chapter 13- spinal cord & spinal nerves Flashcards
what is where a collection of neuron cell bodies are bundled together in the PNS?
ganglia
center & tracts that link a receptor to the CNS is a what?
sensory pathway
the outermost layer of thick collagen covering the spinal cord is called the what?
dura mater
name the liquid the fills the subarachnoid space
cerebrospinal fluid (CSF)
the somatic motor nuclei of the spinal cord are located in the what?
anterior/ventral gray horns
how many funiculi are there in the spinal cord?
6
what kind of info. passes through the dorsal root ganglion & dorsal root?
sensory
how many pairs of spinal nerves in total are there in a human?
31
how many pairs of cervical spinal nerves in total are there in a human?
8 pairs
the stretched spinal roots that extend down the spinal canal of an adult after the coed ends around L2 are called what?
cauda equina
what describes the injury when the nucleus pulpous ruptures through the annulus fibrosis?
herniated disc
in a nerve, axons are bundled in fascicles by the layer of C.T. called the what?
perineurium
why is there a thicker area of the spinal cord in the cervical region & lumbar region?
houses all the motor neurons for movement of the muscles of arms (cervical) & legs (lumbar)
what plexus is composed of axons from cervical nerves 5-8 & thoracic nerve 1?
brachial
nerves from the sacral plexus innervate the what?
lower limbs/legs
loss of sensory function is what?
paresthesia(s)
what is the neural circuit where one neuron synapses on multiple neurons?
divergence
in a reflex arc there must be a what to detect the stimulus & activate the sensory neuron?
receptor
a genetically determined reflex is called a what reflex?
innate
what are the effectors of autonomic/visceral reflexes?
smooth muscle, cardiac muscle & glands
what reflex arc is one that involves one or more interneurons?
polysynaptic
what is a specialized skeletal muscle fiber that functions to detect stretching of the muscle to initiate reflexes to maintain posture or prevent over-stretching?
muscle spindle
nervous system organization:
-CNS = brain and spinal cord
-PNS = all other neural tissue
nerves (strucuture in PNS)
bundles of axons
ganglia (strucuture in PNS)
collection of somas together in one place
center (strucutre in CNS)
collection of somas with a
common function
nucleus (strucutre in CNS)
a center with a visible boundary
neural cortex (strucutre in CNS)
gray matter (somas)
covering the brain
tracts (strucutre in CNS)
bundles of axons with common origins, destinations & functions
columns/funiculi (strucutre in CNS)
large tracts in the
spinal cord
pathways (structure in CNS)
-centers and tracts that link the brain with the body
-sensory pathways: receptor -> CNS
-motor pathways: CNS -> effector
spinal cord:
-45cm (18”) from brain to L2
-inside vertebral canal (stacked vertebral
foramen)
-surrounded by CT: Spinal Meninges
-support and protect spinal cord
dura mater (spinal meninge)
outermost, dense collagen fibers, attaches to periosteum of occipital bone & coccyx by coccygeal ligament, surrounded by epidural space
epidural space
surrounds dura mater & contains blood vessels and adipose
arachnoid (spinal meninge)
middle, two layers: arachnoid membrane & arachnoid trabeculae
arachnoid membrane
simple squamous epithelium, contacts dura mater
arachnoid trabeculae
collagen & elastin fibers that bind to pia mater, fibers pass through subarachnoid space
subarachnoid space
contains cerebrospinal fluid (CSF: for shock absorption & diffusion medium)
pia mater
innermost, fine mesh of collagen & elastin fibers bound to neural tissue, attached to arachnoid trabeculae, has denticulate ligaments
denticulate ligaments
extend through arachnoid to dura mater to prevent lateral movement of spinal cord
spinal cord cross-sectional anatomy
-posterior median sulcus
-anterior median sulcus
central canal of spinal cord
contains CSF for difffusion
gray matter of spinal cord
somas, neuralgia, unmyelinated axons
posterior gray horn (gray matter of spinal cord)
somatic & visceral sensory nuclei