ANS review Flashcards
What are the two major subdivisions of the autonomic nervous system?
Parasympathetic nervous system and the sympathetic nervous system
Which ANS subdivision is known for rest and digest?
parasympathetic NS
What are the effects of the parasympathetic NS?
- increase in salivation - increase digestion- slows heart rate - decreases blood pressure- decrease respiration - empties the bladder and rectum
Which subdivision of the ANS is known for “fight or flight”?
sympathetic NS
What are the effects if the sympathetic NS?
- increase HR - Increase BP- stimulates secretion of epinephrine - increases blood flow to muscles - causes bronchioles to dilates and pupils to dilate
preganglionic fibers of the PSNS exit from the ________ and _______ nerves
cranial and sacral
Preganlionic fibers of the PSNS are _______ and ________ in ganglia
long and synapse
Post ganglionic fibers of the PSNS are ________ and synapse with ___________
short and effector organ
what is the primary function of the PSNS?
fine tune and exert specific organ and homeostatic control (Rest and digest)
Preganglionic fibers of the SNS exit from the _______ and ________ area
thoracic and lumbar spinal
preganglionic fibers of SNS are _______ and _______ at a ganglia
Short and synapse at a ganglia
The post ganglionic fibers of SNS are _______ and synapse with ________
long synapse with effector organ
The the ganglia for PSNS where are they located?
very close or sometimes in the effector organ
Post-ganglionic neurons of SNS can branch many times meaning they can have a ____________
diffuse response
Functions of the SNS are?
The four F’s: 1. Fight–physical stress or injury 2. Flight–exercise or your fleeing from something 3. Fright–mental stress 4. sex
What do most effector organs work as for the two systems?
they work as functional antagonists. The net effect reflects integrated influences of both systems
Some effector organs are under pre-dominant control of only one of the systems for PSNS its what?
Glands within the GI tract
Some effector organs are under pre-dominant control of only one of the systems, for SNS its what organs?
sweat glands adrenal medulla most blood vessels
somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles
A somatic motor neuron is _______ _______ that releases what at the muscle?
one neuron that releases acetylcholine
What receptor do skeletal muscles have for acetylcholine?
nicotinic receptors (Nm)
for PSNS, The sacral neuron release ACh acts that nicotinic receptor (Nn)_______ the post ganglionic neuron
Activates
In PSNS, the post ganglionic neuron when activated release ACh to where?
Muscarinic receptors (M)
Nicotinic receptors are located where?
skeletal muscle, ganglia of PSNS and SNS
Alpha and Beta receptors are located where?
effector organs
What is the effect of activation of SNS on the HR?
increase
What is the effect of activation of SNS on heart contractile force?
increase
What is the effect of activation of the SNS on blood sugar?
increase
What is the effects of the activation of the SNS on bronchiole size?
increase
What is the effect of the activation of the SNS on gastrointestinal activity?
decrease
What is the effect of the activation of the SNS on the pupil size?
increase
What is the effect of the activation of the SNS on the secretion of sweat glands?
increase
if SNS is activated, which organs would vasodilation occur?
skeletal muscles
if SNS is activated, which organs would vasoconstriction occur?
Visceral organs such as GI tract
For each of the following scenarios, describe what system is involved. Challenge yourself and cite which receptor and neurotransmitter is involved at the end organ: A sudden and frightening sight causes a person to describe their reaction as their heart is about to leap out of their chest.
activation of the SNS causes release of Epi and NE from the adrenal gland and SNS nerve endings. Epi and NE act on B1 receptors to increase heart rate and force of contraction
A person’s skin feels cold and clammy.
skin is cold because of less blood flow == vasoconstriction -alpha receptors and NE (SNS)
A person has diarrhea from eating spoiled food.
activation of the PSNS causes increased GI activity–muscarinic receptors and ACh
A drug causes your eyes to dilate. Note, there are two ways this can happen.
anticholinergic–blocking ACh/ muscarinic at the iris OR alpha agonist activating the alpha receptor in the iris
A person took a drug with a side effect that blocks the ability to sweat and then goes to a hot yoga class. How and where is the drug acting to produce this effect? How will the person’s skin appear? Warm or cold?
an anticholinergic because the sweat glands, although on SNS side, the NT is Ach and receptor is muscarinic at gland/organ end. Warm and very dry. warm because skin is vasodilating to get rid of heat
what do most visceral organs have?
dual innervation between both SNS and PSNS
what does dynamic anatognism allow for?
precise control of visceral activity
SNS plays the major role of controlling blood pressure even at rest this is because of what?
because blood vessels are almost entirely innervated by sympathetic neurons with little PSNS neuron innervation
What is vascular tone?
the amount of constriction of a blood vessel
PSNS does innervate the heart, what does this effect?
it has significant effects on heart rate and contractility.
What are baroreceptors?
stretch receptors located in the carotid arteries and aortic arch
what NS does the baroreceptor reflex use to maintain blood pressure within normal limits?
SNS and PSNS
Cholinergic nerve fibers synthesize and release what as a neurotransmitter?
acetylcholine