APPLIED RADIOLOGICAL ANATOMY

ANATOMY

CHEST AND CARDIOVASCULAR

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
The cardiac rate may be altered by impulses from the
A
parasympathetic system
B
sympathetic system
C
autonomic system
D
cardiovascular system
Explanation: 

Detailed explanation-1: -Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines-epinephrine and norepinephrine) to accelerate the heart rate.

Detailed explanation-2: -The autonomic nervous system system modifies cardiac output by extrinsic stimulation. Although the autonomic system regulates extrinsic aspects of cardiac output, each cardiac myocyte has the intrinsic ability auto-depolarize, i.e. to self-initiate a change of electrical charge.

Detailed explanation-3: -Beta-1 receptors are located in the heart. When beta-1 receptors are stimulated they increase the heart rate and increase the heart’s strength of contraction or contractility.

There is 1 question to complete.