Neurobiology 7 Flashcards
Autonomic NS
Regulates involuntary physiologic processes
- HR, BP, RT, GIT, sex function
Composed of sympathetic, para & enteric systems
Function, effector organs, motor pathways of autonomic system
Visceral sensation, cardiac & smooth muscle contraction, gland secretion
Smooth muscle glands, cardiac muscle
Two neurons that synapse outside the CNS
Function, effector organ and motor pathways of somatic NS
Conscious sensation & voluntary movement
Skeletal muscle
One neuron, cell body in CNS
Autonomic NS neurotransmitter & receptors
Cholinergic (bind acetylcholine)
- muscarinic - postganglionic parasympathetic
- nicotinic - preganglionic & somatic
Adrenergic (bind norepinephrine)
- Alpha & beta (depends on tissue)
- postganglionic sympathetic
Sympathetic NS, function, response time, location of ganglia & origin
function - response to stress
response time - fast
location of ganglia - in chain parallel to the spinal cord
origin - lateral horns of thoracic & lumber spinal grey matter
Sympathetic NS, length of motor neurons, neurotransmitter released by presynaptic neuron, neurotransmitter released by post synaptic neuron
length of motor neurons - short preganglionic, long postganglionic
neurotransmitter released by presynaptic neuron = acetylcholine
neurotransmitter released by post synaptic neuron - norepinephrine (sweat glands exception)
Parasympathetic NS
Function, response time, location of ganglia, origin
Function - maintains homeostasis
response time - slower
location of ganglia - in or near target organ
origin - brain stem nuclei & sacral spinal grey matter
Parasympathetic NS
Length of motor neurons, neurotrans released by presynaptic neuron, neurotrans released by postsynaptic neuron
Length of motor neurons - long pregang, short postgang
neurotrans released by presynaptic neuron - acetylcholine
neurotrans released by postsynaptic neuron - acetylcholine
Innervation & location of synaptic NS
Innervates nearly every tissue in the body
Ganglia located in a chain adjacent to the spinal cord
Sympathetic NS pre & post neuro
Short Pregang releases acetylcholine that binds to nicotinic cholinergic receptors
Long Postgang releases norepinephrine that binds to alpha or beta Adrenergic receptors
Sympathetic sweat gland exception to neurotrans
Short pregang release acetylcholine that bind to nicotinic cholinergic receptors
Long postgang release acetylcholine that bind to muscarinic cholinergic receptors
Parasympathetic NS pre & post gang neurotrans
Long pregang releases acetylcholine that bind to nicotinic cholinergic receptors
Short postgang releases acetylcholine that bind to muscarinic cholinergic receptors
Neurotransmitters of adrenal gland
Pregang receptors release acetylcholine that bind to nicotinic cholinergic receptors in the adrenal glands
Endocrine cells spread the signal/chemical to the entire body
80% secrete epinephrine into the blood
20% secrete norepinephrine into the blood
SNS pregang neuron
Short axon, cell bodies in intermediolateral cell column, synapses in sympathetic ganglion
NT = acetylcholine receptor = nicotinic
SNS postgang neuron
Long axon, cell bodies in sympathetic ganglion, synapses on effector organ
NT = norepinephrine, receptor = alpha or beta
Adrenal gland
Endocrine gland, release chemical messengers to blood
Cortex - controlled by pit gland
Medulla - controlled by sympathetic nerves
Releases catecholamines (epinephrine & norepinephrine) dont synapse until they reach the target organ (adrenal)
PNS pregang neuron
Long axon, cell bodies in brain & cervical spinal cord
Synapses in ganglia near or in target organ
NT = acetylcholine, receptor = nicotinic
PNS postgang neuron
Short axon, cell bodies in parasympathetic ganglia
Synapses on effector organ
NT = acetylcholine, receptor = muscarinic
CNS control of respiration
Main coordination is due to neurons in brainstem
SNS ^^ RR & dilates SM of bronchioles
PNS vv RR & contracts SM of bronchioles
CNS control of HR
SA node
SNS
PNS
Sa node - automatically depolarizes to initiate contraction of cardiac muscle
SNS - ^ rate of depolarization of sa node, ^ Ca influx to SM to increase contraction force
PNS - v rate of depolarization
SNS control of BP
Contraction of SM in vessels to GIT
Relaxation of SM in vessels to skeletal muscle
PNS control of BP
Relaxation of SM in vessels to GIT
Contraction of SM in vessels to skeletal muscle
CNS control of urination
PNS - contraction of bladder wall, relax sphincter
SNS - relax bladder wall, contract sphincter
CNS control of Enteric NS
Web like neurons in wall of intestines
SNS - v peristalsis
PNS - ^ peristalsis
nicotinic receptors
Ionotropic (electrical)
Effect skeletal muscle, autonomic ganglia, CNS, adrenal medulla
Muscarinic receptors
Metabotropic (chemical signal)
3 types effecting different muscles
M1 receptors
CNS, salivary gland secretion, stomach acid secretion
M2 receptors
Heart rate, force, av conduction
M3 receptors
SM contraction
Glandular secretion
Vasodilation in GIT
Adrenergic receptors
Metabotropic (chemical receptors)
Alpha 1&2
Beta 1&2
Alpha 1&2 adrenergic receptors
A1 - vasoconstriction, SM contraction
A2 - negative feedback
Beta 1&2 adrenergic receptors
B1 - increases HR
B2 - vasodilation, SM relaxation
NMJ - SM
Neurotransmitter released from axonal swellings called varicosities
SM fibers are electrically connected by gap junctions
Axons dont have terminals, transmitter binds to Metabotropic receptors (g protein, ca, protein synth)
