Physiology

Question 1

where is gastrin produced from ?

Answer 1

G cells in antrum of stomach and duodenum

Question 2

where is somatostatin produced from?

Answer 2

D cells in pancreas

Question 3

where is cholecytokinin produced from?

Answer 3

I cells from duodenum, jejunum

Question 4

where is secretin produced from?

Answer 4

S cells in duodenum

Question 5

where is glucose-dependant insulotropic peptide produced from?

Answer 5

K cells in duodenum, jejunum

Question 6

where is motilin produced from?

Answer 6

small intestine

Question 7

where is vasoactive intestinal polypeptide produced from?

Answer 7

parasympathetic ganglion in sphincters, gallbladder and small intestine

Question 8

where is grehlin produced from?

Answer 8

stomach

Question 9

what substance is responsible for pancreatic HC03 production and what is the purpose of this

Answer 9

produced by secretin as it allows pancreatic enzymes to function

Question 10

what substance increases gallbladder contraction?

Answer 10

cholecystokinin (CKK)

Question 11

action of VIP

Answer 11

vasoactive intestinal peptide
- increases water and electrolyte secretion
- increases relaxation of smooth muscle and sphincter

Question 12

what substance increases bile secretion

Answer 12

secretin

Question 13

what is the action of intrinsic factor and what cells does it act on

Answer 13

acts on parietal cells - binding protein for uptake of vitamin 12

Question 14

what is the action of pepsin and what cells does it act on

Answer 14

acts on the chief cells for protein digestion

Question 15

what is the role of gastrin

Answer 15

increases acid secretion primarily through its efects on enterochromaffn-like cells (ECL)
also has a direct effect on parietal cells

Question 16

role of alpha-amylase

Answer 16

starch digestion

Question 17

role of trypsinogen

Answer 17

converted to active enzyme - trypsin by enterokinase / enteropeptidase - activates other protoenzymes

Question 18

how are monossaccharides (glucose, galactose and fructose) absorbed?

Answer 18

monossacharides are absorbed by enterocytes
glucose + galactose are taken up by GLUT 1
fructose is taken up by fascilitated diffusion by GLUT5
all are transported to blood by GLUT2

Question 19

where is iron, vitamin B12 and folate absorbed?

Answer 19

iron - duodenum
vitamin B12 - terminal ileum
folate - small intestine

Question 20

what are peyers patched?

Answer 20

unencapsulated lymphoid tissue found in lamina propria and submucosa of ileum
(microfold) M cells present angients to immune cells
B cells differentiate into IgA cells which transport into the gut

Question 21

what enzyme catalyses the rate-limiting step in bile acid synthesis

Answer 21

cholesterol 7-alpha hydroxylase

Question 23

What are brunner’s glands and where are they located?

Answer 23

Located in the submucosa of duodenum
Secrete bicarbonate
Acts a protective mechanism for peptic ulcers

Question 24

Pathophysiology of wernicke’s encaphalopathy

Answer 24

Small vessel haemorrhage and necrosis in mammillary bodies of the hypothalamus

Question 25

Atrophy of caudate and putamen

Answer 25

Huntingtons disease

Question 26

Widespread atrophy of cerebral cortex

Answer 26

Alzheimers

Question 27

does neuropeptide Y increase in the fasted or fed state

Answer 27

increases in starved state as it increases appetite

Question 28

where is neuropeptide Y released from

Answer 28

produced by neurones of the arcuate nucleus then secreted from lateral hypothalamus

Question 29

causative organism - hepatic abscess, bloody diarrhoea, abdo pain. recent travel.

Answer 29

E.histolytica

Question 30

E.histolytica on microscopy

Answer 30

trophozoites containing phagocytosed RBCs in the stool