Heart Flashcards
The _____ of the heart is the widest part; the _____ is the narrow end, which points toward the left hip.
Base; Apex
The muscular wall of the heart (which accounts for most of the heart’s mass) is called the _____.
Myocardium
The central layer of the heart’s wall is called the _____.
myocardium
The two uppermost chambers of the heart are the _____.
atria
The two lowermost chambers of the heart are the _____.
ventricles
The partition that separates the left and right chambers of the heart is called the _____. The upper part is the _____, and the lower part is the _____.
septum; interatrial septum; interventricular septum
The shallow groove separating the atria from the ventricles is called the _____ or _____.
atrioventricular groove; coronary sulcus
The purpose of the muscular wall of each _____ is simply to pump blood from one chamber to the next, and so not much muscle is required.
atrium
Blood has to travel further in the _____ circuit than in the _____ circuit: therefore there is more friction, and more strength is required to keep it moving.
systemic; pulmonary
After passing through the capillary beds of the myocardium, venous blood is collected in the _____.
cardiac veins
In almost half of the population, the SA node is supplied with blood by the _____.
circumflex artery
The right atrium, AV node, and nearly all of the right ventricle are usually supplied by the _____.
right main coronary artery
Most veins of the heart join together to form a large vessel called the _____, which is most visible on the _____ aspect of the heart.
coronary sinus; posterior
The _____ and _____ valves prevent backflow into the atria when the ventricles contract: together these are called the _____ valves.
tricuspid; bicuspid; atrioventricular (AV)
The _____ AV valve is the tricuspid valve.
right
The _____ AV valve is the bicuspid (or ‘mitral’) valve.
left
The AV valves are closed by the _____.
intraventricular pressure
(True or False) There are no valves preventing backflow of blood from the heart into the veins which deliver blood to it from the body and lungs.
TRUE
(True or False) Atrial contraction nearly closes the openings through which blood enters the heart.
TRUE
(True or False) Cardiac muscle is capable of switching nutrient pathways to use whatever nutrient supply is available.
TRUE
(True or False) The sarcomeres of cardiac muscle fibers have terminal cisternae at each end.
False
The _____ is the cluster of autorhythmic cells in the heart which spontaneously depolarize the fastest and thus is known as the heart’s _____.
SA node; pacemaker
When clusters of cardiac fibers contract independently, producing rapid and irregular or out-of-phase contractions, the condition is called _____.
fibrillation
Uncoordinated atrial and ventricular contractions are referred to as _____.
arrhythmias
The _____ is the highest, strongest peak on a normal ECG together with the downward deflections that immediately precede and follow it.
QRS complex
After a brief delay, a third peak follows the first two. This third peak is called the _____ and is due to _____.
T wave; ventricular repolarization
A(n) _____ on an ECG is occasionally not followed by a(n) _____; this indicates a heart block.
P wave; QRS complex
The volume of blood contained by the ventricles at the end of an atrial contraction is known as the _____. This term is based on the contents of the _____.
end diastolic volume (EDV); ventricles
During ventricular contraction, the period during which all valves are closed is the _____.
isovolumetric contraction phase
The _____ is the period during which both the atria and ventricles relax.
quiescent period
_____ is the volume of blood remaining in the ventricle when the SL valves close at the end of ventricular systole.
Ending systolic volume (ESV)
An average adult’s stroke volume is _____.
70 ml / beat
_____ is a heart rate of more than 100 beats per minute.
Tachycardia
