16- again Flashcards
1
Q
Action of glucagon=(4)
A
- Secreted by alpha cells in IOL in P, when b g conc
TOO LOW - bind to receptors of target cell membranes
- Activate enzymes in glycogenolysis & gluconeogenesis
- , B g conc INCREASES (R o respiration of g decreases)
2
Q
Action of Adrenaline= (5)
A
- Secreted by adrenal glands, if b g conc is LOW
- Bind to receptors on target cm
- Activates enzymes in glycogenolysis (& inhibits glycogenesis)
- Activates secretion of glucagon
- B g conc increases
3
Q
Action of Insulin (6)
A
- Insulin secreted by beta-cells in IOL, in pancreas when b g conc TOO HIGH
- Bind to receptors on target cell membranes
- Increases permeability of cell membranes (by increasing no of channel proteins in c-s-m)
- more glucose moves in (uptake by FD)
- Activation of enzymes for glycogenesis
- R o respiration of g DECREASES; b g conc DECREASES
4
Q
glycogenolysis
A
glycogen> glucose
5
Q
Glycogenesis
A
glucose> glycogen
6
Q
GlucoNEOgenesis
A
GLYCEROL> glucose
7
Q
Secondary messenger model- process (5)
A
- A/glucagon binds to r on cm (of liver cells)
- Activates ‘Adenylate cyclase’
- Converts ATP> cyclic AMP (cAMP)
- cAMP activates protein kinase A
- Protein kinase A activates cascade of reactions to break glycogen> glucose (glycogenolysis)
8
Q
cause of type 2 diabetes=
A
lifestyle choices lead= glycoprotein receptor to lose responsiveness to insulin
9
Q
kidneys- 3 processes
A
- Glomerular filtrate
- Reabsorption of g + H2O
- loop of Henle
10
Q
kidneys- 1.Glomerular filtrate (3)
A
- High hydrostatic pressure (achieved by smaller diameter of e vs a arteriole)
- Small molecules forced out C ENDOthelium> Bowman’s capsule (g, H2O & minerals) (this forms GF)
- Large proteins remains (such as PP)
11
Q
kidneys- 2.Reabsorption of g+w (4)
A
- Na+ AT out of EPIthelial cells> C (lowers conc in EC)
- Na+ move via FD from PCT> EC (down conc g); co-transporting glucose
- g conc increases in EC & g moves > C, via FD (down conc g)
- WP lowered in C & w molecules more via O down WP g > C (reabsorbed)
12
Q
kidneys-3.Loop of Henle= (6)
A
- Na+ AT out of ascending limb> m &AL is impermeable to water
- Na+ conc in medulla increased & WP lowered
- w moves out of descending limb by osmosis > medulla
- w reabsorbed by C (in medulla)
- Filtrate more concentrated
- Na+ diffuse into DL, reducing WP further
13
Q
How body responds to DECREASE in WP= (5)
A
- Detected by OR in Hypothalamus
- H produces more ADH> Posterior pituitary gland
- PPG secretes ADH > blood
- ADH travels in b > k & attaches to receptors
- ADH increases permeability of cells to water (so more absorbed by osmosis)
- LESS water lost in urine
14
Q
How body responds to increase in WP=
A
1) Detected by OR in Hypothalamus
2) H produces less ADH> PPG
3. PPG secretes less ADH> blood
4. Less ADH travels in b>k & attaches to receptors
5. ADH decreases permeability of cells to water (so less absorbed by osmosis)
6. MORE lost in urine
