CV1 Blood pressure and atherosclerosis Flashcards
How does parasympathetic nervous system stimulation cause hypotension?
It decreases heart rate and dilates blood vessels, reducing cardiac output and total peripheral resistance, which lowers blood pressure.
What are 3 risk factors for orthostatic hypotension and how do they cause a blood pressure drop?
Dehydration – reduces blood volume.
Certain medications – like diuretics and antihypertensives can lower blood pressure too much.
Age-related decline in baroreceptor sensitivity – impairs quick blood pressure regulation when standing up.
What are three disease complications from hypertension?
Rupture of small blood vessels – causes micro-bleeds and inflammation.
Cardiac hypertrophy – reduces stroke volume and increases energy demand.
Atherosclerosis and arteriosclerosis – thickening/hardening of arteries, leading to reduced perfusion.
How do beta-blockers lower blood pressure?
They block norepinephrine/epinephrine from binding to receptors in the heart and blood vessels, reducing heart rate and vessel constriction.
How do ACE inhibitors reduce blood pressure?
They block the enzyme that converts angiotensin I to angiotensin II, preventing vasoconstriction and aldosterone release.
How do ARBs lower blood pressure?
They block angiotensin II from binding to its receptors, preventing vasoconstriction and aldosterone-mediated fluid retention.
How do aldosterone-blockers affect fluid balance and blood pressure?
They prevent sodium (and thus water) reabsorption in the nephron, reducing blood volume and pressure.
How do loop diuretics lower blood pressure?
They prevent sodium reabsorption in the loop of Henle, causing diuresis and reducing fluid volume.
How do calcium channel blockers lower blood pressure?
They prevent calcium from entering smooth muscle cells around vessels, inhibiting contraction and promoting vasodilation.
What is arteriosclerosis?
It’s the thickening and hardening of arterial walls due to smooth muscle and collagen migration into the tunica intima and mineral deposits.
Outline the pathophysiology of atherosclerosis.
Endothelial damage → LDL accumulation and oxidation → macrophage engulfment (foam cells) → fatty streak → smooth muscle & collagen form fibrous cap → plaque hardens with calcium → narrowed lumen and possible rupture.
Name 5 risk factors for atherosclerosis.
Family history
Age (>45 males, postmenopausal females)
Smoking
Hypertension
Diabetes
What are complications associated with atherosclerosis?
Myocardial infarction
Stroke/TIA
Aneurysm
Peripheral artery disease
Gangrene
How do LDL and HDL differ in their role in cholesterol transport?
LDL transports cholesterol to tissues (pro-atherogenic), while HDL returns cholesterol to the liver (anti-atherogenic).
What are healthy cholesterol and lipid ranges?
LDL: < 2.0 mmol/L
HDL: > 1.0 mmol/L (men), > 1.3 mmol/L (women)
Total cholesterol: < 4.0 mmol/L
Triglycerides: < 1.7 mmol/L
Describe the pathophysiology of peripheral artery disease (PAD).
Atherosclerotic plaques in limb arteries reduce blood flow, causing ischemia and symptoms like intermittent claudication, ulcers, cold/pale skin, and weak pulses.
What are common signs and symptoms of PAD?
Intermittent claudication
Cool or discolored limbs
Leg ulcers
Weak/diminished pulses
Severe pain with acute occlusion
Gangrene
How do statins control cholesterol?
They block liver enzymes that produce LDL cholesterol, reducing blood levels of LDL.
What are nursing care considerations for statins?
Monitor for leg cramps
Administer at night
Avoid grapefruit juice
Monitor cholesterol labs
Assess for walking difficulty
