Spinal Cord Flashcards
How many spinal nerves are there?
31
Where do the spinal nerves exit the vertebral column?
Intervertebral and sacral foramina
What comprises spinal nerves?
Bundles of axons, Schwann cells, and connective tissue sheaths.
Cervical enlargement
the location where nerves fibers of upper limbs enter and leave the spinal cord
Lumbosacral enlargement
where nerve fibers exit the spinal cord to supply the lower limbs
Conus medullaris
the tapered part of the spinal cord inferior to the lumbosacral enlargement
Cauda equina
Roots of spinal nerves extending from the lumbosacral enlargement and conus medullaris
Meninges
Connective tissue membranes that surround the spinal cord and brain
Dura mater
The most superficial and thickest membrane of the meninges
Thecal Sac
A sac formed by the dura mater that surrounds the spinal cord
Epidural space
A space between the vertebral canal and dura mater that contains spinal nerve roots, blood vessels, areolar connective tissue, and adipose tissue.
Epidural anesthesia
anesthetic injected into epidural space of spinal cord for women during childbirth
Arachnoid mater
Next deepest meningeal membrane. Thin, whispy
Subdural space
A small space between the arachnoid mater and dura mater.
Contains a small amount of serous fluid
Pia mater
the third, deepest meningeal layer which is bound tightly to the surface of the spinal cord.
What holds the spinal cord in place of the thecal sac?
Denticulate ligaments
Filum terminale
subarachnoid space
The space between the arachnoid mater and the pia mater
What is contained the in subarachnoid space? (3)
weblike strands of arachnoid mater,
blood vessels, and
cerebrospinal fluid.
Spinal anesthesia
Drugs that block action potential transmission are inserted into the subarachnoid space.
Prevent pain sensations in the lower half of the body.
Introduced at L3/L4 of L4/L5 vertebra because spinal cord doesn’t extend as long as the vertebral column.
Lumbar puncture (spinal tap)
removal of CSF from subarachnoid space to examine it for infection
Myelogram
a radiograph of the spinal cord
Which two deep clefts partially separate the two halves of the spinal cord?
Anterior median fissure
Posterior median sulcus
What are the names of three columns of spinal cord white matter?
Ventral
Dorsal
Lateral
What is the subdivision of the columns of the spinal cord called? (3 names)
Tracts or fascicles referred to sometimes as pathways.
A tract vs. a nerve?
A tract - collection of axons inside the CNS
A nerve - a collection of axons outside the CNS
What are the three horns that organize the central gray matter of the spinal cord?
Posterior horn -
Anterior horns - cell bodies of multipolar somatic motor neurons
Lateral horns - autonomic motor neuron cell bodies
What connects the two halves of the spinal cord?
Gray and white commissures
What structure circulates CSF associated with the ventricular system?
The central canal
What types of axons do dorsal roots contain?
Sensory, which are pseudo-unipolar
What types of axons do ventral roots contain?
Motor, which innervate muscles and glands.
Where are the cell bodies of the motor neurons located?
Spinal cord gray matter
