5.4-the best one (hormones)

Question 1

what detects when blood glucose levels are too low?

Answer 1

alpha cells in the islets of Langerhans

Question 2

what is secreted when blood glucose levels are too low?

Answer 2

glucagon

Question 3

where are glucagon receptors located?

Answer 3

on hepatocytes

Question 4

what’s the mechanism of glucagon action?

Answer 4

binds to target receptors
stimulates g protein inside membrane
activates adenyl cyclase which converts atp to cAMP
cAMP activates series of enzyme controlled reactions inside cell

Question 5

what are the effects of glucagon in hepatocytes?

Answer 5

• glycogenolysis
• more fatty acids used in respiration
• amino acids and fats converted to additional glucose by gluconeogenesis

Question 6

what is glycogenolysis?

Answer 6

converting glycogen to glucose

Question 7

what is gluconeogenesis?

Answer 7

non carbohydrate sources like amino acids and fats converted into additional glucose

Question 8

which enzyme does glycogenolysis?

Answer 8

phosphorylase A

Question 9

what is diabetes mellitus?

Answer 9

a condition caused by the body no longer being able to control blood glucose levels.

Question 10

what is type 1 also known as?

Answer 10

juvenile onset diabetes

Question 11

what is type 1?

Answer 11

when the body stops producing insulin/enough insulin

Question 12

causes of type 1?

Answer 12

autoimmune disease-body attacking its own beta cells

viral attack

Question 13

what is type 2?

Answer 13

when the body stops responding to insulin or doesn’t make enough of it

Question 14

what are the type 2 risk factors?

Answer 14

obesity
lack of regular exercise
diet high in sugars, especially refined
afro-carribbean or Asian origin
family history

Question 15

how might stem cell therapy be used to treat type 1?

Answer 15

by using stem cells to grow new islets of Langerhans

Question 16

what is hyperglycaemia?

Answer 16

constant high blood sugar

Question 17

what is hypoglycaemia?

Answer 17

constant low blood sugar

Question 18

what does the pancreas do when blood glucose levels are too high?

Answer 18

releases insulin from beta cells

inhibits glucagon

Question 19

what does the pancreas do when blood glucose levels are too low?

Answer 19

releases glucagon from alpha cells

insulin inhibited

Question 20

what is glucagon?

Answer 20

a hormone released by alpha cells in response to low blood sugar levels. it increases the production of glucose from glycogen.

Question 21

what is insulin?

Answer 21

a hormone released by beta cells in response to high blood sugar levels. it causes the uptake of glucose and its conversion to glycogen.

Question 22

what is glycogenesis?

Answer 22

the conversion of glucose into glycogen for storage.

Question 23

what is the endocrine system?

Answer 23

a communication system using hormones as signalling molecules

Question 24

what are the 2 types of hormone ?

Answer 24

protein/peptide

steroid

Question 25

what are 3 examples of a peptide hormone?

Answer 25

adrenaline insulin glucagon

Question 26

2 examples of steroid hormone?

Answer 26

oestrogen | testosterone

Question 27

do the endocrine glands have ducts?

Answer 27

nah

Question 28

what do endocrine glands consist of?

Answer 28

groups of cells that manufacture + release hormone directly into blood of associated capillaries

Question 29

what does adenyl cyclase do?

Answer 29

converts ATP to cAMP

Question 30

when is a G protein activated ?

Answer 30

when the hormone binds to the receptor

Question 31

what does the G protein activate?

Answer 31

an effector molecule, usually an enzyme, eg adenyl cyclase, that converts an inactive molecule into the active 2nd messenger

Question 32

what is the adrenal cortex?

Answer 32

outer layer of adrenal gland

Question 33

where are adrenal glands found?

Answer 33

above kidneys

Question 34

what is the adrenal medulla?

Answer 34

inner layer of adrenal gland

Question 35

what are the layers of the adrenal cortex outer to inner?

Answer 35

zona glomerulosa zona fasciculata zona reticularis

Question 36

what does the zona glomerulosa release?

Answer 36

mineralocorticoids eg aldosterone

Question 37

what does the zona fasciculata release?

Answer 37

glucocorticoids eg cortisol

Question 38

what does the zona reticularis release?

Answer 38

precursor molecules used to make sex hormones

Question 39

what does the adrenal cortex use to produce steroid hormones?

Answer 39

cholesterol

Question 40

what does aldosterone do?

Answer 40

acts on distal tubules and collecting ducts in kidney-increases absorption of Na+ and decreases K+ absorption, increases water retention increasing blood pressure

Question 41

what do mineralocorticoids do?

Answer 41

control Na+ and K+ concs in blood-contribute to maintaining blood pressure

Question 42

what do glucocorticoids do?

Answer 42

help control metabolism of carbs, fats and proteins in liver

Question 43

in what situation is cortisol released?

Answer 43

response to stress or low blood glucose conc

Question 44

what is glucagon?

Answer 44

hormone that causes increase in blood glucose conc

Question 45

where is the pancreas located?

Answer 45

below stomach

Question 46

what do exocrine glands do?

Answer 46

secrete substances into a duct

Question 47

what is a group of exocrine cells in the pancreas clled?

Answer 47

acinus, plural acini

Question 48

what are acini grouped together into?

Answer 48

small lobules separated by connective tissue

Question 49

where do the cells of the acini secrete the enzymes they synthesise?

Answer 49

into the tubule at the centre of the group

Question 50

what do the tubules of the acini join to form?

Answer 50

intralobular ducts that eventually combine to make pancreatic duct

Question 51

what odes the pancreatic duct do?

Answer 51

carries fluid containing enzymes into 1st part of small intestine (duodenum)

Question 52

what enzymes does the fluid from the pancreatic duct contain?

Answer 52

pancreatic amylase trypsinogen lipase

Question 53

what is trypsinogen?

Answer 53

inactive protease-converted to active form trypsin when enters duodenum

Question 54

what does the pancreatic fluid contain other than enzymes + why?

Answer 54

Na2CO3-makes it alkaline to neutralise contents of digestive system that just left acidic stomach

Question 55

what do alpha cells secrete?

Answer 55

glucagon

Question 56

what do beta cells secrete?

Answer 56

insulin

Question 57

how is type 1 usually treated?

Answer 57

insulin injections

Question 58

what are alternatives to insulin injections to treat type 1 diabetes?

Answer 58

insulin pump therapy islet cell transplantation pancreas transplant

Question 59

what happens during insulin pump therapy?

Answer 59

small device constantly pumps insulin at a controlled rate into blood through needle permanently inserted under skin

Question 60

how is type 2 treated?

Answer 60

change in lifestyle