitting is what that is
33:15next then
33:16teeth teeth let's go through the teeth
33:18and let's talk about teeth so here we've
33:23got teeth first nice picture here
33:25depicting to us baby teeth along with
33:26baby teeth has a sad thing about it is
33:29it's a kid's skull
33:31we're looking at here so we've got baby
33:32teeth and right out here and then here's
33:34the adult teeth basically somebody young
33:38of age so here now when we go through
33:41and we talk basically teeth their
33:43function is that they're involved in
33:45food processing teeth are going to be
33:47involved in food processing what teeth
33:49do for us is they chew or they masticate
33:52food they masticate or they chew our
33:55food by opening and closing our jaw so
34:00here you can see your teeth as well as
34:01from a panoramic x-ray here nice view
34:04depicting both baby teeth and the adult
34:07teeth there you can see the deeper the
34:09deeper lying teeth the adult teeth the
34:13permanent teeth and then the more
34:15superficial teeth are obviously the TTC
34:17in the front so here we can say just
34:24going on a hunch I don't see any baby
34:26teeth in the front about five six years
34:29of age they come out so there's probably
34:31somebody a little bit older where the
34:34rest of these teeth haven't been able to
34:35make their way through yet so here when
34:38we go through the set having a see
34:39something like that but we're here this
34:41is just a panoramic view but when you're
34:43actually seeing a skull you know that
34:44tells you what was there and you know
34:47what not looks like a real skull here
34:48too spongy bone looks pretty good now
34:53here when we go through we talk teeth so
34:56we have permanent teeth our permanent
34:58teeth are our deeper lying teeth we have
35:01a total of 32 32 permanent teeth 16 in
35:08the bottom row and 16 in the top row 32
35:12total permanent teeth sometimes the
35:17wisdom teeth make up
35:19or sometimes they're completely absent
35:22and when they do hear up sometimes they
35:24cause pain sometimes they don't now
35:27let's go through each of the teeth first
35:29let's
35:29check out the permanent teeth here we've
35:31got our incisors first we talk incisors
35:34we have a total of four incisors okay so
35:38when we talk in sizes up now what I'm
35:39gonna do I'm gonna go to the lower row
35:40of teeth okay whichever role you want to
35:42think of and then you have the same
35:43thing on the top so I'll go to the first
35:45sixteen and use double that and then you
35:47have thirty-two I did not say you double
35:49thirty-two you don't have 64 teeth in
35:51your mouth don't tell me I said that 32
35:55total sixteen on the bottom and sixteen
35:58on the top okay for a total of 32 teeth
36:02so let's go through the first 16 and the
36:05reason why I say that is if somebody's
36:06asked me yeah we have 32 teeth no we
36:09don't have 32 teeth I mean you know a
36:12total of 32 pairs of teeth is what they
36:16were asking and I said 32 pairs of teeth
36:19a total of 32 teeth so not 32 pairs 16
36:23pairs equaling 2 total 32 teeth so here
36:29we've got incisors for incisors they're
36:31chisel shaped teeth and they're adapted
36:34for cutting or nipping off pieces of
36:38food next are your canines you have two
36:42canines your canines are conical or
36:45fang-like teeth they're cone shaped or
36:48fang-like teeth and they tear and pierce
36:52food they're responsible for tearing and
36:54piercing food next time we get into the
36:57premolars when we talk premolars
36:59premolars we have a total of four
37:01premolars are bicuspid in shape they're
37:04bicuspid in shape and they're adapted
37:07for grinding or crushing they're adapted
37:11for grinding or crushing in here you can
37:13appreciate then the incisors we went
37:15through we talked about okay see that
37:19all four incisors then we have the
37:21canines and now here we are at the
37:23premolars so four premolars they're
37:27bicuspid in shape they're good for
37:29grinding or crushing food and the last
37:31we have our molars live total of six
37:34molars three on one side and then three
37:36on the other obviously I'm just talking
37:38lower row now you have the same exact
37:40thing on the top so when we talk molars
37:42six molars you see
37:43the best grinders that we have now in
37:46the upper the lower role they locked
37:48together they generate a tremendous
37:50crushing force they generate a
37:53tremendous crushing force hyenas I was
38:01watching last night on discovery hyenas
38:05actually have a good amount of a
38:08tremendous crushing force as well they
38:11actually are they have the strongest
38:14crushing force of animals on land on
38:18land because if we're talking water it's
38:22different very good right alligators I
38:25believe her
38:26Crocs have the data stronger yeah the
38:32tremendous generating or crushing force
38:33there so those are your permanent teeth
38:36so again I went through 16 16 and one
38:39row and then you double down you'll have
38:40a total of 32 teeth next then are your
38:43deciduous teeth your bill your milk
38:46teeth or your baby teeth trying to say a
38:49baby and milk at the same time milk
38:50teeth built teeth now again milk milk so
39:00milk teeth baby teeth they're the first
39:02teeth to appear they appear around six
39:05months of age and then eventually
39:07they're going to be replaced and they'll
39:08be replaced by your permanent teeth or
39:11your adult teeth let's go through now
39:15and you can see those teeth here again
39:17as well and let's go through then the
39:21actual structure of your tooth so when
39:22we go through we talk about the
39:24structure of your tooth first thing I'd
39:26like you to know the tooth gets divided
39:27up into as we can see a crown a root and
39:30between the two you have your neck right
39:32and neck is a constricted region so here
39:35when we go through we talk first the
39:37crown let's talk about the crown the
39:38crown I want you to know is the enamel
39:40covered part it is the enamel covered
39:43part it's the exposed part you can see
39:46it's the part above the gingiva the part
39:49above the gum the enamel surrounds the
39:55tooth as you can see it's around
39:57that tooth like a tight collar it's
40:00going to surround that tooth like a
40:02tight collar next and we have the enamel
40:11so we talked enamel Oh enamel is going
40:14to be this brittle ceramic like material
40:17it's this brittle ceramic like material
40:21it's as thick as a dime so it's very
40:24thin it's as thick as a dime and it
40:27directly bears the force of chewing and
40:31it directly bears the force of chewing
40:36next then is the pulp cavity now we talk
40:40pulp cavity the pulp cavity is number
40:44one surrounded by dentin and it's a
40:50cavity so it's a potential space and
40:52it's gonna contain a number of soft
40:55tissue structures it contains blood
40:58vessels it contains you can see
41:01connective tissue it's gonna contain
41:04also nerve fibers in there as well so
41:09all of those soft connective tissue
41:12basically structures we refer to them as
41:14pulp will collectively refer to them all
41:16as pulp see how that pulp cavity next
41:21then is the root so here down here we've
41:23got the root now we talk about the root
41:25it's the portion that's embedded it's a
41:28portion of the tooth that is going to be
41:31embedded in the jawbone portion that's
41:33embedded in the jawbone now here in
41:35relation to the tooth we've got some men
41:37tongue in relation to the root we have
41:39cementum that we talk cementum cementum
41:41is going to be found number one on the
41:46outer surface of the root you can see so
41:49we talk about the root it's forming
41:50basically that outer surface of the root
41:52of the tooth and the cementum is
41:56calcified connective tissue it is
41:58calcified connective tissue that
42:00attaches the tooth to the periodontal
42:03ligament that will attach the tooth to
42:06the periodontal ligament
42:10now we talk periodontal ligament the
42:12periodontal ligament you can see here
42:14very nicely now the periodontal ligament
42:16is very thin and it's going to anchor
42:18the tooth in their bony alveolus it
42:24anchors the tooth in the bony alveolus
42:26of the jaw helping to form for us a
42:30fibrous joint as we went through and to
42:33beginning a semester
42:34now we refer to this joint as a very
42:41good gumbo Seas joint gum fauci's joint
42:45next thing we have their root canal and
42:47we talked about the root canal the root
42:49canal is basically this again canal like
42:52structure it's this structure that's
42:54gonna basically allow these blood
42:56vessels the softer connective tissue
42:58structures to pass up into the tooth so
43:04the root canal is where the pulp extends
43:06into the root moving down we have the
43:11applica foramen the apical foramen is
43:13going to be the tiny opening that allows
43:15these structures up into the canal and
43:17then eventually into that pulp cavity so
43:20the apical foramen then the neck we see
43:25here is a constricted region constricted
43:28tooth region where now the crown and the
43:31root are going to meet the crown of the
43:34root meet and last year we can
43:38appreciate dentin now we talked about
43:41den Tim you'll see dentin is a
43:43protein-rich
43:45Bowl like material it's a protein rich
43:48bone like material and it's going to be
43:51found underlying the enamel cap it
43:54underlies the enamel cap and as you can
43:57see it forms the bulk or the majority of
43:59the tooth it forms the majority or the
44:02bulk of the tooth it's a very good
44:06depiction of the tooth same thing exact
44:14same thing you're seeing here so when
44:16you talk a root canal alright we'll go
44:20to the dentists have a root canal
44:21basically what they're doing is they're
44:22drilling right into the center
44:24they're going to basically take these
44:25structures out of there and block this
44:28whole pathway up and they'll grind the
44:31tooth down and put a new tooth on top
44:34and it's about 2,000 bucks probably now
44:37I don't know like a thousand bucks ten
44:40fifteen years ago but with inflation
44:42these types of things go up 500 bucks
44:48for a root canal and I think was five
44:49hundred bucks for the tooth probably
44:52maybe 700 800 bucks each now probably
44:53some like that
44:54alright that concludes them this chapter
44:58or no I'm sorry this concludes the first
44:59part of this chapter we'll continue then
45:03with the next part

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