Hypertension Flashcards
Hypertension doubles the risk of
CHD, CHF, stroke
Primary determinant of extracellullar fluid
Sodium
Modulate blood pressure over the short term
Adrenergic reflexes (Norepinephrine, epinephrine, dopamine)
Adrenergic reflexes are mediated by
G proteins and
Intracellular conc of second messengers
Alpha receptors are activated more by
Norepnephrine
Beta receptors are activated more by
Epinephrine
Located on postsynaptic cells in smooth muscle
Alpha 1 receptors
Causes vasoconstriction
➢ Increases renal tubular reabsorption of sodium
•α1 Receptors
Located on presynaptic membranes of postganglionic nerve terminals
α2 Receptors
Stimulates the rate and strength of cardiac contraction
Beta 1
By activation of epinephrine, it relax vascular smooth muscle
➢ Causes vasodilation
Beta 2
Mediated by stretch-sensitive sensory nerve endings in the carotid sinuses and the aortic arch
Arterial baroreflex
3 primary stimuli for renin secretion
- Decreased NaCl transport in the distal portion of the thick ascending limb of the loop of Henle
- Decreased pressure or stretch within the renal afferent arteriole (baroreceptor mechanism)
- Sympathetic nervous system stimulation of renin-secreting cells via β1 adrenoreceptors
Primary factor in regulating the synthesis and secretion of aldosterone
Angiotensin II
Mineralocorticoid
➢ Increases sodium reabsorption by amiloride-sensitive epithelial sodium channels (ENaC) on the apical surface of the principal cells of the renal cortical collecting duct
Aldosterone