Chapter 10 Flash Cards
What are the structures that protect the spinal cord?
vertebral column, vertebral ligaments, meninges, and CSF.
What is the outermost layer of the meninges called? tough and dense.
dura mater.
What is the space between the dura mater and vertebral column?
epidural space
What is the middle layer of meninges, whose arrangements of collagen and elastic fibers resembles a spider web called?
arachnoid mater
the inner layer of the meninges, that is thin and delicate and adheres to the surface of spinal cord and brain is called what?
Pia matter
what is the space where CSF circulates that is between the arachnoid and pia mater called?
subarachnoid space.
where does the spinal cord extend to and from?
lowest part of brain, the medulla oblongata to the upper border of the L2.
what are the two grooves that divide the spinal cord into two hemispheres?
anterior median fissure
posterior median sulcus.
this space is filled with CSF and is located in the center of the gray matter
Central canal
how many pairs of spinal nerves
31
What are the two bundles of axons that connect each spinal nerve to a segment of cord called
roots
this root contains only sensory axons, which conduct nerve impusles from sensory receptors in the skin, muscles, and internal organs into the CNS.
Posterior (dorsal) root
what is the swelling that contains the cell bodies of sensory neurons of the posterior root called?
posterior root ganglion
what does the anterior root of the spinal nerves contain?
axons and motor neurons (autonomic and somatic) which conduct never impulses from the CNS to the effectors.
major function of white matter
has tracts that serve as highways for never impulses.
major function of gray matter
receives and integrates incoming and outgoing information is a site for integration reflexes.
what is contained in the gray matter
cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia
how is the gray matter divided?
subdivided into left and right regions called horns. named relative to their location.
what does the posterior horn contain?
cell bodies and axons of interneurons as well as axons of incoming sensory neurons
what does the anterior (ventral) horn contain
cell bodies of somatic motor neurons that provide impulses for contraction of muscles.
what does the lateral gray horn contain
is only present in the thoracic and upper lumbar segments and contain cell bodies of autonomic motor neurons that regulate the cardiac muscle, smooth muscle, and glands.
What does white matter consist of?
myelinated axons and is organized into columns
each column of the white matter contains one or more ______________ which are bundles of axons
tracts
sensory (ascending) tracts, consist of what
axons that conduct nerve impulses toward the brain.
e.g spinothalamic tract
motor (descending) tracts consist of what?
axons that conduct nerve impulses away from the brain
e.g. corticospinal tract
these are fast involuntary sequences of actions in response to stimuli and they can be simple or complex.
reflexes
if a integration of a reflex occurs in the spinal cord gray matter, what is the reflex called
spinal reflex.
e.g. patellar reflex.
Which nervous system are spinal nerves a part of?
the peripheral nervous system
name the distribution of the 31 pairs of spinal nerves according to the vertebral column from which they emerge.(number of spinal nerves in each section)
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccyx
how are the spinal nerves connected to the spinal cord
by the anterior (motor) and posterior (sensory) root.
sensory information goes through which root
the dorsal root
motor information goes through which root
anterior
what are the layers of connective tissue protective coverings
individual axons wrapped in endoneurium
groups of axons in bundles called fascicles
fascicles wrapped in perineurium
the superficial covering over the entire nerve is called what
epineurium
what is the network of spinal nerve branches and adjacent nerves called?
plexuses
this plexus supplies posterior head, neck, upper part of the shoulder and the diaphragm
cervical plexus
this plexus supplies to the upper limbs, some neck and shoulder muscles
brachial plexus
this plexus supplies the abdominal wall, external genitals and parts of the lower limbs
lumbar plexus