Unit 4 - A & P Module - Heart Anatomy Blood Flow and Conduction System Flashcards
What is the sequence that correlates the electrical signals of the ECG with the mechanical events of the cardiac cycle?
P–R segment—period of atrial contraction
Trace the path of a red blood cell through the heart, starting in the right ventricle:
a. pulmonary artery
b. pulmonary vein
c. lungs
d. left atrium
a, c, b, d
How do pacemaker cells differ from contractile cells?
Pacemakers are autorhythmic but do not contract, whereas contractile cells generate a force of contraction.
In contrast to most other types of excitable cells, cardiac contractile cells __________.
have a plateau phase in the action potential
What is true about the pulmonary and systemic circuits?
The vena cavae carry deoxygenated blood toward the heart and the aorta carries oxygenated blood away from the heart
Which of the following is true regarding pulmonary circulation?
Pulmonary arteries carry deoxygenated blood to the lungs.
During the pacemaker potential, membrane permeability increases for which of the following ions?
Calcium, Sodium, Potassium
According to the anatomical definition, an artery is a blood vessel that __________.
transports blood away from the heart
What does the P wave of the ECG represent?
atrial depolarization
In the electrocardiogram (ECG), the T wave corresponds to the __________.
repolarization of the ventricles
Which of the following mechanical events will occur as a result of the electrical events that produce the QRS complex in an electrocardiogram (ECG)?
Ventricular systole
Calcium is removed from the cytosol of cardiac muscle cells by __________.
Ca2+ ATPases in the sarcoplasmic reticulum, Ca2+/Na+ exchangers in the plasma membrane, and Ca2+ ATPases in the plasma membrane
Put the following structures involved in cardiac impulse conduction in the correct order:
a. AV node
b. Purkinje fibers
c. SA node
d. bundle of His
c, a, d, b
Electrical signaling in the heart begins in the SA node because __________.
it depolarizes the fastest
