Chapter 16 Flashcards
Ascending tracts
Cary information up to the brain
-sensory
Descending tracts
Carry information down to effector
-motor
White matter
-spinal nerves
-ascending and descending tracts
Grey matter
-reflex arc
-autonomic nuclei
Function of the spinal nerves
-pathway for sensory and motor impulses
-reflexes
Spinal meninges
Cover the spinal card
cerebrospinal fluid
Shock absorbing fluid in the spinal cord
Denticulate ligaments
Thickenings of the pia mater
-that project and connect the arachnoid mater to the dura mater
Dura mater
-most superficial
-dense irregular connective tissue
Epidural space
Space between the dura mater and wall of vertebral canal
Arachnoid mater
Middle layer
-avascular covering
-delicate collagen fibres, elastic fibres
Subdural space
Between the dura and arachnoid mater
-contains interstitial fluid
Pia mater
-innermost
-highly vascular
-adheres to the surface of the spinal cord and brain
-contains thin squamous to cubdoial cells
-collagen and elastic fibres
Five parts of the spinal cord
-cervical
-thoracic
-lumbar
-sacral
-coccygeal
Conus medullaris
Tapering inferior end of the spinal cord
Cauda equina
Horses tail
-extends inferioraly from the spinal cords conus medullaris
Film terminal
Attaches conus medullaris to coccyx
Cervical enlargement
Located: inferior cervical part
Function: Innervates upper limbs
Lumbosacral enlargement
Location: through lumbar and sacral
Function: Innervates lower limbs
What are the two longitudinal depressions of the spinal cord
-posterior median sulcus
-anterior median fissure
How many cervical nerves
8
Thoracic nerves
12
Central canal
Circulates the cerebral spinal fluid throughout the spinal cord
Lumbar nerves
5
sacral nerves
5
Coccygeal nerves
1
Grey matter is made up of
Dendrites and cell bodies of neurons
-unmyelinated
White matter is made of up
Myelinated axons
White matter three sub parts
-posterior funiculus
-lateral funiculus
-anterior funiculus
Anterior horn
Somatic motor neuron
-integrates the skeletal muscle
Lateral horn
Autonomic motor neuron
-innervate cardia, smooth and glands
Grey matter four sub parts
-posterior horn
-lateral horn
-anterior horn
-grey commissure
Posterior horn
Incoming sensory information
-terminates here
Gray commissure
Houses narrow central canal
Posterior root
Sensory axons
Anterior root
Motor axons
Rootlets form a
Spinal nerve
Posterior ramus
Innervates deep muscles and skin of the back
Anterior ramus
Innervates anterior and lateral portions of the trunk, upper and lower limbs
Principal plexuses
-cervical
-brachial
-lumbar
-sacral
Plexuses
Axons from anterior rami
-innervate body structures
