Peripheral Nervous System Flashcards
How many cranial nerves are there?
12 pairs
Where do cranial nerves exit from?
Exit from base of brain
What are cranial nerves?
A path of communication from between brain and periphery
What are spinal nerves?
Path of coordination from spinal cord to periphery.
Parallel bundles of axons (and associated Neuroglial cells) wrapped in several layers of connective tissue
How many spinal nerves are there?
31 pairs
What do spinal nerves connect?
Connect spinal cord to receptors, muscles and glands all over the body
Where does the first spinal nerve emerge?
Emerges from spinal cord between base of skull and 1st cervical vertebrae (atlas)
Where do spinal nerves C1-C7 emerge?
Exit spine ABOVE corresponding cervical vertebrae
Where does spinal nerve C8 emerge?
Exits spine between C7-T1 vertebrae
Where do spinal nerves T1-L5 exit?
They exit spine BELOW corresponding vertebrae
Do all spinal nerves align with their corresponding vertebrae?
No - lumbar, sacral and coccyeal nerves descend from ~L2 to their respective levels
What is a nerve root?
Two bundles of axons that connect spinal nerve to spinal cord. Can be sensory or motor
What is Anterior (ventral) root?
a bundle of motor axons.
The pathway of motor neurons travels out
What is a posterior (dorsal) root?
A bundle of sensory axons
The pathway for sensory axons travels in
What is a posterior/ dorsal root ganglion?
A swelling in the posterior root containing cell bodies of sensory neurons (aka unipolar, afferent) of the PNS
