Autonomic nervous system Flashcards
Autonomic Nervous System (3)
1) Division of the PNS
2) Motor neurons that control internal organs
a) Automatically
b) No conscious intervention needed
3) Sensory neurons come from internal organs
a) Cell bodies are in the DRG (Dorsal Root Ganglion)
b) With cell bodies for somatic sensory neurons
Ganglia
Clusters of nerve cells in the PNS
Preganglionic axon (2)
1) A motor neuron cell body located in the spinal cord and brain.
2) This axon synapses with a second motor neuron located in the autonomic ganglion outside the spinal cord
Postganglionic Axon
After synapsing in an autonomic ganglion, the axon of the ganglionic motor neuron synapses on an effector organ in the PNS
The Sympathetic System (fibers and targets) (2)
1) Also called thoracolumbar division
a) Contains preganglionic fibers from thoracic and lumbar segments of the spinal cord
2) Widespread targets
a) Cover large regions and has many effects
Sympathetic “fight or flight” response (3)
Fight or flight response:
a) Muscles need steady, increased supply of glucose and oxygen
b) Accelerates heart beat
c) Dilates bronchi
2) Liver
a) Breaks down glycogen to glucose
3) Digestion
a) Inhibited
Sympathetic system neurotransmitter
Noropinephrine (NE)
Sometimes called adrenergic
Sympathetic Trunk Ganglia (3)
1) Located on both sides of the spinal cord
2) Contain ganglia for the sympathetic nervous system
3) Controls effector organs in the trunk, head and limbs
Celiac Ganglion (Sympathetic System) (2)
1) Largest
2) Controls digestive tract
Superior Mesenteric Ganglion (Sympathetic System) (2)
1) Small intestine
2) Parts of large intestine
Inferior Mesenteric Ganglion (Sympathetic System) (2)
1) Large intestine
2) Kidneys
3) Bladder
4) Sex organs
Parasympathetic System (fibers and targets)
1) Also called craniosacral division
a) Contains preganglionic fibers from the brainstem and sacral divisions of the spinal cord
2) More specific targets
Parasympathetic system functions
1) Called housekeeper system
a) Responses associated with a relaxed state
2) Pupil constriction
3) Slows heart rate
4) Promotes digestion
a) Secretion of digestive glands
b) Smooth muscles of GI tract
Parasympathetic system neurotransmitter (2)
1) Acetylcholine (ACh)
2) Called Cholinergic
Ciliary ganglion (Parasympathetic system) (3)
1) CN III
2) Intrinsic eye muscles
3) Pupil/lens changes
