the spinal chord 14

Question 1

Are the spinal cord meninges continuous with the brain meninges?

Answer 1

Yes.

Question 2

What kind of cavity is the spinal cord found in?

Answer 2

The vertebral cavity, surrounded by bone for protection.

Question 3

the spinal cord is wrapped in meninges for additional protection, what are the 3 layers of connective tissue called?

Answer 3

Outer - dura mater
middle - arachnoid mater
inner - pia mater

Question 4

describe dura mater (outer meninge).

Answer 4

tough and dense connective tissue.

Question 5

what is epidural space?

Answer 5

Lies between dura matter and vertebral column, filled with fat and connective tissue.

Question 6

what is arachnoid mater (middle meninge) madeup of?

Answer 6

Web-like arrangement of collagen and elastic fibres.

Question 7

where does the sub-arachnoid space lie?

Answer 7

below the arachnoid layer and contains cerebrospinal fluid.

Question 7

what is the pia mater (inner meninge) made up of?

Answer 7

transparent layer of collagen and elastic fibres.
it adheres to surface of spinal cord and brain,
contains numerous blood vessels

Question 8

what length is the spinal cord?

Answer 8

ranges from 42-45 cm.

Question 9

wheredoes the spinal cord start and end?

Answer 9

extends from medulla oblongata to 2nd lumbar vertebra.

Question 10

what is the caudal equina (horses tail) formed by?

Answer 10

nerves from lumbar, sacral, and coccygeal regions.

Question 11

what 2 grooves divide the left and right halves of spinal cord.

Answer 11

anterior median fissure and posterior median sulcus.

Question 12

what shape is grey matter on spinal cord?

Answer 12

H shape with 3 horns on each side - anterior, posterior and lateral.

Question 13

the anterior side of grey matter in spinal cord has what type of neurons?

Answer 13

somatic motor neurons.

Question 14

the posterior side of grey matter in spinal cord has what type of neurons?

Answer 14

sensory neurons (somatic and autonomic).

Question 15

the lateral side of grey matter in spinal cord has what type of neurons.

Answer 15

autonomic motor neurons.

Question 16

white matter in spinal cord is organised into columns, what are they?

Answer 16

anterior, posterior, lateral white columns.

Question 17

what do sensory neurons do?

Answer 17

ascending tracts - carry information toward the brain.

Question 18

what do motor neurons do?

Answer 18

depending tracts = carry information down the spinal cord.

Question 19

how many axons/roots to spinal nerves have?

Answer 19

2 bundles of axons.

Question 20

are dorsal roots (posterior rootlets) sensory or Motor axons ?

Answer 20

only sensory axons.

Question 21

are ventral roots/ anterior rootlets sensory or motor axons?

Answer 21

they are somatic and autonomic motor neurons.

Question 22

which nerve, sensory or motor, has circular cell body?

Answer 22

sensory nerve.

Question 23

spinal nerves are named and numbered according to what?

Answer 23

the level of vertebra they energy from.

Question 24

name some functions of the spinal cord.

Answer 24

-routes signals along pathways.
-the grey matter integrates signals.
-reflex= fast involuntary sequence of actions in response to a stimulus.
-inborn reflex eg withdrawal reflex.
- newborn reflexes
learned reflexes eg driving skills
- spinal or cranial integration.

Question 25

what are the steps of reflex arc (patellar reflex)

Answer 25

1) Sensory receptor- responds to stimulus
(Tap below patella)
2) Sensory neuron- to dorsal horn & brain
3) Integrating centre- e.g. single synapse
(Sensory to motor neurons)
4) Motor neuron- from centre to effector
(Via ventral horn)
5) Effector- responder (muscle)