intestines Flashcards

1
Q

what is the small intestine the major site of

A

digestion and absorption

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

what kind of process if absorption and how does it occur

A

selective occurring via specific transporter proteins by diffusion and secondary active transport

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

what are the 2 phases of digestion

A

luminal - enzymes secreted by salivary glands/pancreas
membranous- enzymes attached to epithelial
surface of intestinal cells

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

what happens to anything that remains undigested in the SI

A

passed onto LI for microbial fermentation

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

what are the 4 types of intestinal epithelial cells

A

goblet
enteroendocrine
paneth
enterocytles

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

what do goblet cells do

A

secrete mucous for lubrication and protection of mucosa and HCO3+ for neutralisation of stomach acid

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

function of enteroendocrine cells

A

control digestion function via sensory mechanisms and release hormones

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

function of paneth cells

A

defence against microbial penetration

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

function of enterocytes

A

responsible for absorption via transporter proteins

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

what does SI motility do

A

mix luminal contents due to segmental contractions
propel contents down SI at appropriate rate to allow maximum digestion and absorption due to peristaltic contractions

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

effect of stomach motility after feeding

A

increases

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

what are segmental contractions

A

circular contractions along distended intestine
divide intestinal contents into small segments
mixes contents with digestive juices
moves contents towards mucosal surface for digestion/absorption

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

what is the main type of contraction when digestion is occurring

A

segmental

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

strength of segmental contractions when emptying of stomach

A

intense

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

what is the main type of contraction when digestion/absorption complete

A

peristaltic

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

what is motility regulated by

A

pacemaker cells

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

what provides most energy in herbivores/omnivores

A

carbohydrates

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

what type of maltose is starch

A

straight chained

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

what type of maltose is amylopectin

A

branched chained

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

what type of glucose is glycogen

A

branched chained

21
Q

what bonds are digestible by mammalian enzymes

A

alpha-glycosidic

22
Q

what type of bonds are in starch, amylopectin and glycogen

A

beta-glycosidic

23
Q

what type of bonds are in cellulose

A

beta-glycosidic

24
Q

what type of maltose is cellulose

A

straight chained

25
Q

what are disaccharides

A

attached to enterocyte brush border

26
Q

what are monosaccharides

A

glucose
fructose
galactose

27
Q

what are the only carbohydrates that can be absorbed

A

monosaccharides

28
Q

what is the luminal digestive phase

A

amylase converts starch to maltose
salivary amylase continues digestion in stomach until acid inhibits/destroys it
amylase digestion continues in SI with pancreatic amylase

29
Q

what co-transporter is glucose and galactose absorbed by and type of transport

A

sodium-glucose = SGLT1
secondary active transport

30
Q

what is fructose absorbed by and type of transport

A

facilitative transporter = GLUT5
passive transport

31
Q

where is fructose transferred to and via what

A

liver via hepatic portal vein

32
Q

what is fructose stored as in the liver

A

glycogen

33
Q

what cannot be digested in neonates and why

A

proteins as the they are regarded as foreign material and evoke an immune reaction

34
Q

what enzyme breaks down tri-glycerides into mono-glycerides and free fatty acids

A

lipase

35
Q

what do bile salts do

A

reduce fat droplets to a smaller size = emulsification

36
Q

what are the 2 roots water transport occurs via

A

para-cellular = across tight junctions between epithelial cells
trans-cellular = across cell membrane via transporter proteins

37
Q

major functions of large intestine

A

absorption
fermentation

38
Q

purpose of glands in LI

A

secrete mucous for protection/lubrication

39
Q

what are the 4 layers of the LI

A

mucosa
submucosa
muscularis
serosa

39
Q

does the LI contain digestive enzymes

A

no - purely microbial

39
Q

what are the 2 major cell types in the LI and functions

A

colonocytes - absorption
goblet - secrete mucous

39
Q

anatomy of LI

A

Caecum
colon
rectum

40
Q

what is absorbed in the LI

A

VFAs
Na
Cl
water

41
Q

what is diarrhoea

A

water lost in faeces due to increased secretion and decreased absorption

42
Q

causes of diarrhoea

A

microbial imbalance - overload of guts capacity to absorb causes osmotic flow of water into gut lumen
infections
stress - activation of parasympathetic system increases secretion and motility

43
Q

treatments of diarrhoea

A

intravenous fluids
oral rehydration therapy

44
Q

large intestine contractions

A

segmental
peristaltic
anti-peristaltic
mass movement

45
Q

what is constipation

A

abnormal accumulation of food material in gut usually in colon

46
Q

treatments for constipation

A

oral fluids to soften faecal material
paraffin oils to lubricate
drugs eg enemas to strengthen contractions