Spinal Cord Flashcards
Where does the spinal cord end?
Between L1 and L2 for adults, L2 and L3 for newborns.
Where does the spinal cord begin?
The medulla
What is the end of the spinal cord called?
Conus Medullaris
Where is the cervical enlargement and what does it supply?
C4-T1, it supplies the spinal nerves to form the brachial plexus.
Where is the lumbosacral (lumbar) enlargement and what does it supply?
L1-S3, the anterior rami of the spinal nerves for the sacral plexus.
What is the bundle of spinal nerve roots running through the lumbar cistern (subarachnoid space)?
Cauda equina (Looks like a horses tail)
How many pairs of spinal nerves are there?
31; 8 Cervical, 12 Thoracic, 5 Lumbar, 5 Sacral, 1 coccygeal.
What nerve roots contain sensory (afferent) fibers?
Posterior/Dorsal
What nerve roots contain motor (efferent) fibers?
Anterior/Ventral
What is the filum terminale?
Serves as an anchor for the end of the dural sac, consists mostly pia matter, contains connective tissue, neuroglial tissue.
What is the outmost layer of the spinal cord?
Dura Matter; tough, fibrous, and some elastic tissue.
What is the spinal dural sac?
A long tubular sheath within the vertebral canal.
What is spinal arachnoid mater?
It is a delicate, avascular membrane composed of fibrous and elastic tissue that lines the dural sac and the dural root sheaths, it also encloses the CSF filled subarachnoid space. It is NOT attached to the dura but is held against the surface of the dura from the pressure of the CSF.
What are arachnoid trabeculae?
Delicate strands of connective tissue that span the subarachnoid space connecting the arachnoid and pia mater. CSF sits in this space.
What are denticulate ligaments?
sawtooth like ligaments that run longitudinally along each side of the spinal cord that holds the spinal cord to the dural sac.
What is the foramen magnum?
The bottom part of the skull where the spinal cord comes out.
What is the enlargement of the subarachnoid space in the dural sac, caudal to the conus medullaris, that contains CSF and the cauda equina?
Lumbar cistern
What are the three longitudinal arteries that supply the spinal cord?
1 Anterior spinal artery, 2 posterior spinal arteries.
What are neurons?
structural and functional units of the nervous system specialized for rapid communication. It is composed of a cell body with dendrites (extensions) and an axon which carries impulses away from the body.
What is myelin?
layers of lipid and protein substances that form a myelin sheath around some axons, this greatly increases the velocity of impulse conduction.
How do neurons communicate with each other?
through synapses or points of contact between neurons via neurotransmitters.
What is neuroglia (glial cells or glia)?
nonneuronal, nonexcitable cells that form a major component (scaffolding) of nervous tissue. They support, insulate, and nourish the neurons.
What is a tract?
A bundle of nerve fibers (axons) connecting neighboring or distant nuclei of the CNS.
What is gray matter?
Nervous tissue composed of nerve cell bodies.
