Anatomy of the Spinal Cord and Spinal Nerves

Question 1

what is the nervous system divided into?

Answer 1

central nervous system (brain and spinal cord)
and peripheral nervous system (cranial nerves + spinal nerves and autonomic nerve trunks with their associated ganglia)

Question 2

spinal cord conducts…

Answer 2

conducts information to and from the brain through axonal tracts

Question 3

the spinal cord connects with spinal nerves, it processes…

Answer 3

it processes afferent information from muscles, tendons, joints, ligaments, blood vessels skin and viscera and discharges efferent commands that control muscles and regulate glands

Question 4

spinal cord is a reflex centre producing…

Answer 4

producing subconscious respsonses of muscles and regulate glands

Question 5

the spinal cord is a direct continuation of…

Answer 5

the brain stem (medulla oblongata)

Question 6

where does the spinal cord leave the skull from?

Answer 6

leaves the skull from the foramen magnum and runs through the vertebral column
from medulla oblongata to the level of 6th/7th lumbar vertebrae

Question 7

centre of the spinal cord contains?

Answer 7

contains a central canal filled with CSF and lined with ependymal cells

Question 8

spinal cord is divided into?

Answer 8

into segments

Question 9

reason for dividing of spinal cord into segments?

Answer 9

is the attachment of dorsal and ventral roots

Question 10

each dorsal or ventral root is made of?

Answer 10

made of thousands of axons
axons of each root are bound together laterally and they form spinal nerves

Question 11

dorsal roots convey? and ventral roots carry?

Answer 11

dorsal roots convey sensory (afferent) input to the spinal cord and ventral roots carry motor (efferent) roots to the muscles and glands

Question 12

each segment gives rise to?

Answer 12

to paired spinal nerves

Question 13

what is the spinal ganglion present on?

Answer 13

present on each dorsal root

Question 14

cell bodies outside the brain and spinal cord are called…

Answer 14

ganglion

Question 15

paired spinal nerves emerge from the spinal cord through where?

Answer 15

through spaces formed between the vertebrae

Question 16

Dorsal branches of spinal cord (medulla spinalis) innervate?

Answer 16

epaxial tissues

Question 17

ventral branches of spinal cord innervate?

Answer 17

innervate hypaxial tissues, which include limbs

Question 18

spinal ganglion on the dorsal root just prior to?

Answer 18

just prior to its union with the ventral root at the level of intervertebral foramen

Question 20

at the thoraco-lumbar junction, how are segments positioned?

Answer 20

segments are positioned within corresponding vertebrae

Question 21

how many sacral segments are located within the L5 vertebra?

Answer 21

three

Question 22

where does functional spinal cord terminate at?

Answer 22

terminates at L6/L7

Question 23

the end of the spinal cord is the?

Answer 23

the conus medullaris

Question 24

what is the cauda equina?

Answer 24

it is the bundle of spinal nerves remaining after the termination of the spinal cord

Question 25

what does the cauda equina consist of?

Answer 25

consists of the spinal nerves L6-Cd5 and includes those that form the sciatic (L6-S1) and pudendal (S2-3) nerves

Question 26

what is the filum terminale?

Answer 26

it is a glial continuation persisting beyond the functional end of the spinal cord (contains no neural fibres, only fibrous connective tissue: strand of glial and ependymal cells) it stabilises the spinal cord by attaching distally to bony coxes

Question 27

what is the brachial nerve plexus?

Answer 27

it is a complex, interwoven network of nerves the cervical enlargement involves cord segments C6-T2 from which nerves forming the brachial plexus arise

Question 28

what is the brachial plexus formed by?

Answer 28

formed by the ventral branches of spinal nerves C6, C7, C8, T1 and T2

Question 29

large somatic nerve plexus gives origin to?

Answer 29

gives origin to the nerves that supply the thoracic limb

Question 30

lumbar nerve plexus?

Answer 30

it is a complex interwoven network of nerves lumbar enlargement with a similar relationship to the lumbosacral plexus involved cord segments L5-S1 plexus

Question 31

what is the lumbar nerve plexus formed by?

Answer 31

formed by the ventral branches of spinal nerves L4, L5, L6, L7 and S1 (may reach S3)

Question 32

gray matter - spinal cord cross section?

Answer 32

consists of neurons, neuroglia rich blood supply gray due to perikaryal (cell body) neuron cell bodies, dendrites, axons

Question 33

white matter, of spinal cord?

Answer 33

myelinated and nonmyelinated axons white due to the lipid composition of the myelin

Question 34

gray matter of spinal cord divided into?

Answer 34

divided into horns, dorsal, ventral and lateral or named columns

Question 35

dorsal horn contains?

Answer 35

contains cell bodies of the interneurons on which afferent neurons terminate

Question 36

ventral horn contains?

Answer 36

contains cell bodies of the efferent motor neurons supplying skeletal muscles

Question 37

autonomic nerve fibres supplying?

Answer 37

supplying cardiac and smooth muscle and exocrine glands originate from lateral horns

Question 38

white matter of the spinal cord is organised into?

Answer 38

into tracts (funiculus)

Question 39

tracts are grouped into?

Answer 39

into columns that extend the length of the cord each of these begins or ends within a particular area of the brain and each is specific in the type of information that it transmits

Question 40

spinal nerves (bundles of axons) connect with?

Answer 40

they connect with each side of the spinal cord by a dorsal root and ventral root

Question 41

afferent fibres carrying incoming signals enter the spinal cord through the?

Answer 41

through the dorsal root

Question 42

efferent fibres carrying outgoing signals leave through the?

Answer 42

through the ventral root

Question 43

cell bodies of afferent neurons at each levels are?

Answer 43

they are clustered to for dorsal root ganglion

Question 44

spinal nerves carry both what fibres?

Answer 44

they carry both afferent and efferent fibres

Question 45

where does the first cervical spinal nerve leave the spinal cord?

Answer 45

lateral vertebral foramina

Question 46

which roots of the spinal cord carry afferent information?

Answer 46

dorsal roots

Question 47

why must be ventral branches for brachial plexus?

Answer 47

because limbs are in ventral direction and must be last vertebrae of cervical

Question 48

thick bundle of elongated nerve roots within the lower vertebral canal is known as the?

Answer 48

known as the cauda equine