E1 L1 - Autonomic Nervous System Flashcards
Autonomic Nervous System
Involuntary; even at rest nervous system at work
Two main systems of autonomic
Sympathetic (fight or flight)
Parasympathetic (rest and digest)
Regulation of ANS
of the activity of smooth and cardiac muscle, glands, lymphoid and some adipose tissues
Very essential for function
Autonomic tone ANS
involuntary; means that these pathways are active to some degree at rest
sympathetic and parasympathetic often but not always
Oppose each other
Somatic Nervous System
Motor neuron; control skeletal muscles, mostly voluntary
ANS is a ___ neuron path
2
First Neuron (CNS)
Preganglionic Neuron
Located in CNs
Projects to the ‘autonomic ganglia”
Second Neuron (Peripheral):
Postganglionic neuron
Located outside of CNS in the autonomic ganglia
Projects to target organ
Ganglia definition
Group of cell bodies outside of CNS
Primary transmitter of all preganglionic neurons
Acetylcholine
Transmitter in all PSNS postganglionic neurons
Acetyl choline
Transmitter in most SNS postganglionic neurons
Norepinephrine
Also have…
ACh in sweat glands
Epinephrine in adrenal medulla
Dopamine in renal vasculature
Parasympathetic Neurons Preganglionic
Long
Synapse with postganglionic neurons at or near organ
Release acetylcholine to activate nicotinic receptors on postganglionic neurons
Parasympathetic Postganglionic neurons
Short
Synapse on the target organ
Release acetylcholine to activate muscarinic receptors on the target organ
Sympathetic Preganglionic neurons:
Ganglia is close to spinal cord
Paravertebral sympathetic ganglion
Release acetylcholine to activate nicotinic receptors on postganglionic neurons
Sympathetic Postganglionic Neurons;
Long
Synapse on the target organ
Release norepinephrine to activate adrenergic receptors on target organs
SWEAT GLAND CONTROLLED BY SYMPATHETIC
Parasympathetic Neurons and synapses have focus on
Medulla (cardiac and smooth muscle, gland cells ,nerve terminals)
Sympathetic neurons and synapses have focus on
Spinal Cord
Sweat Glands
Cardiac and smooth muscle, gland cells, and nerve terminals
Renal Vascular Smooth muscle
Epi NE
Exception: Adrenal Gland
Pregang do not synapse in paravertebral sympathetic ganglion
Pregang neurons synapse DIRECTLY ON adrenal gland, release ACH, activate nicotinic receptors ON adrenal gland
Adrenal glands release epinephrine into systemic circulation
Exception: Kidneys
Affected by dopamine, (mainly synthesized locally, not ANS)
Q: Most postganglionic sympathetic neurons release what neurotransmitter
Norepinephrine
