spinal cord, nerves and injuries

Question 1

what does the spinal cord end at?

Answer 1

conus medullaris

Question 2

what anchors spinal cord to coccyx?

Answer 2

filum terminale

Question 3

where does the spinal cord end on the vertebral column?

Answer 3

L1 or L2 in adults and L4 in infants

Question 4

what is the collection of nerve roots at the end of the spinal cord called?

Answer 4

cauda equina

Question 5

what are the three meningeal layers?

Answer 5

• dura mater
• arachnoid
• pia

Question 6

what is the arachnoid mater separated from the dura mater by?

Answer 6

subdural space

Question 7

what is the subarachnoid space filled with?

Answer 7

CSF and blood vessels

Question 8

what does the pia mater contain?

Answer 8

rich supply of blood vessels

Question 9

how many pairs of spinal nerves are there?

Answer 9

31

Question 10

what do dorsal roots of the spinal cord contain and relay?

Answer 10

cell bodies of sensory neurons within dorsal root ganglion that relay sensory input

Question 11

what do ventral roots contain and relay?

Answer 11

contain axons of motor neurons (somatic) and relay motor commands to effector glands and muscles

Question 12

what are the two grooves on spinal cord cross-section?

Answer 12

ventral and dorsal median fissure

Question 13

do afferent fibers carry impulses or relay outgoing impulses?

Answer 13

incoming

Question 14

what do the lateral horns contain?

Answer 14

consist of cell bodies of autonomic motor neurons

Question 15

what are the three white columns?

Answer 15

• dorsal
• lateral
• ventral

Question 16

what are the three directions fibres of white columns may run?

Answer 16

• ascending
• descending
• transverse

Question 17

what are pathway characteristics of spinal cord?

Answer 17

• decussation
• relay
• somatotopy
• symmetry

Question 18

what do the tracts dorsal column-medial lemniscal, fasciculus cuneatus/gracilis relay?

Answer 18

• fine touch
• vibration
• pressure
• proprioception (conscious)

Question 19

what does the lateral spinothalamic tract relay?

Answer 19

pain and temp

Question 20

what do the anterior (ventral) and posterior (dorsal) spinocerebellar tracts relay?

Answer 20

proprioception (unconscious)

Question 21

what does the anterior (ventral) spinothalamic tract relay?

Answer 21

crude touch

Question 22

what does the lateral corticospinal tract relay motor commands of?

Answer 22

voluntary motor commands that control skeletal muscles of limbs

Question 23

what does the ventral corticospinal tract relay motor commands of?

Answer 23

voluntary motor commands that control skeletal muscles of the axial skeleton, pectoral girdle, and pelvic girdle

Question 24

what are the motor commands relayed by the tectospinal tract?

Answer 24

turns neck so eyes can focus on moving object

Question 25

what are the motor commands relayed by the vestibulospinal tract?

Answer 25

maintains muscle tone and balance

Question 26

what are the motor commands relayed by the rubrospinal tract?

Answer 26

possibly influences the tone of distal limb flexor muscles

Question 27

what are the motor commands relayed by the reticulospinal tract?

Answer 27

muscle tone and visceral motor functions

Question 28

what is paralysis in spinal cord injuries?

Answer 28

loss of motor functions

Question 29

what is paraesthesias?

Answer 29

abnormal sensations, sensory loss

Question 30

what leads to flaccid paralysis?

Answer 30

damage to lower motor neurons in the ventral horn

Question 31

what is spastic paralysis?

Answer 31

damage to PMC or to upper motor neuron tracts