Spinal Cord/Nerves Flashcards
The spinal cord begins as a continuation of _____ (the most inferior portion of the brain stem) extending from the foramen magnum of the ____ bone to its termination as the ____ between L1 - L2
the medulla oblongata
occipital
conus medullaris
Three meninges, from outer to inner:
Dura Mater (only 1 layer, unlike brain dura mater)
Arachnoid mater
Pia Mater
The spinal meninges surround the spinal cord, and are continuous with the cranial meninges, which encircle the brain
Forms a sac from the level of the foramen magnum to the second sacral vertebra
Dura mater
____ between the dura mater and the wall of the vertebral canal contains a cushion of fat and connective tissue further cushioning the spinal cord
Epidural space
Between the dura mater and the arachnoid mater is the thin ____ space, which contains interstitial fluid
subdural
Contains blood vessels that supply oxygen and nutrients to the spinal cord
Pia mater
thin transparent connective tissue layer that adheres to the surface of the spinal cord and brain
Pia mater
Between the arachnoid mater and the pia mater is a space filled with cerebrospinal fluid called the ____
subarachnoid space
Membranous, thickened extensions of the pia mater that project laterally and fuse with arachnoid mater and inner surface of dura mater
Denticulate ligaments
Suspend the spinal cord within its dural sheath, protecting it against sudden displacement
Denticulate ligaments
Delicate strands of tissue emanating from the arachnoid mater
Arachnoid trabeculae
slide 9
Span the subarachnoid space, connecting the arachnoid and the pia
Arachnoid trabeculae
slide 9
In adults the spinal cord extends from the medulla oblongata to the superior border of the ___ lumbar vertebra
second
The ___ enlargement and ___ enlargement accommodate nerves to and from the upper and lower limbs, respectively
cervical
lumbar
Inferior to the lumbar enlargement the spinal cord tapers to a conical-shaped portion termed the ___, which in adults ends at the level of the IV disc between vertebrae L1 & L2
conus medullaris
The ___ is an extension of the pia mater that arises from the conus medullaris to anchor the spinal cord to the coccyx
filum terminale
Nerves that arise from the inferior part of the spinal cord do not immediately leave the vertebral column, but rather continue in the vertebral canal in fine strands collectively termed the ___
cauda equina
___ are the paths of communication between the spinal cord and the nerves innervating specific regions of the body
Spinal nerves
Two bundles of axons connect each spinal nerve to a segment of the cord. Each bundle is called a root, which in turn is composed of smaller bundles of axons called ___
rootlets
The roots are posterior (or dorsal) root and anterior (or ventral) root
Each posterior root has a swelling, the posterior (dorsal) root ganglion, which contains the cell bodies of ___ neurons
sensory
The ___ root and rootlets contain axons of motor neurons, which conduct nerve impulses from the CNS to effectors (muscles and glands)
anterior (ventral)
The gray matter of the spinal cord is shaped like the letter H, or a butterfly, and is surrounded by white matter. The gray ___ forms the crossbar of the H.
commissure
Anterior horns contain cell bodies of somatic ___ neurons and ___ nuclei that provide nerve impulses for the contraction of skeletal muscles.
motor
___ gray horns contain somatic and autonomic sensory nuclei. The gray commissure connects gray matter of the right and left sides.
Posterior