What are the two important functions of the spinal cord? - ✔✔ structural and functional link between the brain and torso/limbs of the body
spinal
... [Show More] reflexes
Do spinal reflexes require input from the brain?
How fast do they respond to a stimulus? - ✔✔ no input from brain required
quickest reaction to a stimulus
The superior end of the spinal cord is continuous with ____ and its inferior end tapers to from - ✔✔ continuous with the medulla oblongata
inferior end tapers to form the conus medullaris
The conus medullaris terminates at approximately the... - ✔✔ superior border of the small of your back
What are the two longitudinal depressions that extend the full length of the spinal cord? - ✔✔ the posterior median sulcus and the anterior median fissure
What are the four continuous subdivisions of the spinal cord (from superior to inferior)? - ✔✔ cervical (continuous with medulla oblongata)
thoracic
lumbar
sacral
Why are the cervical enlargement and lumbosacral enlargements wider? - ✔✔ because of the presence of a greater number of neurons within the spinal nerves extending from these spinal cord parts to innervate the upper and lower limbs, respectively
The spinal cord is associated with how many spinal nerves? - ✔✔ 31 pairs
8 cervical nerves
12 thoracic nerves
5 lumbar
5 sacral
1 coccygeal
Each spinal nerve anchors to the spinal cord by - ✔✔ two roots, a posterior and an anterior
The posterior root houses what
they relay signals where? - ✔✔ sensory neurons that extend from sensory receptors
they relay signals from the sensory receptors TO the spinal cord
The sensory neurons that compose the spinal nerves are what type of neurons? - ✔✔ unipolar
The cell bodies of the sensory neurons that compose the spinal nerves are located external to the spinal cord and form the - ✔✔ posterior root ganglion
The anterior root contains ____ neurons that extend to ____ - ✔✔ motor neurons that extend to effectors
The anterior root motor neurons control what - ✔✔ muscles and glands
The motor neurons that compose the spinal nerves are what type of neuron - ✔✔ multipolar
What's a significant difference between anterior and posterior roots?
Why? - ✔✔ anterior roots lack a ganglion along its length
the dendrites and cell bodies of motor neurons are within the spinal cord and the anterior root contains only the axons of these neurons
Each spinal nerve forms where?
Is what type of nerve? - ✔✔ forms where both roots join, so they're classified as a mixed nerve
Collectively, spinal nerve roots form a structure called - ✔✔ the cauda equina
What is the vertebral canal - ✔✔ the stacked vertebral foramina that houses the spinal cord and caudal equina
What are the spinal cord meninges layers, from deep to superficial - ✔✔ pia mater
arachnoid mater
dura mater
Pia mater of the spinal cord extensions form what two structures - ✔✔ denticulate ligaments - numerous, paired triangular extensions that suspend and anchor the spinal cord laterally to the arachnoid and dura mater
filum terminale - thin strand of pia mater that anchors the conus medullar is to the coccyx bone - extends within the cauda equina
The arachnoid mater of the spinal cord is composed of - ✔✔ a web of collagen and elastic fibers termed the arachnoid trabeculae
Immediately deep to the arachnoid mater is the - ✔✔ subarachnoid space
What is the difference between the dura mater of the spinal cord and dura mater covering the brain? - ✔✔ the dura mater of the spinal cord only has one layer
What are the two spaces associated with the dura mater? - ✔✔ the subdural space (internal to dura mater) and the epidural space (external to dura mater)
The epidural space of the dura mater houses what - ✔✔ apidose and areolar CT and blood vessels
Gray matter within the spinal cord is ____ located and it's shape resembles - ✔✔ centrally located
shape resembles a letter H or a butterfly
Spinal cord gray matter is subdivided into - ✔✔ a posterior horn, a lateral horn, an anterior horn and a bar that connects the left and right sides called the gray commissure
What forms the posterior horns of spinal cord gray matter? - ✔✔ dendrites and cell bodies of interneurons
The posterior horn gray matter on each side of the spinal cord is subdivided regionally into both - ✔✔ somatic sensory nuclei and visceral sensory nuclei
The somatic sensory nuclei is the site for - ✔✔ synapses between somatic sensory neurons and the interneurons within the posterior horns of the spinal cord
The visceral sensory nuclei is the location for - ✔✔ synapses between visceral sensory neurons that extend from visceral sensory receptors to the interneurons within the posterior horns of the spinal cord
The gray matter of the anterior horns of the spinal cord is made from - ✔✔ the dendrites and cell bodies of somatic motor neurons that collectively form the somatic motor nuclei which form the entire anterior horn on each side of the spinal cord
The lateral horns of the spinal cord is located only where - ✔✔ within the T1-L2 parts of the spinal cord
The gray matter of the lateral horns of the spinal cord is made up of - ✔✔ dendrites and cell bodies of autonomic motor neurons
they form the autonomic motor nuclei which makes up the entire lateral horn on each side of the spinal cord
Why is the gray commissure an unusual gray matter region? - ✔✔ because it primarily houses unmyelinated axons
The central canal fo the gray commissure has what purpose - ✔✔ it's a small, internal channel that extends through the center of the gray commissure along the entire length of the spinal cord, it contains CSF that enters the space from the fourth ventricle of the brain
What are the three distinct anatomic structural regions of the white matter of the spinal cord? - ✔✔ posterior funiculus - lies between the posterior gray horns on the posterior side of the cord and posterior median sulcus
lateral funiculus - on each lateral side of the spinal cord
anterior funiculus - composed of white matter that occupies the space on each anterior side of the cord between anterior gray horns and anterior media fissure [Show Less]