intestines

Question 1

what is the small intestine the major site of

Answer 1

digestion and absorption

Question 2

what kind of process if absorption and how does it occur

Answer 2

selective occurring via specific transporter proteins by diffusion and secondary active transport

Question 3

what are the 2 phases of digestion

Answer 3

luminal - enzymes secreted by salivary glands/pancreas
membranous- enzymes attached to epithelial
surface of intestinal cells

Question 4

what happens to anything that remains undigested in the SI

Answer 4

passed onto LI for microbial fermentation

Question 5

what are the 4 types of intestinal epithelial cells

Answer 5

goblet
enteroendocrine
paneth
enterocytles

Question 6

what do goblet cells do

Answer 6

secrete mucous for lubrication and protection of mucosa and HCO3+ for neutralisation of stomach acid

Question 7

function of enteroendocrine cells

Answer 7

control digestion function via sensory mechanisms and release hormones

Question 8

function of paneth cells

Answer 8

defence against microbial penetration

Question 9

function of enterocytes

Answer 9

responsible for absorption via transporter proteins

Question 10

what does SI motility do

Answer 10

mix luminal contents due to segmental contractions
propel contents down SI at appropriate rate to allow maximum digestion and absorption due to peristaltic contractions

Question 11

effect of stomach motility after feeding

Answer 11

increases

Question 12

what are segmental contractions

Answer 12

circular contractions along distended intestine
divide intestinal contents into small segments
mixes contents with digestive juices
moves contents towards mucosal surface for digestion/absorption

Question 13

what is the main type of contraction when digestion is occurring

Answer 13

segmental

Question 14

strength of segmental contractions when emptying of stomach

Answer 14

intense

Question 15

what is the main type of contraction when digestion/absorption complete

Answer 15

peristaltic

Question 16

what is motility regulated by

Answer 16

pacemaker cells

Question 17

what provides most energy in herbivores/omnivores

Answer 17

carbohydrates

Question 18

what type of maltose is starch

Answer 18

straight chained

Question 19

what type of maltose is amylopectin

Answer 19

branched chained

Question 20

what type of glucose is glycogen

Answer 20

branched chained

Question 21

what bonds are digestible by mammalian enzymes

Answer 21

alpha-glycosidic

Question 22

what type of bonds are in starch, amylopectin and glycogen

Answer 22

beta-glycosidic

Question 23

what type of bonds are in cellulose

Answer 23

beta-glycosidic

Question 24

what type of maltose is cellulose

Answer 24

straight chained

Question 25

what are disaccharides

Answer 25

attached to enterocyte brush border

Question 26

what are monosaccharides

Answer 26

glucose fructose galactose

Question 27

what are the only carbohydrates that can be absorbed

Answer 27

monosaccharides

Question 28

what is the luminal digestive phase

Answer 28

amylase converts starch to maltose salivary amylase continues digestion in stomach until acid inhibits/destroys it amylase digestion continues in SI with pancreatic amylase

Question 29

what co-transporter is glucose and galactose absorbed by and type of transport

Answer 29

sodium-glucose = SGLT1 secondary active transport

Question 30

what is fructose absorbed by and type of transport

Answer 30

facilitative transporter = GLUT5 passive transport

Question 31

where is fructose transferred to and via what

Answer 31

liver via hepatic portal vein

Question 32

what is fructose stored as in the liver

Answer 32

glycogen

Question 33

what cannot be digested in neonates and why

Answer 33

proteins as the they are regarded as foreign material and evoke an immune reaction

Question 34

what enzyme breaks down tri-glycerides into mono-glycerides and free fatty acids

Answer 34

lipase

Question 35

what do bile salts do

Answer 35

reduce fat droplets to a smaller size = emulsification

Question 36

what are the 2 roots water transport occurs via

Answer 36

para-cellular = across tight junctions between epithelial cells trans-cellular = across cell membrane via transporter proteins

Question 37

major functions of large intestine

Answer 37

absorption fermentation

Question 38

purpose of glands in LI

Answer 38

secrete mucous for protection/lubrication

Question 39

what are the 4 layers of the LI

Answer 39

mucosa submucosa muscularis serosa

Question 39

does the LI contain digestive enzymes

Answer 39

no - purely microbial

Question 39

what are the 2 major cell types in the LI and functions

Answer 39

colonocytes - absorption goblet - secrete mucous

Question 39

anatomy of LI

Answer 39

Caecum colon rectum

Question 40

what is absorbed in the LI

Answer 40

VFAs Na Cl water

Question 41

what is diarrhoea

Answer 41

water lost in faeces due to increased secretion and decreased absorption

Question 42

causes of diarrhoea

Answer 42

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

Question 43

treatments of diarrhoea

Answer 43

intravenous fluids oral rehydration therapy

Question 44

large intestine contractions

Answer 44

segmental peristaltic anti-peristaltic mass movement

Question 45

what is constipation

Answer 45

abnormal accumulation of food material in gut usually in colon

Question 46

treatments for constipation

Answer 46

oral fluids to soften faecal material paraffin oils to lubricate drugs eg enemas to strengthen contractions