Autonomic Nervous System Physiology Flashcards Preview

Cardiovascular Unit 1 > Autonomic Nervous System Physiology > Flashcards

Flashcards in Autonomic Nervous System Physiology Deck (25)

What is the universal neurotransmitter for preganglionic neurons in the ANS?



Which has a higher preganglionic to postganglionic ratio, parasympathetic or sympathetic?

The sympathetic has a higher ratio (10:1) than the parasympathetic (3:1)


T or F?

The parasymphatethic has ganglia located near the spinal cord


The sympathetic has ganglia located near the spinal cord.

The parasymphthetic has ganglia located near the target organs.


T or F?

The postganglionic parasympathetic neurons release acetylcholine and the postganglionic sympathetic neurons release epinephrine and norepinephrine.


Sorry if these are too simple, I just wanted to do a quick refresher for myself.


What makes the adrenal medulla special in regards to the sympathetic nervous system?

The postganglionic cells located here secrete epinephrine and norepinephrine into the blood stream to bind to adrenergic receptors. Thus, these act as hormones as opposed to neurotransmitters.


T or F?

The sympathetic nervous system primarily controls vasodilation and vasoconstriction


Increased sympathetic leads to vasoconstriction as well as increased heart rate and force of contraction


Which 4 cranial nerves are part of the parasympathetic nervous system?

III (oculomotor), VII (facial), IX (glosspharyngeal), X (vagus)


Which has longer postganglionic axons, sympathetic or parasympathetic?



By which mechanism are neurotransmitters (Ach and Norepi) released from postganglionic neurons of the ANS?



Where are nicotinic receptors primarily located?

They are primarily present in the cell bodies of postganglionic neurons of the autonomic ganglia


Where are the muscarinic receptors primarily located?

Muscarinic receptors are present on the effector cells of cardiac muscle, smooth muscle, and glands


T or F?

The nicotinic receptor is a ligand-gated, selective channel


It's a ligand-gated, non-selective channel that opens when Ach binds it and allows for Na and K to move across the membrane, leading to depolarization and excitation.


What kind of proteins are associated with muscarinic receptors in the cell membrane?

G proteins. They carry out a lot of different physiological functions within the cell.


T or F?

There are 2 types of muscarinic receptors


There are 5 subtypes. That's why there's such variety in what can happen when Ach binds to a muscarinic receptor and activates the G protein.


How many different subtypes of adrenergic receptors are there?

T or F?

Norepinephrine (NE) activates all of the adrenergic receptors

There are 4 types (alpha 1, alpha 2, beta 1, beta 2)


NE only activates alpha 1, alpha 2, and beta 1. Epinephrine activates all 4.


T or F?

Beta blockers (propanalol) are good treatment for hypertension and coronary artery disease


Epinephrine or a more selective B2 blocker would also be good for people w/ asthma who are experiencing bronchoconstriction.


Give the CV related action, an agonist (sympathomimetic) and antagonist (parasympathomimetic) of the adrenergic receptor: Alpha 1

Vasoconstriction in skin. 

Agonist: Phenylephrine

Antagonist: Doxazosin


Give the CV related action, an agonist (sympathomimetic) and antagonist (parasympathomimetic) of the adrenergic receptor:

Alpha 2

CV: Presynaptic inhibition of NE release, some vasoconstriction

Agonist: Clonidine

Antagonist: Trazodone


Give the CV related action, an agonist (sympathomimetic) and antagonist (parasympathomimetic) of the adrenergic receptor:

Beta 1

CV: Increased heart rate

Agonist: Dobutamine

Antagonist: Atenolol


Give the CV related action, an agonist (sympathomimetic) and antagonist (parasympathomimetic) of the adrenergic receptor:

Beta 2

CV: Increased heart rate. Vasodilation in skeletal muscle

Agonist: Albuterol

Antagonist: Butaxamine


In the baroreceptor reflex, what response is expected when you have low blood pressure?

A relative increase in sympathetic output. The opposite is also true.


What is the effect in the heart if there is increased Ach release (ie increased parasympathetic)

The heart will beat slower with less force.


Why is the hypothalamus so important in homeostasis?

It's the head control ganglion.

It controls different responses/reflexes of the autonomic nervous system.

It also controls release of hormones via the pituitary gland (vasopressin release which helps to control blood pressure).

The hypothalamus coordinates the ANS and humoral responses.


What's the effect of vasopressin?

It causes increased vasoconstriction as well as increased water retention in the kidneys in response to low blood pressure.


What do renin and angiotensin do in response to low blood pressure?

Renin activates angiotensin to angiotensin I which then goes on to become angiotensis II which constricts blood vessels, increases water retention in the kidneys, and activates neurons in subformical organs.

Controlled by the hypothalamus.