autopharm 1 Flashcards
(58 cards)
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
