homeostasis

Question 1

what is homeostasis

Answer 1

physiological control systems that maintain the internal environment within restricted limits in responce to extrenal change

Question 2

why do endotherms(warm blooded) have greater range of tolerance

Answer 2

they have homeostatic controls to withstand more conditions

Question 3

what are the advantages of intrinsic protein receptors

Answer 3

the hormone does not have to enter the cell

Question 4

decribe the secondary messanger system for blood glucose regulation

Answer 4

adrenaline binds to intrinsic receptors in the plasma membrane
adenylate cyclase is activated
cyclic amp is formed by atp
protien kinase is activated
glycogen hydrolised to glucose

Question 5

what is gluconeolysis

Answer 5

making new glucose from lipids and amino acids

Question 6

what is glycogenolysis

Answer 6

splitting of glycogen

Question 7

what is glycogenesis

Answer 7

making of glycogen

Question 8

name the parts of the islets of langerhan and what they do

Answer 8

beta cells - secret insulin
alpha cells - secretes glucagon

Question 9

describe what happens when there is a rise in glucose concentration

Answer 9

detection by beta cells in the islets of langerhans
insulin produced and secreted and travels in the blood to bind to receptors on target cell causing muscle and liver to take in glucose leads to glycogenesis
stops glycogenolysis and gluconeogenesis

Question 10

short and long term concequences of low blood pressure

Answer 10

confused and fatigued because nerves cannot function lon term
short term water potential of cells increase

Question 11

describe what happens when there is a fall in blood glucose concentration

Answer 11

detection by alpha cells which produce and secrete glucagon
it binds to receptor cell adrenaline cyclase is released making camp from atp which phosphorylises protien kinase converting glycogen to glucose

Question 12

describe the actions of glucagon

Answer 12

active enzymes effect in liver hydrolysis of glycogen to glucose
synthesises glucose from amino acids and glycerol

Question 13

describe the action of adrenaline

Answer 13

adenylate cyclase activated atp to camp
phosphorylation to activate protein kinase
glycogen to glucose

effects liver and muscles

Question 14

type 1 diabetes

Answer 14

doesnt produce insulin

Question 15

type 2 diabetes

Answer 15

resistant to your own insulin

Question 16

what can diabetes cause

Answer 16

high blood pressure because more osmosis into plasma membrane

blindness
stroke
amputation

Question 17

how do oral medications help diabetes

Answer 17

reduces glucose absorption in the ileum
stop starch digesion by inhibiting
amalyase
reduced glycogenolysis
increases insulin production from beta cells

Question 18

5 molecules that move into glomerular filtrate

Answer 18

h2o , glucose , hormones , amino acids , o2

Question 19

what 5 things that prevents the movement of small molecules out of capillaries into filtrate

Answer 19

enothelium and basement membrane
epithelial cells and renal capsual
podocytes
hydrostatic pressure in fluid of renal capsual space
osmotic pressure of glomerous filtrate

Question 20

what % of water reabsorption happens in the proximal convoluted tube

Answer 20

85 % out the the total 99%

Question 21

adaptations of the epithelial cell for reabsorption

Answer 21

micro villi to increase surface area so more diffusion happens
mitrochondria produces atp in oxidative phosphorylation
sodium potatsium pump

Question 22

what is the structure and function of the ascending limb of the loop of henle

Answer 22

thicker wall
starts narrow and the widens
impermeable to water but permeabel to mineral ions

Question 23

what is the structure and function in the decending limb in the loop of henle

Answer 23

thinner wall
narrow
permeable to water

Question 24

explain counter current flow in the loop of henle

Answer 24

the ascending limb and decending limb flow in opposite directions to maintain conc gradient across the whole length of the loop

Question 25

describe the distal convoluted tubule

Answer 25

final ajustments to water , salt to maintain pH of the blood they have microvilli and many mitrochondria reabsorbs by active transport hormones affect the walls permeability

Question 26

describe the collecting duct

Answer 26

found in the medulla connects the nephron and the ureter moves out of the collecting duct by osmosis due to the concentration gradient created by active transport of minerals in the ascending loop water leaves by channel proteins adh controls water loss

Question 27

describe movement in the loop of henle

Answer 27

descending limb water leaves by osmosis decreasing water potential in the tube ascending limb sodium moves out by facilitaed diffusion when the conc gradient is high and then active transport lowering water potential of the tissue surounding the tube

Question 28

what is the hypothalamus

Answer 28

region of the brain which acts as a control centre of the involuntry nervous system

Question 29

what is an osmoreceptors

Answer 29

cells within the hypothalmus that detects changes in blood water potential

Question 30

what is a pituitary gland

Answer 30

endocrine gland situated at the base of the brain anterior (front ) and posterior ( back)

Question 31

what is ADH

Answer 31

hormone produced by hypothalmus and secreted by posterior pituitary gland

Question 32

what happens when blood water potential is too high

Answer 32

detected by the osmoreceptor in the hypothalmus posterior lobe of pituitary gland releases less ADH walls of collecting duct and distal convoluted tube become less permibale more urine is less concentrated water potential gradient decreases

Question 33

what happens when blood water potential is too low

Answer 33

cells shrivel and this is detected by the osmoreceptors in hypothalmus posterior lobe of pituotary gland releases ADH ADH reaches collecting duct via blood making it more permiable to H2O less urine and is more concentrated

Question 34

describe the action of ADH

Answer 34

binds to protiens on the surface of the cell leading to the activation of the enzyme phosphorylase casuing vesicles containing aquaporins to fuse with cell surface membrane increasing its permeability to water