4910: C13 Diseases of the Cardiovascular System Flashcards
What is the role of the cardiovascular system
To regulate blood flow to the tissues to deliver oxygen and nutrients & retrieve wastes from cell metabolism. Thermoregulation. Hormone transport, tissue defense and repair, gas exchange.
What are the three tissue layers of the heart?
Epicardium - outer layer. Myocardium - middle layer, responsible for muscle contraction. Endocardium - inner layer.
The right side of the heart is ?, and pumps blood to ?
Is comprised of the R atrium - which receives blood from the inferior and superior vena cava, and the R ventricle - which pumps deoxygenated blood to the lungs via the pulmonary arteries.
The left side of the heart is the ?, and pumps blood to ?
Is comprised of the L atrium - which receives oxygenated blood from the lungs via the pulmonary veins, and the L ventricle - which pumps blood into systemic circulation via the aorta.
left ventricular hypertrophy (LVH)
Enlargement of the left ventricle; most commonly related to hypertension and/or congestive heart failure.
ejection fraction
The % of the LVEDV that is ejected in the systolic phase; in normal, apparently healthy adults, the typical ejection fraction is 50% to 60%; defined mathematically as stroke volume ÷ LVEDV
diastolic blood pressure
pressure that occurs as ventricles relax (diastole phase of the cardiac cycle)
stroke volume
The volume of blood that is ejected from the left ventricle with each systolic phase; defined mathematically as LVEDV - LVESV.
systolic blood pressure
Pressure exerted when ejected from the ventricles (systole phase of the cardiac cycle)
cardiac output
heart rate X stroke volume. V of blood ejected from the LV each minute.
Which cranial nerve stimulates the SA node
The vegas nerve - parasympathetic
The three layers of veins and arteries
Tunica externa - elastic, collagenous connective tissue. Tunica media - smooth muscle fibers. Tunica interna - endothelium.
What is the devise used to measure BP
sphygmomanometer
What three things affect cardiac output and peripheral vascular resistance?
The sympathetic nervous system (SNS), kidneys, RAAS.
When BP falls ? is secreted by the ?, which acts to ?
norepinephrine, SNS, which increases BP through vasoconstriction.
When BP falls the kidneys secret what hormone?
Renin
How renin influences blood pressure?
Renin catalyzes the conversion of angiotensinogen to angiotensin I. Angiotensin I is converted to II in the lungs.
Role of angiotensin II in BP
Is converted in the lungs. Causes adrenal cortex to release aldosterone which increases water reabsorption in the kidneys. Also, increases Na+ retention and vasoconstriction. Also increases thirst.
Three reasons renin is released
renal hypotension, SNS stimulation, decreased Na+
If peripheral resistance increases BP will
Increases
If CO increases BP will
Increases
Hypertension increases risk of?
MI, stroke, renal failure, accelerated atherosclerosis.
Essential hypertension
No specific cause
Secondary hypertension
Caused by other diseases
Factors correlated with the onset of essential hyper tension?
Genetics, V of blood in vascular system, blood flow to kidneys, atherosclerosis, obesity, family hx, dietary factors, life style factors.
Normal blood pressure
120/80 mmHg &
Prehypertension
120-139 / 80-89 mmHg or
Stage I hypertension
140-159 / 90-99 mmHg or
Stage II hypertension
160-179 / 100-109 mmHg or
Complications of HTN: target organ damage
Increased risk of TIA, heart disease, nephropathy, peripheral artery disease, retinopathy
Pharmacological Interventions for HTN
Diuretics, ACE inhibitors, Angiotension II Receptor Blockers (ARB), Beta-adrenergic blocking Agents
Diuretics
Primary action is to decrease blood V, which lowers BP.
Three categories of diuretics?
loop inhibitors (Lasix), potassium sparing (aldactone), thiazide diuretics (Lopressor)
ACE Inhibitors
Angiotension converting enzyme inhibitors. Inhibit vaso constriction. Captopril
Angiotension II Receptor Blockers (ARBs)
Cause vasodilation. Cozaar, Hyzaar Benicar, Micardis, Diovan
Beta-adrenergic blocking agents
block beta-receptors in the heart to decrease HR and CO. propanolol, atenolol (tenormin), acebutolol
a-Recptor antagonists
Block the vascular muscle that normally respond to sympathetic stimulation and thus will reduce stroke volume. Cardura, Minipress, Hytrin
Ca Channel Blocking Agents
Ca antagonists. Major action is that by affecting the movement of Ca the blood vessels relax therefore ↓ vasoconstriction; also slows heart rate. ex. Cardizem, Verapimil
Aldosterone Antagonist
Suppressor the actions of aldosterone. ex. Spironolactone, eplernone
Direct renin inhibitors
By blocking renin, increases vaso dilation
Lifestyle Modifications to treat BP
Maintain a healthy BMI, DASH diet, reduce Na+ intake, Aerobic physical activity, alcohol in moderation
Nutrition therapy goals for treatment of HTN
wt reduction, assess dietary intake, meet DASH goals, tailor PA goals
Which lifestyle modification has the greatest effect in regard to reducing systolic blood pressure?
wt loss
The success of the DASH diet in helping to control BP results from which characteristic of the diet?
Increased intake of fruits, vegetables, and low-fat dairy.
Which type of medications are the most effective in lowering LDL-C levels?
HMG-CoA reductase inhibitors.
The regulation of MAP involves what three systems
The SNS, the RAAS, & renal function.
Parasympathetic nervous system ? blood pressure?
Decreases HR via the vegas nerve and the SA and AV nodes. Acetylcholine is released
The sympathetic nervous system ? BP?
Increases HR
What neurotransmitter is released by the SNS to increase HR?
norepinephrine
When there is a water deficit what hormone is released by the hypothalamus
Vasopressin is released. It acts to increase water reabsorption, increasing blood volume and thus BP.
Role of angiotensin II in BP regulation?
Stimulated the adrenal cortex to release aldosterone, which causes an increase in reabsorption of Na+ and Cl-. Salt retention = water reabsorption as well and increased BP.
Long term regulation of BP is regulated by?
Urine output, and thirst
Short-term BP regulation is accomplished by?
The baroreceptor reflex, the autonomic nervous system, which increases CO and total peripheral resistance.
Hypertension (HTN)
A chronic elevation in BP.
HTN can lead to
HF, kidney failure, MI, stroke, and aneurysms. Also, vision problems, decreased ejection fraction, arrhythmias, sudden cardiac death.
Primary HTN
aka essential HTN. Is idiopathic = 90% of all cases.
Secondary HTN
Result of other disease including: renal disease, CVD, and endocrine or neurogenic disorders
Standard aspects of the HTN nutrition intervention
DASH, wt loss, Na+, Alcohol, K+, Ca2+, Mg, PA, smoking cessation
Benefits of wt loss and HTN
A 10% wt loss lowers BP
JNC-7 recommendation for PA
30 minutes /day to reduce BP by 4-9mmHg.
One teaspoon of table salt contains X sodium
2300mg
Atherosclerosis
Thickening of the blood vessel walls specifically caused by the presence of plaque.
Arteriosclerosis
General term for thickening of the blood vessel walls with a resulting loss of vascular elasticity and narrowed lumen.
infarct
cellular necrosis due to lack of oxygen
What caused increased dyslipidemia in hypothyroidism?
A lipogenic enzyme that down-regulates LDL receptors has decreased activity.