Autonomic and Somatic Nervous Systems - Efferent Neural Function Flashcards
Any nervous tissue located outside of the brain and spinal cord
Peripheral Nervous System
Functions of PNS
Sensing the environment, activating tissue/organ responses
The 2 divisions of PNS are…
Somatic (muscles and movement) and Autonomic (internal organs)
A bundle of neuron axons in the PNS
Nerve (cranial and spinal)
A grouping of nerve cell bodies in the PNS
Ganglion
How many pairs of cranial nerves?
12
Name a cranial nerve that is sensory (axons bring message to brain from body).
Optic – function is vision; neurons from retina
-Arises from diencephalon
Name a cranial nerve that is motor (axons bring message away from brain/spinal cord).
Hypoglossal – function is motor to muscles of tongue
-Arises from medulla
Name a cranial nerve that is mixed (some neurons from the CNS, some to the CNS).
Facial – Sensory to tongue/mouth and Motor to salivary glands, facial expression muscles
function sensory (taste) to rostral 2/3rds of tongue; parasympathetic to salivary and lacrimal glands; motor to muscles of facial expression
Spinal Nerves
- Sensory and motor (leave through ventral root) from the spinal cord.
- ALL spinal nerves are MIXED
- Location implies function
Somatic Nervous System
- motor info to muscles
- one neuron between spinal cord and muscle
- no synapse until you get to target tissue (neuromuscular junction)
- NT = acetylcholine
- Always excitory
What effector cells are innervated in the somatic? How many neurons in a “motor response”?
Skeletal muscle
1 neuron with the cell body in the grey matter
What effector cells are innervated in the autonomic? How many neurons in a “motor response”?
Smooth muscle, visceral tissues
2 neurons with a synapse in the periphery (in a ganglion)
In the spinal nerves, sensory always…
Enter through dorsal root (horn) ONLY
In the spinal nerves, motor always…
Leave through ventral root (horn) ONLY
The Autonomic can be…
Excitory or inhibitory
Autonomic Nervous System divided into…
Sympathetic
Enteric
Parasympathetic
SHORT pre-ganglionic axon, LONG post-ganglionic axon
Thoracolumbar: region of the spinal cord where the ganglion (synapse) is
Sympathetic
LONG pre-ganglionic neuron, SHORT post-ganglionic neuron
Craniosacral: region of spinal cord where the ganglion (synapse) is
Parasympathetic
Sympathetic
- ) Function
- ) Types of receptors
- ) Location of synapse
- ) Length of axons
- ) Fight or Flight
- ) Mainly adrenergic
- ) Thoracolumbar
- ) Short pre-ganglionic neuron
Parasympathetic
- ) Function
- ) Types of receptors
- ) Location of synapse
- ) Length of axons
- ) Rest and digest
- ) Mainly cholinergic
- ) Craniosacral
- ) Short post-ganglionic neuron
With regards to spinal nerves, the sensory neurons enter the spinal cord through the __________ horn and motor neurons leave the spinal cord through the _________ horn
Sensory - dorsal
Motor - ventral
T or F: There is a single neuron that travels from the spinal cord to the target tissue
True
T or F: The neurotransmitter used at the target tissue is acetylcholine
True
T or F: Target tissues of the somatic nervous system include internal organs and smooth
muscle
False
T or F: Neurons in the somatic nervous system always have an excitory effect on the target
tissue
True
When this branch of the autonomic nervous system is activated, effects include an
increase in heart rate and a decrease in digestive function
Sympathetic
The motor portion of the sympathetic nervous system has two neurons: the axon of the
pre-ganglionic neuron is relatively _______ and the axon of the post-ganglionic neuron is
relatively_______.
Short, long
What neurotransmitter is released from the post-ganglionic neurons in the
parasympathetic nervous system?
Acetylcholine
