Author Question: A nursing instructor is explaining the role of vascular smooth muscle cells in relation to increases ... (Read 96 times)

Engineer · **on:** Jun 25, 2018

A nursing instructor is explaining the role of vascular smooth muscle cells in relation to increases in systemic circulation.

During discussion, which neurotransmitter is primarily responsible for contraction of the entire muscle cell layer thus resulting in decreased vessel lumen radius?
A)
Nitric oxide
B)
Adrenal glands
C)
Fibroblast growth factor
D)
Norepinephrine

Question 2

Following cardiac surgery, the nurse suspects the patient may be developing a cardiac tamponade. Which of the following clinical manifestations would support this diagnosis? Select all that apply.

A)
Muffled heart tones
B)
Narrowed pulse pressure
C)
Low BP84/60
D)
Heart rate 78
E)
Bounding femoral pulse

smrtceo · **Reply #1 on:** Jun 25, 2018

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.