Nerves, spinal cord, meninges Flashcards
Afferent nerves are associated with which pathway?
sensory
Efferent nerves are associated with which pathway?
motor
name the three different types of neurons?
multipolar, pseudounipolar, bipolar
give examples of multipolar, pseudounipolar, and bipolar neurons?
Multipolar: Motor nerve cells,
Pseudounipolar: sensory
Bipolar: sensory neurons for special senses
Give an example of a neuroglia?
schwann cells/ oligendendrocytes
Sensory neurons send information from where to where?
PNS to CNS
Motor neurons send information from where to where?
CNS to PNS
At which two levels is there a slight enlargement of the spinal cord?
cervical and lumbosacral
what is a negative to regions of enlargement?
enlarged regions are more susceptible to spinal stenosis (narrowing of the canal from inflammation)
where does the spinal cord start?
medulla oblongata
Where does the spinal cord end?
L1/L2
what is the portion of spinal cord called after L2?
conus medullaris is point of spinal cord ending, fuse to form filum terminale
what is the cauda equina?
Spinal nerves below L2
what is white matter?
myelinated axons
what is gray matter?
collection of cell bodies
Describe the four portions of gray matter?
ventral horn, dorsal horn, lateral horns
what are the ventral horns?
cell bodies for motor
what are the dorsal horns?
collect info from sensory
what are lateral horns?
cell bodies for symp
What problem would occur for a lesion above C5?
breathing affected
result of a lesion to C5-T1?
complete/incomplete quadriplegia
result of a lesion to T1-L4?
paraplegia
result of a lesion to L4-S1?
incomplete paraplegia
where do nerves exit the spinal cord?
through the intervertebral foramen
which diseases narrow the intervertebral foramen?
disc herniation, compression fracture, arthritis, bone spurs
what affect does narrowing of IV have?
May irritate spinal nerves exiting
at what level is a narrow spinal cord irritation common?
L5 because the nerves are large and foramen is narrow
describe the process of the stretch reflex?
rapid stretch of muscle fibers causes impulse along sensory nerve, axon terminals receive signal, motor neuron in anterior horn triggers contraction, interneuron in posterior horn causes inhibition
What is a dermatome?
skin segments supplied by spinal cord
what is a myotome?
muscle segment supplied by spinal cord
Where is the dura mater?
outer layer
where is the arachnoid mater?
underside of dura mater
where is the epidural space?
inbetween dural sac and vertebrae
