Gut L1

Question 1

what is the function of the mucous neck cell?

Answer 1

• secretes mucus

Question 2

what is the function of the surface mucous cell?

Answer 2

secretes mucus

Question 3

what is the function of the parietal cell?

Answer 3

secretes HCl and intrinsic factor

Question 4

what is the function of the chief cell?

Answer 4

secretes pepsinogen

Question 5

what is the function of the

G cell?

Answer 5

secretes hormone GASTRIN

Question 6

what is the length of the small intestine

Answer 6

6m

Question 7

where is the submucosal plexus located?

Answer 7

between circular muscle and sub mucosa

• controls SECRETION by GI tract
• main sensory neuron for SECRETION is CHEMORECEPTORS

Question 8

where is the myenteric plexus located

the main sensory neuron for motility is what

Answer 8

between the 2 muscle layers

• controls MOTILITY, FREQ and STRENGTH of GI tract contraction
• the main sensory neuron for motility is DISTENSION

Question 9

what is the role of Brunner’s gland

where is it

Answer 9

bicarbonate sectretion

in the jejunum

Question 10

what is the effect of coeliacs disease

Answer 10

• low in microvilli O less absorption (20x)

Question 11

Crohns disease can lead to what

Answer 11

short bowel syndrome if some of the bowel is surgicallly removed O not enough s.a to absorb nutriets

Question 12

describe the duodenum

the duodenum is how much

Answer 12

the first 12cm of s. i

• has a high vol of food
• high conc of nutrients
• highly vascularised O appears red
• cont Brunner’s glands
• cont plicae (additional folding)

Question 13

describe the jejunum

Answer 13

• cont Brunners glands
• highly vascularised O dark appearabce
• long villi, large s.a

Question 14

describe the ileum

Answer 14

• part of s.i that joins to l. int
• paler appearance
• Peyer’s patches (lymphatics)
• short villi O smaller s.a

Question 15

enterocytes are what type of cell?

Answer 15

absorbative cells

Question 16

what are tight junctions?

give exaples of the proteins involded

Answer 16

• cells joined together by projections of cell membrane
• occludin and claudin proteins
• decrease permeability

Question 17

what is the role of hormones in the gut

Answer 17

• control secretions
• control motility
• feedback to hypothalamus for control

Question 18

endocrine cells of the gut can be what?

Answer 18

open
- clear connection to gut lumen ( eg for pH, glucose presence)

closed
- no connection to gut lumen but still respons to diet to release hormones

Question 19

whata re the properties of an endocrine cell in the gut

Answer 19

• highly polarised (hormone containing secretory granules towards basal pole of cell
• close to CAPILLARY network of lamina propria
• close to ENTERIC NS, has receptors for NEURAL MODULATION

Question 20

hormone secretion in the gut is controlled by what?

Answer 20

1) the contact with nutrients which increases blood levels

2) by triggering the enteric NS

Question 21

where are Peyer’s patches?

Answer 21

• in the LAMINA PROPRIA
• catch microorganisms and other antigens
• uses DENDRITIC CELLS, B-LYMPHOCYTES & T- LYMPHOCYTES
• covered by MICROFOLD cells which lack microvilli
• M cells sample antigen directly from lumen, deliver ti to antigen presenting cells
• gut associated lymphoid tissue

Question 22

in the colon longitudinal musc is in how many bands? what is it called?

Answer 22

• 3 bands

Question 23

which is the only oart of GI that cont skeletal muscle?

Answer 23

• colon (external muscle sphincter)

Question 24

what kind of folding is found in in the colon

Answer 24

• basolateral folding

Question 25

everything absorbed goes where

Answer 25

• liver
  (hepatic portal)
  EXCEPT LIPIDS go to lacteal