the spinal chord 14 Flashcards
Are the spinal cord meninges continuous with the brain meninges?
Yes.
What kind of cavity is the spinal cord found in?
The vertebral cavity, surrounded by bone for protection.
the spinal cord is wrapped in meninges for additional protection, what are the 3 layers of connective tissue called?
Outer - dura mater
middle - arachnoid mater
inner - pia mater
describe dura mater (outer meninge).
tough and dense connective tissue.
what is epidural space?
Lies between dura matter and vertebral column, filled with fat and connective tissue.
what is arachnoid mater (middle meninge) madeup of?
Web-like arrangement of collagen and elastic fibres.
where does the sub-arachnoid space lie?
below the arachnoid layer and contains cerebrospinal fluid.
what is the pia mater (inner meninge) made up of?
transparent layer of collagen and elastic fibres.
it adheres to surface of spinal cord and brain,
contains numerous blood vessels
what length is the spinal cord?
ranges from 42-45 cm.
wheredoes the spinal cord start and end?
extends from medulla oblongata to 2nd lumbar vertebra.
what is the caudal equina (horses tail) formed by?
nerves from lumbar, sacral, and coccygeal regions.
what 2 grooves divide the left and right halves of spinal cord.
anterior median fissure and posterior median sulcus.
what shape is grey matter on spinal cord?
H shape with 3 horns on each side - anterior, posterior and lateral.
the anterior side of grey matter in spinal cord has what type of neurons?
somatic motor neurons.
the posterior side of grey matter in spinal cord has what type of neurons?
sensory neurons (somatic and autonomic).
the lateral side of grey matter in spinal cord has what type of neurons.
autonomic motor neurons.
white matter in spinal cord is organised into columns, what are they?
anterior, posterior, lateral white columns.
what do sensory neurons do?
ascending tracts - carry information toward the brain.
what do motor neurons do?
depending tracts = carry information down the spinal cord.
how many axons/roots to spinal nerves have?
2 bundles of axons.
are dorsal roots (posterior rootlets) sensory or Motor axons ?
only sensory axons.
are ventral roots/ anterior rootlets sensory or motor axons?
they are somatic and autonomic motor neurons.
which nerve, sensory or motor, has circular cell body?
sensory nerve.
spinal nerves are named and numbered according to what?
the level of vertebra they energy from.
name some functions of the spinal cord.
-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.
what are the steps of reflex arc (patellar reflex)
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)
