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60 terms

A&P Lab Spinal Cord and Spinal Nerves

Johnson Anatomy Lab 2
STUDY
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axons going to and from the spinal cord are bundled as
nerves
spinal chord begins as the _____ _____ exits the skull and enters the ____ ____ of the 1st cervical vertebra (C1)
medulla oblongata vertebral foramen
spinal chord travels within successive vertebral foramina, a passage called the _____ _____
vertebral canal
the end of the spinal chord is found at the _____ vertebra in adults
L1
cone-shaped termination of the spinal cord is the ____ ____
conus medularis
spinal cord has a ____ ____ in the region of the upper limb
cervical enlargement
spinal cord has a _____ _____ in the region of the lower limb
lumbar enlargement
_____ _____ formed from the "segments" of the spinal cord and exit the vertebral column through the _____ _____
spinal nerves intervertebral foramina
bundle of spinal nerves that pass through the vertebral canal on their way to the appropriate intervertebral foramen
cauda equina
within cauda equina lies the ____ ____, an extension of the pia mater
filum terminale
vertebral column is composed of __ certvical, __ thoracic, ___ lumbar, ___ fused sacral, and __-__ fused coccygeal vertebrae
7 12 5 5 3 5
___ vertebral levels, each containing muscles, skin, and bones; neurons that supply instruction to/form these levels travel within ____ _____
32 spinal nerves
each of the bodies segments is supplied by a different ____ ____
spinal nerve
outermost and toughest layer that protects the spinal cord
dura mater
unlike the brain, the duramater is surrounded by a space filled with fat, the ___ ___
epidural space
dura mater extends outward around the spinal nerves and becomes known as the ____, the outermost layer of a nerve
epineurium
deep to the dura, the ____ ____ and ___ ___ can be identified
arachnoid mater subarachnoid space
deepest meningal layer in direct contact with the spinal cord
pia mater
pia mater has at least 20 pairs of lateral projections called ____ ____ that anchor the spinal cord to the dura mater and limit the movement of the cord
denticulate ligaments
as the spinal cord comes to an end at the conus medularis, the pia mater continues a thin threat the anchors the end of the spinal chord to the sacrum
filum terminale
_____ ___ anchors the end of the spinal chord to the ______
filum terminale sacrum
outer region of the spinal cord; consists of myelinated axons that are oriented vertically to communicate with higher and lower regions of the CNS
white matter
____ ____ lies internal to the white matter and contains unmyelinated neurons of the CNS and interneurons; also portions of sensory neurons and motor neurons reside within
gray matter
gray matter is organized into 3 columns; the ______, ________, and _____ horns
dorsal ventral lateral
located at the center of the spinal chord; cavity in continuity with the ventricles of the brain
central canal
systems of neurons that bring info up to the brain are called ____ ____; travels along 3 neurons considered 1st, 2nd, and 3rd order neurons
ascending pathways
(ascending) ___ order sensory neuron extends form the source of the stimulus to the _____ horn where it synapses with ______
first dorsal interneurons
(ascending) ____ order ____ extends from the dorsal horn, decussates (crosses) to the ______ (opposite) side, and then it's axon enters the white matter; the axon then runs up to the ____ where it synapses
second interneuron contralateral thalamus
(ascending) ____ order _____ extends form the thalamus to the appropriate part of the somatosensory cortex
third interneuron
(descending) ____ _____ neuron aka pyramidal neuron originates in the ____ ____ _____
upper motor primary motor cortex
(desending) primary motor cortex --> white matter via upper motor interneuorn --> decussation occurs in the ____ --> tract continues down spinal chord --> at appropriate signal level axon leaves tract and enters the _____ ______ where it synapses with lower motor neuron
medulla ventral horn
_____ ____ neuron of the peripheral nervous system;leaves the spinal cord to innervate skeletal muscles
lower motor
spinal nerve forms from the joining of two major tributaries, the _____ and _____ roots
dorsal ventral
carries sensory info to the dorsal horn of the spinal cord; has a large collection of cell bodies that form the ____ ____ ____
dorsal root ganglion
____ neurons are unique in having the cell body in the middle of the course of the axon; unipolar
sensory
neurons have their cell bodies in the ventral and lateral horns of the spinal cord
ventral root
axons of the _____ _____ are entirely motor
ventral root
____ ____; to skeletal muscles: located in _____ horn
somatic motor ventral
_____ ____; to smooth muscles and glands: located in _____ horn
visceral motor lateral
_____ _____; from skin, skeletal muscles, joints: located in _____ horn
somatic sensory dorsal
_____ _____; from the viscera: located in _____ horn
visceral sensory dorsal
spinal nerve branches into _____
rami
_____ _____ carries somatic motor and sensory to the posterior body wall
dorsal ramus
____ ____ carries somatic motor and somatic sensory to the lateral and anterior body wall
ventral ramus
gray and white _____ _____ carry visceral motor (sympathetic) and visceral sensory neurons to and from the viscera
communicating rami
_____ _____ and its ____ run parallel to the spinal cord and send branches towards the thoracic and abdominal cavities
sympathetic chain ganglia
pattern of ventral rami in thorax where ____ _____ travel along inferior surface of the ribs and send small branches to nearby muscles, bones, and skin from
intercostal nerves
spinal nerve's ventral rami join to form a network of nerves called a _____
plexus
ventral rami join to form _____ ______ formed of C5-T1 spinal nerve rami; supplies upper limb
brachial plexus
ventral rami join to form ____ ____ formed of L2-S2 rami; supplies lower limb
lumbosacral plexus
____ ____: involuntary circuits in which the brian is not involved in the response to stimulus
spinal reflexes
______ reflexes are the simplest reflexes involve a sensory neuron and its synapse with a motor neuron
monosynaptic
monosynaptic relfexes: stimulus travels along a sensory neuron that has an axon terminal in the _____ horn where neurons are stimulated
ventral
reflex in which the stretch of the muscle reflexively causes contraction of the same muscle leading to greater stability of joints
stretch
patellar reflex is one example of a _____ reflex; which is a type of _______ reflex
stretch monosynaptic
reflex which involve one or several interneurons
polysynaptic
withdrawal reflex is an example of a ______ reflex; most are protective in nature
polysynaptic
______ reflex: stimulus travels along a sensory neuron that synapses with one or several interneurons; several sets of motor neurons are stimulated in your hip, thigh, and lower leg to withdraw from the painful stimulus
polysynaptic
________ reflex pathway: 1. stimulation of stretch receptor 2. signal occurs along sensory neuron 3. synapse with motor neuron 4. signal occurs along motor neuron 5. muscle is stimulated to contract
monosynaptic
_______ relfex pathway: 1. stimulation of pain receptor 2. signal occurs along sensory neuron 3. synapse with interneurons 4. signal occurs along motor neuron 5. muscle stimulated to contract, withdrawing limb from pain
polysynaptic