General concepts of the nervous system

Question 1

gray matter

Answer 1

nerve cell bodies lie within this

looks like an H

CELLULAR

divided into horns

Question 2

white matter

Answer 2

interconnecting fiber tract systems

FIBER nature

funculi

anterior (ascending/descending motor tracks, pain and temperature tracks that ascend)
lateral (same as anterior)
posterior (sensory info from all areas of the body below the head taken up to areas of the brain)

Question 3

afferent

Answer 3

sensory

toward CNS

Question 4

efferent

Answer 4

motor

from the CNS

Question 5

how many pairs of spinal nerves

Answer 5

31

Question 6

how many thoracic nerves

Answer 6

12

Question 7

how many cervical pairs

Answer 7

8

Question 8

how many lumbar nerves

Answer 8

5

Question 9

how many sacral

Answer 9

5

Question 10

how many coccygeal nerves

Answer 10

1

Question 11

NOTE: a ganglion exists on the dorsal root, which contains what?

Answer 11

the cells bodies of all the afferent sensory fibers, except for vagal afferents, below the level of the head

Question 12

where does the first spinal nerve exit?

Answer 12

between the skull and CV1

Question 13

how are spinal nerves numbered and where do they exit?

Answer 13

exit intervertebral foramina EXCEPT for in the cervical region

Question 14

mixed nerve

Answer 14

motor and sensory formed at the junction of a dorsal and ventral root

Question 15

dorsal root ganglion

Answer 15

is a nodule on a dorsal root of the spine that contains cell bodies of nerve cells (neurons) that carry signals from sensory organs toward the appropriate integration center.

nucleus-group of cell bodies found within the central nervous system

ganglion- nerve cell bodies located outside the CNS

Question 16

dermatone

Answer 16

the unilateral area of skin innervated by the sensory fibers of a single spinal nerve

Question 17

central nervous system

Answer 17

brain and spinal cord

Question 18

PNS

Answer 18

12 cranial nerves and 31 pairs of spinal nerves

Question 19

lateral horn

Answer 19

“column”

discontinuous

found from C8 to L2 and picks up again at L2-3,4

gives rise to autonomic (parasympathetic and sympathetic) nerve fibers (not under our control)

Question 20

anterior horn

Answer 20

ventral

filled with cells that are motor cells that go to all muscles of your body

selectively stimulate one of these, a muscle would twitch

Question 21

posterior horn

Answer 21

cell bodies that give rise to fibers that communicate with other areas

Question 22

rootlets

Answer 22

coalesce to form root

which eventually form a single spinal nerve

Question 23

spinal nerve

Answer 23

where dorsal and ventral roots come together ***

short entity (1 cm in length)

bifurcates and forms dorsal ramus and ventral ramus (larger)

Question 24

are spinal cord segments and spinal column segments different? Do they correspond?

Answer 24

yes
and
no b.c the spinal cord does not span the entire length of the spinal column ***

spinal column segments–> vertebra

so if a T12 vertebra was crushed it would be effecting the lumbar spinal cord segments

Question 25

spinal cord segment gives rise to ...

Answer 25

rootlets --> roots--> spinal nerve--> bifurcate and form dorsal and ventral ramus which will coalesce to form single spinal nerve

Question 26

pseudounipolar sensory neuron

Answer 26

has both peripheral process (conducting impulses from the receptor organ) toward the cell body and a central process (continues from the cell body into the CNS) these are part of the PNS brings in sensation information their cell body sits in the dorsal root ganglion central fibers come in a synapse will cell in the posterior horn

Question 27

is there any part of your body that will not feel sensation ?

Answer 27

NO nerves that go to all parts of your body have both sensory and motor components (mixed nerves) so dorsal and ventral ramus are also mixed nerves!***

Question 28

3 things that dorsal rami innervate

Answer 28

skin of the back deep back muscles zygopathoseal facet joints of back (joints of the spine)

Question 29

ventral primary ramus

Answer 29

forms all the somatic nerve plexuses of the body innervate ventral torso

Question 30

somatic plexus

Answer 30

cervical brachial lumbosacral

Question 31

fibers within spinal nerves

Answer 31

General somatic afferent General visceral afferent General somatic efferent general visceral efferent

Question 32

peripheral visceral structures?

Answer 32

you have visceral structures all over (so even a sweat gland is visceral structure out in the periphery, so not just in the gut) errector pili organ vessel sweat gland

Question 33

exteroreceptor

Answer 33

bringing things in to the CNS

Question 34

interoreceptors

Answer 34

proprioceptive -understand and feel limbs in a certain position without looking at it

Question 35

all of the visceral afferents or somatic afferents all have their cell bodies where? GSA's and GVA's

Answer 35

in the dorsal root ganglion so if asked where you find cell bodies that are responsible for innervating the cutaneous areas of the skin, they are found in the dorsal root ganglion

Question 36

the only spinal nerve that has reduced or absent dorsal root ganglion is...

Answer 36

spinal nerve C1 -has to do with development

Question 37

anterior horn

Answer 37

where all the motor neurons (cell bodies) sit for all the skeletal muscles in the entire body below the head

Question 38

general somatic afferent

Answer 38

transmit sensations from the body to the CNS (transmit info from skeletal muscles, tendons, and joint capsules and from the outside of the boyd concerning pain, touch, and temp)

Question 39

general somatic efferent

Answer 39

transmit impulses to skeletal muscles

Question 40

general visceral afferent

Answer 40

transmit pain or subconscious visceral reflex sensations (distention, blood gas) from hollow organs and blood vessels to the CNS

Question 41

general visceral efferent

Answer 41

transmit impulses to smooth muscle and glandular tissue innvervate smooth muscles, cardiac muscle, and glands autonomic

Question 42

plexus formation comes from

Answer 42

following targets out periphery

Question 43

two things about brachial plexuses

Answer 43

the fibers of a single spinal nerve entering the plexus are distributed to multiple branches of the plexus (one spinal nerve contributing fibers to many different peripheral nerves) the peripheral nerves derived from the plexus contain fibers from multiple spinal nerves (one peripheral nerve distributing sensory fibers to many different spinal nerves)

Question 44

posterior (primary) rami of spinal nerves

Answer 44

supply nerve fibers to the synovial joints of the vertebral column, deep muscles of the back and the overlying skin in a segmental pattern as a general rule the posterior rami remain separate from each other (do not merge to form major somatic nerve plexuses)

Question 45

dermatomal map

Answer 45

distribution of a single spinal nerve -gives you spinal origin no C5 in the trunk

Question 46

difference between dermatone and peripheral nerve

Answer 46

area of skin innervated by a single spinal nerve peripheral nerves may have several spinal nerves in them - peripheral nerve delivers innervations to dermatones - gives nervous origin that has many spinal levels within it

Question 47

1 place that is a 1 to 1 correlation (of innervation of the skin by a single spinal nerve)

Answer 47

independent intercostal nerves