Spinal Cord Flashcards
Cervical Level
7 Vertebrae
8 spinal nerves
Thoracic Level
Twelve vertebrae and spinal nerves
Lumbar Level
Five vertebrae and spinal nerves
Sacral and Coccygeal levels
Five spinal nerves each
The ________ vertebrae are the most fragile
Cervical
Vertebral levels of greatest mobility
C1 - 2
C5 - 6
T12 - L1
Epidural space contains:
Venous plexus
Dura Mater
the outermost covering of spinal cord
forms a layer under the dura and extends
trabeculae to the pia mater
Arachnoid
intimate with the cord
Forms the denticulate ligaments
Pia Mater
This fills the subarachnoid space
Cerebrospinal Fluid
Anchoring cord of denticulate ligaments
Denticulate ligaments extend from the cord through the arachnoid to the dura
Spinal nerves also anchor the cord in the vertebral canal
the caudal cone-shaped end of the
spinal cord. It extends to the L1 - L2 interspace
Conus Medullaris
consists of the pia and arachnoid that
extend from the conus medullaris to the coccyx (tail bone)
Filum Terminale
consists of posterior and
anterior roots and occupies the lumbar cistern
The Cauda Equina (horse’s tail)
Posterior Root
carries sensory signals toward the
cord. A posterior root ganglion is found along the
posterior root. It contains the neuron cell bodies of
the nerve fibers that make up the posterior root.
carries motor signals away from
the cord
Anterior Root
_________ ________ of the spinal nerve serves the posterior aspect of the body and contains both posterior and anterior root fibers
Posterior Ramus
__________ ________ of the spinal nerve serves the anterior aspect of the body and contains both posterior and anterior root fibers
Anterior Ramus
contain autonomic fibers and branch off the spinal nerve at levels T1-L2
Gray and White communicating rami
Internally the cord consists of:
Gray matter which is made up of neuron cell bodies
White matter which is made up of myelinated axons
Externally the cord is subdivided into regions by:
longitudinal grooves called sulci or fissures. A
fissure is a deep sulcus
Early in development the cord extended __________________________________. At that time spinal nerves grew out between vertebrae to connect the cord with ____________ ___________.
the entire length of the vertebral canal; peripheral structures
Later in development the cord stopped growing but ___________________________________. As a result the cord was drawn cranially within the
vertebral canal but the nerves persisted in exiting the canal through_________________.
the vertebral column continued to grow larger; the original foramina
The caudal end of the cord in the adult corresponds with
the L1 - L2 interspace of the vertebral column
Gray matter consists of
Nerve cell bodies and dendrites
T or F: There is myelin in gray matter
False
Lipophilic stains are attracted to lipid and stain the myelin dark. As a result, in stained tissue the:
White matter is dark, Gray matter is light
consists of the fibers that make
up the white matter that lies between the two
posterolateral sulci
Posterior Funiculus
consists of the fibers that make up the
white matter that lies between the posterolateral
sulcus and the anterolateral sulcus.
Lateral Funiculus
consists of the fibers that make
up the white matter that lies between the two
anterolateral sulci
Anterior Funiculus
receives incoming sensory messages
Posterior Horn
consists of motor neurons of the
autonomic nervous system
Lateral Horn
consists of motor neurons of the
somatic nervous system
Anterior Horn
consists of sensory fibers from the upper extremities which begin to enter at level
T-6. This cross-section must be above T-6.
Fasciculus Cuneatus
The lateral horn is seen only between
Levels T1-L2
Lamina I
relays sensory signals
Lamina II
Substantia Gelatinosa (important in pain)
Lamina V
relays sensory signals
Annulus fibrosus
Fibers weaken and rupture
Nucleus pulposus
remnant of the notochord
The nucleus herniates through the break in the annulus fibrosus and
puts pressure on nearby nerves
Cervical Spondylosis
Bony ridges (osteophytes) on the vertebral bodies cause a narrowing of the intervertebral foramina
