Lecture 6 - Vascular Function 2

Question 1

Alpha 1 receptor?

Answer 1

Gq - activates Phospholipase C -> IP3 (Ca release) and DAG (PKC)

Question 2

Alpha 2 receptor?

Answer 2

Gi - decreased cAMP and PKA

Question 3

Modulation of Adrenergic Neurotransmission - inhibitory?

Answer 3

Ach, adenosine, DA, histamine, PG E1 and E2

Question 4

Modulation of Adrenergic Neurotransmission - excitatory?

Answer 4

angiotensin II, adrenaline

Question 5

Cholinergic nerves?

Answer 5

PNS, release Ach, binds M3 (muscarinic) receptor of endothelium of blood vessels release NO and vasodilating; absence of endothelium from vascualr damage means SM receptor activation -> vasoconstriction

Question 6

Noradrenaline effects?

Answer 6

decreased: skeletal muscle flow, skin flow, kidney flow, splanchnic flow

Question 7

Adrenaline?

Answer 7

increased: skeletal muscle flow, splanchnic flow; decreased: skin flow, kidney flowq

Question 8

Affinity of alpha receptors?

Answer 8

Adren > (or equal to) Noradren&raquo_space; isoprenline

Question 9

Affinity of beta 2 receptor?

Answer 9

Isoprenaline > adrenaline&raquo_space; noradren (Gs)

Question 10

Skin circulation?

Answer 10

affinity of receptors proportional to local temperature, symp. Ach stimulation of sweat glands activats kinin cascade, Bradykinin and lysylbradykinin dilate pre-cap vessels, constrict post-cap vessels and increase capillary permeability

Question 11

Cerebral blood flow?

Answer 11

autoregulation over perfusion pressures 80 - 160 mmHg to maintain constant flow, driven by local metabolites; flow is far more sensitive to pCO2 than pO2