The heart muscle is stimulated by nerves and self-excitable.
Autorythmic cells use which of the following ions for the rising phase of an action potential?
Calcium
Potassium
Sodium
None of the Above
Atrial excitation begins when...?
Sinoatrial node generates an impulse.
An impulse is delayed at the atrioventricular node.
The impulse passes to the heart apex.
The heart is stimulated by the parasympathetic cardioaccelatory centre.
Ventricular is represented by which letter on the electrocardiograph shown?
P
Q
R
S
T
The heart sound (lub-dup) are associated with the opening of the heart valves.
Which of the following are true of the cardiac output?
CO is the amount of blood pumped by each ventricle in one minute.
CO is the product of heart rate and stroke volume.
CO is the amount of blood pumped out by a ventricle with each beat.
CO is the number of heart beats per minute.
Cardiac reserve is the difference between resting and maximal CO.
End Systolic Volume (ESV) is the amount of blood collected in a ventricle during diastole.
Which of these best describes preload?
The amount ventricles are stretched by contained blood.
The back pressure exerted by blood in the large arteries leaving the heart
The cardiac cell contractile force.
Which of the following decrease heart contractability?
Acidosis
Temperature Extremes
Increased extracellular K+
Calcium channel blockers
Sympathetic nervous system (SNS) stimulation is activated by stress, anxiety, excitement, or exercise.
What is the Atrial (Bainbridge) Reflex?
A sympathetic reflex initiated by increased blood in the atria.
A parasympathetic reflex initiated by increased blood in the ventricles.
A sympathetic reflex initiated by increased blood in the ventricles.
A parasympathetic reflex initiated by increased blood in the atria.
The hormone thyroxin decreases heart rate.
Congestive heart failure (CHF) is caused by:
Coronary atherosclerosis
Persistent high blood pressure
Multiple myocardial infarcts
Dilated cardiomyopathy
Which of these are examples of Congenital Heart Defects?
Ventricular Septal Defect
Coarctation of the Aorta
Tetralogy of Fallot
All of the Above
The decline in cardiac reserve is an age related change that can affect the heart?