Chapter 14 Flashcards
major functions of spinal cord
provides structural/functional link between the brain and the rest of the body
sensory input is from where?
from the body
motor commands are from where?
from the brain
sensory input _____ the cord
ascends
motor commands ____ the cord
descend
spinal reflex properties
does not involve the brain; has a very fast reaction to a stimulus
(note: not all reflexes are spinal reflexes!)
what part of the neural tube does the spinal cord develop?
caudal end of the neural tube; “tail” end
what happens to the neural canal during spinal cord development?
becomes the central canal of the cord
sulcus limitans forms at what week of development?
6th week
sulcus limitans
horizontal grooves
where does the spinal cord extend from?
the medulla oblongata
where does the spinal cord travel through?
the vertebral canal
end of the spinal cord
conus medullaris
where can you find the conus medullaris? (in other words, where does the spinal cord end?)
around the L1 vertebra
roots of remaining spinal nerves that extend down from the conus medullaris; “horse tail”
cauda equina
4 sections of the cord
cervical, thoracic, lumbar, sacral
cervical enlargement
widened region of cord that provides neurons for upper limbs
lumbar enlargement
widened region of cord that provides neurons for lower limbs
review!!!
epineurium, perineurium, and endoneurium
epi - whole nerve
peri - fascicle
endo - each axon
how many cervical nerve pairs?
8
how many thoracic nerve pairs?
12
how many lumbar nerve pairs?
5
how many sacral nerve pairs?
5
how many coccygeal nerve pairs?
1
vertebral foramina
protects the whole spinal cord
intervertebral foramina
protects the spinal nerves
meninges
pia mater, arachnoid mater, dura mater
denticulate ligaments (in pia mater)
lateral extensions that limit side-to-side movement
filum terminale (in pia mater)
inferior (to coccyx) extensions that limit superior movement
subarachnoid space (in arachnoid mater)
contains CSF
subdural and epidural space (in dura mater)
subdural - contains interstitial fluid
epidural - contains adipose + areolar CT, also blood vessels
gray matter in spinal cord
central/deep in the cord; OPPOSITE of brain
dorsal gray horns contain:
axons of sensory neurons
lateral gray horns contain
cell bodies of autonomic motor neurons
ventral gray horns contain
cell bodies of somatic motor neurons
commissures contain
unmyelinated axons connecting L/R sides
dorsal nuclei
sensory
ventral nuclei
motor
after the intervertebral foramen, the spinal nerve ____
splits!!!
dorsal ramus
small branch that innervates muscles of skin and back
ventral ramus
larger branch that splits into multiple branches; may participate in a plexus
rami communicantes
small branches of autonomic fibers
dermatomes
skin segments that are supplied by single spinal nerve
