Overview and Development of Back

Question 1

Anterior horn

Answer 1

Lower motor neuron cell bodies

Question 2

Anterior roots

Answer 2

Lower motor axons

Question 3

Posterior horn

Answer 3

Sensory neuron cell bodies

Question 4

Posterior roots

Answer 4

Sensory axons

Question 5

Posterior root ganglion

Answer 5

Sensory neuron cell bodies

Question 6

Spinal nerve

Answer 6

Mixed motor and sensory axons

Question 7

Anterior rami

Answer 7

Motor and sensory axons to muscles and skin of the anterior trunk and limbs

Question 8

Posterior rami

Answer 8

Motor and sensory axons to muscles and skin of the back

Question 9

C4 dermatome

Answer 9

Top of shoulder

Question 10

C6 dermatome

Answer 10

Thumb

Question 11

C8 dermatome

Answer 11

5th digit of hand

Question 12

T4 dermatome

Answer 12

Nipple

Question 13

T10 dermatome

Answer 13

umbilicus

Question 14

L1 dermatome

Answer 14

inguinal region

Question 15

L4 dermatome

Answer 15

medial heel and ankle

Question 16

L5 dermatome

Answer 16

antero-lateral leg and dorsum of foot

Question 17

S1 dermatome

Answer 17

posterior lateral lower limb

Question 18

S2 dermatome

Answer 18

Posterior medial lower limb

Question 19

Denticulate ligament

Answer 19

Tether pia mater and spinal cord to dura mater; divide anterior and posterior roots within dural sheath

Question 20

How far does the spinal cord extend in the vertebral column? What are the anterior and posterior roots called that stretch below that?

Answer 20

~L2; cauda equina

Question 21

Tip of spinal cord

Answer 21

Conus medullaris

Question 22

Thread of pia mater that tethers the conus medullaris to the coccyx

Answer 22

Filum terminale

Question 23

Anesthetic injection can be where…?

Answer 23

Epidural space or sacral hiatus

Question 24

Sample CSF from?..

Answer 24

subarachnoid space

Question 25

Structures encountered on a midline tap

Answer 25

Skin >> subcutaneous fat >> thoracolumbar fascia >> supraspinous ligament >> interspinous ligament >> dura mater >> arachnoid mater >> subarachnoid space

Question 26

Ascent of spinal cord

Answer 26

3 month embryo - spinal cord runs full length of vertebral canal 5 month embryo - conus medullaris at S1 level Newborn - conus at L3 level

Question 27

Nutrient arteries

Answer 27

Given off of large vessels to supply periosteum

Question 28

Posterior branches of arterial supply

Answer 28

Supply transverse and spinous processes and back muscles

Question 29

Spinal branches of arterial supply

Answer 29

Enter intervertebral foramina and split to supply bone and meninges

Question 30

Posterior and anterior spinal artery

Answer 30

Supply spinal cord; run along length

Question 31

Radicular or segmental medullary arteries

Answer 31

Travel along spinal nerve and roots

Question 32

Venous drainage

Answer 32

Spinal veins and basivertebral veins>> internal and external vertebral venous plexus >> large veins of body and heart

Question 33

Somites

Answer 33

4 occipital, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 2-3 coccygeal; develop on either side of the neural tube and notochord

Question 34

Each somite breaks into 3 functionally different parts...

Answer 34

Dermatome - deep dermis of body Myotome - muscle of body wall and limbs Sclerotome - vertebrae and axial bones

Question 35

Origin of typical spinal nerve

Answer 35

Anterior horn axons - myotome Posterior root ganglion axons - dermatome and posterior horn Sclerotomes - split in half as fissures develop so axons can pass

Question 36

Vertebral development

Answer 36

Intervertebral discs and intervertebral foramina will remain at fissure sites Annulus fibrosis develops from sclerotome Nucleus pulposus - notochord

Question 37

Primary ossification centers

Answer 37

Form in vertebral body, pedicles, and lamina

Question 38

Secondary ossification centers

Answer 38

Transverse and spinous processes; fuse to rest of vertebra

Question 39

Spina bifida occulta

Answer 39

Failure of neural arch (spinous process) to ossify; marked by tuft of hair

Question 40

Meningocele

Answer 40

Meninges and CSF herniate through the hole left by the failed neural arch

Question 41

Meningomyelocele

Answer 41

Same as meningocele with added herniation of the spinal cord and/or roots

Question 42

Rachischisis

Answer 42

Failure of neural tube to fold properly; neural arch cannot form; typically lose motor function

Question 43

Lumbarization of S1 or Sacralization of L5 vertebrae caused by...

Answer 43

Abnormalities in Hox gene expression

Question 44

Innvervation of dura mater

Answer 44

Recurrent meningeal nerves