spinal cord and spinal nerves

Question 1

describe arachnoid mater

Answer 1

• thinner more delicate than dura
• continuous w/ arachnoid
• ends at S2

Question 2

what is the main function of denticulate ligament

Answer 2

anchor spinal cord to dura

Question 3

structure and function of filum terminale

Answer 3

• only pia mater no neurons

- anchor spinal cord to coccyx

Question 4

where is the epidural space and what does it contain

Answer 4

• btwn bones forming vertebral canal and dura mater

- contains: fat, vertebral plexus of veins

Question 5

where is the subarachnoid space and what does it contain

Answer 5

• btwn pia and arachnoid mater
• ends at S2
• contains: CSF

Question 6

what is the function of the motor neuron

Answer 6

• info sent from spinal cord to muscle

- efferent pathway

Question 7

what are the components of the motor neuron

Answer 7

• cell body: found in ventral grey matter of spinal cord
• one axon connected to cell body
• upper and lower neurons

Question 8

upper vs lower neurons of motor neurons

Answer 8

• upper: before it exits the spinal cord

- lower: leaving the spinal cord to go to muscles

Question 9

what is the function of a sensory neuron

Answer 9

• info sent from peripheral receptor to spinal cord

- afferent pathway

Question 10

components of sensory neuron

Answer 10

• cell body found in dorsal root ganglia

- one axon that splits into peripheral and central processes

Question 11

peripheral vs central processes of the sensory neuron’s axon

Answer 11

• peripheral: goes to skin to get signals then back to cell body
• central: leaves the cell body and goes to spinal cord

Question 12

where does the spinal cord start and end

Answer 12

• continuation of medulla oblongata of brain stem

- ends at conus medullaris @ L1/L2

Question 13

what and where are the spinal cord enlargements

Answer 13

• lots of neurons to innervate upper and lower limbs
• cervical: C4-T1
• lumbosacral: L4-S3

Question 14

what does grey matter contain?

Answer 14

• unmyelinated axons
• cell bodies of interneurons
• cell bodies of motor neurons in ventral horn

Question 15

what does white matter contain

Answer 15

• myelinated axons
• sensory neurons carrying info to spinal cord
• connecting neurons whose axons relay info to brain
• motor neurons whose axons convey info from brain to spinal cord

Question 16

where are segmetns located in the cervical region of the spinal cord

Answer 16

• next to corresponding vertebrae

- take almost vertical path before leaving spinal cord

Question 17

where are segments located T1-Cox

Answer 17

• segments originate superior to corresponding vertebrae

- dont exit intervertebral foramen until below corresping vertebrae

Question 18

what kind of neurons to spinal nerves contain

Answer 18

sensory (dorsal ROOTS) and motor (ventral ROOTS)

Question 19

what happens when the spinal nerve exits the intervertebral foramen?

Answer 19

-splits into dorsal and ventral ramus

Question 20

what are somatic nerve plexi

Answer 20

ventral rami from specific segemtns of spinal coredthat innervates skin and musles of specific region of body

Question 21

what and where are the 4 somatic nerve plexi

Answer 21

• cervical: C1-4
• brachial: C5-T1
• lumbar: L1-4
• sacral: L4-S4

Question 22

where do the 4 somatic nerve plexi innervate

Answer 22

• cervical: anterior and lateral back
• brachial: upper limb
• lumbar: anterior and medial thigh and lower ab wall
• sacral: poasterior thight, gluteal region, perineum, leg and foot

Question 23

what happens when there is a complete lesion to a nerve

Answer 23

paralysis of muscles supplied by damaged nerve if there are no other nerves innervating those muscles

Question 24

what happens when there is a branch lesion to a nerve

Answer 24

paralysis of the muscles supplied by that branch along w/ loss of senssation

Question 25

what happens when there is a lesion to a spinal nerve

Answer 25

• muscles weakness

- partial loss of sensation

Question 26

what happens where there is a lesion to the spinal cord

Answer 26

widespread bilateral loss of sensation and muscle paralysis below site of injury