Spinal cord and brainstem anatomy

Question 1

Afferent nerve fibers

Answer 1

• Sensory fibers

- Carry information from sensory receptors towards the CNS

Question 2

Efferent nerve fibers

Answer 2

Motor nerves

-Carry information from CNS to the periphery

Question 3

Spinal rootlets

Answer 3

Thin bundles of afferent and efferent fibers/axons

Question 4

Spinal root

Answer 4

Formed by group of rootlets that converge(dorsal root[sensory]/ventral root[motor])

Question 5

Spinal nerve

Answer 5

Formed by the union of the dorsal and ventral root(including autonomic)

Question 6

spinal segment

Answer 6

The region between two groups of rootlets

Question 7

Number of spinal cord pairs and groups

Answer 7

31 pairs of spinal nerves -part of the PNS

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Question 8

Cranial nerves(CN) emerging from brainstem

Answer 8

CN III -> XII

part of PNS

Question 9

Conus Medullaris

Answer 9

Between bony vertebral level L1-L2 where the spinal cord ends as a cone tip

Question 10

Caudal equina

Answer 10

Collection of nerve roots that travel inferior and continue after the conus medullaris

Question 11

Filum terminale

Answer 11

extension of the pia mater that anchors the spinal cord caudally to the coccyx

Question 12

Subdivisions of the spinal cord gray matter

Answer 12

Dorsal horn(laminae I-VI)
Intermediate zone (lamina VII)
ventral horn(Laminae VIII- IX)
area around central canal(lamina X)

Question 13

Subdivisions of the spinal cord white matter

Answer 13

Dorsal funiculus
lateral funiculus
ventral funiculus

Question 14

Propriospinal fibers

Answer 14

Confined to the spinal cord
located at the margins of the gray matter. allow for neuronal communication at the same and distant spinal cord levels probably important for reflex circuitry

Question 15

direction of white matter size change

Answer 15

Gets smaller rostral to caudal

due to more sensory fibers accumulating going rostral

Question 16

Gray matter size change

Answer 16

Cervical and lumbar enlargement

due to anterior horn cells that project their axons to the upper and lower extremeties

Question 17

Lateral horn

Answer 17

T1-L3 ONLY
gray matter
site of preganglionic sympathetic neuronal cell bodies

Question 18

Cranial nerves( list with names)

Answer 18

CN I (Olfactory)
CN II (Optic)
CN III (Oculomotor)
CN IV (Trochlear)
CN V (Trigeminal)
CN VI (Abducens)
CN VII (Facial)
CN VIII (Vestibulocochlear)
CN IX (Glossopharyngeal)
CN X (Vagus)
CN XI (Spinal Accessory)
CN XII (Hypoglossal)

Question 19

CN-I (entrance point)

Answer 19

Enters into the anterior fossa(only one)

Question 20

CN-II

Answer 20

Passes from the orbit and into the middle cranial fossa

Question 21

CN-III-VI

Answer 21

emerge from the brainstem within the posterior craial fossa, travels anteriorly to reach the middle cranial fossa where it passes through a foramen to exi the cranial cavity

Question 22

CN-VII-XII

Answer 22

emerge from the brainstem and exit from a foramen in the posterior cranial cavity

Question 23

Parts of the brainstem

Answer 23

Tectum(dorsal)
Tegmentum
Basal portion(ventral)

Question 24

Tegmentum

Answer 24

Midregion where the reticular formation is located