chapter 7
Modified sympathetic tissue where preganglionic neuron communicates and medulla release NE and E to go into bloodstream and go throughout the body
adrenal medulla
NE and Epi bind to 2 classes of __________
adrenergic receptors
two types of adrenergic receptors
alpha and beta
can a cell be both inhibitory and excitatory?
You cannot have a cell with both inhibitory and excitatory. Only one each so it will either be inhibitory or excitatory
ACh is degarded by:
acetylcholinesterase (AChE) - enzyme
beta receptors
-generally inhibitory -subclasses beta 1,2,3
indolamines
serotonin
parasympathetic neuron effects
-Preganglionic neuron releases ACh to cholinergic receptors: nicotinic and muscarinic - excitatory -Pace of AP frequency must stay the same when the message is passed along -ACh is the neurotransmitter of parasympathetic - released by both pre and post neurons
effect of cholinergic receptors at target tissue
-decrease heart rate -decrease respiratory rate -increase digestive secretion and motility
alpha receptors
-generally excitatory -subclasses alpha 1 and 2
effects of adrenergic receptors at target tissue
-increase heart rate (B1 receptor) -increase blood (glucose) -decrease digestive secretion and motility (alpha 2 receptor) -increase sweat gland secretion (alpha 1 receptor)
muscarinic receptors:
-on all gland, smooth muscle and cardiac muscle cells that receives cholinergic innervation -receptors are linked to G proteins -ACh binds, G protein cascade causes ion channels to open or close -excitatory or inhibitory due to subclasses of muscarinic receptors
nicotinic receptors:
-on neuromuscular junctions (skeletal muscle), all ANS postganglionic neurons, in the adrenal medulla -receptors are ligand gated channels -ACh binds and channels open; depolarizing the cell -excitatory
As long as neuron is firing APs it is releasing _________, but AChE gets rid of ________ previously when it stops
ACh
how many cranial and spinal nerves are there
Cranial- 12 Spinal- 31
where is acetycholinesterase found? what does it do?
Found at synapse and breaks down ACh so that you cannot continue effect
NE receptors are linked to ___________. function by means of???
G proteins; 2nd messeneger (cyclic AMP)
exception of beta adrenergic receptors being generally inhibitory
NE binding to B receptors of the heart stimulatory
involuntary, cardiac, smooth muscle, glands
autonomic NS
One neuron will leave CNS and stop somewhere along the path to pass signal to second neuron which then takes it to effector
autonomic nervous system
acetylcholine binds to what type of receptor
cholinergic
skeletal muscles are only innervated by ____________
cholinergic receptors
One neuron gives off a bunch of branches and talks to many postsynaptic neuron - called divergent pathway
divergence
catecholamines
dopamine, norepinephrine, epinephrine
most viscera receive nerve fibers from both parasympathetic and sympathetic division
dual innervation
NE and Epi are degraded by:
enzyme monoamine oxidase (MAO)
synthesis of the three catecholamine NTs depends on:
enzyme present in the axon terminals
causes smooth muscles of the digestive tract to contract
excitation
Anytime ACh binds to the channel for nicotinic receptors, it causes ___________________
excitation/depolarization
cluster of cell bodies in PNS
ganglion
produces slower heart rate
inhibition
acetylcholine binds to 2 classes of cholinergic receptors:
nicotinic and muscarinic
Receptors that nicotine in cigarettes bind to
nicotinic receptors
where are adrenergic receptors found?
on glands, smooth muscle and cardiac muscle cells that receive adrenergic innervation
how many neurotransmitters can be released by each neuron
only one
long preganglionic, short postganglionic
parasympathetic
supplies cranial sacral
parasympathetic
• "Rest and digest" • Keeps body energy use as low as possible • Directs digestion and elimination activities
parasympathetic
second neuron ANS
postganglionic neuron
first neuron ANS
preganglionic neuron
One neuron leaves the CNS, and goes all the way to effector (muscle) - somatic motor neuron
somatic nervous system
voluntary, skeletal muscle
somatic nervous system
short preganglionic, long postganglionic
sympathetic
supplies cervical thoracic lumbar
sympathetic
• "Fight or flight" system • Prepares the body to respond to an emergency or threatening situation (or vigorous exercise)
sympathetic
autonomic splits up into:
sympathetic and parasympathetic