ICPP 8 Autonomic Nervous System Flashcards
What does the ANS control?
All involuntary functions
Is the ANS afferent or efferent?
Entirely efferent
Regulated by afferent inputs
What are the divisions of the ANS?
Parasympathetic- rest + digest
Sympathetic - fight or flight
What type of response comes about from the sympathetic response?
Fight or flight
What type of response comes about from the parasympathetic response?
Rest + digest
Where do the parasympathetic nerves come from?
Cranial/medullary region
Sacral region
Where do the sympathetic nerves come from?
Thoracic + lumbar region
Are the pre or post ganglionic axons myelinated?
Pre-ganglionic - myelinated
Post-ganglionic - unmyelinted
Cholinergic meaning
Uses acetylcholine as neurotransmitter
What neurotransmitter is released from all pre ganglionic neurons?
Acetylcholine
What receptors does pre-ganglionic ACh act on?
Nicotinic ACh receptors
What type of receptor are nicotinic ACh receptors?
Ligand gated channels
What neurotransmitters do parasympathetic post-ganglionic neurons release?
Acetylcholine
What neurotransmitters do MOST sympathetic post-ganglionic neurons release?
Noradrenaline
What receptors do post-ganglionic ACh act on?
Muscarinic ACh receptor
What receptors do post-ganglionic NA act on?
Adrenoreceptors
(Alpha 1 + 2)
(Beta 1, 2 + 3)
What does noradrenergic mean?
Uses noradrenaline as neurotransmitter
What type of a receptor are muscarinic ACh receptors?
GPCR
What type of receptors are adrenoreceptors?
GPCR
What neurotransmitters do SOME sympathetic post-ganglionic neurons release?
Acetylcholine
What do sympathetic post-ganglionic neurons in adrenal glands differentiate into?
Neurosecretory chromaffin cells
What do chromaffin cells do?
Release adrenaline to blood stream from adrenal medulla
What are chromaffin cells?
Post ganglion sympathetic neurons which don’t project to a target tissue
Release adrenaline from adrenal medulla
Effect of parasympathetic release of ACh on heart
bradycardia - SAN
decrease cardiac conduction velocity - AVN
Effect of parasympathetic release of ACh on smooth muscle
bonchial contraction - lungs
^ intestinal mobility/secretion - GI tract
bladder contraction + relaxation - GU tract
penile erection - GU tract
ciliary muscles + iris sphincter contraction - eye
Effect of parasympathetic release of ACh on glands
Increase sweat, salivary + lacrimal secretion
What receptor does ACh from the parasympathetic post ganglionic neuron act on in heart?
Muscarinic
M2
What receptor does ACh from the parasympathetic post ganglionic neuron act on in smooth muscle?
Muscarinic
M3
What receptor does ACh from the parasympathetic post ganglionic neuron act on in glands?
Muscarinic
M1/3
What receptor does NA from the sympathetic post ganglionic neuron act on in heart?
Beta adrenoreceptors
B1
one heart two lungs
What receptor does NA from the sympathetic post ganglionic neuron act on in smooth muscle?
B2
Effect of sympathetic release of NA on heart
Tachycardia - SAN
Positive inotropy/contraction - ventricles
Effect of sympathetic release of NA on smooth muscle
arteriolar + venous contraction - vasculature
bronchiolar/intestinal/uterine relaxation - lungs,GI/GU tract
bladder sphincter contraction - GU tract
radial muscle contraction - eye
Effect of sympathetic release of NA on glands
Increased secretion - salivary
Effect of sympathetic release of NA on kidney
Renin release
Which sympathetic post ganglions neurones release ACh?
Those innervating sweat glands and hair follicles
Sympathic nervous system targets
Blood vessels
Parasympathetic nervous system targets
Glands
What axons are myelinated?
Pre ganglionic axons
What lies either side of the spinal cord in the sympathetic nervous system?
Sympathetic chains - chain of ganglia
What do transversing sympathetic nerves form?
Splanchic nerves
How do sympathetic nerves get to the GI tract?
Transverse»_space; splanchnic nerves
What are the 4 specialised parasympathetic ganglia in the head?
Ciliary ganglion
Pterygopalatine ganglion
Submandibular ganglion
Otic ganglion
