Answer to Question 1
Ans:
D
Feedback:
Nerve cells and circulating hormones are responsible for vasoconstriction of the vessel walls. Because they do not enter the tunica media of the blood vessel, the nerves do not synapse directly on the smooth muscle cells. Instead, they release the neurotransmitter, norepinephrine, which diffuses into the media and acts on the nearby smooth muscle cells, resulting in contraction of the entire muscle cell layer and thus reducing the radius of the vessel lumen. This increases the systemic circulation.
Answer to Question 2
Ans:
A, B, C
Feedback:
Cardiac tamponade results in increased intracardiac pressure, progressive limitation of ventricular diastolic filling, and decreased stroke volume and cardiac output. This accumulation of fluid results in tachycardia, elevated CVP, jugular vein distention, fall in systolic BP, narrowed pulse pressure, and signs of shock. Heart sounds may be muffled. A pulse rate of 78 is normal (not tachycardic). With pulsus paradoxus, the arterial pulse as palpated at the carotid or femoral artery becomes weakened (not bulging) or absent with inspiration.