Hsf: Spinal Nerves

Front 1

Parts of Neurons

Back 1

-Dendrites
-Axons (1-1micrometer)=nerve fibers

Front 2

Largest Collections of neurons form the ______ and _____ ____

Back 2

Brain and Spinal Cord

Front 3

Central Nervous System

Back 3

-Brain and spinal cord protected by skull and vertebral column

Front 4

Peripheral Nervous System

Back 4

-Cell bodies and nerve fibers outside the brain and spinal cord

Front 5

Afferent (Sensory Nerve Fibers)

Back 5

-Carry impulses arising from the stimulation of peripheral receptors TOWARD the CNS

Front 6

Efferent (Motor Fibers)

Back 6

-Carry impulses from the CNS TO the effector organs

Front 7

Many of the ____ ________ whose fibers form the PNS are located within the CNS

Back 7

-cell bodies

Front 8

Nerves

Back 8

-Bundles of axons that lie outside the CNS
-Most contain Sensory and Motor Fibers

Front 9

Cranial Nerves

Back 9

-Nerves that leave the brain and exit through the skull
-12 pairs

Front 10

Spinal Nerves

Back 10

-Nerves leaving the spinal cord and exiting b/w vertebrae
-31 pairs

Front 11

Connective Tissue (Around Nerves)

Back 11

-Nerves Bound together outside of CNS
-Contains Collagen, Elastic Fibers and Fat
-3 Levels: Epineurium, Perineurium, Endoneurium

Front 12

Schwann Cells

Back 12

-Forms sheath around one or more nerve fibers
-May have unmyelinated axons embedded in it (cells not wrapped around)

Front 13

Myelinated

Back 13

-schwann cells wrapped around=greater than 2micrometers

Front 14

_______ in the level of origin of nerve branches is common

Back 14

Variation

Front 15

The spinal nerves arise form the spinal cord within the ______ ______ and pass out through the ___________ ________.

Back 15

-Verterbral Canal
-Intervertebral Foramina

Front 16

Spinal Nerves (#)

Back 16

-8 Cervical
-12 Thoracic
-5 Lumbar
-5 Sacral
-1 Coccygeal

Front 17

Spinal Segment

Back 17

-Longitudinal extent of the spinal cord to which a pair of spinal nerves is attached

Front 18

The first cervical nerve leaves the vertebral canal by passing between the _______ bone of the skull and the _______ _______ vertebra, the _______

Back 18

-occipatol bone
-first cervical vertebra
-the atlas

Front 19

8th Cervical Nerve Leaves...
The rest of the Nerves

Back 19

-B/w C7 and T1
-Exit below their respective vertebrae

Front 20

Spinal Nerve (def)

Back 20

-Union of the dorsal and ventral roots, which emerge from each spinal cord segment

Front 21

Fibers forming the dorsal root are ______ and arise from cell bodies located in the _____ or ______ _____ ______

Back 21

-Afferent
-Spinal
-Dorsal Root Ganglion (distal end of dorsal root)

Front 22

The nerve fibers of the ventral root are _______ and arise from cell bodies located in the _______ ______

Back 22

-Efferent
-Spinal Cord

Front 23

______ and ______ roots come together _____ to the dorsal root ganglion.

Back 23

Dorsal an ventral roots

Front 24

______ and _______ fibers intermingle to form "mixed" nature of the spinal nerve and its branches.

Back 24

Sensory and Motor

Front 25

'Smaller' Dorsal Rami

Back 25

-Course Posteriorly
-Supply deep back muscles and the skin of posterior aspect of the head, neck and trunk (Fig 3)

Front 26

'Larger' Ventral Rami

Back 26

-Innervates te anterior and lateral aspects of the trunk and all prats of the upper and lower extremities

Front 27

Unit: Dorsal and Ventral Rami

Back 27

Indt: Thoracic
Unite and Form: Cervical, Brachial, and Lumbosacral Plexuses

Front 28

Meningeal Ramus

Back 28

-Leaves the spinal nerve to re-enter the intervertebral foramen and supply the structures within the vertebral canal.

Front 29

During early development, _______ _______ is apparent, each spinal segment supplying ______ and ______ structures contatined int eh corresponding body segment or somite

Back 29

-Segmental Innervation
-Sensory and Motor

Front 30

In the adult, _______ is lost in most parts of the body. (Embryology)

Back 30

segmentation

Front 31

Adult Segmental Pattern

Back 31

-Spinal Nerve is distributed to a circular band encircling the body

Front 32

Obliteration of Regular Segmentation (Fusion)

Back 32

-Mesoderm of somites migrates distally into the limb buds and fuse=forms plexus and joins other rami

Front 33

General Rule: Each _____ entering a plexus contributes to several _______ nerves and each ____ nerve contains fibers from several ventral rami.

Back 33

-ramus
-peripheral
-peripheral (has its own area of distribution)

Front 34

Dermatome

Back 34

-Area of skin supplied by the sensory fibers of a single spinal nerve, via its dorsal and ventral rami
-supplied mainly by spinal nerve of the corresponding segment
-segments immediately above and below also contribute to its innervation

Front 35

Dermatome: Touch, Pain , Temp

Back 35

-Overlap greater for touch

Front 36

Dermatome:
-Ring Finger
-Nipples
-Umbilicus
-Inguinal Region
-Anterior Knee

Back 36

-Mid FInger: C

Front 37

Segmental Innervation: Trunk

Back 37

Corresponds to distribution of the intercostal nerves

Front 38

Segmental Innervation: Proximal Muscle of Limbs

Back 38

More Rostral segments of the cervical and lumbosacral enlargements of the spinal cord

Front 39

Segmental Innervation: Distal Muscle of Limbs

Back 39

Caudal Segments of cervical and lumbosacral enlargements of the spinal cord

Front 40

Section of a single spinal nerve _______ several muscles, but does not _______ them.

Back 40

-Weakens
-Paralyze

Front 41

Autonomic dysfunction occurs in the area of its _______.

Back 41

distribution