Autonomic Nervous System Flashcards
Sensory, ___ neurons conduct signals ___ CNS
Afferent, to the CNS
Motor, ___ neurons conduct signals ___ CNS
Efferent, away from CNS
What is the basis of feedback regulation
Nerves contain both sensory and motor functions
Somatic efferent neurons
Supply voluntary muscles
Visceral efferent neurons
Supply involuntary smooth muscle and blood vessels
How many somatic motor neurons span from the CNS to the structure that they innervate
One
What is the peripheral motor part of the autonomic nervous system
Visceral efferent system
What is different about the visceral nervous system from the somatic nervous system
The visceral has a second motor neuron interposed between the CNS and the innervated structure
What connects the two nerves of the visceral motor neurons as they span from the CNS to their innervated structure
Ganglion
Ganglion definition
Collection of neuronal cell bodies located outside the CNS
Groups of neuronal cell bodies located in the CNS
Nuclei
Preganglionic neuron vs postganglionic
Referring to the two neurons of the visceral efferent system on their way to a structure, pre is the one with its cell body in the CNS, post is the one with the cell body as the ganglion
What occurs when a preganglionic axon meets a post ganglionic
Synapse
2 divisions of the autonomic/visceral motor neuron nervous system
Sympathetic and parasympathetic
Where are the preganglionic cell bodies located in the sympathetic nervous system
The segments of the spinal cord from the 1st T to 5th L vertebrae (thoracolumbar portion)
What is released at the postganglionic nerve endings of those of the sympathetic autonomic nervous system
Norepinephrine
Where are the preganglionic cell bodies of the parasympathetic nervous system located
In nuclei in the brain stem associated with cranial nerves III, VII, IX, X and in the 3 S segments of the vertebrae (craniosacral portion)
What is different about the postganglionic cell bodies of the neurons of the sympathetic vs parasympathetic nervous system
Sym: ganglion are usually only a short distance from the spinal cord
Parasym: ganglion are really close to the structure that is being innervated
What is released at the postganglionic nerve endings of those of the parasympathetic autonomic nervous system
Acetylcholine
Somatic afferent neurons innervate…
Cutaneous surface, striated muscle, tendons, joints, eye and inner ear
Visceral afferent neurons innervate…
Muscosal surface of organs, exocrine glands and vascular structures
Differences between sensory afferent and motor efferent
- All neurons in afferent have only one (no ganglion)
2. No synapses in afferent (synapse is the CNS)
The ventral roots of the spinal cord segments contain the axons of the ___ neurons
Motor
The dorsal roots of the spinal cord segments contain the axons of the ___ neurons
Sensory
Where do the ventral and dorsal roots of spinal nerves unit to form one spinal nerve
At the level of the intervertebral foramen
What joins the spinal nerve to the sympathetic trunk
Ramus communicans
What is found at each location where a ramus joins the sympathetic trunk
Ganglion (called sympathetic trunk ganglion)
What nerves leave the caudal thoracic and lumbar portion of the sympathetic trunk
Splanchnic (course into abdominal cavity)
Each preganglionic sympathetic axon must pass through ___ of its spinal nerve to reach the sympathetic trunk
Ramus communicans
The ramus communicans of T1 to L5 contains…
Both preganglionic and postganlionic axons
Where is the cervicothoracic ganglion located
Medial to the dorsal end of the 1st intercostal space on the lateral side of longus colli
What is the function of the brachial plexus
Provides a pathway for postganglionic axons to reach the thoracic limb
What spinal nerves contribute to the formation of the brachial plexus
1-2T, 7-8C
Vertebral nerve
A branch of the cervicothoracic ganglion that follows the vertebral artery through the transverse foramina
Ansa subclavia
Goes around subclavian artery, connects middle cervical ganglion and cervicothoracic ganglion
The ventral vagal trunk is found…
On the esophagus
The dorsal vagal trunk if found…
Near the diaphragm (dorsal to esophagus)
What divides the thoracic and lumbar regions of the thoracolumbar nervous system
Major splanchnic nerve
What vertebrae do the sympathetic nerves arise from
T1 to L4/5
What vertebrae/nerves do parasympathetic nerves arise from
Cranial nerves 3, 7, 9 and 10; S1-3 vertebrae
