How does adrenaline affect the heart?

Answer 1

Naturally secreted adrenaline acts directly on the pacemaker of the heart ,SINU -ATRIAL, node to speed the heart contraction rate and at the same time inhibiting the slowing down effect of the neurotransmitter Acetyl Choline. the acceleration is done at the expense of the diastolic(relaxation) time

Adrenaline also acts directly on the cardiac muscle cells to increase the force of contraction thus ejecting more blood per heart beat.

Answer 2

Message:


Hello Calvin,
Well, I'm going to try and answer your question. Actually, you've come
across a rather complicated subject. On the surface of the muscle cells
which make up the heart there are a number of specialized proteins called
receptors. There are receptors for adrenaline and for acetylcholine. These
receptors are large proteins which have a part of their structure on the
outside of the cell (i.e. the part that receives adrenaline or
acetylcholine) and a part on the inside of the cell (which is involved in
modulating the contractile force generated by the muscle). When the
receptor for adrenaline captures a molecule of adrenaline released from a
nerve or circulating in the bloodstream a number of things happen. The
binding of adrenaline causes a change in the shape of the receptor such
that part of the receptor on the inside of the cell is more able to
stimulate the contraction of the muscle. It does this in a number of ways.
For example it can stimulate the production of a molecule called cyclic AMP
which can then activate a number of enzymes which modulate contractility.
Also, stimulation of adrenergic receptors can directly activate some of the
proteins found in the cell membrane which are responsible for the
electrical activity of the cell. In a similar fashion, acetylcholine binds
to its receptor and essentially causes the opposite response, that is a
decrease in the contractile force generated by the muscle. Alcohol is a
different matter entirely. Basically, little is know about the specific
mechanisms by which alcohol decreases heart rate. Alcohol, of course is a
general depressant. Some of its metabolites (breakdown products) may
actually cause the release of adrenaline causing a further complication to
its effects. I hope this helps.

Answer 3

It increases the heart rate and the force of contraction.
(same as epinepherine)

Answer 4

Howdy! Someone in my Facebook group shared this link so I came to give it a look. I'm definitely enjoying the information. I am book-marking and will be tweeting it to my followers!

Answer 5

it increases the rate at which the heart pumps

Answer 6

I'm not sure