Cardiovascular concepts, hypertension and BPH

Question 1

Myocardium

Answer 1

thickest in the ventricles

highly specialized

cells are not replaced after cellular necrosis

Question 2

Largest chamber

Answer 2

left ventricle is largest chamber

pumps blood to body tissues

Question 3

Cardiac cycle - Systole

Answer 3

squeeze

ventricle contract

blood pushed against AV valves & they shut

blood pushes through semilunar valves into aorta & pulmonary trunk

Question 4

Cardiac cycle - Diastole

Answer 4

ventricles relaxed

blood entering atria

blood flows through AV values into the ventricles

semilunar valves are closed

Question 5

coronary arteries

Answer 5

deliver nutrients to the myocardium

subject to atherosclerosis (vessels narrowing leads to angina pectoris

decreased oxygen = lactic acid build up

Question 6

cardiac output

Answer 6

amount of blood pumped by each ventricle per minute

average is 5L/min (4-8 LPM)

CO = stroke volume x HR

Question 7

stroke volume

Answer 7

amount of blood pumped by a ventricle in a single contraction

determined by contractibility & end diastolic volume

Question 8

Sterling’s Law

Answer 8

the strength (force) of contraction (contractibility) is proportional to the muscle fiber length (stretch)

Question 9

Preload

Answer 9

degree of blood in ventricles & degree of which myocardial fibers are stretched before contraction

determined by venous return

drugs that constrict being = increase preload

drugs that dilate veins = decrease preload

increased preload = increased CO

Increased volume = increased preload

decreased volume = decreased preload

Question 10

Afterload

Answer 10

resistace in the aorta that must be overcome for blood to be ejected from the left ventricle

mean arterial pressure

increased afterload = decreased SV

increased afterload = decreased CO

hypertension = increased afterload

antihypertensives = decreased afterload

Question 11

MAP calculation

Answer 11

   3

Question 12

heart rate

Answer 12

controlled by autonomic nervous system

effected by epinephrine, TH

drugs that increased HR + increased CO

rapid HR doesn’t allow chambers to fill = possible decrease in CO

Question 13

Blood pressure

Answer 13

factors: CO, peripheral vascular resistance (systemic vascular resistance), blood volume

BP = CO x SVR

increased CO = Increased BP

Question 14

antidiuretic hormone

Answer 14

released by posterior pituitary

potent vasoconstrictor

assist kidneys w/water conservation

Question 15

RAAS

Answer 15

renin released by kidneys when BP is decreased

angiotensin II if formed

increased CO

constricts arterioles

promotes release of aldosterone

Question 16

Atrial Natiuretic peptide (ANP)

Answer 16

secreted from right atrium

enhances sodium & water excretion

suppresses ADH & aldosterone

decreases sympathetic outflow

Question 17

Neural Regulation

Answer 17

BP regulated by vasomotor sensor

baroreceptors: sense pressure in large vessels (aorta & carotid artery) decrease stretch because decreased volume cause increase HR & vasoconstriction
chemoreceptors: sense levels of O2, CO2 & pH