chapter 13 spinal cord and spinal nerves
what divides the spinal cord partially into right and left sides?
anterior median fissure and posterior median sulcus
where are the motor neurons?
anterior/ventral
_____ mater is thin and wispy
arachnoid
what is in the center of the spinal cord
central canal
what runs the length of the spinal cord
central canal
in pia mater, what is the subarachnoid space filled with? (that separates it from the arachnoid mater)
cerebrospinal fluid
what enlargements foes the spinal cord contain?
cervical and lumbar
which root of the spinal never is responsible for motor neurons leaving the spinal cord?
ventral
how many pairs or coccygeal nerves
1
how many pairs of thoracic
12
how many pairs of spinal nerves are there
31
there are ___ parts of the spinal nevers
31
how many pairs of lumbar
5
how many pairs of sacral
5
how many pairs or cervical
8
what are the three components of meninges?
dura, arachnoid, pia (mater)
how are spinal cords named and numbered
according to the region and level of the spinal cord from which they emerge
the epidural space is the site of epidural ______ injections
anesthesia
in the spinal cord of gray matter, what type of horn does the below describe? cell bodies of the somatic nervous system
anterior
in the spinal cord of gray matter, what type of horn does the below describe? voluntary
anterior
where does the spinal cord begin
as a continuation of the medulla oblingata
where does the spinal cord end in an adult?
at the second lumbar vertebra
in the spinal cord of gray matter, the lateral horn is in the _____ nervous system; whereas, the anterior horn is in the ______
autonomic, somatic
epidural space is filled with what three things?
blood vessels, loose connective tisse and fat
what is the spinal cord protected by?
bony vertebrae, meninges
meninges is continuous with the meninges of the ____
brain
a short distance from the spinal cord is where spinal nerves ___, this ____ are called rami
branch, branches,
how does the spinal cord convey sensory and motor information ?
by way of the ascending and descending tracts
what is the tapered inferior portion of the spinal cord?
conus medullar
what are spinal nerves formed by?
convergence of dorsal and ventral roots, a mixed neerve
section of the spinal cord
cross (figure 13.3 p, 424)
in the spinal cord of gray matter, what type of horn does the below describe? involuntary
lateral
what type of reflex is associated with the withdrawal reflex, contrelateral collateral branches of the sensory neurons cross over to the other side of the cord & synapse with interneurons that excite the extensors of the opposite limb - allows the weight to be shifted to the opposite leg ( for example)
crossed extensor
what type of ligaments are extensions of the pia to the dura, which suspend the spinal cord within the vertebral column
denticulate
____ is the area of skin supplied with sensory innervation by a pair of spinal nerves
dermatome
which root of the spinal cord contains sensory bodies?
dorsal root ganglion
___ mater is the toughest, most superficial
dura
what are the name of the three meninges?
dura, arachnoid, pia
what are the 3 connective tissue of the nerves?
endonerirem, perineureum, epineureum
what type of connective tissue of nerves does the below describe? covers a single myelinated axon
endoneureum
what are the three connective tissue coverings associated with spinal nerves?
endoneurium, perineurium, epineruium (endo, peri, epi)
what is the dura mater separated from the periosteum of the vertebrae by?
epidural space
what type of connective tissue of nerves does the below describe? covers a bundle of fascicles (the entire nerve)
epineureum
the 31 pairs of spinal nerves are named for the location of ___ from the spinal cord
exit
what arises from the tapered inferior portion of the spinal cord?
filum terminale and cauda equina
the spinal cord extends from the ___ ___ to the ___ _____
foramen magnum, L2 vertebrae
what type of reflex detects muscle tension , protects muscle & tendon from damage by too much tension, ipselateral
golgi tendon
in the spinal cord, what type of matter does the below describe? unmyelinated axons , dendrites & cell bodies
gray
what is the gray matter in the spinal cord divided into?
horns
in the spinal cord of gray matter, what type of horn does the below describe? cell bodies of the autonomic nervous sysem
lateral
Golgi tendon organs detect muscle tension -> send APs to inhibirotry _____ in the spinal cord -> inhibit ____ neurons to the muscle -> muscle relaxes, prevents muscle damage
interneurons, motor
in the arachnoid mater, the subdural space separating it from the dura is filled with ______ fluid
intestinal
in the gray matter of the spinal cord, the lateral horn is _____; whereas, the anterior horn is ____
involuntary, voluntary
muscle spindle detects the amount of stretch --> sends APs to the spinal cord & synapses with motor neurons that contract the muscle (ex. ___-___ reflex)
knee jerk
what is dura mater separated from?
the periosteum of the vertbrae
what is the connective tissue covering the spinal cord?
mengines
since all spinal nerves contain sensory and motor axons they are
mixed nerves
stretch reflex: muscle spindle detects the amount of stretch --> sends APs to the spinal cord & synapses with _____ neurons that contract the muscle
motor
the anterior horn is also known as the ___ horn
motor
what type of connective tissue of nerves does the below describe? covers a small bundle of axons (fascile)
perineureum
Spinal nerves & their branches - part of the ______ nervous system
peripheral
__ mater contains blood vessels
pia
___ mater adheres to the spinal cord
pia
some rami converge with other rami to make a ____
plexus
what do the cervical and lumbar enlargements serve as in the spinal cord?
points of orgin for nerves to limbs
in the spinal cord of gray matter, what type of horn does the below describe? sensory input
posteior
what two roots do the spinal nerves connect to each segment of the spinal cord by?
posterior or dorsal / anterior or ventral
branches of the spinal nerve include
posterior ramus, anterior ramus, meningeal branch, rami communications
how are spinal nerves typically connected with the spinal cord?
posterior root and an anterior root
what are the three horns of gray matter in the spinal cord?
posterior, lateral, anterior
where are the sensory axons
posterior/dorsal
All the reflexes involve ____ ______ - inhibition of antagonistic muscles so they do not contract
reciprocal innervation
inhibition of antagonistic muscles so they do not contract
reciprocal innervation
____ __ is the smallest portion of the nervous system that can receive a stimulus and respond to it
reflex arc
involves sensory receptor, sensory neuron, integrating center (CNS) , motor neuron, effector organ
reflex arc
_____ are homeostatic, can be modified by high brain centers
refluxes
arachnoid mater
right under the dura mater, literally right below it, kind of like an envelope
peripheral nerves consist of ______ cells, ____, and ______ tissue
schawnn, axons, connective
dorsal root of spinal nerve
sensory axons (dorsal root ganglion contains sensory cell bodies)
Spinal nerves formed by convergence of dorsal & ventral roots , a mixed nerve (carries both ____ and _____ information)
sensory, motor
all spinal nerves contain both ____ and ____ axons
sensory, motor
the dorsal root and ventral root converge to form a ___ ___
spinal nerve
stretch reflex: muscle ___ detects the amount of stretch
spindle
____ reflex helps maintain posture; detects the amount of stretch of a muscle, ipselateral
strech
pia mater is sepereated from anachnoid mater by the ______ space
subarachnoid
arachnoid mater is repeated by the dura by the ______ space
subdural
what is the function of the meninges,
they are coverings that continuously run around the spinal cord and brain
what is the spinal cord protected by?
vertebral column, the meninges, cerebrospinal fluid, and denticulate (veronica's mom can dance)
in the spinal cord, what type of matter does the below describe? myelinated axons of ascending and descending pathways in the spinal cord
white
what is the white matter in the spinal cord divided into?
white columns
Pain receptors send APs to the spinal cord -> excite motor neurons to the flexor muscles, flexors contract resulting in _______ of the limb from painful stimulus
withdrawal
what type of reflex removes a body part from painful stimulus, ipselateral?
withdrawal (flexor)