Block 1 Lecture 5 -- ANS Review Flashcards
What are the components of the peripheral nervous system?
1) somatic ns
2) enteric ns
3) autonomic ns
Where is the cell body of an alpha-motor neuron?
ventral horn
Where is Ach made in an alpha-motor neuron?
soma, transported to synapse
What are the 5 ways to regulate somatic activity (relax muscle)?
1) stop brain signal
2) stop signal in sc
3) post-synaptic receptor
4) nerve terminal
5) cell body
Where are the cell bodies in the enteric nervous system?
intramural plexus of the intestinal wall
What are the NTs in the enteric nervous system?
serotonin (5-HT)
dopamine
What are the NTs in the autonomic nervous system?
Ach
NE
Epi
What sweat glands in the sympathetic nervous system use sympathetic adrenergic receptors?
Apocrine
piloerection
What sweat glands in the sympathetic nervous system use muscarinic receptors?
Eccrine
What are characteristics of sympathetic nervous system?
1) thoracolumbar chain (short pre-ganglionic neurons)
2) diverse (ramified) connectivity
3) coordinated organ regulation
MoA of ondansetron?
5-HT3 antagonist
– acts on 5-HT3 receptors locally (in gut) and centrally (CTZ in area postrema of brainstem)
What is the CTZ?
Chemotactic Trigger Zone (vomiting reflex)
What are characteristics of the parasympathetic nervous system?
1) craniosacral; long-preganglionic
2) independent organ regulation
3) specific connectivity
What does SLUDGE stand for?
1) salivation
2) lacrimation
3) urination
4) decreased HR
5) gastric emptying
6) emesis
Which autonomic system is essential for life?
parasympathetic
What is the function of the PNS?
conservation of energy, maintenance of organ
Fx of beta-1 in heart
SA: increase HR
atria: increase FOC and CV
Fx of M2 in heart
SA: decrease HR
Function of b2 in vsm?
dilation for skeletal muscle, lung, liver
Function of a1 in vsm?
constriction for skin and visceral organs
Fx of b2 in lung
relax bronchiole sm
Fx of a1 in lung
decreases bronchiole secretions
Fx of M3 in lung
increase in secretions
slight contraction of bronchiole sm
Fx of b2 in GI
relaxes sm
Fx of a1 in GI
contract sphincters
decrease secretions
Fx of M1/M3 in GI
increase secretion, motility, tone (1 and 3)
Fx of M2 in GI
relax sm of sphincters
Fx of a1 in eye re: pupil size
contraction of radial muscle to increase pupil size
Medical term for dilation
mydriasis
Medical term for pupil constriction
miosis
Fx of M3 in eye re: pupil size
contraction of circular muscle to reduce pupil size
Fx of b2 in eye re: accommodation?
relax ciliary muscle to thin lens for far vision
Fx of M3 in eye re: accommodation
contraction of ciliary muscle to thicken lens for near vision
Fx of b3 in urinary bladder?
b3 in detrusor
relaxation
Fx of a1 in urinary bladder
a1 in sphincters/trigone
contraction
Fx of M3 in bladder
M3 in detrusor
contraction
Fx of M2 in bladder
M2 on sphincters…
relaxation
Fx of b2 in liver
gluconeogenesis, glycogenolysis
Fx of b3 on adipocytes
lipolysis, thermogenesis
Fx of b2 in skeletal muscle
??? unknown
Fx of a1 in sweat glands?
piloerection emotional sweating (not thermoreg) in armpits, ear canals, perianal
Fx of M3 in sweat glands?
cholinergic-mediated SNS end-organ response
– thermoreg
