Intro to the Nervous System Flashcards
Is white matter myelinated, or unmyelinated?
Myelinated
What type of information do nerves in the ventral roots carry? What about dorsal roots? What makes up a spinal nerve?
Dorsal roots carry sensory information
Ventral roots are motor
Spinal nerves are mixed; roots have come together
Sympathetic nerve cell bodies are found in the ______ _____ of spinal segments ____ to ____.
Sympathetic nerve cell bodies are found in the lateral horn of spinal segments T1-L2 (hence the name thoracolumbar)
The spinal cord ends at what vertebral level? What is the tip of the spinal cord called?
L1/L2. Tip is called the conus medullaris
Autonomic motor neurons supply what three things? How many nerves are involved in an autonomic pathway?
Cardiac muscle, smooth muscle, glands. There are two nerves in the autonomic pathway.
From where do parasympathetic preganglionic fibers arise?
CN nerves III, VII, IX, and X
Which parasympathetic nerves innervate the digestive tract?
Vagus innervates the gut down to the left colic flexure, and the pelvic splanchnic (S2-4) does the rest
Which neurotransmitter is used by pre- and post-ganglionic parasympathetic nerves? What about sympathetic nerves?
Parasympathetic nerves use Ach at both neurons
Sympathetic uses Ach at the first and NE at the second (except for sweat glands that use Ach)
Where do parasympathetic preganglionic synapses happen?
In the parasympathetic ganglia in the head or in intramural ganglia of thoracic and abdominal viscera
Where are postganglionic sympathetic neuronal cell bodies found?
In the chain ganglia/sympathetic trunk
Where are cell bodies that carry visceral afferents following sympathetics found? What info do they carry?
They are found in the dorsal root ganglia from T1-L2 and carry visceral pain info
Where are the cell bodies carrying visceral afferents that follow parasympathetics found?
They are located in the spinal ganglia associated with S2-S4 spinal nerves and in the sensory ganglia of the vagus nerve (CN X) near the base of the skull
What is the basis for referred visceral pain?
Visceral afferents end in a segmental level of the spinal cord that also receives somatic afferents
Where do preganglionic sympathetic fibers that ultimately innervate a thoracic organ synapse? What about preganglionic sympathetic synapses that ultimately innervate an abdominal organ?
Sympathetic preganglionic synapses to a thoracic organ happen at paravertebral ganglion.
Sympathetic preganglionic synapses to an abdominal organ happen at prevertebral ganglion (preaortic).
