This topic contains a solution. Click here to go to the answer

Author Question: In most patients, the sinoatrial (SA) and atrioventricular (AV) nodes are supplied by the _____ ... (Read 44 times)

pane00

  • Hero Member
  • *****
  • Posts: 579
In most patients, the sinoatrial (SA) and atrioventricular (AV) nodes are supplied by the _____ coronary artery.
 
  a. right
  b. left main
  c. circumflex
  d. left anterior descending

Question 2

Stimulation of beta2 receptor sites results in _____.
 
  a. increased heart rate
  b. peripheral vasoconstriction
  c. constriction of renal blood vessels
  d. relaxation of bronchial smooth muscle



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Sammyo

  • Sr. Member
  • ****
  • Posts: 329
Answer to Question 1

A
The SA node receives its blood supply from the SA node artery that runs lengthwise through the center of the node. The SA node artery originates from the right coronary artery in about 60 of people. The AV node is supplied by the right coronary artery in 85 to 90 of the population. In the remainder, the circumflex artery provides the blood supply.

Answer to Question 2

D
Beta2 receptor sites are found in the arterioles of the heart, lungs, and skeletal muscle. Stimulation results in dilation. Stimulation of beta2 receptor sites in the smooth muscle of the bronchi results in dilation.





 

Did you know?

The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.

Did you know?

People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.

Did you know?

When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

Did you know?

The top five reasons that children stay home from school are as follows: colds, stomach flu (gastroenteritis), ear infection (otitis media), pink eye (conjunctivitis), and sore throat.

For a complete list of videos, visit our video library