Week 7 - Spinal Cord

Question 1

In an adult, the spinal cord originates at the level of ___________, and ends at the level of ____________.

Answer 1

foramen magnum

inter-vertebral disk L1-L2

Question 2

Arbitrarily, the spinal cord is divided into _________ segments, namely: ___ cervical; ___ thoracic; ___ lumbar; ___ sacral; and ___ coccygeal. The segments are represented by emerging from the spinal cord roots of the _______ nerves.

Answer 2

31
8
12
5
5
1
spinal

Question 3

The anterior (ventral) roots of each spinal nerve represent a bundle of axons from ___________ and __________ motor neurons of the spinal cord. These neurons (soma) are correspondingly situated within the _______ gray horns and _______ gray horns of the spinal cord.

Answer 3

somatic
visceral
ventral
lateral

Question 4

The posterior (dorsal) roots of each spinal nerve represent a bundle of axons from__________ and _________ sensory neurons, somas of which are situated within __________ .

Answer 4

somatic
visceral
dorsal root ganglia

Question 5

The spinal cord is of the following approximate length __________ and width __________. It is flattened in __________________ direction.

Answer 5

45cm
2cm
anterio-posterior

Question 6

There are two spinal cord enlargements: the ________________ enlargement, which represents the _____________ segments of the spinal cord, supplying upper trunk and upper extremities, and the lumbar enlargement, which represents the segments ________________ of the spinal cord, supplying the lower trunk and the lower extremities.

Answer 6

cervical
C4-T1
T9-T12

Question 7

The spinal cord is divided onto two halves by the __________ fissure and the __________ sulcus.

Answer 7

anterior median

posterior median

Question 8

The end of the spinal cord is called ____________ as it is narrows down, and resembles a cone or a sharpened pencil. This structure is anchored to the coccyx by the extension of the pia matter, resembling thin thread. It is called: _____________.

Answer 8

conus medullaris

filum terminale

Question 9

Horizontally, the spinal cord is anchored to the spinal column by projections of the pia matter, which are called: ________________.

Answer 9

denticulate ligaments

Question 10

The spinal cord is covered by the following meninges from the outside to inside direction: ____________.

Answer 10

dura mater, arachnoid mater, pia mater

Question 11

Overall, the spinal cord is protected from the physical injury by the following layers: ________________.

Answer 11

vertebra, epidural space (adipose tissue), dura mater, arachnoid mater, subarachnoid space (CSF), pia mater

Question 12

The outside matter of the spinal cord is _______________ and represents spinal cord ________________. There are the following white matter columns: __________________________.

Answer 12

white matter
funiculli
anterior white columns, posterior white columns, lateral white columns

Question 13

List spinal cord tracts to master and whether they are motor or sensory tracts: _______________________________.

Answer 13

pyramidal/corticospinal tracts - motor

dorsal column tracts, spinocerebellar tracts, spinal thalamic tracts - sensory

Question 14

The gray matter of the spinal cord is in a shape of a _________, and is comprised of ___________. There are ________ horns, ____________ horns, and in some segments (____________) ___________ horns.

Answer 14

H or butterfly
horns
anterior
posterior
thoracic, lumbar, sacral (T1-L3, S2-S4)
lateral

Question 15

Posterior or dorsal horns hold ______ neurons. Anterior or ventral horns hold __________ neurons. Lateral horns hold _________ neurons.

Answer 15

somatic & visceral sensory
soma of somatic motor
soma of visceral motor

Question 16

The cross-bar of the gray matter and surrounding white matter represent the connections between right and left halves of the spinal cord. They are called respectively as the following: __________ and ___________.

Answer 16

median gray commissure

median white commissure

Question 17

Cortico-spinal (pyramidal) R/L tracts (situated within ____________ and ___________ columns of the spinal cord), are efferent tracts, connecting upper motor neurons of the opposite hemisphere with the lower motor neurons of the _______________. This paired tract provides conscious control of _________________.

Answer 17

lateral
anterior
ventral gray horns of the spinal cord
skeletal muscle contraction

Question 18

Posterior (dorsal) column R/L tracts are afferent tracts, conducting the following sensations from the body below the head to the opposite hemisphere (somato-sensory areas) via the thalami for the conscious use: ______________.

Answer 18

conscious proprioception, vibration, fine touch, stereognosis

Question 19

Spino-cerebellar (R/L postero- and antero-lateral) tracts are afferent tracts, carrying the following sensations from the body below the head to the corresponding cerebellar hemispheres for sub-conscious use: __________.

Answer 19

subconcious proprioception, vibration

Question 20

Spino-thalamic tracts (R/L lateral and anterior) are afferent tracts providing the following sensations from the body below the head to the contra-lateral thalamus, and, subsequently, to the somato-sensory areas of the opposite site hemispheres: _____________________.

Answer 20

pain, temperature, light or crude touch

Question 21

Spinal nerves are very short. They are only ________cm in length. They are located within _______.

Answer 21

1

intervertebral foramena

Question 22

First seven cervical spinal nerves emerge from the spinal cord at the level: ____________.

Answer 22

above corresponding vertebrae

Question 23

The eighth cervical spinal nerve emerges from the spinal cord at the level of: _________________.

Answer 23

between C7 & T1

Question 24

All subsequent spinal nerves below C8 emerge from the spinal cord at the level of: ___________.

Answer 24

below corresponding vertebra

Question 25

The spinal nerves, emerging from the spinal cord below vertebrae L2, comprise the following “tail-like” structure: ______________.

Answer 25

cauda equina

Question 26

As the spinal nerves emerge from the spinal cord, they split onto ____________ and ____________ rami.

Answer 26

posterior/dorsal

anterior/ventral

Question 27

_____________ rami of certain spinal nerves represent the roots of _____________ nerves. They intermingle together and comprise the plexi (networks) of ___________ nerves.

Answer 27

anterior
peripheral
peripheral

Question 28

Retrograde degeneration of a neuron is __________

Answer 28

degeneration along an axon approaching the soma

Question 29

Anterograde degeneration of a neuron is ________. It is also known as _________

Answer 29

degeneration along an axon approaching the synaptic plate

Wallerian degeneration

Question 30

The CNS develops from which embryonic layer?

Answer 30

ectoderm

Question 31

Describe sensory pathway from 1st order to 3rd order sensory neurons

Answer 31

dorsal root ganglia
posterior/dorsal horns (spinal gray matter)
thalamus

Question 32

Anterior/Ventral rami supply the __________ of the body, including _________ extremities

Answer 32

muscles and the skin of the sides and front of the body

upper & lower

Question 33

Posterior/Dorsal rami supply the __________

Answer 33

back of the trunk