A&P Spinal Cord and Spinal Nerves Flashcards
Because they contain both sensory and motor axons, spinal nerves are considered to be _____ nerves.
mixed
The five components of a reflex arc, in order from the beginning to the end, are (1) _____, (2) _____, (3) _____, (4) _____, and (5) _____.
sensory receptor, sensory neuron, integrating center, motor neuron, effector
T/F: Gray matter of the spinal cord contains somatic motor and sensory nuclei, autonomic motor and sensory nuclei, and functions to receive and integrate both incoming and outgoing information.
true
T/F: The epidural space is located between the wall of the vertebral canal and the pia mater.
false
receptors that monitor changes in muscle length
muscle spindles
a balance-maintaining reflex
crossed-extensor reflex
operates as a feedback mechanism to control muscle tension by causing muscle relaxation when muscle force becomes too extreme
tendon reflex
reflex arc that consists of one sensory and one motor neuron
monosynaptic reflex
acts as a feedback mechanism to control muscle length by causing muscle contraction
stretch reflex
sensory impulses enter on one side of the spinal cord and motor impulses exit on the opposite side
contralateral reflex arc
sensory impulses enter on one side of the spinal cord and motor impulses exit on the opposite side
contralateral reflex arc
Occurs when sensory nerve impulse travels up and down the spinal cord, thereby activating several motor neurons and more than one effector
intersegmental reflex arc
polysynaptic reflex initiated in response to a painful stimulus
flexor (withdrawal) reflex
receptors that monitor changes in muscle tension
tendon (golgi tendon) organs
maintains proper muscle tone
stretch reflex
reflex pathway that contains
sensory neurons, interneurons,
and motor neurons
polysynaptic reflex
motor nerve impulses exit the spinal cord on the same side that sensory impulses entered the spinal cord
ipsilateral reflex arc
protects the tendon and muscle from damage due to excessive tension
tendon reflex
a neural circuit that coordinates body movements by causing contraction of one muscle and relaxation of antagonistic muscles or relaxation of a muscle and contraction of the antagonists
reciprocal innervation
the joining together of the anterior rami of adjacent nerves
plexus
spinal nerve branches that serve the deep muscles and skin of the posterior surface of the trunk
posterior (dorsal) ramus
spinal nerve branches that
serve the deep muscles and skin of the posterior surface of the trunk
posterior (dorsal) ramus
spinal nerve branches that serve the muscles and structures of the upper and lower limbs and the lateral and ventral trunk
anterior (ventral) ramus
area of the spinal cord from
which nerves to and from the upper limbs arise
cervical enlargement
area of the spinal cord from
which nerves to and from the lower limbs arise
lumbar enlargement
the roots form the nerves that
arise from the inferior part of the spinal cord but do not leave the vertebral column at the same level as they exit the cord
cauda equina
contains motor neuron axons and conducts impulses from the spinal cord to the peripheral organs and cells
anterior (ventral) root
avascular covering of spinal cord composed of delicate collagen fibers and some elastic fibers
arachnoid matter
contains sensory neuron axons and conducts impulses from the peripheral receptors into the spinal cord
posterior (dorsal) ramus
superficial spinal cord covering of dense, irregular connective tissue
dura mater
an extension of the pia mater that anchors the spinal cord to the coccyx
filum terminale
extending the length of the spinal cord, these pia mater thickenings fuse with the arachnoid mater and dura mater and help to protect the spinal cord from shock and sudden displacement
denticulate ligaments
thin transparent connective tissue composed of interlacing bundles of collagen fibers and some elastic fibers adhering to the spinal cord’s surface
pia mater
space within the spinal cord filled with cerebrospinal fluid
central canal
spinal nerve branch that supplies vertebrae, vertebral ligaments, blood vessels of the spinal cord, and meninges
meningeal branch
provides the entire nerve supply of the shoulders and
upper limbs
brachial plexus
provides the nerve supply of the skin and muscles of the
head, neck, and superior part of the shoulders and chest
cervical plexus
provides the nerve supply of the anterolateral abdominal
wall, external genitals, and part of the lower limbs
lumbar plexus
supplies the buttocks, perineum, and lower limbs
sacral plexus
formed by the anterior rami of C1–C4 with some
contribution by C5
cervical plexus
formed by anterior rami of S4–S5 and coccygeal nerves
coccygeal plexus
formed by the anterior rami of L1–L4
lumbar plexus
formed by the anterior rami of C5–C8 and T1
brachial plexus
formed by the anterior rami of L4–L5 and S1–S4
sacral plexus
phrenic nerve arises from this plexus
cervical plexus
median nerve arises from this plexus
brachial plexus
sciatic nerve arises from this plexus
sacral plexus
femoral nerve arises from this plexus
lumbar plexus
supplies a small area of skin in coccygeal region
coccygeal plexus
injury to this plexus can affect breathing
cervical plexus
