Which of the following is not important in preventing backflow of blood?
- chordae tendineae
- papillary muscles
- AV valves
- endocardium
Which valve separates the left atrium from the left ventricle?
- mitral
- tricuspid
- pulmonary
- aortic
Which of the following lists the valves in the order through which the blood flows from the vena cava through the heart?
- tricuspid, pulmonary semilunar, bicuspid, aortic semilunar
- mitral, pulmonary semilunar, bicuspid, aortic semilunar
- aortic semilunar, pulmonary semilunar, tricuspid, bicuspid
- bicuspid, aortic semilunar, tricuspid, pulmonary semilunar
Which chamber initially receives blood from the systemic circuit?
- left atrium
- left ventricle
- right atrium
- right ventricle
The ________ layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.
- pericardial sac
- endocardium
- myocardium
- epicardium
The myocardium would be the thickest in the ________.
- left atrium
- left ventricle
- right atrium
- right ventricle
In which septum is it normal to find openings in the adult?
- interatrial septum
- interventricular septum
- atrioventricular septum
- all of the above
Which of the following is unique to cardiac muscle cells?
- Only cardiac muscle contains a sarcoplasmic reticulum.
- Only cardiac muscle has gap junctions.
- Only cardiac muscle is capable of autorhythmicity
- Only cardiac muscle has a high concentration of mitochondria.
The influx of which ion accounts for the plateau phase?
- sodium
- potassium
- chloride
- calcium
Which portion of the ECG corresponds to repolarization of the atria?
- P wave
- QRS complex
- T wave
- none of the above: atrial repolarization is masked by ventricular depolarization
Which component of the heart conduction system would have the slowest rate of firing?
- atrioventricular node
- atrioventricular bundle
- bundle branches
- Purkinje fibers
The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer ventricular contraction while no blood is being ejected?
- systole
- diastole
- quiescent
- isovolumic contraction
Most blood enters the ventricle during ________.
- atrial systole
- atrial diastole
- ventricular systole
- isovolumic contraction
The first heart sound represents which portion of the cardiac cycle?
- atrial systole
- ventricular systole
- closing of the atrioventricular valves
- closing of the semilunar valves
Ventricular relaxation immediately follows ________.
- atrial depolarization
- ventricular repolarization
- ventricular depolarization
- atrial repolarization
The force the heart must overcome to pump blood is known as ________.
- preload
- afterload
- cardiac output
- stroke volume
The cardiovascular centers are located in which area of the brain?
- medulla oblongata
- pons
- mesencephalon (midbrain)
- cerebrum
In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?
- It increases.
- It decreases.
- It remains constant.
- There is no way to predict.
What happens to preload when there is venous constriction in the veins?
- It increases.
- It decreases.
- It remains constant.
- There is no way to predict.
Which of the following is a positive inotrope?
- Na+
- K+
- Ca2+
- both Na+ and K+
The earliest organ to form and begin function within the developing human is the ________.
- brain
- stomach
- lungs
- heart
Of the three germ layers that give rise to all adult tissues and organs, which gives rise to the heart?
- ectoderm
- endoderm
- mesoderm
- placenta
The two tubes that eventually fuse to form the heart are referred to as the ________.
- primitive heart tubes
- endocardial tubes
- cardiogenic region
- cardiogenic tubes
Which primitive area of the heart will give rise to the right ventricle?
- bulbus cordis
- primitive ventricle
- sinus venosus
- truncus arteriosus
The pulmonary trunk and aorta are derived from which primitive heart structure?
- bulbus cordis
- primitive ventricle
- sinus venosus
- truncus arteriosus