Ex. Nutrition Ch. 3 - Digestion And Absorption Of Food Nutrients

Front 1

What is bolus?

Back 1

a ball of chewed food mixed with saliva

Front 2

What are Passive Transort and Active Transport?

Back 2

Passive Transport = substances pass through the plasma membrane without and energy requirement

Active Transport = requires metabolic energy for the exchange

Front 3

1. What is Simple Diffusion?

Back 3

1. The free movement of molecules across the plasma membrane powered by unequal concentrations (kinetic energy only)

Front 4

1. What is Facilitated Diffusion?

Back 4

1. the binding of a lipid insoluble molecule to a lipid-soluble carrier (permease) to cross the membrane

Front 5

1. What are 4 examples of lipid insoluble substances?

Back 5

1. Hydrogen, sodium, cacium, potassium ions, glucose, amino acids

Front 6

1. What do lipid insoluble molecules need to pass through a cell membrane?

Back 6

Permease

Front 7

1. Wha tis Osmois and why does it occur?

Back 7

1. Osmosis is a diffusion process that moves water (solvent) through a membrane.

It occurs b/c of a difference in concentration on both sides of the membrane

Front 8

1. What is an isotonic solution?

Back 8

1. a solution in which the concentration of nonpenetrating solute such as sodium choloride qeualizes inside and outside the cell wall

Front 9

1. What energy is used for active transport?

Back 9

1. ATP

Front 10

1. What type of transport mechanism does intestinal glucose use?
2. Describe this process
3. What direction does it move?

Back 10

1. coupled transport
2. Sodium and glucose couple together and are pumped through the plasma membrane into the cell
3. One direction only (intestine to blood)

Front 11

1. What is bulk transport and what two processes does it consits of?

Back 11

1. Bulk transport is the movement of macronutrients and large particles through cell membranes by an energy-requiring process.
The 2 processes of bulk transport are exocytosis and endocytosis.

Front 12

1. Describe Exocytosis
2. Descrive Endocytosis

Back 12

1. Exocytosis = transfers hormones, nerotransmitters, and mucous secretions from inside the cell to outside the cell
2. the opposite.

Front 13

1. What connects the pharanx to the stomach?

Back 13

1. esophogus

Front 14

1. what is peristalisis?

Back 14

1. the rythmic expansion and contraction of the esophogus that propels smal round food masses down the esophogus.

Front 15

1. What is the esophogeal sphincter?

Back 15

1. A ring of smooth muscle at the end of the esophogus that allows the food mass entry into the stomach.

Front 16

What 3 stimuli control the sphincters?

Back 16

1. Nerves, hormones, and hormone like substances

Front 17

1. What is the function of the partietal cells?

Back 17

1. They exrete hydrocholoric acid via the gastric clands in the stomach to aid the digestion process

Front 18

How much digestion takes place in the stomach and what are the two exceptions?

Back 18

little digestion takes place in the stomach.
2 exceptions are aspirin and alcohol

Front 19

1. What is chyme?

Back 19

1. A slushy, acidic miscture of food and digestive juices.

Front 20

1. How long does it take the stomach to empty after a meal?
2. How long can the stomach retain a high fat meal?
3. What controls the time and rate of the emptying of the stomach?

Back 20

1. 1-4 hours depending on the meal
2. 6 hours
3. The nervous system via hormones and peristolic waves

Front 21

1. What % of digestion occurs in the small intestine?
2. What are the first 3 sections of the small intestine?

Back 21

1. 90% of all digestion = small intestine
2. Duodenum
jejunum
ileum

Front 22

What section of the smal lintestine does most of the digestion?

Back 22

jejunum

Front 23

1. What are Villi?

Back 23

1. fingerlike protrusions that absorbe nutrients in the intestines.

Front 24

1. What system does the villi use to absorb nutrients and what type of energy powers it?

Back 24

1. Active transport
2, ATP

Front 25

1. What are the microvilli

Back 25

1. small projections found on the villi that aborb carbs, proteins, lipids, electrolytes, alcohol, vitamins, and minerals

Front 26

1. How much time does it take the GI tract to eliminate food start to finish?

Back 26

1-3 days

Front 27

1. Where is bile produce, stored, and secreted?

Back 27

1. Produced by the liver
stored and secreted by the gallbladder

Front 28

what is emulsification?

Back 28

the digestion of lipid droplets by bile so the small intestine can absorb them.

Front 29

What happens to bile once it has done it's job in the intestines?

Back 29

Some bile is excreted in feces but most returns to the liver

Front 30

1. What does the body do to protect the intestines from them hydrocholoric acid from the stomach?

Back 30

1. The pancreas secrete alkali-containing juice to buffer the acids. Protects against uclcers and damage.

Front 31

What are the other two names for the large intestine?

Back 31

Colon, Bowel

Front 32

1. What is the only significant secretion of the large intestine and what does it do?

Back 32

1. Mucos
protects the intestinal wall and helps to bind fecal matter together

Front 33

1. What is amylase?

Back 33

1. amylase = salivary enzyme that attacks starch and reduces it to simple sugars

Front 34

What is pancreatic amylase and where does it do it's job?

Back 34

1. pancreatic enzyme that completes the hyrdolysis of starch into smaller glucose molecules... happens in the duodenum.

Front 35

What macronutrient provides the most energy for intense aerobic exercise and in what proportion? ( %)

Back 35

Carbohyrdate provides 80% of the energy for intense aerobic exercise.

Front 36

What happens to monosaccharides once they cross the intestinal wall? ( 4 steps)

Back 36

1. samll intestines epithelial cells secrete monosaccharides into the bloodstream for transport by capillaries to the hepatic portal vein.
2. Hepatic portal vein emties directly to the liver
3. the liver removes most of the glucose, fructose, and galactose.
4. peripheral tissues absorb the rest

Front 37

Where does intestinal blood go once it leaves the intestines?

Back 37

Goes to the liver

Front 38

Where does lipid digestion begin and through what substance?

Back 38

lingual lipase in saliva starts the lipid digestion process

Front 39

1. What happens to lipids when they reach the stomach?
2. What happens to longer chain lipids (12-18 Carbon fatty acids)?

Back 39

1. gastric lipase works along with lingual lipase to continue breaking down lipids.
2. long chain fatty acids are digested in the small intestine

Front 40

What is CCK and what does it do?

Back 40

CCK = peptide hormone released from the wall of the duodenum.

Controls the release of enzymes into the stomach and small intestine.

Front 41

What are micelles and what happens to them in the digestive process?

Back 41

Micelles = fat-bile salt culsters.
They form when water-insoluble monoglyceride and free fatty acid end products form lipid hydrolysis bind with bile salts.
They are broken apart into bile and triacyglycerides. Bile returns to the liver.

Front 42

1. What are the 2 routes that triacyglycerols take once they are ready for absorbtion?
2. What determines the rout which they take?

Back 42

1. hepatic portal system or lymphatic system
2. their chain length determines the rout (long chain travels to lymphatics)

Front 43

1. What happens to medium chain Triacyglycerols in the hepatic portal system?

Back 43

1. They bypass the lymphatic system and go straight to the liver for subsequent tissue use in energy metabolism.

Front 44

1. What happens to long chain fatt acids once they are absorbed into the epithelial cells? (3 big steps)

Back 44

1. They reform into triacyglycerols then combine with protein, cholesterol, and phospholipids to form fatty droplets called chylomicrons.
2. Chylomicrons move up through the lymphatic system into the neck where they are hydrolized by lipoprotein lipase
3. They are now free fatty acids and glycerol, and will be used by peripheral tissues,

Front 45

1. how efficient is the protein digestion process (What % of feces is protein at the end)?

Back 45

protein digestion = very efficient
3% protein found in feces

Front 46

1. What are the final end products of protein digestion that are ready to be absorbed into the intestinal mucosa? (3)

Back 46

1. simple amino acids, dipeptides, tripeptides

Front 47

1. What is gastrin?
2. What 2 big functoins does gastrin perform?

Back 47

1. Gastrin = peptide hormone that:
a. controls pepsins release from stomach wall
b. stimulates gastric hydrochloric acid secretion

Front 48

What 5 objectives does the acidificatoin of ingested food achieve?

Back 48

1. Activates Pepsin
2. Kills pathogens
3. improves Fe and Ca absorbtion
4. Inactvates hormones of plant and animal origin
5. denatures food proteins

Front 49

1. About how much of protein is hydrolyzed in the stomach before it passes inthe duodenum?

Back 49

1. Only about 15% - hyrolyzed by pepsin

Front 50

1. Where are the final steps in protein digestion carried out?

Back 50

1. small intestine

Front 51

What is trypsin and what does it do?

Back 51

Trypsin - enzyme produced by the pancrease that breaks protein down into tripeptides, dipeptides, and single amino acids.

Front 52

What happens to free amino acids when they are ready for absorbtion by the intestinal walls?

Back 52

a. they are coupled with Na+ for delivery to the liver through active transport via the hepatic vein.

Front 53

1. What happes to dipeptides and tripeptides when they are ready for absorbtion by the intestinal wall? (2 big steps)

Back 53

1. They are moved into the (intestinal) epithelial cells by a single membrane carrier that uses H+ for active transport.
2. once inside the cytoplasm they hydrolyze into amino acids and flow into the bloodstream

Front 54

Where are amino acids and more complex proteins absorbed in the digestive process?

Back 54

The small intestine

Front 55

1. When amino acids reach the liver, one of three things occurs. What are the three possibilities?

Back 55

1. conversion to glucose (glucogenic amino acids)
2. conerstion to fat (ketogenic amino acids)
3. Direct release into the bloodstream as albumin or free amino acids.

Front 56

1. When free amino acids have been sent into the bloodstream by the liverl, what happens to them?

Back 56

1. They synthesize into biologically important proteins, peptides (hormones), and amino acids derivitaves such as choline and phosphocreatine

Front 57

How and where are vitamins absorbed in the digestive process?

Back 57

Absorbed via passive process in the jejunum and ileum

Front 58

1. What are fat soluble vitamins absorbed with in the small intestine?
2. once fat soluble vitamins are absorbed, what happens to them?

Back 58

1. fat soluble vitamins are absorbed with dietary fat (90%)
2. chylomicrons and lipoproteins carry them to the liver and body's fatt tissues

Front 59

Who absorbs calcium better, women or men?

Back 59

Men

Front 60

What process in the small intestine determines the absorbtion of water (both ingested and in food)

Back 60

The passive process of osmosis

Front 61

What 5 factors affect gastric emptying rage (GER)?

Back 61

1. solution volume (+ volume = more GER)
2. caloric content (+ calories = less GER)
3. Meal osmoality
4. temperature (cooler increases GER)
5. pH - higher acidic food decreases GER

Front 62

What 3 factors explain exercise-related alterations in nutrient and fluid absorbtion?

Back 62

1. Exercise mode
2. Environmental Temp
3. Type of food/liquid ingested

Front 63

What are the 2 positive health benefits for the GI tract that are gained by a PA lifestyle?

Back 63

1. Increased GER
2. Reduced incidence of liver disease, gallstones, colon disorders and constipation

Front 64

What dietary habits cause constipation the most?

Back 64

high fat low water diets

Front 65

What foods improve diarrhea and which foods should be avoided?

Back 65

improve diarrhea = broth, tea, toast, and low-fiber potassium rich foods.

avoid lactose, fructose, caffeine, and sugar alcohols

Front 66

What is functional dispepsia?

Back 66

chronic pain in the upper abdomen without obvious cause.