Where does the impulse for cardiac contraction originate?

a. Superior vena cava
b. Inferior vena cava
c. Sinoatrial (SA) node
d. Vagus nerve


ANS: C
Muscular contractions of the atria and ventricles are controlled by an electrical impulse that originates in the sinoatrial (SA) node.

Health Professions

You might also like to view...

Which of the following is a major concern of tablet splitting?

A) sub-therapeutic or super-therapeutic dosing B) the amount of tablets needed C) metabolism D) the tool used to cut tablets

Health Professions

Inspection of the airway pressure waveform of a patient receiving volume-controlled continuous mandatory ventilation assist-control with constant flow reveals a large dip or drop in pressure at the beginning of inspiration

Which of the following problems is most likely? a. The trigger setting is improper. b. The inspiratory flow is inadequate. c. The set volume is too large. d. The pressure limit is too low.

Health Professions

A stature disorder in which the body produces either too much or too little growth hormone is a disorder of which endocrine gland?

A) Right adrenal B) Anterior pituitary C) Left adrenal D) Posterior pituitary

Health Professions

Calculate the velocity of red light with a wavelength of approximately 4.0 nm (nm = 10^-9).

a. 7.5 × 10^-1 nm/sec b. 7.5 × 10^18 nm/sec c. 1.2 × 10^-17 nm/sec d. 1.2 × 10^1 nm/sec

Health Professions