Lecture 12 main points

Question 1

list the functions of the spinal cord

Answer 1

part of CNS that extends from the brain, may relay structure between CNS and PNS
control rapid changes to environment

Question 2

reflex circuits

Answer 2

control some of most rapid reactions to environmental changes

Question 3

what does white matter consist of and what function does it serve

Answer 3

major sensory and motor tracts to and from the brain of the body (axons)

Question 4

what does gray matter consist of and what function does it serve

Answer 4

site for integration of post synpatic potentials (IPSP and EPSP)
cell bodies

Question 5

where does the spinal cord start and end

Answer 5

starts as a continuation of the medulla oblongata extending to termination at the conus medullaris

Question 6

where is the conus medullaris

Answer 6

between L1 and L2

Question 7

what connective tissue structures surround the spinal cord

Answer 7

bony vertebral column and the spinal meninges

Question 8

list the three meninges that surround the spinal cord from superficial to deep and list key features of each

Answer 8

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

Question 9

what are denticulate ligaments and what is their function

Answer 9

fibrous structure that help to anchor the spinal cord in place

Question 10

list the three spaces and their location with respect to the meninges

Answer 10

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

Question 11

what is the cervical enlargement and its function

Answer 11

correlates with sensory input and motor output to the upper extremities

Question 12

what is the lumbar enlargement and its function

Answer 12

handles motor output and sensory input to and from the legs

Question 13

what is the cauda equine

Answer 13

collection of nerve roots at inferior end of vertebral canal

Question 14

what is filum terminale

Answer 14

extends to coccyx, fibrous extension of conus pia mater covered in dura
anchors spinal cord to the coccyx

Question 15

in general going from superior to inferior what happens to the size of the spinal cord

Answer 15

gets progressively smaller

Question 16

what are the two roots of the spinal cord

Answer 16

posterior (dorsal) root
anterior (ventral) root

Question 17

what are the features and functions of the posterior roots

Answer 17

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

Question 18

what are the features and functions of the ventral root

Answer 18

contain motor neurons, which conduct nerve impulses from the CNS to effectors
muscles and glands

Question 19

contrast the location of white and gray matter of the spinal cord and the brain

Answer 19

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

Question 20

what does spinal white matter consist of

Answer 20

nerve fibers, axons

Question 21

what does spinal gray matter consist of

Answer 21

cell bodies

Question 22

what is a spinal tract

Answer 22

a bundle of neuronal axons that are all located in the specific area of the cord and all traveling to the same place

Question 23

how are tracts named

Answer 23

formed using the compound words that denote the origin of the tract and the place where it ends

Question 24

spinothalamic tract

Answer 24

goes from spinal cord to brain - afferent

Question 25

corticospinal tract

Answer 25

goes from cortex of the brain to the spinal cord - efferent

Question 26

vestibulospinal tract

Answer 26

from brain to spinal cord therefore efferent

Question 27

how many spinal nerves are there

Answer 27

31 pairs

Question 28

list the connective tissue sheaths of a spinal nerve

Answer 28

perineurem, epineureum

Question 29

what is a dermatome and how are they named

Answer 29

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

Question 30

what is a plexus of nerves

Answer 30

large braided ropes of nerves

Question 31

list examples of plexus of nerves

Answer 31

cervical plexus, brachial plexus, solar plexus, lumbar plexus, sacral plexus, coccygeal plexus

Question 32

list the functions of the brain

Answer 32

control center for registering sensation, making decisions, taking actions, intellect, emotions, behavior, memory

Question 33

what hard structure surrounds the brain

Answer 33

cranium - skull

Question 34

list the cranial meninges

Answer 34

dura, arachnoid, and pia mater

Question 35

what are the differences between cranial and spinal meninges

Answer 35

cranial dura mater has mostly 2 fused layers, spinal has 1
there is no epidural space around the brain