Exam 4 MCQs Flashcards
During rapid depolarization of a ventricular contractile cell, the voltage-gated sodium channels close when the membrane potential reaches approximately what mV level?
+30mV
During re-polarization, __________ ions rush out of the ventricular contractile cell.
Potassium
The amount of blood pumped by the left ventricle in one minute is called the_________.
Cardiac output
When a chamber fills with blood and is preparing to begin the next cardiac cycle, the chamber is_________.
In diastole
________are the most abundant cell population of the formed elements of the blood.
Erythrocytes
The primary function of white blood cells (WBCs) is to_________.
Help defend the body against pathogens.
Formed elements that are nucleated and capable of amoeboid movement are________.
Leukocytes
What MECHANICAL event is occurring during the P-Wave?
Atrial systole
What ELECTRICAL event is occurring during the P-wave?
Atrial depolarization
Why is atrial re-polarization not illustrated on an ECG?
The QRS complex masks it
A hemoglobin molecule contains_________.
Four protein chains, four heme groups, and four iron ions.
The most abundant type of WBC in a normal blood sample is the_________.
Neutrophil
Which blood type is the “universal donor”?
O-
The release of norepinephrine at synapses in the myocardium results in________.
An increase in stroke volume.
In the process of hemoglobin recycling, each heme molecule is stripped of its iron and converted to which pigmented organic compound?
Biliverdin
