Unit 3 C&D answer Exam Prep
1) The cardiac muscle contraction occurs when Ca++ enters the myofibers through slow channels. 3C 2
2) Voltage gated Na+ channels are associated with depolarization (contraction) and K+ channels are associated with repolarization (relaxation). 3C 2
3) Contractile myocardial fibers use Na+ to initiate Action Potentials while auto-rhythmic fibers use Ca++. 3C 3
4) Damage to the AV node is referred to as heart block. 3C 4
5) The P wave of a normal electrocardiogram indicates SA node depolarization and atrial contraction. 3C 5
6) The QRS complex of a normal electrocardiogram indicates ventricular depolarization and contraction. While at the same time, but not seen on a normal electrocardiogram, atrial repolarization or returning to a resting state. 3C 5
7) The T wave of a normal electrocardiogram indicates ventricular repolarization and relaxation, at which time the chamber fill with blood. 3C 5
8) Heart sounds other than those caused by closing of valves are called murmurs. 3C 6
9)Bradycardia is a slow, sinus or normal rhythm, while Tachycardia is a fast, sinus of normal rhythm. 3C 6
10)In Systole the heart contracts and blood is pumped out, while during Diastole the heart relaxes and the chambers fill with blood. 3C 7
11) Stroke Volume is the amount of blood pumped per beat, while the End Diastolic Volume is the amount of blood collected in the ventricle during diastole and End Systolic Volume is the amount of blood remaining in the ventricles after contraction. 3D 1
12) Preload is the amount the ventricles are stretched by contained blood, that is blood received and blood pumped out. 3D 1
13) Parasympathetic Nervous System dominants resting cardiac autonomic stimulation, slowing the heart rate and causing vagal tone. 3D 2
15) The dicrotic notch refers to the brief rise in aortic pressure caused by backflow of blood rebounding off the aortic semilunar valve. 3C 7
16) Starlings law of the heart states that the heart contracts less forcefully when it fills with more blood. True or False 3D 1
17) Control of blood flow through a capillary bed occurs at its precapillary sphincter.3D 5