Card Set Information
Classifications of HTN
1. optimal BP
3. HTN stage 1-2-3
140/90 (one med)
160/100 (one or two meds)
180/110 or greater
CV mortality is more closely related to SBP OR DBP?
Marked or shapr increase in DBP to 120mm Hg
No end organ damage evident
Can reduce BP over hours to days
End organ damage
BP needs decrease within several min to hours
Where are the pressure sensitive neurons located?
Aortic arch and carotid sinus
Where are the Alpha-1 receptors located?
Smooth muscle cells within walls of arterioles in skin, mucosa, viscera, kidneys and within walls of veins- causes vasoconstriction to increase BP.
Where are the Beta-1 receptors located?
Cells of SA node and AV node. Increase HR, conductivity, force of contraction and increase CO which increases BP.
3 things that stimulate Renin secretion?
1. Decrease in NaCl transport in the ascending limb of the loop of Henle.
2. Decrease pressure or stretch within the renal afferent arteriole (baroreceptor mechanism).
3. Sympathetic NSstimulation of renin secreting cells via B1 adrenoreceptors.
RENIN SECRETION IS INHIBITED BY THE OPPOSITE OF THE THE ABOVE FACTORS.
STEPS OF rENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM
1. Low BP detected by juxtaglomuerular cells in renal afferent arterioles.
2. Renin release by renal affernt arterioles.
3. Renin stimulates production of Angiotensin I.
4. Angiotensin I turns into Angiotensin II
5. ATI (brain, renal, nyocardial, vascular, and adrenal tissue) and ATII (brain, adrenal medulla, and uterine tissue) receptors stimulated.
6. Sympathetic stimulation of cardia system- direct vasoconstriction, increase epinephrine release from adrenal medulla, and increase in sympathetic activity.
7. Increased release of aldosterone which stimulates Na and K pumps in renal tubules.
*HCTZ and metolazone
*MOA- decreases plasma volume
*Lowers BP 10-15 mm Hg in most pts
*Sometimes used with vasoldilator or sympathomimetic drugs.
*Decrease potassium, increase uric acid, increase glucose, increase lipid levels, decrease magnesium levels.
2. CLORTHALIDONE (HYGROTON)
*Decreases potassium, increase uric acid, increase glucose, increase lipid levels, decreace mag levels
* 1-2 times more potent than HCTZ for BP