physiology

Question 1

4 functions of the digestive system

Answer 1

digestion, secretion, absorption, motility

Question 2

what type of connective tissue is the submucosa

Answer 2

thick irregular connective tissue

Question 3

what are the two nerve plexuses in the submucosa

Answer 3

myenteric and submucosal plexus

Question 4

what nerve contributes to sympathetic control of the digestive system

Answer 4

splanchnic nerve

Question 5

what are the two types of starch called

Answer 5

a amylose and amylopectin

Question 6

what is transported when glucose and proteins are absorbed by co transport and why

Answer 6

water because an osmotic gradient is created

Question 7

what is the transporter that cotransports glucose and NA

Answer 7

SGLT1

Question 8

what is the transporter that transports fructose across the apical membrane

Answer 8

GLUT 5

Question 9

what is the transporter that transports carbs across the basolateral membrane

Answer 9

GLUT 2

Question 10

what are the 2 types of exopeptidase

Answer 10

aminopeptidase and caboxylpeptidase

Question 11

how are di/tripeptides transported across the apical membrane

Answer 11

NHE3 pump pumps H+ ions out into the lumen and NA ions into the cell then PEP T1 transporter cotrasnports dipeptides with the H+ ions in

Question 12

what are micelles made of

Answer 12

bile salts, phospholipids, fatty acids, monoglycerides

Question 13

what happens to fats when they cross the apical membrane

Answer 13

reassembled in the smooth ER to triglycerides and coated in amphiphatic protein to stop reagregation then transported to the Golgi. here they leave the cells as chylomicrons and enter the lacteals

Question 14

why do chylomicrons enter lacteals and not the blood

Answer 14

can’t pass through the endothelial cells tight junctions

Question 15

what does iron bind to if not absorbed into the blood

Answer 15

ferritin

Question 16

what does iron bind to in the blood

Answer 16

transferrin

Question 17

what is vitamin B12 needed for

Answer 17

to mature blood cells

Question 18

what are the two classes of vitamins

Answer 18

water soluble and fat soluble

Question 19

what are fat soluble vitamins

Answer 19

A, D, E, K

Question 20

what are water soluble vitamins

Answer 20

B group, C, folic acid

Question 21

what are the three layers of the muscularis externa in the stomach

Answer 21

oblique, longitudinal, circular

Question 22

what is saliva composed of

Answer 22

water, mucins, amylase, electrolytes, lysozymes,

Question 23

what are the 3 salivary glands

Answer 23

submandibular, sublingual, parotid

Question 24

what does parasympathetic control of saliva lead to

Answer 24

watery solution

Question 25

what does sympathetic control of saliva lead to

Answer 25

thick mucous- lots of mucous (a1 ) and amylase (b2)

Question 26

what occurs in the oral phase of swallowing

Answer 26

tongue pushes the bolus to the back of the mouth

Question 27

what occurs in the pharyngeal phase of swallowing

Answer 27

soft pallete covers nasopharyngeal opening, epiglottis goes over, pharynx muscles contract

Question 28

what is the final phase of swallowing

Answer 28

oesophageal phase

Question 29

function of the stomach

Answer 29

produces intrinsic factor, dissolve food, sterilise food, mix up food,

Question 30

how are the exocrine glands arranged in the pacreas

Answer 30

arranged in lobules that are composed of acinar cells and duct cells. lobules- intercalated ducts- interlobular ducts, interlobular ducts, main pancreatic ducts

Question 31

what are the electrical impulses for peristaltic waves conducted through

Answer 31

gap junctions in the longitudinal muscle layer

Question 32

what causes the BER to surpass threshold

Answer 32

gastrin, distension of the stomach causes long/short reflexes, if there's fat in the duodenum it reduces contractions

Question 33

what are enterogastrones

Answer 33

hormones released from glands in the duodenum (secretin and cck) they act to inhibit gastric acid secretion and gastric emptying.

Question 34

what regulates the secretion of acid

Answer 34

parasympathetic- ACh, gastrin, prostaglandis, histamine

Question 35

how is acid neutralised in the duodenum

Answer 35

by bicarbonate released from brunners glands. bicarbonate binds with HCL which forms carbonic acid which breaks down to water and CO2

Question 36

what stimulates the release of bicarbonate from brunners glands

Answer 36

secretin and acid arriving in the stomach causes long and short reflexes

Question 37

what is secretin released from

Answer 37

S cells

Question 38

what are the septa

Answer 38

the branches of connective tissue that forms the hexagonal lobules

Question 39

what is bile made of

Answer 39

bile pigments, bile acid, lecithin, cholesterol, toxic metals, bicarbonate

Question 40

what are bile pigment s

Answer 40

break down products of haemoglobin- bilirubin

Question 41

what are bile acids

Answer 41

made in the hepatocytes from cholesterol, when joined with glycine and Taurine they become soluble (bile salts)

Question 42

what is different about the histology of the gall bladder

Answer 42

no submucosa

Question 43

what two ducts join to form the bile duct

Answer 43

common hepatic duct and cystic duct

Question 44

how does the secretion of CCK affect the secretion of bile

Answer 44

causes sphincter of oddi to relax and the gall bladder to contract

Question 45

what are the blood vessels in the liver called

Answer 45

hepatic sinusoids

Question 46

role of the large intestine

Answer 46

reasbsorb water, vitamin K production, digest short chain fatty acids,

Question 47

what causes the start of the defecation reflex

Answer 47

parasympathetic causes MMC which push the material to the rectum this causes it to distend. the distension triggers the reflex

Question 48

how is water secreted into the large intestine

Answer 48

chlorine is released from the crypts, which causes water to go into the lumen too

Question 49

how does chlorine enter the crypts

Answer 49

enters via Na/K/cl channel in basolateral membrane and leaves via chlorine channel in apical membrane

Question 50

what initiates the MMC

Answer 50

hormone- motilin

Question 51

what is the ileoceacal relfex

Answer 51

gastric emptying causes an increase in segmentation, this triggers the opening of the ileocaecal valve so chyme enters the colon and causes distension this then causes the valve to close

Question 52

what cells produce mucus in the intestine

Answer 52

goblet cells

Question 53

symptoms of constipation

Answer 53

headaches, nausea, loss of appetite, abdominal distension

Question 54

what are enterotoxic bacteria

Answer 54

bacteria that produce enterotoxins, these maximally turn on cl secretion, by elevating second messengers so too much water enters the intestine

Question 55

what are enterokinases

Answer 55

the enzyme bound in the brush border which converts trypsinogen to trypsin