Exam 3: Autonomic Nervous System Flashcards
1
Q
Somatic Nervous System
A
- innervates skeletal muscle and receives sensory information from senses
- volunatry
- CNS and PNS components
2
Q
Autonomic Nervous System
A
- innervates the viscera (organs)
- influences smooth muscle, cardiac muscle, and glands of skin and viscera
- CNS and PNS components
- controls the 4 F’s ( Feeding, Fleeing, Fighting, Fornication)
- motor system
3
Q
Hierarchy of ANS
A
- hypothalamus oversees ALL ANS activity, CEO/president
- middle management are the autonomic nervous centers in the brainstem (pons, mesencepalon, medulla)
- the ordinary workers are the preganglionic and postganglionic neurons
4
Q
Somatic Motor
A
-uses a single neuron to go from spinal cord to skeletal muscle
5
Q
Autonomic Motor
A
- uses two neurons to go from the spinal cord to the target tissue
- 1st is preganglionic neuron
- 2nd is postganglionic neuron
6
Q
Preganglionic Neuron
A
- cell body located in CNS
- axon will synapse with the postganglionic neuron
7
Q
Postganglionic Neuron
A
- cell body located in an autonomic ganglion
- this axon will connect to the target tissue (effector)
8
Q
Why does ANS use 2 neurons in chain to an organ?
A
- ANS has a limited number of neurons
- ganglion=hub
- allows for convergence and divergence of ANS info
- more efficient with 2 neurons
9
Q
Sympathetic Division of ANS
A
- thoracolumbar
- originates in lateral horns of T1-L2 region of spinal cord
- emergency situations
- fight or flight response
- mass activation effect-all parts of sympathetic divison may be turned on at once
10
Q
Parasympathetic Division of ANS
A
- craniosacral
- some cranial nerves and parts of the sacral region of the spinal cord
- maintains a homeostatic environment
- “rest and digest” response
- parasympathetic activity is usually discrete and localized
11
Q
Generalizations
A
- most organs are innervated by both sympathetic and parasympathetic divisions
- most cranial and spinal nerves contain both somatic and autonomic axons
12
Q
Parasympathetic Division (CN’s and Sacral Components)
A
- cranial components are part of CN III (Oculomotor), VII (Facial), IX (Glossopharyngeal), and X (Vagus)
- sacral components from S2-S4 segments of the spinal cord
- pelvic splanchnic nerves are part of this division
13
Q
Pelvic Splanchnic Nerves
A
-branches off spinal cord going directly to organs
14
Q
Pathway for Axons
A
- Cell bodies of preganglionic motor neurons located in parts of certain cranial nerves, or in the sacral part of the spinal cord
- Preganglionic axons synapse in terminal ganglia which are located close to or on the organ being innervated
- Parasympathetic postganglionic axons travel from the terminal ganglia to the target organ
15
Q
Sympathetic Division: Components
A
- cell bodies of preganglionic motor neurons in lateral horns of T1-L2 segments of spinal cord (preganglionic axons exit to spinal nerve then go into the
- white rami
- sympathetic trunks
- gray rami
- splanchnic nerve
- prevertebral (collateral) ganglia
- sympathetic postganglionic axons
