HTN Pathophysiology Flashcards
Arterial Pulse pressure
the difference between the systolic and the diastolic readings during ejection.
an indicator of stiffness and inflammation in the blood-vessel walls.
Arterial Baroreceptors
The most important arterial baroreceptos are located on the carotid sinus (at the bifurcation of the external and internal carotids) and in the aortic arch.
They respond to stretching of the arterial wall.
Chemoreceptors
Sensitive to changes in oxygen, carbon dioxide, and hydrogen ion concentration in the blood
Located in the carotid bodies which lie in the bifurcation of the two common carotids and the aortic bodies of the aorta
Parasympathetic Nervous system
contributes to the regulation of heart function, but has little control over the blood vessels
Sympathetic nervous system stimulation
cause both arteriolar constriction and arteriolar dilation. The ANS has an important role in maintaining a normal blood pressure.
The Renin-angiotension-aldosterone system
plays an important role in regulating blood volume and systemic vascular resistance, which together influence cardiac output and arterial pressure.
Renin
released by the kidneys, stimulates the formation of angiotensin in blood and tissues, which in turn stimulates the release of aldosterone from the adrenal cortex.
Juxtaglomerular (JG) cells
cells associated with the afferent arteriole entering the renal glomerulus are the primary site of renin storage and release in the body.
macula densa
senses the amount of sodium and chloride ions in the tubular fluid.
When NaCl is elevated in the tubular fluid renin release is…
inhibited.
In contrast, a reduction in tubular NaCl stimulates renin release by the JG cells.
The two most significant regulators of aldosterone secretion are
Angiotensin II
Concentration of potassium ions in extracellular fluid: Small increases in blood levels of potassium strongly stimulate aldosterone secretion.
