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
what are disaccharides
attached to enterocyte brush border
26
what are monosaccharides
glucose fructose galactose
27
what are the only carbohydrates that can be absorbed
monosaccharides
28
what is the luminal digestive phase
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
what co-transporter is glucose and galactose absorbed by and type of transport
sodium-glucose = SGLT1 secondary active transport
30
what is fructose absorbed by and type of transport
facilitative transporter = GLUT5 passive transport
31
where is fructose transferred to and via what
liver via hepatic portal vein
32
what is fructose stored as in the liver
glycogen
33
what cannot be digested in neonates and why
proteins as the they are regarded as foreign material and evoke an immune reaction
34
what enzyme breaks down tri-glycerides into mono-glycerides and free fatty acids
lipase
35
what do bile salts do
reduce fat droplets to a smaller size = emulsification
36
what are the 2 roots water transport occurs via
para-cellular = across tight junctions between epithelial cells trans-cellular = across cell membrane via transporter proteins
37
major functions of large intestine
absorption fermentation
38
purpose of glands in LI
secrete mucous for protection/lubrication
39
what are the 4 layers of the LI
mucosa submucosa muscularis serosa
39
does the LI contain digestive enzymes
no - purely microbial
39
what are the 2 major cell types in the LI and functions
colonocytes - absorption goblet - secrete mucous
39
anatomy of LI
Caecum colon rectum
40
what is absorbed in the LI
VFAs Na Cl water
41
what is diarrhoea
water lost in faeces due to increased secretion and decreased absorption
42
causes of diarrhoea
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
treatments of diarrhoea
intravenous fluids oral rehydration therapy
44
large intestine contractions
segmental peristaltic anti-peristaltic mass movement
45
what is constipation
abnormal accumulation of food material in gut usually in colon
46
treatments for constipation
oral fluids to soften faecal material paraffin oils to lubricate drugs eg enemas to strengthen contractions