Cardiovascular

Question 1

How does first degree AV block show up on EKG, and what causes it?

Answer 1

• prolonged PR intervals
• delayed conduction between atria and ventricles
• hyperkalemia, myopathy

Question 2

What do supernumerary P-waves on 2nd degree block EKG show?

Answer 2

intermittent conduction between atria and ventric;es

Question 3

How does a 3rd degree block look on ekg?

Answer 3

• supernumerary P-waves

- no consistent relationship between P-wave and QRS complex (atria and ventricles contracting independently)

Question 4

Describe isovolumic phases of the cardiac cycle.

Answer 4

• all 4 valves closed
• pressure changes
• volume remains constant

Question 5

What does a Wigger’s diagram show?

Answer 5

pressure over time

Question 6

What influences cardiac output?

Answer 6

• body position
• pregnancy
• age
• sleep, activity
• fitness
• meals

Question 7

What does chronotropic mean?

Answer 7

influencing heart rate

Question 8

What does ionotropic mean?

Answer 8

influencing force of contraction

Question 9

What does dromotropic mean?

Answer 9

influencing conduction through AV node

Question 10

What does lusitropic mean?

Answer 10

influencing relaxation (after contraction)

Question 11

What is Starling’s Law of the Heart?

Answer 11

• Force of ventricular contraction increases as the ventricular myocardium is stretched (greater EDV leads to more forceful contraction)
• as preload increases, so does force of contraction

Question 12

preload

Answer 12

resistance (or work that must be performed) to pump the ventricular blood out of the heart

Question 13

afterload

Answer 13

the resistance of the discharge of blood imposed by the backpressure of the blood in the arteries and veins

Question 14

Venous compliance

Answer 14

• change in volume that accompanies a change in pressure
• veins are 20 more compliant than arteries
• because of this, 2/3 of circulating blood resides in veins

Question 15

Elevated central venous pressure occurs in what types of patients?

Answer 15

• right heart failure
• restrictive cardiomyopathy
• pericardial disease
• tricuspid valve stenosis
• SVC syndrome

Question 16

Musculovenous pump

Answer 16

one-way check valves in veins of limbs

Question 17

What effect would epinephrine binding to beta-2 receptors have on flow?

Answer 17

• would cause vasodilation

- increasing flow

Question 18

How does local regulation act to maintain homeostasis is flow increases?

Answer 18

-will vasoconstrict

Question 19

metabolic (active) hyperemia

Answer 19

blood vessels dilate to bring more blood to metabolically active tissue

Question 20

reactive hyperemia

Answer 20

compensatory increase in flow following removal of a restriction that was blocking blood flow to a tissue

Question 21

if local flow decreases, what mechanisms will act to cause vasodilation?

Answer 21

• myogenic autoregulation
• active hyperemia
• reactive hyperemia

Question 22

How do baroreceptors elevate BP?

Answer 22

baroreceptor decreased firing leads to

• sympathetic activation, parasympathetic decrease
• constriction of arteries and veins
• elevated cardiac output (elevating BP)

Question 23

How do baroreceptors decrease BP?

Answer 23

Firing rate of baroreceptors goes up, leading to

• parasympathetic activation, sympathetic decrease
• decrease in HR and CO
• decreasing MAP