Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MED310B > digestion and absorption > Flashcards

digestion and absorption Flashcards

1
Q

where does most absorption take place

A

in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

absorption in the stomach

A

absorbs some non polar substances such as alcohol and aspirin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do enteroendocrine cells secrete

A

various hormones including gastrin (G cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

processing time of different types of food

A

carbohydrates empty fastest followed by high protein foods
meals with high triglyceride content remain in the stomach the longest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

small finger like projcections that protrude from the mucosal lining to increase nutrient absorption surface area

A

vili

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

hair like projections that aid in the absorption of nutrients

A

microvili

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the mucosal epithelal cell layer of the small intestine house

A

enterocytes
brush border
goblet cells
crypt cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

enterocytes

A

absorptive cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

brush border

A

microvilli covered cells expressing digestive enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

goblet cells

A

secrete mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

crypt cells

A

epithelial stem cell which replenish dead/ sloughed off cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

most nutrients consumed as macromolecules

A

must be enzymatically broken down (chemical digestion) before absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

most carbs in diets

A

polysaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

starch and cellulose

A

from plant products (pasta and breads)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

glycogen

A

from animals and animal products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

cellulose

A

dietary fibre is not a substrate of digestive enzymes and therefore cannot be digeseted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

structure of starch

A

branched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

structure of glycogen

A

super brancehd

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

structure of cellulose

A

fibre that is packed and rows and column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

disaccharides

A

sucrose (sugar) and lactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

monosaccharides

A

glucose and fructose (absorbable forms of carbs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what digests polysaccharides

A

salivary and pancreatic amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

salivary amylase

A

inactivated by the acids in the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

pancreatic amylase

A

continues polysaccharide digestion in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what do amylases do

A

reduce starch or glycogen to either maltose (glycose disaccharide) or short branched polysaccharide called limit dextrins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

digestion of carbs to monosaccharides

A

completed by brush border enzymes boundot the apical membranes of absorptive cells lining the small intestine

27
Q

brush border enzymes

A

dextrinase and glycoamylase
sucrase
lactase
maltase

28
Q

dextrinase and glgycoamylase

A

breaks down limit dextrins and straight chain glucose polymers into glucose monomers

29
Q

sucrase

A

hydrolyzes sucrose into glucose and fructose

30
Q

lactase

A

hydrolyzes lactose to glucose and galactose

31
Q

maltase

A

hydrolyzes maltose to two glucose molecules

32
Q

how is fructose absorbed

A

by facilitated diffusion

33
Q

gluctose and galactose digesiton

A

enter epithelial cells via active cotransport with sodium

2 Na ions enter for each glucose transported. excess Na is pumped out by the basolateral sodium pump which required ATP for energy

34
Q

how do sports drinks use Na linked glucose transport

A

provide energy to high preformance athletes

monosaccharides enter the bloodstream thorugh facilitated diggusion across the basolateral membrane. they then travel to the liver for processing

35
Q

protein digestion

A

must be digested into small peptides and amino acids prior to absorption

36
Q

enzymes for protein digestion

A

to protect the secretory cells from digestive enzymes, the enzymes are stored in these cells in an inactive form, called zymogens

secreted zymogens are converted into active enzymes by proteolytic activation

37
Q

expopeptidases

A

cleave off individual amino acids from one end of the polypeptide
digestion of small peptides into amino acisd

38
Q

endopeptidases

A

break bonds in the middle of the polypeptide to produce shorter polypeptides

39
Q

endopeptidases example

A

pepsinogen

40
Q

pepsinogen

A

is secreted by chief cells in the stomach
it is partially activated by hydrogen ions secreted in the parietal cells in the stomach
the pancreas secretes several zymogens into the duodenum

41
Q

what are the zymogens being secreted into the duodenum

A

trypsin, chymotripsin,

42
Q

what does enterokinase do

A

converts trypsinogen to trypsin
trypsin then activates other zymogens

43
Q

exopeptidases example

A

caboxypeptidases (procarboxypeptidases) and aminopeptidase

44
Q

caboxypeptidases (procarboxypeptidases) and aminopeptidase

A

finish protein digestion by cleaving amino acids from the carboxyl and amino ends of a polypeptide chain respectivel

45
Q

amino acid and small peptide absorption

A

small peptides and amino acids are actively transported into the intestinal epithelial cells by cotransport with ions

amino acids are then tranported across the basolateral membrane by facilitated diffusion and diffuse into the blood

46
Q

most dietary lipids are

A

triglycerides (90%)

47
Q

lipids and mizing

A

dont mix with stomach contents bc they are hydrophobic and cant be reached by digestive enzymes

48
Q

bile salts

A

facilitates the action of digestive enzymes by emulsifying fat globules down into smaller droplets (micelles)

49
Q

bile salt synthesis and secretion

A

synth in hepatocytes and secreted in the bile

50
Q

lingual lipase

A

saliva and stomach

51
Q

gastric lipase

A

gastric lumen

52
Q

pancreatic lipase

A

small intestine

53
Q

what happens when lipids interact with lipase

A

monoglycerides and fatty acids are liberated through the action of lipase and they retain their association with bile acids and complex with other lipids to form structures called micelles

54
Q

fate of lipid containing chylomicrons

A

transported into the lymphatic vessel underlying the epithelial cell layer (lacteal)

large numbers of absorbed chylomicrons appears milky and the lymphatics are easy to see in the small intestine

55
Q

vitamin digestion

A

consumed in their absorptive form and do not undergo digestion
the mechanism of absorption of vitamins depends on whether the vitamin is hydrophobic or hydrophilic

56
Q

hydrophobic/ fat soluble vitamins

A

ADEK

absorbed with lipids therfore bile salts can help absorption of these vitamins

57
Q

water soluble vitamins

A

are absorbed by active transport or facilitated diffusion

folate, thiamine, riboflavin, niancin, pantothenic acid, biotin, vitamin B6, bitamin B12, vitamin C

58
Q

mineral absorption

A

occurs by active transport

80% of sodium enters the GI tract through secretions and 20% is ingested

59
Q

calcium absorption

A

regulated based on the bodys needs

enhanced by the homrones 1,25 OH vitamin D3 which increases the amount of calcium binding protien therefore calcium absorption is dependent upon sufficient dietary vitamin D

60
Q

iron absorption

A

both in the redduced inorganic form Fe2+ and when bound to heme

61
Q

water absorption

A

passive: driven by an osmotic gradient across the mucosal epithelium created by the transport of solutes (mainly sodium) from the lumen to the interstitial fluid

62
Q

sources of water

A

drinking water (2l/day)
secretions from the stomach, intestine, acessory glands (7l/day)

63
Q

fact about water

A

approx 70% of the water that is initially present in the duodenum is typically absorbed by the time chyme reaches the colon

MED310B (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions