systemic hypertension

Question 1

describe nervous system control of blood pressure (sympathetic control)

Answer 1

nervous activity to heart for inc HR and contractility
nervous innervaion of bv that control resistance to flow
enhanced vasoconstrictor effect to kidneys, spleen, intestines

Question 2

describe short term blood pressure control

Answer 2

baroreflex control of arterial pressure

Question 3

what are the low pressure receptors and what do they do

Answer 3

atrial and pulmonary artery reflexes
sensitive to change in chamber/vessel distension
role is to detect pressure alterations in low-pressure region of circulation
atrial natriuretic peptide released during atrial distention

Question 4

the kidneys in long-term blood pressure control

Answer 4

long term control linked to homeostasis of fluid V
pressure diuresis = renal output of water in response to inc pressure
pressure natriuresis = salt output i response to inc pressure

Question 5

salt intake and arterial pressure regulation

Answer 5

increase arterial pressure

1. salt inc ecf osmolality => thirst => fluid intake => inc ecf V
2. salt intkae => ecf osmolality => inc antidiuretic hormone => renal h20 reabsorption => inc ecf V

Question 6

what can contribute to developmen of hypertension

Answer 6

lifestyle, RAAS activation, large artery stiffening, renal disease

Question 7

describe RAAS control

Answer 7

decreased arterial pressure -> renin from kidney -> angiotensinogen -> angiotensin 1 converting enzyme in lung = renal retention of salt and water and vasoconstriction -> inc arterial pressure

Question 8

describe large artery stiffening

Answer 8

age-related reduction in compliance of large elastic arteries
increases size and velocity of reflected waveform
increase SBP and pulse pressure
decline in elastin alongside concomitant increase in collagen content

Question 9

describe lifestyle risk factosr

Answer 9

obesity is primary cause hypertension: 
elevated cardiac output
elevated symp nerve activity 
ANG II + aldosterone elevation 
impaired renal-pressure natriuresis
arterial stiffening 

exaggerated by ageing

Question 10

how does hypertension lead to hypertensive heart disease

Answer 10

concentric LV hypetrophy
pressure-induced wall stress + elevated preload
structural and electrical remodelling: excess o2 demand, arrhythmia development, predisposition to pump failure

Question 11

why is there an increased risk of stroke for hypertensive patients

Answer 11

high intraluminal stress -> altered endothmlial and smooth muscle function -> ischaemic lesions and thrombi formation
local or multi-focal oedema
inc permeability of BBB
accelerated atherosclerosis
cerebral vessel remodelling -> inc vascular resistance

Question 12

how can we control BP with interventions

Answer 12

ACE inhibitors or angiotensin receptor blockage

commonly + betablockers or Ca chan blockers