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. The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate. Such factors as stress, caffeine, and excitement may temporarily accelerate your heart rate, while meditating or taking slow, deep breaths may help to slow your heart rate.
Answer:
Each arrow indicates a dependency
Explanation:
D depends on A, B, C; and C depends on B and D. Whereas A and B are each independent
The theory that proposes that the universe emerged form an explosion (The Big Bang) is known as the Big Bang Theory.
Hope it helped,
BioTeacher101
Punnett square-
R r
R RR Rr
r Rr rr
So RR, Rr, and rr are possible outcomes.
The answer is D.
