AP 150: Heart Questions
During a cardiac cycle, how many of the four chambers contract at any one time?
2
Parasympathetic innervation of the heart occurs via
CN X
Cardiac muscle tissue contains fewer mitochondria than are found in skeletal muscle tissue.
False
Match the branch of the nervous system with its effect on heart rate and output. Increases rate and force of contractions
Sympathetic innervation
Though the autonomic innervation by autonomic centers in the brainstem cannot initiate a heartbeat, it can increase or decrease the heart rate.
True
The external layer of the heart wall is the
epicardium
Match the chamber of the heart with the structure(s) from which it receives blood. pulmonary veins
left atrium
Match the chamber of the heart with the structure(s) from which it receives blood. left atrium
left ventricle
The serous fluid within the pericardial cavity works to
lubricate the membranes of the serous pericardium.
The layer of the heart wall composed of cardiac muscle tissue is the
myocardium
The fibers that extend through the walls of the ventricles and allow the rapid, immediate spread of the impulse throughout the ventricular myocardium are called _______ fibers.
purkinje
Match the chamber of the heart with the structure(s) from which it receives blood. coronary sinus
right atrium
Match the chamber of the heart with the structure(s) from which it receives blood. Right atrium
right ventricle
The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges called
trabeculae carneae.
Unidirectional flow in the heart is ensured because the heart contains __________ that prevent backflow.
valves
Match the branch of the nervous system with its effect on heart rate and output. Decreases the heart rate
Parasympathetic innervation
The cardiac cycle is
all the events involved with a single heart beat
The valve that prevents backflow of blood into the right ventricle is the _______ _______ valve.
pulmonary semilunar