lecture 4

Question 1

stages of hypertension values

Answer 1

prehypertension 120-139/80-89
stage 1 140-159/90-99
stage 2 160-179/100-109
stage 3 >180/>110

Question 2

why does increased age increase bp

Answer 2

increased Arterial stiffness

Question 3

what are the determinents of blood pressure

Answer 3

mean systemic arterial pressure ( CO x TPR), blood volume, elasticity of vessels

Question 4

cause of renovascular hypertension

Answer 4

mainly atherosclerosis ( esp older patients) but can be due to fibromuscular dysplasia ( more comon in younger pts )

Question 5

what organs are effected by cvd

Answer 5

heart , kidneys, nervous system , eyes

Question 6

how does hypertension come about

Answer 6

• increased sympathetic output and decreased parasympathetic output will increase bp due to increased peripheral resistance by vasoconstriction and increased heart rate and force of contraction

Question 7

cardiac accelerator nerves

Answer 7

drive sympathetic output by increasing heart rate and contractility

Question 8

vasomotor nerves

Answer 8

drive vasoconstriction

Question 9

what is chronotropy

Answer 9

heart rate

Question 10

whats inotropy

Answer 10

force of contraction

Question 11

SA node is the

Answer 11

pacemaker

Question 12

AV node does what

Answer 12

conduction delay

Question 13

where does noradrenaline act on to influence bp and how

Answer 13

beta 1 receptors to increase plasma membrane permeability to sodium and calcium ions in nodal cells. This means theres faster depolarization in nodal cells to reach the threshold faster - so SA node fires more often (+chronotropy)

Question 14

how does parasympathetic influence lower bp and how

Answer 14

ACh acts on M2 receptors, increasing permeability t potassium ions and decreasing sodium and calcium permeability. The K efflux leads to hyper polarisation, so it takes longer to reach a threshold - SA node doesnt fire as often ( - chronotropy)

Question 15

how is arterial blood pressure regulated

Answer 15

by baroreceptor and chemoreceptor reflexes - sympathetic is immediate and hormonal control is long term ( eg vasopressin, ag2, alsosterone. This decreases the total peripheral vascular resistance, meaning that pressure is decreased -> laminar flow

Question 16

What is vasopressin

Answer 16

antiduiretic hormone

Question 17

what is laminar flow

Answer 17

the normal flow of blood

Question 18

how are the kidneys effected by low blood pressure

Answer 18

leads to intrarenal redisribution of pressure and increased absorption of salt and water
in arterioles, it leads to increases renin and angiotensin 2 production- causing direct constriction of renal arteroles and stimulation of aldosterone synthesis - increases sodium absorption.
This increases intravascular blood volume

Question 19

which system is important for blood pressure control

Answer 19

RAAS - activated in response to blood flow in kidneys