5 Flashcards
What is hypertension a risk factor for? (5)
Heart attack Stroke Heart failure Renal failure Aneurysms
What does chronic hypertension do to the endothelium
Increases oxidative stress on endothelium - can lead to atherosclerosis
What is hypertension
140/90
Who need immediate hypertensive treatment
Patients with >15 % probability of an adverse cardiovascular event within the next 5 years
What is the formula for BP
CO x TPR
What is the formula for CO
HR x SV
What are determinants of stroke volume
Venous return, myocardial contractility
What are determinants of TPR
Blood viscosity, vessel radius, smoothness, length
What are determinants of vascular tone (3)
Mediators secreted by sympathetic nerves (noradrenaline)
Mediators secreted by vascular endothelium (prostanoids, NO, peptides, EDHFs)
RAAS
What is the mechansim of stimulation of contraction
Depolarisation of the membrane causing opening of voltage-gated Ca2+
Entry of Ca2+ into the cells due to opening of ligand-gated channels
Release of Ca2+ via IP3
Increasing sensitivity of Ca2+ via actions on MLCK
Phosphorylation of myosin
What leads to decreased intracellular Ca2+
Activation of adenylyl cyclase and guanylyl cyclase
Increase in K efflux
How does an increase in K efflux cause a decrease in Ca2+ influx
Inhibition of Ca2+ entry through voltage-gated channels
What do ATR in blood vessels do
Vasoconstriction
also via increased noradrenaline release from sympathetic nerves
What do ATR in adrenal cortex do
Salt retention
Aldosterone section leads to Na reabsorption and water retention in kidney
What do ATR in heart and vasculature do
Cell growth
Hyperplasia + hypertrophy
