Long term control of blood pressure Flashcards
Recognise the role of the kidneys in regulating plasma volume and therefore blood pressure
Controlling plasma volume is used to regulate MAP
Sodium transport builds up a concentration gradient. Making the collecting duct permeable to water will result on lots of water reabsorption, little urine and conserve plasma volume. Making it impermeable to water results on little absorption, lots of urine and a reduction in plasma volume
- Identify the receptors involved in sensing plasma volume
These cardiopulmonary reflexes are tonically active, and they can alter peripheral resistance with changes in intracardiac, venous, or pulmonary vascular pressures. The receptors are located in the atria, ventricles, and pulmonary vessels.
where is renin produced
juxtaglomerular of the kidneys (granule cells)
what triggers renin production
activation of sympathetic nerves to juxtaglomerular apparatus
decreases distension of afferent arterioles
decreased delivery of Na/Cl through the tubules
what triggers renin production
activation of sympathetic nerves to juxtaglomerular apparatus
decreases distension of afferent arterioles
decreased delivery of Na/Cl through the tubules
what does renin do
converts inactive angiotensinogen to angiotensin I which in turn converted by angiotensin converting enzyme to angiotensin II
what does angiotensin II do
- Stimulates release of aldosterone from the adrenal cortex
- increases release of ADH from the pituitary
- is a vasoconstrictor which increase TPR
- is a negative feedback system
where is antidiuretic hormone produced
synthesised in the hypothalamus, released from the posterior pituitary
what triggers ADH release
a decreased blood volume sensed by cardiopulmonary baroreceptors
an increase in similarity of interstitial fluid sensed by osmoreceptors
circulating angiotensin II
what does ADH do
Increase permeability of the collecting duct to water therefore reduces diuresis and increases plasma volume. causes vasoconstriction
what does ANP and BNP stand for
atrial natriuretic peptide and brain natiuretic peptide
where are ANP and BNP produced
myocardial cells in atria and the ventricles respectively
what triggers ANP and BNP production
increased distension of atria and ventricles a sign of increased MAP
what do ANP and BNP do
Increase excretion of Na+ (natriuresis)
Inhibit the release of renin
Act on medullary CV centres to reduce MAP
