GI 1

Question 1

what are the FOUR functions of the GI tract

Answer 1

digestion. absorption, excretion and host defence

Question 2

where does digested food go to after the intestine

Answer 2

blood or lymphatic system

Question 3

what is excreted

Answer 3

non absorbable components of food, drugs, steroids, cholesterol

Question 4

true or false - the immune system of the GIT is highly developed

Answer 4

true

Question 5

what makes up the small intestine

Answer 5

duodenum, jejunum and ileum

Question 6

pick the odd one out
-> the accessory organs are the pancreas, bladder and esophagus

Answer 6

esophagus -> liver

Question 7

what is the mucosa made up of

Answer 7

epithelium, lamina propria and muscularis mucosa

Question 8

what are the 4 structures of the GIT

Answer 8

mucosa, submucosa, muscularis externa and serosa

Question 9

what kind of junctions make up the epithelial layer

Answer 9

tight junctions

Question 10

how is the epithelial layer polarized

Answer 10

one surface is different compared to the other - basolateral and apical arrangement -> different transport proteins

Question 11

the epithelial layer provides selective uptake of _______

Answer 11

nutrients, electrolytes and water

Question 12

what can pass through tight junctions

Answer 12

water and small ions

Question 13

describe the lamina propria

Answer 13

made of connective tissue, small blood vessels, lymphatic vessels and immune cells

Question 14

what kind of muscle is the muscularis mucosa made up of

Answer 14

smooth muscle

Question 15

true or false - muscularis mucosa is involved in contraction of the GIT

Answer 15

false

Question 16

true or false - the submucosa is made up of connective tissue

Answer 16

true

Question 17

what are the similarities between submucosa and lamina propria

Answer 17

made up of connective tissue, blood and lymphatic vessels

Question 18

what is the importance of the submucosa

Answer 18

contains nerve cell bodies that relay information to and away from the mucosa

Question 19

which part of the GI tract regulates muscle function

Answer 19

the muscularis externa

Question 20

how are the fibres in the inner and outer layer of muscle in the muscularis externa oriented

Answer 20

inner layer - fibres oriented to cause narrowing of lumen
outer layer - fibres oriented to shorten tube

Question 21

describe the serosa

Answer 21

made up of connective tissue, covers the intestine and forms a connection point to the abdominal wall

Question 22

how does the blood flow to the liver

Answer 22

through the portal vein

Question 23

what are the two purposes for the portal circulation

Answer 23

remove wastes and process nutrients

Question 24

true or false - the liver receives a lot of oxygenated blood

Answer 24

false - it carries more nutrient rich blood and less oxygenated blood

Question 25

what are the 4 ways the GI reflexes are initiated

Answer 25

1. distension of wall 2. pH of contents 3. osmolarity 4. concentration of digestion contents

Question 26

what are the three receptors important to the GIT

Answer 26

mechano, osmo and chemo

Question 27

what is the name of the two nerve networks in the GI process

Answer 27

myenteric and submucosal plexus

Question 28

true or false - the submucosal plexus influences the smooth muscle

Answer 28

false - it influences secretion

Question 29

true or false - the myenteric plexus influences smooth muscle

Answer 29

true

Question 30

match the description to the correct chemical messenger hormone secreting gland cell -> target cells in one or more distant places in the body

Answer 30

endocrine

Question 31

how do the autocrine chemical messengers work

Answer 31

autocrine substance acts on same cell that secreted the substance

Question 32

how do paracrine chemical messengers work

Answer 32

target cells in close proximity to site of the release of paracrine substance

Question 33

name the four GI hormones

Answer 33

secretin, CCK, gastrin and glucose dependent insulinotropic peptide

Question 34

true or false - most GI hormones affect only one type of target cell

Answer 34

false - they affect more than one type

Question 35

what are the functions of CCK

Answer 35

stimulates pancreas to increase digestive enzyme secretion and gall bladder contraction

Question 36

describe the negative feedback control system of CCK

Answer 36

fatty acids and amino acids triggers secretion of CCK into blood -> absorption of fatty acids and AAs which stops secretion of CCK

Question 37

match the major release site to the major hormone gastrin

Answer 37

stomach antrum / G cells

Question 38

match the major release site to the major hormone secretin

Answer 38

small intestine

Question 39

match the major release site to the major hormone CCK

Answer 39

small intestine / I cells

Question 40

match the major release site to the major hormone Glucose dependent insulinotropic peptide

Answer 40

small intestine / K cells

Question 41

gastrin -> increase or decrease motility/HCl

Answer 41

increase HCl and motility

Question 42

secretin -> increase or decrease motility/HCl

Answer 42

decrease HCl and motility

Question 43

CCK -> increase or decrease motility/HCl

Answer 43

decrease HCl and motility

Question 44

what is the major action of GIP

Answer 44

increases insulin

Question 45

what causes the movement of contents of the stomach

Answer 45

contraction and relaxation of the two outer smooth muscle layers of the GIT

Question 46

explain pacemaker cells

Answer 46

-> found in the GIT -> constantly undergoing spontaneous depolarization/repolarization cycles

Question 47

the slow waves of the pacemaker cells are the _________

Answer 47

basic electrical rhythm

Question 48

what kind of neurotransmitters further depolarize the membrane

Answer 48

excitatory neurotransmitters

Question 49

how is the frequency of contraction maintained

Answer 49

through the basic electrical rhythm

Question 50

true or false - the number of action potentials fired is proportional to the force of contraction

Answer 50

true