Physiology - Autonomics and Cardiovascular

Which of the following statements correctly describes the parasympathetic nervous system?

Your answer:
long post-ganglionic neurons innervate arterioles and veins
pre-ganglionic and post-ganglionic neurons utilize acetylcholine as their neurotransmitter
post-ganglionic neurons exert their effects on adrenergic receptors in the target tissues
pre-ganglionic fibers originate in the thoracic spinal cord
activation causes dilation of the pupils

Chromaffin cells in the adrenal medulla release:

Your answer:
nitric oxide
acetylcholine
angiotension II
nicotine
epinephrine

Which of the following contains a correct sequence of blood flow through the heart?

Your answer:
pulmonary veins, left atrium, left A-V valve, left ventricle, aortic valve
right atrium, right ventricle, mitral valve, aorta, systemic vasculature
super vena cava, tricuspid valve, right atrium, right A-V vavle, right ventricle
right ventricle, aortic valve, aorta, systemic vasculature, inferior vena cava, left atrium
left ventricle, pulmonary valve, pulmonary artery, lungs, right atrium, right ventricle

In a healthy individual at rest, which of the following conditions applies?

Your answer:
the volume of blood pumped per minute from the left heart is equal to the volume of blood pumped per minute from the right heart
blood flow in the pulmonary vasculature is less than blood flow in the systemic vasculature
blood flow to all tissues and organs is equal
the pressure generated by the left ventricle is equal to the pressure generated by the right ventricle
none of the above

Phase 2 of the action potential in cardiac ventricular cells is primarily due to increased membrance permeability to:

Your answer:
calcium
cAMP
sodium
potassium
chloride

Desmosomes in the intercalated discs of the myocardium are most important during muscle contraction because they contribute to:

Your answer:
sequestration of calcium
cell-cell adhesion
aerobic capacity
myocyte contractility
cell-cell transmission of action potentials

In the electrocardiogram, the QRS complex represents the:

Your answer:
depolarization of the SA node
depolarization of the ventricles
repolarization of the ventricles
delay at the AV node
depolarization of the atria

If action potential propagation at the AV node was blocked, which of the following events would you expect to observe?

Your answer:
slowing of the rate of contraction of the ventricles
increased rate of contraction of the ventricles
increased rate of contraction of the atria
ventricular fibrillation
none of the above

Which of the following statements regarding the pacemaker potential of SA node cells is true?

Your answer:
the rate of depolarization of pacemaker cells is intrinsic and cannot be modulated
pacemaker cells have a resting membrane potential that is close to the potassium equilibrium potential
pacemaker cells will not depolarize in the absence of sympathetic stimulation
the pacemaker potential is caused by potassium entering the cell via slow channels
the pacemaker potential is slower in achieving threshold when acetylcholine is applied

The second heart sound ('dub') follows the T wave of the ECG and is directly caused by which of the following events:

Your answer:
repolarization of the atria
closing of the aortic and pulmonary valves
contraction of the ventricles
repolarization of the ventricles
closing of the A-V valves

Ventricular pressure exceeds aortic pressure during which phase or phases of the cardiac cycle?

Your answer:
isovolumetric ventricular contraction and ventricular ejection
ventricular ejection only
isovolumetric ventricular relaxation
atrial systole only
diastole and atrial systole

Sympathetic stimulation increases cardiac output by which of the following mechanisms?

Your answer:
it slows the rate of pacemaker depolarization of cells in the SA node
it increases venous tone by vasoconstriction
it decreases the rate of cross-bridge cycling in ventricular cells
it decreases total blood valume
a and d

Arterial pressure is maintained during diastole by:

Your answer:
contraction of the atria during late diastole
depolarization of the ventricles
turbulent fluid flow following constriction of the arteries
recoil of the elastic walls of the arteries
decreased peripheral resistance following ventricular relaxation

Which of the following best describes the anatomical and functional characterisitcs of the capillaries as compared with other vessel beds?

Your answer:
capillaries are lined by smooth muscle cells
capillaries are the site of the greatest flow velocity
all capillaries have fenestrations to permit exchange of nutrients and waste products
capillaries are highly elastic vessels
capillaries provide the largest total cross-sectional area of the vascular beds

Blood pressure is being measured using the auscultatory method. When are the first sounds heard in a stethoscope that is placed below the cuff?

Your answer:
when cuff pressure equals mean arterial pressure
when the A-V valves close
when the aortic and pulmonary valves close
when cuff pressure equals diastolic pressure
at peak systole

Vasodilation of arterioles would:

Your answer:
a and c
favor filtration of plasma into the interstitial fluid
none of the above
increase flow of lymph
favor resorption of fluid into capillaries

Active hyperemia refers to:

Your answer:
decreased blood flow to tissues that results in vasodilation
decreased blood flow to tissues that results in vasoconstriction
increased metabolic activity that results in vasoconstriction
increased oxygen demand that results in increased blood vessel growth
increased metabolic activity that results in vasodilation

Blood vessels in the skin:

Your answer:
respond primarily to metabolic regulation of flow
dilate in response to systemic sympathetic activation
lack capillary beds
dilate in response to sympathetic modulation form the hypothalamus
have a high resting arteriolar tone

Which of the following statements correctly applies to the areterial baroreceptors:

Your answer:
increased firing causes an increase in sympathetic activity
they detect increases and decreases in arterial blood pressure
they are located in the medulla
they fire in response to relaxation of arteriolar smooth muscle cells
they decrease firing in response to stretch of the arterial walls

With a few minutes after donation of 1 pint of whole blood to a blood bank, which of the following would be decreased compared with pre-donation values?

Your answer:
heart rate
a and d
the percentage of cardiac output flowing to the kidneys
total peripheral resistance
stroke volume

Which of the following variables will be increased immediately following henmorrhage, compared with pre-hemorrhage values?

Your answer:
heart rate
cardiac output
venous return
firing of baroreceptors
all of the above

Which of the following does not contribute to increased stroke volume during exercise:

Your answer:
increased end-diastolic volume
increased contractility of cardiac muscle
increased venous return
increased length of filling time during diastole
increased sympathetic stimulation of ventricular muscle

During acute episodes of moderate exercise in a healthy individual, blood flow to the heart is:

Your answer:
increased
unchanged
decreased
shunted to the pulmonary circulation
insufficient to maintain a faster contraction rate

Severe hypotension can lead to which of the following?

Your answer:
prolonged increase in sympathetic discharge to all tissues
increased blood flow to skin and kidneys
chronic pain
increased urine production
decreased heart rate

The principle mechanism of anaphylactic (allergic) shock is:

Your answer:
a large increase in fluid loss from the lymph nodes
prolonged vasodilation due to release of histamine
prolonged vasoconstriction due to release of angiontensin II
decreased fluid volume due to dehydration
prolonged vasoconstriction due to release of histamine

Physical endurance training increases a person's:

Your answer:
maximal cardiac output
maximal heart rate
resting blood pressure
resting heart rate
all of the above

Which of the following might be prescribed to alleviate hypertension? (read carefully)

Your answer:
an alpha-adrenergic receptor agonist (mimetic)
an anti-diuretic
a beta-adrenergic receptor antagonist (blocker)
a cholinergic receptor antagonist (blocker)
adrenaline

Ventricular wall thickening can be caused by which of the following?

Your answer:
hypertention
hemorrhage
chronic endurance exercise
a and c
all of the above

The driving pressure for blood flow in the right coronary artery is:

Your answer:
greater than that in the left coronary artery
less than that in the left coronary artery
equal to that in the left coronary artery
less than that in the pulmonary artery
b and d

Atherosclerosis:

Your answer:
results in thinning of the arterial walls
can cause ventricular fibrillation
is alleviated by treatment with vasoconstrictor drugs
is typically associated low blood levels of cholesterol and heavy exercise
is associated with decreased coronary vessel resistance