CARDIOVASCULAR PHYSIOLOGY Flashcards
With regard to resistance in the cardiovascular system, the parameter with the largest effect is
a) vessel length
b) radius
c) heart rate
d) viscosity
e) pressure
b) radius
An increase in cardiac sympathetic activity would most likely and immediately:
a) increase stroke volume
b) decrease inotropy
c) decrease chronotropy
d) increase pulmonary pressure
e) increase angiotensin II levels
a) increase stroke volume
The component of the conduction system providing the only electrical connection between the atria and the ventricles is the:
a) R wave
b) ECG
c) atrioventricular bundle
d) sinoatrial node
e) Purkinje fibres
c) atrioventricular bundle
With regards to the Frank-Starling law of the heart, an increase in venous return to the heart will result in:
a) increased sympathetic activity
b) an increase in end diastolic volume
c) decreased cardiac output
d) a decrease in stroke volume
e) decreased angiotensin
b) an increase in end diastolic volume
What is bradycardia?
Bradycardia means your heart rhythm is slow or irregular. It can cause dizziness or shortness of breath during normal activities or light exercise.
what happens when you stimulate the vagus nerve?
Stimulation from the left mid-cervical vagus nerve most commonly causes voice alteration, cough, dyspnea, dysphagia, and neck pain or paresthesias. Left cervical VNS is believed to minimize potential cardiac effects such as bradycardia or asystole (primarily mediated by the right vagus nerve).
A decrease in arterial blood pressure would most likely and immediately lead to:
a) increased afterload
b) decreased afterload
c) increased stroke volume
d) vasodilation
e) a decrease in sympathetic nerve activity
b) decreased afterload
An increase in blood pressure results in:
a) decreased firing rate in the aortic baroreceptor nerve
b) increased heart rate
c) activation of chemoreceptors
d) an increase in sympathetic nerve activity
e) increased firing rate in the aortic baroreceptor nerve
e) increased firing rate in the aortic baroreceptor nerve
In terms of the structural organisation of the cardiovascular system, the factor contributing most to blood pressure is:
a) angiotensin II
b) the parallel arrangement of the vascular beds
c) low resistance in the arterioles
d) the serial arrangement of the vascular beds
e) high resistance in the veins
b) the parallel arrangement of the vascular beds
If acetylcholine is applied to the heart, but cardiac output is to remain constant, which of the following would have to happen?
a) Rate of conduction of impulses through the AV bundle must increase.
b) Venous return must decrease.
c) The oxygen content of blood in the coronary circulation must increase.
d) Stroke volume must increase.
e) Force of contraction must decrease.
d) Stroke volume must increase.
The Frank-Starling Law of the Heart states that:
a) the absolute refractory period for the heart must be longer than the duration of contraction for efficient heart functioning.
b) cardiac output equals heart rate times stroke volume.
c) the heart is dependent upon the autonomic nervous system for a stimulus to contract.
d) a greater force of contraction can occur if the heart muscle is stretched first.
e) the heart contracts to the fullest extent possible for the conditions, or not at all.
d) a greater force of contraction can occur if the heart muscle is stretched first.
On an ECG, depolarisation of the ventricles is represented by the:
a) T wave
b) QRS complex
c) P wave
d) S-T segment
e) P-Q interval
b) QRS complex
On an ECG, depolarisation of the atria is represented by the:
a) P-Q interval
b) S-T segment
c) QRS complex
d) P wave
e) T wave
d) P wave
If heart rate increases to very high levels, then:
a) the oxygen content of blood falls to levels insufficient to maintain cardiac activity.
b) the autonomic nervous system will release more epinephrine to the SA node to stabilise the heart rate.
c) stroke volume increases to keep cardiac output constant.
d) end-diastolic volume drops because ventricular filling time is so short.
e) end-systolic volume increases because the valves are open.
a) the oxygen content of blood falls to levels insufficient to maintain cardiac activity.
The term afterload refers to:
a) end-diastolic volume.
b) the pressure in blood vessels necessary to cause the semilunar valves to close.
c) the maximum possible cardiac output above resting cardiac output.
d) end-systolic volume.
e) the pressure that must be overcome before semilunar valves can open.
e) the pressure that must be overcome before semilunar valves can open.
Increased stimulation of the heart by the cardiac accelerator nerves causes:
a) stimulation by acetylcholine of muscarinic receptors on the SA node and cardiac muscle fibers of the ventricles.
b) stimulation by norepinephrine of the SA node, but no effect on the cardiac muscle fibers of the ventricles.
c) stimulation by norepinephrine of the SA node and of the alpha receptors on the cardiac muscle fibers of the ventricles.
d) stimulation by acetylcholine of nicotinic receptors on the SA node and cardiac muscle fibers of the ventricles.
e) stimulation by norepinephrine of the SA node and of the beta receptors on the cardiac muscle fibers of the ventricles.
e) stimulation by norepinephrine of the SA node and of the beta receptors on the cardiac muscle fibers of the ventricles.
Stimulation of the heart by autonomic nerve fibers traveling with the vagus nerve causes:
a) decreased heart rate and no change in ventricular contractility.
b) increased heart rate and increased ventricular contractility.
c) decreased heart rate and decreased ventricular contractility.
d) decreased heart rate and increased ventricular contractility.
e) increased heart rate and no change in ventricular contractility.
a) decreased heart rate and no change in ventricular contractility.