Neuron
A nerve cell; the basic building block of the nervous system.
multipolar neuron
a nerve cell that has many dendrites and a single axon-most common in the nervous system -motor neurons -cell body is located in the anterior horn of the gray matter-carry efferent nerve signals to stimulate voluntary muscle control
pseudounipolar sensory nerves
double process extending from cell body -conducts impulses from receptor organ toward cell body, then from cell body into the CNS-sensory nerves of body -cell bodies found in the PNS-carry affrerent nerves
Bipolar neurons
-rare, found in olfactory epithelium, the retina of the eye, and the vestibulochochlear nerve
Neuroglia
Supporting cells that support, insulate, and protect neuronsinclude satelite cells and shwann cells
cell body of neuron
contains the nucleus
axon
A threadlike extension of a neuron that carries nerve impulses away from the cell body.
dendrites
Branchlike parts of a neuron that are specialized to receive information.
Central Nervous System
Brain and spinal cord
Peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body
nucleus
collection of cell bodies in the CNS
gray matter
cell bodies and dendrites
white matter
Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.
nerve fiber
axon, nerulema, and surrounding endoneural connective tissue
nerve
bundles of nerve fibers, the layers of connective tissue binding them together, and the blood vessels (vasa nervorum) that serve them-arranged in bundles called fascicles
ganglion
A cluster of nerve cell bodies, often of similar function, located in the PNS.
afferent
conducting nerve pulses inward toward the central nervous system
efferent
conducting nerve pulses outward away from the CNS
somatic afferent
neurons that bring in sensory impulses from skin, skeletal muscles, bones, ligaments and tendons to CNS
Somatic efferent
transmit impulses to skeletal voluntary muscles
visceral afferent
transmit pain from subconcious visceral reflex sensations from hollow organs and blood vessels to CNSblood gas, blood pressure levels
Visceral efferent
transmit impulses to smooth muscles and glandilar tissues
extrinsic back muscles
moves limbs of the anterior trapezius, the latissimus dorsi, the rhomboid major and minor, and the levator scapulae.innervated by the anterior rami of spinal nerves or cranial nerve XI
intrinsic back muscles
erector spinae muscle groupmaintain posture and move the vertebral column innervated by the posterior rami of the spinal nerves
Dura mater
Outermost layer of the meninges
arachnoid mater
middle layer of the meninges
pia mater
thin, delicate inner membrane of the meninges
subarachnoid space
space between the pia mater and the arachnoid membranecontains cerebrospinal fluid
epidural space
separating dura from surrounding bonecontains fat, connective tissue, and venous plexis
explain the developmental basis of the medullary cone occuring at the L1 vertebrae and its effect on the relationship between the spinal cord level of orgin and location vertebral canal exit for the lower lumbar sacral spinal nerves
-Early in development the spinal cord runs the entire length of the spine -as development progesses the vertebrae grow much faster than the spinal cord the segments lose alignment -this creates very long nerve roots for more inferior spinal nerves-these nerve roots are called caudaequina
specify the nerves whose dorsal and ventral roots form the cauda equina within the lumbar cistern
the lumbar, sacral, and coccygeal nerves
spinal nerve labelled
0
ventral root carries what type of fibers
motor fibers
dorsal root carries what type of fibers
sensory fibers
spinal nerve carries what type of fibers
both motor and sensory
ventral primary ramus carries what type of fibers
both
dorsal primary ramus carries what type of fibers
both
where do cervical spinal nerves exit
exit above the cervical cord segment
where do thoracic and lumbar spinal nerves exit
exit below thoracic and lumbar cord segments
label dorsal and ventral horn
0
List in correct spatial sequence the structures through which a somatic efferent axon will pass in projecting to its effector organ in the ventrolateral or dorsal body wall
anterior horn-ventral root-spinal nerve-ventral ramus or dorsal ramus-ventrolateral body wall or dorsal body wall
list in correct spatial sequence the structures through which a somatic afferent axon will pass in returning sensory information to the CNS from a receptor in the ventrolateral or dorsal body wall
ventrolateral body wall-ventral ramus-spina nerve- dorsal root-DRG-dorsal horn
specify the spinal nerve that exits each of the intervertebral foramina in the cervical, thoracic, lumbar, and sacral regions of the vertebral column
C1-C7 spinal nerve exit above corresponding vertebraeC8 exits above T1T1-T12 exit below corresponding vertebraeL1-L5 exit below corresponding vertebraeS1-S5 exit below corresponding vertebrae
Specify the nerves whose dorsal and ventral roots for the cauda equina within the lumbar cistern
spinal nerves L1-L5 make up cauda equina
explain the anatomical basis of the rash pattern characterisitc of a herpes zoster infection
rash pattern in line with dermatome associated with corresponding spinal nerve
dermatome C4 relates to
Upper arms and Neck
dermatome T4 relates to
Nipples area
dermatome T6 relates to
costal margin level
dermatome T10 relates to
umbilicus region
dermatome L1 relates to
iliac region
specify the vertebral level that corresponds to the location of the conus medullaris in the adult
Lumbar L1 vertebrae
specify the location of the internal and external vertebral venous plexes
the internal venous plexes lie in the epidural space in the vertebral canal the external venous plexes lie in front of the vertrebral body
explain the role of Batson's plexus in the metastasis of cancers and the spread of infections
Batsons plexus interconnects with deep pelvic and thoracic veins and in doing so allows metastatic cancers arising from the rectum, colon, prostate, or pelvic region to spread to the brain or vertebral column
Define the term plexus as it relates to the peripheral nervous system
latin for braid-is a branching network of vessels or nervesthere are 4 nervous plexus-cervical, brachial, lumbar, and sacral plexus
what spinal nerve does the patellar knee jerk test
L4 spinal cord
what spinal nerve does the biceps tendon reflex test
C5
what spinal nerve does the triceps tendon reflex test
C7
what spinal nerve does the brachioradialis tendon reflex test
C6