The Spine

Question 1

what are the three functions of the spinal cord?

Answer 1

sensory in from body to brain, motor from brain to body and controls reflexes

Question 2

what is the spinal cord protected by?

Answer 2

meninges

Question 3

what are meninges?

Answer 3

membranes that cover the spinal cord and brain

Question 4

what are the layers of meninges?

Answer 4

Dura mater (leather like), subdural space filled with interstitial fluid, Arachnoid mater, subarachnoid space filled with CSF, pia mater (thin layer lining)

Question 5

spinal cord in new born is from?

Answer 5

magnum foramen to L4

Question 6

spinal cord in adult is from?

Answer 6

magnum foramen to L1

Question 7

spinal nerve is composed of what two roots?

Answer 7

dorsal - sensory and ventral - motor

Question 8

dorsal root gangion are composed of?

Answer 8

cell bodies of sensory neurons

Question 9

what are the sensory tracts in the spinal cord?

Answer 9

1. dorsal columns 2. spinothalamic tracts 3. spinocerebellar tracts

Question 10

what is the dorsal column responsible for?

Answer 10

proprioception, vibration, pressure, two point discriminative, discriminative touch

Question 11

what is the spinothalamic responsible for?

Answer 11

temperature, pain, deep pressure, crude touch

Question 12

what is the spinocerebellar responsible for?

Answer 12

unconscious proprioception

Question 13

what are the motor tracts in the spinal cord?

Answer 13

direct (pyramidal) pathway and indirect (extrapyramidal) pathway

Question 14

what is direct (pyramidal) tract responsible for?

Answer 14

precise, voluntary movement

Question 15

what is indirect (extrapyramidal) pathways responsible for?

Answer 15

programmed/automatic movement

Question 16

what are intergrating centres?

Answer 16

found in CNS where sensory impulses are relayed to motor neurons

Question 17

what are flexes?

Answer 17

automatice responses to environmental change

Question 18

what type of reflexes are there?

Answer 18

stretch, tendon, cross extensor and flexor reflex

Question 19

what is stretch reflex?

Answer 19

mono synaptic reflex, to prevent over stretching

Question 20

what is tendon reflex?

Answer 20

when tendon stretches, muscle relaxes and antagonistic muscle contracts

Question 21

what is flexor reflex?

Answer 21

pain signal activates motor fibre and muscle group pulls away from pain

Question 22

what is cross extensor reflex?

Answer 22

occurs with flexor reflex, after limb pulls away, contralateral limb comes in place to maintain balance

Question 23

spinal nerves is branched from?

Answer 23

the spinal cord through intervertebral foramina

Question 24

how many pairs of spinal nerves are there?

Answer 24

31 pairs

Question 25

how many spinal nerves are there is each category?

Answer 25

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

Question 26

what are plexus?

Answer 26

network of nerves

Question 27

what are the plexus of the body?

Answer 27

cervical (phrenic), brachial (ulnar, median, radial), lumbar (femoral), sacral (sciatic)

Question 28

significance of Cervical plexus

Answer 28

ventral rami of c1-c5, skin and muscles of head, neck and superior shoulders and chest - phrenic nerve *phrenic nerve*

Question 29

significance of Brachial plexus

Answer 29

ventral rami of c5 - T1, shoulders and upper limbs, roots from superior, middle and inferior trunk *ulnar, medial, radial nerve*

Question 30

significance of lumbar plexus

Answer 30

L1-L4, innervates abdominal wall, external genitals and anterior-medial thigh *femoral nerve*

Question 31

significance of sacral plexus

Answer 31

L4-S4, innervates buttocks, perineum and part of lower limb *sciatic nerve*

Question 32

what are dermatones?

Answer 32

area of skin that is supplied by 1 nerve, overlapping prevents loss of sensation if 1 nerve damage

Question 33

to induce local anesthetics

Answer 33

3 nerves needs to be blocked