Physiology 534 Exam Iv: Autonomic Function Neuro-Effector

Front 1

Lacrimal gland

Back 1

PS postganglionic fibers-->Ach release-->muscarinic receptors-->tear secretion

Front 2

Skin blood vessels

Back 2

Sympathetic postganglionic fibers-->release NE-->alpha-adrenergic-->constriction

Front 3

Heart rate pacemaker

Back 3

Dual, reciprocal innervation

a. PS postganglionic fibers-->Ach-->Muscarinic cholinergic receptors-->decrease rate of cardiac pacemaker cells

b. Sympathetic postganglionic fibers-->NE-->B adrenergic receptors-->increase rate of cardiac pacemaker cells

Front 4

Fat cells

Back 4

Adrenal medulla-->circulating Epi-->B-adrenergic receptors-->lipolysis

Front 5

Arterioles in skeletal muscles

Back 5

-Innervated & non-innervated receptors

a. Sympathetic postganglionic fibers-->NE-->alpha Adrenergic-->constriction

b. Adrenal Medulla-->circulating Epi-->B-adrenergic receptors-->dilation

Front 6

Ach causes endothelial cells release NO

Back 6

Ach binds to M3-->NO synthase activation causing Arginine-->NO.

NO diffuses out of endothelial cells into vascular smooth muscle cells. Binds to the GC which converts GTP to cGMP-->relaxation of smooth muscle.

Front 7

Are there non-innervated receptors affecting arterioles in skeletal muscle?

Back 7

-Inject Ach into blood stream-->binds to M3 receptors-->NO released-->dilation

-Or injection of muscarine, blockade of AchE

Front 8

Are skeletal muscles innervated by cholinergic nerves?

Back 8

No, because not innervated by PS

Front 9

How does NO mediate PS effects in external genitalia?

Back 9

PS nerves release NO & Ach

NO-->corpus cavernosum smooth muscle-->binds to GC-->production of cGMP-->dilation of muscle

-cGMP is then broken down to GMP by Phosphodiesterase

Front 10

Sildenafil (Viagra) effects where?

Back 10

Phosphodiesterase inhibitor so does not break down cGMP to GMP

Increase cGMP-->promotoes dilation of the corpus cavernosum

Front 11

Does the sympathetic NS normally respond as a unit?

Back 11

No, sympathetic NS can evoke a "mass discharge" but typically it is very subtle.

Ex: These responses do not happen as a unit:

a. diaphoresis (sweating) with heat stress
b. Piloerection (goosebumps) with cold stress
c. Mydriasis (dilation of pupils) in a dark room
d. Ejaculation

Front 12

Is the fight/flight responds equivalent to sympathetic activation?

Back 12

Combination of both somatic and autonomic functions.

Somatic responses vary with each situation.

Front 13

List of responses that are not symapthetic

Back 13

1. increased rate and depth of respiration (somatic)
2. lacrimal secretion (PS)
3. defecation (PS)
4. micturition (PS)
5. release of hormone cortisol (hypothalamus & pituitary)
6. Vasovagal syncope (fainting): loss of sympathetic tone

Front 14

Is activation of the sympathetic NS bad for you?

Back 14

No, but over long term, the effects of NE can be bad. It can lead to changes at the gene level, hypertrophy of myocytes, proliferation of CT, and death of myoctyes.

Front 15

Is the ANS the involuntary NS?

Back 15

Not always, micturition and there are some somatic responses that are not voluntary such as taking a breath or spinal reflexes

Front 16

Should adrenergic effects be equated with sympathetic effects?

Back 16

No, all ganglionic transmission in SNS and PNS is cholinergic.?

Sweat glands are sympathetic NS but cholinergic.

Front 17

Should cholinergic effects be equated with parasympathetic effects?

Back 17

If you consume cholinergic drugs, do not always get PS effects.