Brainscape's Knowledge GenomeTM

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


See full index

Body Systems > The small intestine > Flashcards

The small intestine Flashcards

1
Q

how is the pancreas attached to the small intestine

A

via the common bile duct

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

what is the function of the brush border enzymes

A

intergral memnbrane proefins
on surfaces of microvilli
break down material n contact with brush border

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

what is peristalsis

A

waves of muscular contraction which move contents along the length of the GIT

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

describe the muscles involved in peristalsis

A

circular muscles contract behind bolus while circular muscles ahead of bolus relax
longitudinal muscles ahead of the muscles contract shortening adjacent segments
wave of contraction in circular muscles forces bolus forward

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

which muscles contract first in peristalsis

A

longitudinal then circular behind the bolus

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

what is segmentation

A

alternative contraction of neighbouring segments which churn and mix contents with intestinal secretions

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

describe the migrating motor complex

A

when the gut is empty
MMC’s generate every 90 mins stimulated by motion (22 aa peptide secreted by M cells and erythromycin)
these are to help clean the gut, slow strong peristaltic waves

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

what inhibits MMC’s

A

feeding

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

what hormones are secreted from APUD cells

A

CCK from I cells
secretin from S cells
MOtilin from M cells
gastrin from G cells

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

where does bicarbonate come from

A

pancreas

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

where does mucus come from

A

goblet cells

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

what foods must be digested before absorption

A

carbs
lipids
proteins

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

describe carb digestion

A

soluble amylases only break down internal a1-4 bonds, remaining short china carbs are broken down by enzymes on the brush border
glucose and galactose actively absorbed by SGLT1
fructose passively via GLUT5 transporter

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

where does protein digestion start

A

in the stomach -15% but pepsin is inactivated in the duodenum

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

where is enterkinase secreted from

A

crypt cells

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

what is the role of trypsinogen (released from the pancreas) in protein digestion

A

converted to trypsin by enterokinase which converts proenzymes to the active enzymes

17
Q

what are 5 proenzymes in protein digestion

A 
trypsinogen 
chymotrypsinogen 
proelastase 
procarboxypeptidase a
procarboxypeptidase b
18
Q

what are large proteins digested by within the protein chain

A

typsin
chymotrypsin
elastase

19
Q

what is the role of carboxypeptidases

A

cut at the last peptide bond

20
Q

what is the specific role of carboxy A

A

cuts peptide with C terminal neutral AA such as serine

21
Q

what is the specific role of carboxy b

A

peptide cut with C terminal basic AA such as arginine

22
Q

how are amino acids taken up into the cell

A

via sodium linked secondary active transporters

23
Q

how are di/tri peptides taken up by cells

A

proton linked secondary active transport

24
Q

what is the role of M cells in protein absorption

A

phagocytose large proteins into cells

25
Q

how are fats digested

A

bile slats break up lipid droplets increasing surface area as fats cannot dissolve in water
amphipathic bile slats causes emulsification

26
Q

what is the role of the pancreas in fat digestion

A

pancreatic lipase cells off outside fatty acids leaving a monoglyceride plus 2 free fatty acids

27
Q

once fats are turned into monglycerides or mixed with bile salts what happens to them

A

diffuse close to the brush border and are resythesised and packaged in into chylomicra which are exocytosied which drain into lymphatic lacteals

28
Q

describe bile salt recycling

A

conjugated bile salts are actively absorbed in the distal ileum

29
Q

describe how iron is absorbed

A

absorbed in fe 2 state and starts in the duodenum
Dcytb reduces iron from fe3+
either absorbed within haem or via cotransport with H+
iron leaves the cell via FP1 and ends to plasma transferrin
bilirubin is a bi product of absorbing iron

30
Q

how is calcium absorbed

A

actively reabsorbed in the dude which is regulated by vit D
in the rest of the small bowel it is reabsorbed paracellularly
Ca binds to calbindin in the cell
leaves cell via na / ca anti porter

31
Q

how are fat soluble vitamins absorbed

A

ADEK

absorbed with lipids as they are dissolved in lipid droplets and enter into chylomicrons

32
Q

how are water soluble vitamins absorbed

A

require special transport proteins usually Na+ linked

33
Q

how is Vit B12 absorbed

A

absorbed only hone bound to intrinsic factor which is released from gastric parietal cells in the ileum

34
Q

what is the role of aldosterone in digestion

A

absorption of Na and K secretion in colon are aldosterone regulated

35
Q

what happens to acidity as you move through the GIT

A

acid in stomach and becomes more alkaline

36
Q

how much is absorbed in the small intestine compared to large

A

7L/day

1.9L/day

Body Systems (77 decks)

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