Spinal Cord Flashcards
Spinal Cord Location
Rests within Vertebral Canal
From Foramem Magnum to L1 Vertebra
Cervical Enlargement
Contains neurons that innervate upper limb
Lumbar Enlargement
Contains neurons that innervate lower limb
Conus Medullaris
Pointed end of Spinal Cord
Cauda Equina
Collection of nerve roots coming off of conus medullaris
Filum Terminale
Thin strand of pia mater that anchors canus medullaris to coccyx
How many pairs of nerves in Cervical?
8
How many pairs of nerve in Thoracic?
12
How many pairs of nerves in Lumbar?
5
How many pairs of nerves in Sacral?
5
How many pairs of nerves in Coccygeal?
1
What is a nerve?
Typically is a structure you can see with the naked eye (macroscopic)
In contract, an axon is MICROscopic.
Also formed from may axons bundled together in connective tissue wrappings
Epidural Space Description
Space between Dura Mater and Vertebra. It is filled with fat and blood vessels
Dura Mater
*Superficial
Contains Dense CT, “Tough Mother”
Arachnoid Mater
*Middle Structure
Thin, Spider-Web like membrane
Subarachnoid Space
Space between arachnoid and pia mater
Filled with CSF
Pia Mater
*Deep
Thin layer of CT. “Delicate Mother” and adheres to the spinal cord
Central Canal
Space within gray matter of spinal cord
Lined with Ependymal Cells and Contains CSF
Spinal Cord Divisions
Divided into an inner gray matter and an outer white matter
Gray Matter
Contains Nerve Cell Bodies of Somatic Motor Neurons
Anterior (Ventral) Horns
Cell bodies of somatic motor neurons
Innervate skeletal Muscle
Lateral Horns
Cell bodies of autonomic motor Neurons
Prominent only in T1-L2 Regions
Innervate Cardiac Muscle, Smooth Muscles, Glands
Posterior (Dorsal) Horns
Interneurons and axons of sensory neurons
Gray Commissure
Unmyelinated Axons crossing from one side to another and contains a central canal
White Matter
Bundles of Myelinated Axons. Contains ascending and descending spinal cord tracts
Anterior Funiculi
Space between anterior gray horns and anterior median fissure
Lateral Funiculi
White region on lateral side
Posterior Funiculi
Between posterior gray horns on posterior side and posterior median sulcus
Spinal Cord Tracts Definition
Bundles of axons that run in the white matter of the spinal cord. Each funiculus contains both ascending and descending tracts.
Tracts given names according to starting and ending points
Ascending Tracts
Sensory Axons, go from body TO brain
Descending Tracts
Motor Axons; from brain TO body
How many pairs of spinal nerves?
31
Spinal Nerve Formation
Anterior Root: Axons of Motor Neurons
Posterior Root: Axon of Sensory Neurons
*Posterior Root Ganglion: Attached to posterior root, contains cell bodies of sensory neurons
