autopharm 1 Flashcards
functions of the autonomic nervous system
- Maintains homeostasis of key visceral functions
- Control is involuntary
> Respiration
> Circulation
> Digestion
> Metabolism
> Body temperature
> Eliminatory organs
> Endocrine and reproduction
where are the ganglia of autonomic nerves?
efferent pathways (outgoing)
are autonomic nerves myelinated or not?
n Myelinated preganglionic nerves (rapid impulse)
n Non-myelinated post-ganglionic nerves (slow impulse)
does the autonomic NS increase or decrease organ activity?
can do both
divisions of autonomic NS
SNS and PNS
organization of the ANS, central and peripheral
Central (hypothalamus, medulla oblongata, and spinal cord) ̈ Peripheral (pre- and post-ganglionic neurons; ganglia)
outflow of SNS vs PNS
S - thoracolumber
P - craniosacral (CN 3, 7, 9, 10)
ganglia organization of SNS vs PNS
S - near spinal cord
P - close to end organ
axon comparison SNS vs PNS
S -short preganglionic/ long postganglionic
P - long preganglionic/ short postganglionic
ratio of pre/post ganglionic neurons, SNS vs PNS
S - one pre to many post
P - one pre to one post
distribution of SNS vs PNS
S - generalized response, diffuse discharge
P - limited response, discrete discharge
how do SNS and PNS generally work together?
antagonists, generally
̈ Most viscera innvervated by both SNS and PNS
̈ Net activity is result of integration of both systems
̈ Activity of one system exaggerated by blocking the activity other system
is the PNS essential for life?
yes
what are the characteristics of the discharges of the PNS
discrete and localized
what are the general functions of the PNS?
̈ Functions to conserve and store energy
- decreases Heart rate and blood pressure
- Pupillary constriction
- increases GI movements and secretions
- increases Absorption of nutrients
- Empties urinary bladder and rectum
is the SNS essential for life?
no
what are the general functions of the SNS? during stress?
> Involved in the expenditure of energy
-increase heart rate and blood pressure
-splenic contraction
-vasoconstriction of vessels in the skin
-pupillary dilation
-bronchodilation
̈ Fine adjustments made to a changing environment
̈ Can discharge as a single unit ie. flight or fright response !! ̈
During stress the SNS
§ Regulates body temperature
§ increase Blood glucose
§ Provides vascular response to hemorrhage
§ Responds to oxygen deficits
§ Responds to excitement or work
§ Provides resistance to fatigue
§ Causes pilomotor responses
Chemical transmission of nerve impulses in both PNS and SNS occurs between….
̈ Pre- and post-ganglionic neurons
̈ Post-ganglionic neurons and effector organ
what neurotransmitter do cholinergic neurons use? What neurons are this type?
̈ Synthesize and release acetylcholine (ACh)
̈ Include the following neurons
> All motor fibers (somatic) to skeletal muscle (Not part of ANS)
> All pre-ganglionic efferent neurons of both SNS and PNS
> Post-ganglionic neurons of PNS
what neurotransmitter do adrenergic neurons use?
- Synthesize and release catecholamines Norepinephrine
n Norepinephrine (NE)
n Epinephrine (adrenal medulla)
n Limited release of dopamine by some neurons
Which neurons in the body are adrenergic?
n Post-ganglionic neurons of SNS
n Adrenal medulla (modified sympathetic ganglion)
> Receives sympathetic pre-ganglionic fibers
> Releases primarily epinephrine and some NE
how is norepinephrine produced?
-tyrosine taken up by the cell
-tyrosine hydroxylase converts tyr to DOPA
-dopa decarboxylase converts DOPA to dopamine
-dopamine > NE
what type of adrenoceptors are there?
alpha 1,2
beta 1,2,3
how is acetylecholine produced?
nerve cell takes up choline
-combines with AcCoA from mitochondria to make ACh
-after release, acetyl cholinesterases separate into choline, acetate
what type of cholinoreceptors are there?
nicotinic - Nn, Nm
muscarinic - M 1,2,3,4,5
functions of SNS during stress
During stress the SNS
§ Regulates body temperature
§ increase Blood glucose
§ Provides vascular response to hemorrhage
§ Responds to oxygen deficits
§ Responds to excitement or work
§ Provides resistance to fatigue
§ Causes pilomotor responses
SNS and PNS effects on general homeostasis?
SNS:
-stress response
-expends energy
PNS:
-maintains homeostasis
-saves energy
SNS effects on SA and AV nodes, and relevant receptors
-increase rate, conduction > B1
SNS effects on cardiac muscle, and relevant receptors
-increase contractility > B1
Effects of SNS on heart and relevant receptors
-increase rate/conduction of SA, AV nodes > B1
-increase contractility of cardiac muscle > B1
Effects of PNS on heart, and relevant receptors
-decrease rate of SA, AV nodes: M2
-decrease contractility of cardiac muscle: M2
action of SNS on blood vessel SM and relevant receptors
Smooth muscle
-constriction of skin, splanchnic vessels: a1
-dilation of skeletal muscle vessels: b2 & M3
action of PNS on blood vessels and relevant receptors
-endothelium, release of endothelial relaxation factor (NO): M3
effect of SNS on splenic SM and receptor
-contraction, a1
effect of SNS on bronchiolar SM and receptor
-relaxation, b2
effect of PNS on bronchiolar SM and receptor
constriction, M3
effect of SNS on GI tract SM and receptors
-walls, decreased motility; a2, b2
-sphincters, contraction; a1
effect of PNS on GI tract SM and receptors
-walls, increase motility; M3
-sphincters, relaxes; M3
SNS effect on bladder and receptors
-bladder wall, relaxes; b2
-sphincter, contracts; a1
PNS effect on bladder and receptors
-bladder wall, contraction; M3
-sphincter, relaxation; M3
SNS effect on pregnant uterus and receptors
-relaxes; b2
-contracts; a1
SNS effect on penis, sem. ves. and receptors
-ejaculation; a1
PNS effect on penis, sem. ves. and receptors
-erection; M3
SNS effect on salivary gland and receptors
-increase secretion; a1
>minimal, viscous
PNS effect on salivary gland and receptors
-increase secretion; M3
>profuse, watery
SNS effect on liver and receptors
glycogenolysis/ gluconeogenesis; a1, b2
SNS effect on adipose tissue and receptors
lipolysis; a1, b1, b2, b3
SNS effect on kidney and receptors
renin release; b1
SNS effect on pancreas beta cells and receptors
-decrease secretion; a2
-increase secretion; b2
SNS effect on iris and receptor
contraction of radial muscle (mydriasis); a1
PNS effect on iris and receptor
contraction of sphincter muscle (miosis); M3
effect of SNS on ciliary muscle and receptor
relaxation for far vision; b2
effect of PNS on ciliary muscle and receptor
contraction for near vision; M3
effect of PNS on lacrimal tear glands and receptor
secretion, m3
effect of SNS on sympathetic nerve terminals and receptors
-autoreceptors, decrease NE release; a2
effect of PNS on sympathetic nerve terminals and receptors
-heteroreceptors, decrease NE release; M2
effect of SNS on parasympathetic nerve terminals and receptor
-heteroreceptor, decrease ACh release; a2
effect of PNS on parasympathetic nerve terminals and receptor
-autoreceptor, decrease ACh release; M2
