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Exam 1 review — Transcript

by Savannah Gilmore · 6,489 words · 1,006 segments · language en · Watch on YouTube

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0:02All right, guys. Hopefully this one
0:06works. And we have been having some
0:08technology issues, but hopefully this
0:09one works. We're going to do it again.
0:12Um, but this is just your exam review.
0:15Um, it is a supplemental help for your
0:17exam. So, please remember to review
0:20notes, look at those things that your
0:23professors have pointed out in class or
0:25on the slides, the things that are
0:26highlighted or bolded. um and concepts
0:30just in general, not just rope
0:32memorization. But I think you guys are
0:34going to do great and this is definitely
0:35going to help you a lot. So let's get
0:37started. So to begin, we're going to go
0:40through chapter one starting with macro
0:42versus micronutrients. So
0:44macronutrients, we need these in big
0:46amounts like grams. And these are going
0:49to be proteins, carbs, lipids, and
0:52water. Those are the things we need in
0:55larger amounts and are classified as
0:57macronutrients. Micronutrients on the
0:59other hand are smaller amounts. So we
1:03need them in smaller amounts like
1:04milligs, micrograms,
1:06etc. And they include vitamins and
1:08minerals.
1:12We have six classes of essential
1:13nutrients. Um these essential nutrients,
1:16they do a specific biological function.
1:18And when we don't have the minimum diet,
1:20we're going to see a decline in function
1:21in our body. Um, and typically we can
1:24add them back into our diet before real
1:27hardcore damage occurs. Um, as long as
1:30they haven't been too severely
1:32deficient. And these are going to
1:34include our vitamins, minerals, carbs,
1:36proteins, fats, or lipids, and water.
1:41So, here's just a big um table. You
1:45don't need to know it. You just need to
1:46know the different between energy
1:48yielding and non-energy yielding
1:49nutrients. So, our energy yielding
1:51nutrients, those are going to be our
1:53carbs, our fats or lipids, and our
1:56protein. They're actually giving us
1:57energy that our um bodies can use. Um
2:01and then our non-energy yielding
2:03nutrients. These are going to be
2:04vitamins and minerals. So our body's not
2:06taking these and converting them into
2:08ATP or energy for us, but they are being
2:11used in our body to perform various
2:13functions.
2:15All right, we'll keep going. So we have
2:17different functional categories for
2:19these nutrients. Um some provide energy,
2:23promote growth and development, and
2:25regulate body processes. A lot of these
2:27are going to do the same thing, but um
2:30the ones that provide energy, like we
2:32just talked about, carbs, proteins,
2:34lipids, um the ones that promote growth
2:37and development, proteins, lipids,
2:39vitamins, minerals, water, and the same
2:43ones regulate our body processes.
2:47All right, so we'll start with our
2:48macronutrient carbohydrates. And our
2:51carbohydrates are going to be made of
2:52carbon, oxygen, hydrogen. They provide
2:55four kal per gram. Know that. That's
2:58important to know. Um it's our major
3:00source of energy in most cells. Um we
3:02use carbohydrates the most for energy.
3:04And there's two types. There's simple
3:06and there's complex. Simple are readily
3:08usable forms of carbohydrates like table
3:11sugar, which is sucrose and blood
3:13glucose. And our complex carbohydrates
3:15are going to include starch, glycogen,
3:17and fiber. Our starch, it's a storage
3:20form of carb in foods. And our fiber is
3:22something we cannot digest and it forms
3:25structures in the plant cell walls.
3:28Great for our gut, but we can't really
3:30digest it.
3:34All righty. The next one we'll talk
3:35about is protein. Protein has a unique
3:38um difference between it and carbs and
3:41that is that it has nitrogen, the only
3:44macro nutrient um of the three that have
3:47nitrogen in it. Um, and it also provides
3:494 ks per gram similarly to carbs, but
3:53it's made of amino acids. There's 20
3:55amino acids, but nine are essential,
3:58which means we have to get them from
4:00food, from our diet. Our body does not
4:02make them. And protein is important in
4:05structural components in our body such
4:06as bone, muscle, blood, cell membranes,
4:10especially enzymes, and immune factors.
4:15All righty. Lipids, fats, our last
4:17energy yielding macronutrient. It's
4:20going to be carbon, oxygen, and hydrogen
4:22just like our carbs were made out of the
4:25same thing, but it provides 9 kals per
4:28gram, which is the most out of all our
4:30macronutrients. So, 9 kals. Keep that in
4:33mind for your exam. Um, there's two
4:36types of lipid categories. We have
4:38saturated fats and unsaturated.
4:41saturated I think like S for saturated
4:44means solid room temperature. Um they're
4:47mainly found in animal sources. They
4:49raise our blood cholesterol which can
4:51lead to cardiovascular disease. Um the
4:53ones that we really want to make a
4:54staple in our diet are unsaturated fats.
4:57They're liquid at room temperature and
4:59they're mainly found in plant sources
5:01like think olive oil, canola oil,
5:02vegetable oil and they're a lot better
5:04for us than saturated fats for our heart
5:06health.
5:09Water is another macronutrient that we
5:11need in the largest quantity. Although
5:14it doesn't produce um we our body
5:16doesn't use it to make ATP like the
5:19other ones, but we do need it for all
5:22sorts of functions. Um it's used for as
5:25a solvent, lubricant, a medium for
5:27nutrient transport to our cells and
5:29helps regulate our body temperature. And
5:31we get it from food and drink. And it
5:33actually is the byproduct of metabolism
5:36or byproducts of breaking down our
5:38lipids, proteins, and fat or carbs.
5:43And then this is just a note. We're made
5:45of of 60 to 70% water, which is probably
5:48why we need it in the largest quantity.
5:52All right, here's just a practice. Um,
5:54we won't I won't go through it totally,
5:56but um I'll just show you guys how you
6:00would go about solving this. Um,
6:04perfect. So, we know that
6:08our
6:11carbs, sorry. Okay, we know that our
6:13carbs produced four kals per gram. So
6:17you would just take however many grams
6:19of carbs we have and we would multiply
6:21that by the four because it produces or
6:24it gives us four cakeals per gram and
6:26then you would multiply that out to get
6:28the total cake. So again fat it's 9
6:31kowals per gram. So you multiply that by
6:349. Protein for
6:37alcohol is seven although it's not
6:39really considered an energy yielding
6:40nutrient just because of how it's
6:42metabolized in our body but it is seven.
6:45And then you would just multiply that
6:46out to get the total. So if that makes
6:49sense, we will just
6:52go ahead and get rid of these.
6:55All righty.
6:57Perfect. We'll keep going along.
7:00As long as that makes sense to everyone.
7:03Okay. So this is just a quick summary
7:04slide, but carbs produce 4k calories per
7:06gram. Protein 4k cows per gram. Alcohol
7:09again not a nutrient because it's not
7:10really producing um energy in our body
7:12like carbs, proteins, and fats does. but
7:14it's still considered one of these. Um,
7:17and then fats, 9 ks per gram. We use
7:21these energy producing nutrients um or
7:23energy yielding nutrients I should say
7:25to build new compounds in our body to
7:27perform movements with our muscles and
7:30to promote nerve transmission within our
7:32nervous system and also to maintain ion
7:35balance within cells like our blood
7:38cells um just different cells in our
7:40body. So we use energy to do work.
7:45Okay. So what influences our food
7:47choices? Well, there's two major
7:49factors. Um and it's hunger and versus
7:52appetite. So hunger is a physiological
7:55internal need for food. Like your body
7:57is telling you I need food to keep going
8:00to survive. So it's physiological. We
8:02really need it for um processes in our
8:04body to function. While appetite on the
8:06other hand is just a psychological
8:08desire to eat food. So, we may not need
8:12food, but our brain is telling us we
8:14want food. So, that's the main
8:16difference between hunger and appetite.
8:18Um, nutritional status, malnutrition, it
8:22can refer to over nutrition or under
8:24nutrition. So, it's just malnutrition is
8:26just meaning we're not in that just
8:28right desirable nutrition state.
8:32Under nutrition, this is when our
8:33nutrient intake is not meeting our
8:35needs. So it's less than what we need or
8:38our nutrient surplus stores are
8:40depleted. So the the energy um stores we
8:43have in our body are depleted. We really
8:45need that food. So we're under um we
8:48have under nutrition. Um over nutrition
8:51obviously the opposite. It's a
8:53consumption of more nutrients than the
8:55body needs. So more calories than we
8:56need, more energy than we need. So we're
8:58probably going to store it as fat which
9:00could lead and often does lead to
9:01obesity.
9:03All righty.
9:06the scientific method. You guys had some
9:11brief overview of this. So, we're just
9:12going to go through it again, but just
9:14make sure you kind of know what each of
9:16these do in maybe the step-wise order.
9:19But our first step, it's a little
9:20covered, but it's observation where
9:23we're seeing something, we're
9:24identifying a problem or a phenomenon.
9:26Then our second step is we're going to
9:28see that and then come up with an
9:30explanation for it. So, we're going to
9:32form our hypothesis.
9:34Then from that hypothesis we formed,
9:35we're going to experiment. We're going
9:37to design a study to test our
9:39hypothesis. From that experiment, we're
9:41going to collect data and analyze the
9:43results. We're going to use statistic
9:45methods, various methods to identify
9:48patterns, correlations, differences, and
9:50we're going to record those. Then we're
9:52going to conclude. We're going to either
9:54say, you know what, my guess, my
9:56hypothesis was correct, so we're going
9:57to accept it. Or we're going to say, you
9:59know what, my hypothesis was so wrong,
10:01and we're going to reject it. or maybe
10:03we just need to modify it. And finally,
10:06we're going to send it for peer review
10:07and ultimately publication. So many
10:10people are going to look through it to
10:11make sure that we did what we're
10:13supposed to and went through the right
10:14channels and then we would submit it for
10:16publication.
10:19All right. So there's many experimental
10:21designs in nutrition research. Um
10:24various ways to experiment. In vitro
10:27means in glass. So like test tube
10:29experiments. While in vivo, vivo in life
10:32means that we're experimenting organisms
10:35in their natural habitat. So not
10:37isolated into a test tube or whatever.
10:40Um the gold standard for experimental
10:42designs is going to be a randomized
10:45control trial. And there's various kinds
10:47of these. We have a double blind where
10:49the participant nor the researcher knows
10:51what's going on um or which group is
10:53getting which um intervention. We have a
10:56crossover study where participants
10:59receive both the treatment and the
11:01placebo. So you're kind of each person
11:03is being their own tester. Um but it's a
11:07great way to do it. Or the placebo study
11:10which is fake treatment such as like a
11:12sham pill or just um not the real thing.
11:19All right. So that was chapter one and
11:21we're going to go into chapter two.
11:23So these ones can get confusing. the
11:25dietary reference intake. So, we're
11:27going to try to keep these straight
11:28together. And there's five standards of
11:30DRI. We have our estimated energy
11:32requirements, our ES. We have our
11:34recommended dietary allowance, our RDAs,
11:37adequate intakes, AIS, tolerable upper
11:40intake levels, ULS, and estimated energy
11:42requirements, EERS. Um, they differ by
11:45life stage. So, different life stages it
11:48may differ. But there's another one
11:50that's not technically a DRRi, but it's
11:53still one that we use and it's an
11:54acceptable macronutrient distribution
11:56range. So these are set for our
11:58macronutrients such as carbs, fats, and
12:00proteins and they're a percentage range
12:01that we can use for diets.
12:06All right, so our first one, ES, they
12:09meet the needs of half of the
12:11population. So their nutrient amounts
12:14are estimated to meet the needs for half
12:16of a population. So that's kind of what
12:18set this one apart. And Ess cannot be
12:20set without a functional um biioarker.
12:24So this means functional markers can
12:25include like enzymes, cells, organs, um
12:29just how your body is using these
12:31things. And this is for groups, not
12:33individualized. So that's something else
12:35to note. But know that ES meet needs for
12:39half of the population. It's not
12:41everybody.
12:43RDA's recommended dietary allowances.
12:45These meet the needs for nearly all
12:47individuals like in 98% of individuals.
12:50It's based on ERS, multiple ERS. And
12:54this nutrient is set to prevent disease,
12:57not to prevent deficiency, but it's
13:00going to be higher than what the average
13:01person needs. So know that this is going
13:04to meet the needs of nearly everybody
13:06and is based on ES. So those are just
13:09some things to note. Um, adequate
13:11intakes. These are set for nutrients
13:13where we don't have enough research of
13:15functional markers to have an E. So, we
13:19know we don't have enough research about
13:20this. So, we're just going to set an
13:21adequate intake. And these can be used
13:23for individuals. You know, our Esser
13:26more for groups, not individuals. AIS,
13:28they can be used for individuals. Um,
13:30these are based on experimental
13:31estimates. Um, and
13:35yeah, to maintain to find nutritional
13:37status. So, AI's target intake level for
13:40a nutrient based on people's estimated
13:42dietary intakes.
13:45All righty. Tolerable upper intake
13:47levels. So, these are the max daily
13:49intake you can um have without it
13:52causing adverse health effects. It's not
13:55really a nutrient goal cuz you do not
13:57want to be intaking the max amount you
14:00can every day. So, our nutrient intake
14:02should remain below this upper limit
14:05ceiling.
14:09And then we have estimated energy
14:10requirements, our last RDI. And these
14:13are our average daily energy needed for
14:16like for each life stage group. Um it
14:19depends on various things like how much
14:21we're exercising, how much energy we're
14:23expending, height, weight, gender, age,
14:27um and overall they're used the this um
14:29estimate is used to promote healthy body
14:32weight, quality of life, etc.
14:36Here's a great summary slide if you
14:37guys, this is in your notes, you can
14:39find it. Um, it's a great summary slide
14:41for all of these. But again, ES
14:44represent half of the population, more
14:47for groups, not individuals. RDAs used
14:50to evaluate current intake for specific
14:53nutrient. It can be more individualized.
14:56AIS when we don't have that E, we have
15:00we'll do experimental research to
15:02establish an AI. um an upper limit or
15:05upper level intake. This is the max
15:08amount. So, we usually want to stay
15:09under this ceiling. It's the max amount
15:11we can have before bad effects. ERS that
15:15estimated energy requirement. How many
15:18calories, how much energy are we needing
15:20according to various factors like
15:21exercise, height, weight, gender, etc.
15:24And then our AMDR nutrient range, that
15:27percentage of each macronutrient that we
15:28need.
15:31All right, guys, stick with me. So,
15:33nutrient density of food. You guys did
15:35this in your case study, so you should
15:36be good to go on this. But again, here's
15:39a reminder calculation. Um, to calculate
15:42nutrient density, we're going to divide
15:44the amount of nutrient in a serving,
15:45divided by our recommended daily intake,
15:47and get that value. And then we're going
15:49to divide our calories in a serving
15:50divided by our EER, our daily calorie
15:53need, and we're going to get that value.
15:55And then we're going to compare the two
15:57values. So the food is going to be
15:59nutrient dense if it if it provides a
16:01greater contribution to your nutrient
16:03need than your calorie need. So if this
16:05number is larger than this one, it's a
16:07nutrient-dense food. So here's an
16:09example problem you guys can do. Again,
16:10this is straight from your notes. So I
16:13you guys did this example in class. Um
16:16down here we can see that these produce
16:20similar calories. Actually, soda
16:22produces a lot more calories, but look
16:24at all the nutrients we're getting from
16:26milk.
16:27So, milk is clearly more nutrient-dense
16:29than soda.
16:32Okay, nutrition facts panels. There's so
16:34much on here, but we're going to try to
16:36simplify it. So, what I've highlighted
16:38here are all the things that are
16:39required on a nutrient fact label. Our
16:42serving size is required. Calories,
16:45fats, saturated fat, trans fats,
16:47cholesterol, sodium, potassium, carbs,
16:49dietary fiber, added sugars, and
16:52protein. Not to mention a few
16:55micronutrients like calcium, iron,
16:57vitamin D, which isn't on here. Those
17:00things are required. So, our DRRI,
17:03they're recommendations from the food
17:05and nutrition board. Um, again, we
17:09talked about all of those earlier, our
17:11ERS, AIS, all that. Um, our DRVs or
17:14daily recommended values are set for
17:17energy producing nutrients and
17:19cholesterol and sodium. And they're
17:21found over here. They're percent daily
17:22values. They're based on a 2,000 calorie
17:25per day diet. Um, so keep that in mind
17:28and you can see them over here. Um, and
17:31then RDI are set for vitamins and most
17:34minerals on a food label.
17:36So again, you can find that over there.
17:38Percentage value as well.
17:41All right. So just some brief overview
17:44of the dietary guidelines that we try to
17:46follow. Um, follow a healthy eating
17:48pattern across lifespan. Focus on
17:50variety and nutrient density and how
17:53much. Moderation is key on some things
17:56because every food has a place in our
17:58diet. No food is bad. Um, limit calories
18:02from added sugars and saturated fats and
18:04reduce sodium. Remember those three
18:05things that Mr. Hand is always talking
18:07about, but that we want to watch out for
18:09are added sugars, saturated fats, and
18:11and sodium. Those are the ones we want
18:13to limit and have in moderation. Um, and
18:17we should try to shift to healthier food
18:19and beverage choices, um, and support
18:21healthy eating patterns for all. And
18:23then these are just ways that we can put
18:24them into action, these dietary
18:26recommendations. Um, take into account
18:28your current health status, your family
18:30history. Maybe your family history has
18:32or maybe your family has history of
18:34heart disease. So maybe you need to be
18:35more cautious about certain foods. Um,
18:38identify specific changes you need to
18:39make. Develop a plan to achieve these
18:42changes and then see whether the changes
18:45are really effective. Are they helping
18:47you follow those dietary guidelines?
18:51Okay, my plate. This is a fun one and a
18:55really great tool for using in our daily
18:57life. Um, it helps us balance our
18:59calories. Um, basically
19:03avoid oversized portions when it comes
19:05to making your My Plate. Um, foods that
19:08you really don't have to worry about and
19:10you can increase a lot are your fruits
19:12and vegetables. You want to make half of
19:13your plate fruits and vegetables. make
19:15at least half of your grains whole
19:17grains and switch our milk from whole
19:21fat to low fat or fat-free option. Um,
19:24foods to reduce again those added
19:26sugars, sodiums, saturated fats. And
19:29then swap out water instead of high
19:32sugar drinks. Those are the main
19:34recommendations for my plate.
19:37All right, guys. We just made it through
19:38chapter 2. Last chapter to go. We get
19:41into digestion in this chapter. So our
19:44first we'll start with the organization
19:45of the human body. So how is the human
19:47body organized? Well, we start at a
19:48chemical level. Our atoms combine to
19:50form our cells. Cells combine to form
19:52tissue. Tissues combine to form organs.
19:55Organs work together to form an organ
19:58system. And then organ systems work
19:59together to make you and me organisms.
20:02So I think it makes pretty pretty good
20:03sense. But just keep those stepwise
20:06order in mind.
20:10major digestive organ system. The major
20:13organs, mouth, esophagus, stomach, small
20:16intestine, large intestines, and anus.
20:18And these are in the order of which
20:20digestion occurs. Um, and then we have
20:22accessory organs that help out, but
20:24they're not main organs um that are a
20:27part of the digestive system, but still
20:28really important, and that's the liver,
20:30pancreas, and gallbladder, or in other
20:32words, llamas get pizza. A helpful way
20:34to remember if you need.
20:38All righty. So the functions of the
20:40digestive system
20:42main function is to absorb the nutrients
20:44that we're that we're intaking excreting
20:47waste making nutrients for cells out of
20:49the energy that we intake. Um it plays a
20:52role it plays a role in immune system
20:55and it houses the microbiota in our body
20:58and our gut which is really vital for so
21:01many things but especially digestion and
21:04a healthy gut. Um, our digestive system
21:07is controlled by hormones and the
21:09nervous system.
21:11All right. So, the GI tract, it's made
21:13of four layers and I have it organized
21:15as the very innermost layer to the
21:17outermost layer. So, we have the mucosa
21:20in the very innermost layer which is the
21:22epithelial cells and glands. Then we
21:24have one layer out is the sub mucosa
21:27that has the blood vessels and they and
21:29it carries nutrients in those. Um and
21:31then one more layer out we have muscle
21:34that is actually moving the food forward
21:36which we'll talk about later the
21:37difference between paristalsis and
21:39segmentation. Um and then we have the
21:41sarosa which is actually protecting the
21:43tract overall. And then just a little
21:45fun fact that you guys mentioned or that
21:47Mr. Hen mentioned in class but our GI
21:49tract is 15 ft long which is pretty wild
21:52that it fits inside of our body's
21:55sphincters. These are really important
21:57part of the digestive system. They're
21:59ringing like muscles and they open and
22:01they close to control the flow of the
22:03food that you're eating and the flow of
22:05the contents in the GI tract. Um the
22:08lower esophageal sphincter, again the
22:10numbers correlate to where they're
22:11located. Um and they do kind of what you
22:15think they do depending on where they're
22:17located, but the lower esophageal
22:19sphincter, it prevents backflow of the
22:22stomach back into the esophagus. Um,
22:24pyloric sphincter controls the flow of
22:26stomach contents into the small
22:27intestine so that it does not flow back
22:29into the stomach. The sphincter of odi
22:32it controls the flow of bile from the
22:33common bile duct into the small
22:35intestine. Ilioal valve prevents the
22:37contents of the large intestine from
22:39re-entering the small intestine and the
22:41anal sphincter prevents defecation until
22:43the person wants to do so. So all of
22:46these basically are preventing backflow
22:49and keeping the food moving forward
22:52which is essential for digestion.
22:54Okay. So speaking of food moving
22:56forward, how food is actually moving
22:58because without um segmentation
23:01paristalsis, our food is just going to
23:03be sitting in one spot which is not
23:06good. It might move a little because of
23:08gravity but overall it's not going to
23:09move very well. So parasolsis and
23:12segmentation great way to know the
23:14difference between these is paristelsis
23:16we're actually pushing forward. So
23:19parasolsis starts with a P. Pushing
23:21forward starts with a P. That's how I
23:22remember. So paristelsis we're actually
23:25moving forward. Segmentation on the
23:26other hand is just mixing back and
23:28forth. So it's mixing the food in with
23:30enzymes which is also great for our
23:32digestion. But so each are important but
23:35they're doing different things. So
23:36again, paristelsis food is mixing with
23:38digestive secretions, but it's actually
23:41getting propelled or pushed down the GI
23:43tract and it's waves of contractions
23:45because we do have that muscle layer on
23:48um in our GI tract that is actually
23:50doing the squeezing and shortening to
23:51push it. Segmentation, it's the back and
23:54forth movement, breaking apart context,
23:56make content, mixing with enzymes, and
23:58it's occurring in small intestine
24:00alongside of paristelsis.
24:03um mass movements, paraselsis over wides
24:06widespread area happening in the large
24:08intestines and then finally elimination,
24:11urine, feces, vomiting, all ways that we
24:13eliminate food or um excretions. Um a
24:17normal time for a meal to make it
24:21through your digestive system is 24 to
24:2260 hours, which is a really long time.
24:25Um so when you're eating something, it's
24:27going to be um working its way for a
24:30while.
24:32Wonderful. the wonderful world of
24:34enzymes or in other words aces. Most
24:36enzymes you see are going to end in aces
24:39or ACE which is super helpful. Not all
24:41of them but a lot of them. Um what are
24:43enzymes? They are proteins and they
24:45speed up reactions. That's their main
24:48function. That's what they're there for.
24:50They act on a specific substance. Um
24:52carbs, proteins, fats, whatever it may
24:54be. Most enzymes are going to be made in
24:57our pancreas and small intestine which
25:00our small intestine is essential for
25:02absorption. So it makes sense that the
25:03pancreas and small intestines are making
25:05our enzymes. But a small amount are made
25:07in our stomach and our salivary glands
25:09in our mouth. Um they the enzymes
25:12catalyze hydrarolysis reactions or we
25:14removing water to break um bonds or
25:17whatever it may be. And then inadequate
25:20enzyme production can lead to some
25:22issues like incompleted digestion or
25:25limited absorption. We're not getting
25:26all the nutrients we could. So it's
25:28important to have enzymes for digestion.
25:31Some other secretions to know in our
25:33mouth we have saliva and there's enzymes
25:35in saliva that break down starch. In our
25:37stomach we have acid which activates um
25:41enzymes that break down protein. We have
25:43bile in our small intestines which help
25:45break down fat um through
25:47emulsification,
25:49but we'll talk more about that later.
25:51Okay, so moving through the GI tracts,
25:52we're going to start where digestion
25:54begins, the mouth and the esophagus. So
25:56digestion begins in the mouth, and we're
25:59going to chew food, mix it with enzymes,
26:01break it down mechanically by chewing,
26:04and our saliva is going to mix with the
26:06food, forming a bolus, which is like a
26:08big lump of food. And we're going to
26:11swallow that bolus and it's going to go
26:12through our esophagus and our epiglatus
26:14is going to cover the larynx so that
26:16that food is not going where it's not
26:18supposed to be. Um, and then what's in
26:20our saliva? Many things to help break
26:23down what we're eating, although we're
26:25not breaking down a lot in our mouth.
26:27Um, lizoomes to destroy bacteria, mucus
26:30to kind of lubricate and then like kind
26:32of like hold the bolus together because
26:34it's like slimy and gross. Um, it's like
26:37the slimy gross glue. And then
26:40amalayise, which breaks down a small
26:42portion of starch into simple sugars,
26:43not a lot, but a little bit. And then
26:45lipase, which begins fat digestion.
26:49All right, guys. We're doing great.
26:50Ramas there. Um, this is just a small
26:52caveat, but smell and taste. A lot of
26:55you are going to know this, but we have
26:56five um tastes. Salty, sour, sweet,
26:59bitter, unami, umami, excuse me. Um, and
27:02taste is enhanced by our oldactory cells
27:04in the nose. So a lot of times if you
27:06can't smell, you can't taste food very
27:08well because olfactory cells in our nose
27:10help us to taste better.
27:13Okay. Now that our food has moved
27:15through the mouth and esophagus, we get
27:17to the stomach. Food enters the stomach
27:20via that sphincter we talked about that
27:21lower esophageal sphincter and digestion
27:24continues to the stomach. But a small
27:26amount of digestion occurs here. really
27:28only protein gets digested here or
27:30broken down by enzymes because it's so
27:32acidic because gastric juices in our
27:34stomach contain HCL which is
27:37hydrochloric acid and intrinsic factor
27:40from parietal cells but we have a nice
27:43enzyme here that breaks down protein and
27:47pepsinogen this is the non-active form
27:50but it becomes activated by HCL
27:54into something that can digest the
27:56protein so pepsinogens is important for
27:58protein digestion and gastroglyphase
28:01from chief cells. So, a little bit of of
28:02fat breakdown occurs here. Gastrin, it's
28:05a hormone made in the stomach and it
28:07controls the release of HCL and
28:09pepsinogen.
28:11So, that's something to know. It's a
28:13hormone. Like we talked about, hormones
28:15do control our um or part of our reg
28:19regulation of our digestive system.
28:22All right, guys. We'll keep moving. So
28:23in our stomach, gastrin leads to the
28:26release of HCL and pepsinogen. And like
28:28I said, HCL, hydrochloric acid,
28:30activates our pepsinogen
28:33into pepsin. And our pepin breaks down
28:37proteins to small peptides, which are
28:39like smaller chains of amino acids.
28:44All righty.
28:47In the stomach, the bolus goes through
28:50the lower esophageal sphincter into the
28:52stomach. And in the stomach, secretions
28:56make the bolus become like a kim, which
28:59is like a more like liquid version of
29:01the food. It's just like a slushy slush.
29:03It's really nice picture. Um, and then
29:06once it's a kim in the stomach, it keeps
29:09going to the small intestine and the
29:11pyloric sphincter allows the kim to flow
29:13into the small intestine. um and it
29:15closes so that it doesn't go back up
29:17into the stomach. And then glucose
29:19depend dependent insulin tropic peptide
29:22slows the release into the small
29:24intestine. I don't this isn't really
29:26something you need to spend a lot of
29:28time memorizing at all, but it's just
29:30something to note. Um in our stomach
29:32expands a lot. It can expand from 2 oz
29:35to 16 cups when it's full. Um, and food
29:39typically stays in our stomach from like
29:401 to four hours
29:43or sorry, it's like takes about 1 to
29:45four hours from the stomach for the food
29:46to get from the stomach to our small
29:48intestine.
29:50All righty. So, we've moved from the
29:52mouth, esophagus now to and the stomach
29:55to the small intestine. This is our
29:58major side of absorption um or digestion
30:00and absorption. Most of absorption
30:03occurs here. So on the exam if you'd
30:05asked like which organ does the most
30:08absorption in the digestive system you
30:10would say the small intestine. Um and
30:13it's divided into three sections. The
30:14dueum, the jugenum and the ilium.
30:19So here's all the things that kind of
30:21get absorbed and digested in the small
30:24intestine. We have glucose, minerals,
30:26amino acids, vitamins, alcohol, water,
30:28fat. So literally almost b everything
30:32does get absorbed here minus a few
30:36things.
30:38All right. In the small intestines we
30:39have small intestine villi which um
30:44circular folds and finger-like
30:45projections on the surface of our small
30:48intestine brush border. They their main
30:51goal is to increase the surface area and
30:54cause kime to like move slowly through a
30:57spiral path to allow for more absorption
31:00and it also helps mix the kim with more
31:03digestive juices and um again that
31:06surface area allows it to come into
31:07contact with even more villi.
31:10Um this process all is aided by
31:12segmentation too which again remember
31:14segmentation is not moving forward it's
31:16just like mixing.
31:19Villi are lined with interasittes and um
31:22they secrete enzymes which help absorb
31:25nutrients and other cells also secrete
31:28mucus and hormones. Um interosytes have
31:31a brush border. They're that are lined
31:33with microbilli and microbilli are
31:36another thing that are covered with
31:37digestive enzymes that help us to digest
31:40and absorb even more food. Okay, again
31:44our accessory organs, llamas get pizza,
31:46liver, gallbladder, pancreas. They work
31:49alongside of our small intestine to aid
31:51in digestion and absorption because
31:53again most of our enzymes are produced
31:56by our pancreas and our small
31:57intestines. Um but bile is produced by
32:00the liver, stored in the gallbladder and
32:02it helps us in fat digestion and
32:04absorption. Um by emulsifying fat which
32:07is basically just means breaking large
32:09fat into smaller tiny droplets. Um and
32:12then um bile is reabsorbed in the illium
32:16which is a portion of the small
32:17intestine and it can be returned to the
32:20liver. So we actually recycle the bile
32:22or interohypatic circulation. Fancy way
32:26of saying we recycle bile. a small
32:28amount of bile not reabsorbed and it's
32:30excreted in feces.
32:34Um our pancreas again pancreas produce a
32:37lot of those enzymes and juices that we
32:38need to digest food. Our sodium
32:41bicarbonate it helps neutralize acidic
32:43kime cuz remember kim is coming from the
32:45stomach where we had HCl and just a lot
32:47of acid gastrin like all that stuff
32:50that's just causes it to be a very
32:52acidic environment. So sodium
32:54bicarbonate helps neutralize the acidic
32:56kim when it gets to the small intestine.
32:58Pancreatic amalase helps digest starch
33:01in the small intestine. Pancreatic
33:03lipase digest fats and then proteases
33:06digest proteins. So these kind of um
33:08these words the names of the enzymes go
33:10with kind of what they digest
33:13which is helpful some of them.
33:16Okay. So we've moved from mouth,
33:17esophagus, stomach, small intestine, and
33:19now we're at the large intestine.
33:21There's three main parts of our large
33:23intestine. We have the colon, the anus,
33:24and the rectum. There's three main
33:26functions, but our large intestine
33:28houses our microbiota where live
33:30bacteria is living in our gut that helps
33:32us um to keep our GI tract healthy and
33:36helps us um just so there's so many
33:40benefits. Some it's even linked to
33:41mental health in some cases. Um some
33:43research suggests. So, it's really good
33:45to have healthy bacteria in our guts. Um
33:50it forms and expels feces our large
33:51intestines and then it also absorbs
33:53water and electrolytes.
33:55Um the large intestine is the main site
33:57where electrolytes are absorbed like
33:59sodium and potassium but essentially
34:01everything else is absorbed in our small
34:03intestine.
34:06our gut microbiota. Again, this live
34:08bacteria helps us control pathogenic
34:10bacteria, synthesize vitamin K, help
34:13with lactose digestion, and digesting
34:16and metabolizing complex carbs, fibers,
34:18and starches, and synthesized biotin.
34:21So, there's so many benefits to um our
34:24gut microbiota.
34:28Okay, so what the actual bacteria in our
34:32gut microbiota are called probiotics.
34:35They're the live bacteria. We can find
34:37these in food and supplements, but they
34:39colonize our large intestine and they
34:41provide health benefits. Like we just
34:42talked about all those health benefits.
34:44So, here's some foods they can be found
34:46in yogurt, kefir, miso, a lot of
34:48supplements you can get from the store.
34:50Um the prebiotics on the other hand,
34:53they're not the live bacteria. They're
34:55the food for the live bacteria to um use
34:59to grow. in um their various food
35:03ingredients, but they're non-digestible
35:05carbohydrates. Um they promote the
35:07growth of healthy bacteria. Again,
35:09prebiotics are the food for probiotics.
35:12Um some examples are inulin and
35:15resistant starches.
35:18So here again, probiotics are alive.
35:20Remember that they're the living ones.
35:22Prebiotics, they're just a form of fiber
35:24that serve as a food for probiotics. And
35:26here's some sources. Um, maybe just keep
35:29in mind a few of those in case you get a
35:32question.
35:35All right, foods that increase acid
35:36reflux. Not a fun condition to have. Um,
35:39but foods that increase it are typically
35:41more acidic. Um, obviously like citrus
35:44fruits, caffeine, chocolate even. You
35:47probably don't think that's acidic, but
35:48it actually is more acidic than others.
35:51um fatty foods, especially spicy foods,
35:54onions, tomatoes, all these things kind
35:56of have to watch out for if you have
35:58acid reflux.
36:01Intestinal gas. Intestinal gas, it's
36:03when um we have fermentation of those
36:05undigested carbohydrates or prebiotics
36:08that we intake by bacteria in large
36:11intestine. So if we don't digest the
36:14carbs and they make it to our large
36:15intestine, um fermentation happens and
36:18it builds up gas.
36:22We call it intestinal gas. Okay. The
36:24main difference between constipation and
36:25diarrhea. Some of this you'll probably
36:28just know from just common sense. Um but
36:31constipation is when we have difficult
36:33or infrequent bowel movements, um slow
36:35movement, fluid is absorbed in many
36:38cases or many causes, excuse me. um
36:41diabetes, IBS depression can cause this,
36:43pregnancy, anti-depressants can cause
36:45this, medication supplements and a low
36:48fiber diet. So, we can really help this
36:51um with a higher fiber diet. So, fiber
36:53is important. Um diarrhea on the other
36:56hand, it's very loose, watery stools
36:58like more than three times a day. Not a
37:00comfy situation to be in. Um, there's
37:03multiple causes for having diarrhea, but
37:05we could have bacterial or viral
37:07infections from maybe we had
37:09contaminated food or water, parasites,
37:11food intolerances, IBS, intestinal
37:14diseases, large amounts of unabsorbed
37:17substances. So, if we get too much of
37:18those unabsorbed carbs, complex carbs,
37:21that could be really not a good deal.
37:24Um, or other unabsorbed substances for
37:27that matter. Um, fluid secreted instead
37:30of absorbed. So yeah, we don't absorb
37:32the fluid that we should be. Um and it's
37:34secreted in diarrhea.
37:36Not fun. Um treatment for constipation.
37:40Again, high-fiber diets. So adding fiber
37:42to our diets is really important for um
37:46for constipation treatment and regular
37:48bowel movements in general. Um drinking
37:50more fluids, developing um more regular
37:54bowel habits, relaxing some also
37:57exercise. Exercise is really important.
37:59So, these are great ways um that we can
38:01actually um help with this versus we you
38:06can take some medications if it's
38:07serious like laxative stool softeners.
38:10Um but you might want to avoid lubricant
38:12laxatives like mineral oil cause some
38:15unforeseen side effects. Um so IBS
38:19versus IBD irrital bowel syndrome it's
38:22in 10 to 15% of the population
38:24unfortunately. Um, it's going to be
38:26characterized by irregular bowel
38:28function, abdominal pain, and
38:30distension.
38:32Treatment could be to watch trigger
38:34foods. You just have to keep an eye out
38:35for the foods that trigger you. A FODMAP
38:38diet, which we briefly talked about in
38:40class. Um, not a fun thing to have to
38:42follow. Smaller meals, peppermint oil,
38:45maybe have to go gluten-free. Just have
38:47to see what works for you. Um some
38:50causes abnormal abnormal intestinal
38:53motility, stress,
38:56altered gut immunity, intestinal
38:58dispiosis, many causes, not a fun thing.
39:01On the other side of it, we have
39:03inflammatory bowel disease. And this
39:05happens in one in every 225 people. So
39:08that's quite a few people um across the
39:11world. But it's it can be it's basically
39:15chronic intestinal disease um such as
39:17like ulcerative colitis, Crohn's
39:20disease. Um it's when reoccurring
39:23inflammation and ulceration of the large
39:25intestines. So this is not a fun um
39:27situation and could be really painful
39:29and uncomfortable. Um treatments
39:31typically it's medication, antibiot
39:34antibiotics and surgery. And we really
39:37don't know the cause, but it's an
39:39inflammatory response. Could be um or
39:42could be genetic. We don't really know.
39:46Okay guys, that is all I have for you
39:48tonight. Um but go crush your first
39:50exam. You guys are going to do great.
39:52And remember to
39:54review your notes. Um use this as a
39:57supplemental review guide, but review
40:00those notes. Look at those main bolded
40:02underlined highlighted things. things
40:04that maybe Professor Hand or Professor
40:06Mingi have pointed out to you. Um, yeah.
40:09And you're going to do great.
40:12All right, guys.

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