Lecture 12 main points Flashcards
list the functions of the spinal cord
part of CNS that extends from the brain, may relay structure between CNS and PNS
control rapid changes to environment
reflex circuits
control some of most rapid reactions to environmental changes
what does white matter consist of and what function does it serve
major sensory and motor tracts to and from the brain of the body (axons)
what does gray matter consist of and what function does it serve
site for integration of post synpatic potentials (IPSP and EPSP)
cell bodies
where does the spinal cord start and end
starts as a continuation of the medulla oblongata extending to termination at the conus medullaris
where is the conus medullaris
between L1 and L2
what connective tissue structures surround the spinal cord
bony vertebral column and the spinal meninges
list the three meninges that surround the spinal cord from superficial to deep and list key features of each
dura mater - tough outermost layer: encloses entire cord
arachnoid mater- meddle, delicate cobweb covering attached to the inside of the dura and forms the roof of the subarachnoid space
pia mater - very thin, delicate , transparent layer that is pressed up against the cord
filled with blood vessels that supply nutrients to the spinal cord
what are denticulate ligaments and what is their function
fibrous structure that help to anchor the spinal cord in place
list the three spaces and their location with respect to the meninges
epidural space - between dura mater and wall of the vertebral canal
subdural space - lies between dura and arachnoid, contains a film of interstitial fluid
subarachnoid space- lies between the arachnoid and pia mater, contains CSF that acts as a shock absorber, chemical environment, and suspension system for brain and spinal cord
what is the cervical enlargement and its function
correlates with sensory input and motor output to the upper extremities
what is the lumbar enlargement and its function
handles motor output and sensory input to and from the legs
what is the cauda equine
collection of nerve roots at inferior end of vertebral canal
what is filum terminale
extends to coccyx, fibrous extension of conus pia mater covered in dura
anchors spinal cord to the coccyx
in general going from superior to inferior what happens to the size of the spinal cord
gets progressively smaller
what are the two roots of the spinal cord
posterior (dorsal) root
anterior (ventral) root
what are the features and functions of the posterior roots
only sensory
each posterior root has a swelling - a dorsal root ganglion, which contains the cell bodies of sensory interneurons that relay information from some peripheral sensory neurons to the spinal cord
what are the features and functions of the ventral root
contain motor neurons, which conduct nerve impulses from the CNS to effectors
muscles and glands
contrast the location of white and gray matter of the spinal cord and the brain
in the spinal cord the white matter is on the outside, and gray matter is on the inside
in brain, white matter is on the inside and gray matter is on the outside
what does spinal white matter consist of
nerve fibers, axons
what does spinal gray matter consist of
cell bodies
what is a spinal tract
a bundle of neuronal axons that are all located in the specific area of the cord and all traveling to the same place
how are tracts named
formed using the compound words that denote the origin of the tract and the place where it ends
spinothalamic tract
goes from spinal cord to brain - afferent
corticospinal tract
goes from cortex of the brain to the spinal cord - efferent
vestibulospinal tract
from brain to spinal cord therefore efferent
how many spinal nerves are there
31 pairs
list the connective tissue sheaths of a spinal nerve
perineurem, epineureum
what is a dermatome and how are they named
an area of skin that is innervated by a single spinal nerve, indicated by the letter and number of a particular segmental portion of a spinal nerve
what is a plexus of nerves
large braided ropes of nerves
list examples of plexus of nerves
cervical plexus, brachial plexus, solar plexus, lumbar plexus, sacral plexus, coccygeal plexus
list the functions of the brain
control center for registering sensation, making decisions, taking actions, intellect, emotions, behavior, memory
what hard structure surrounds the brain
cranium - skull
list the cranial meninges
dura, arachnoid, and pia mater
what are the differences between cranial and spinal meninges
cranial dura mater has mostly 2 fused layers, spinal has 1
there is no epidural space around the brain
