module 5 Flashcards
whats the five regions of the spinal cord top to bottom
cervical thoracic lumbar sacral coccyx
where does the spinal cord terminate
conus medullaris
how many cranial nerves does each section of the spinal cord have
cervical nerves=8 thoracic nerves=12 lumbar nerves=5 sacral nerves =5 coccygeal nerves=1
whats the spinal cord enclose and protected by
the verbal column
what do the Doral roots contain
axons of sensory neurons
what do dorsal roots ganglion contain
cell bodies of sensory neurons
what do ventral roots contain
axons of motor neurons
what does damage within spinal or peripheral nerve equal
a loss of sensation
sharp, stabbing pain
Abnormal sensation- tingling, numbness, prickling, itching or burning
Muscle paralysis
Loss of relax activity
A drop in blood pressure
Problems with digestion, urination and defection
whats the caudal equina
the The lumbar, sacral and coccygeal nerve roots travel beyond the conic medallaris to reach the point of spinal nerve exit from the vertebral column.
-this collection of nerve roots
protection of spinal cord
vertebral column
Cerebrospinal fluid: also nourishes the neural tissue and removes waste products
Spinal meninges
what are the spinal meninges
(Same order as brain)
Dura matter
Subdural space (serous fluid and blood vessels)
Arachnidoid mater
Subarachnoid space (CFS and blood vessels)
Pia mater
whats the spinal meninges separated from the vertebral columns by
an epidural space
filled with adipose tissue and blood vessels
Site of anaesthetic injection eg during child birth
whats a lumbar puncture involve and used to do
involves the insertions of a needle into the subarachnoid space beyond L3
-does not damage spinal cord
used to windrow CFS fluid for diagnostic testing (eg. Meningitis) or reducing intracranial pressure
Used to administer drugs
whats the neural tissue of the spinal cord
divides into a left and right side by two groves. Anterior (ventral) median fissure and posterior (dorsal) median sulcus
whats the arrangement of white and grey matter I spinal cord
Identical arrangement on both sides
OUTER white matter INNER grey matter (opposite to the brain)
what the posterior (dorsal) side do
receives and processes sensory input
whats the anterior (ventral) side do
receives and directs motor output
whats gray matter composed of in spinal cord
composed of neuron cell bodies and dendrites, unmyelinated axons and neuroglia.
Varies in size down the spinal cord
Encloses a central canal, filled with cerebrospinal fluid
whats the grey commissure
connects the two gray matter halves and is the site where axons cross from one side of the CNS to the other. (is why the right side of the brain goes to the left side of the body and viversa.
what the posterior(dorsal) grey horns contain
contain sensory nuclei, receive and process incoming sensory input.
Sensory nuclei of posterior gray horns, contain the cell bodies of interneurons.
STEPS: cell bodies of interneurons to Doral root to dorsal root ganglion to axon of sensory neuron.
whats the lateral grey horns contain
contains motor nuclei, receives and direct autonomic motor output to effectors.
Autonomic motor nuclei of lateral grey horns, contain the cell bodies of preganglion neurones which receive autonomy motor output from; hypothalamus, reflex centres within the spinal cord ALO direct motor output towards glands, cardiac and smooth muscles.
where are lateral grey horn located
thoracic and lumbar regions only
what does anterior (ventral) grey horns contain
contains motor nuclei, receive and direct somatic motor output to effectors
Somatic motor nucleus of the anterior grey horns, contain the cell bodies of lower motor neurone, recieve somatic motor output from; primary motor cortex and reflex centres within the spinal cord ALSO direct motor output towards skeletal muscles.
whats white matter composed of
composed of myelinated(mainly) and unmyelinated axons.
anterior white commissure; connects the two white matter halves and is the site where axons cross from one side of the CNS to the other
whats the white matter subdivided into
Posterior (dorsal) white columns
Lateral white columns
Anterior (ventrail) white columns
what do white columns contain
ascending and descending spinal cord tracts= bundles of axons
what do ascending tracts do
onduct sensory input to the brain
what does descending tracts do
conduct motor output away from the brain.
what does the name of the tract reveal
Eg. Lateral spinothalmic tract
origin=spine
Destination=thalamus
Tract location= lateral white column
whats the fascicles gracilis and faciculus cuneatus sensory information conducted
fine touch, vibration, pressure, proprioception (conscious)
whats the lateral spinothalamic sensory information conducted
pain and temperature
anterior (ventral) spinocerebellar
posterior (dorsal) spinocerebellar
proprioception (unconscious)
anterior (ventral) spinothalamic
crude touch, pressure
lateral corticospinal tracts do
somatic motor output that controls the skeletal muscles of the limbs
anterior (ventral) corticospinal tracts
somatic motor output that control the skeletal muscles of the axil skeleton neck and trunk
what does the spinothalamic pathway steps
first order neurons conduct sensory input from receptor into the spinal cord via a dorsal root.
synapse with second order neutrons within a sensory nucleus of a posterior tray horn.
Second order neurons:
conduct sensory input to the thalamus
Amend the spinal cord in a anterior spinothalmic tract (for crude touch and pressure) and a lateral spinothalamic tracts (for pain and temperature sensations)
Synapse with third order neutrons in the thalamus.
Third order neurons:
- conduct sensory input to the primary somatosensory context.
whats the posterior column pathway steps
First order neurons:
- conduct sensory input into the spinal cord (via Dorsal root) and up to the medulla oblongata.
-ascend the spinal cord in a fascicles gracilis or fascicles cuneatus tract
synapse with second order neurons in medulla oblongata.
Second oder Neurons:
conduct sensory input to the thalamus
Synapse with third oder neurons in the thalamus.
Third order Neuron:
- conduct the sensory input to the PNS.
whats the spinocerebellar pathway steps
First order neurons:
conduct sensory input from proprioceptors into the spinal cord via a dorsal root.
Synapse with second order neurons within a sensory nucleus of a posterior tray horn.
Second order neurons:
conduct sensory input to the cerebellum
Ascend the spinal cord in an anterior or posterior spinocerbellar tract (DAMAGE to this tract will impair cerebellar function).
- cerebellum uses this propioceptive information to maintain posture, balance, and ensure smooth, coordinated movements (conscious).
whats the lateral corticospinal pathway
Upper motor neurons:
conduct somatic motor output from primary motor cortex
Descend the spinal cord in a lateral cortcospinal tract.
Direct the motor output to lower motor neurone in a motor nucleus of an anterior gray horn.
Lower motor neurone:
exit via spinal cord via vernal root.
whats the anterior coritcospinal pathway steps
Upper motor neurons:
conducts somatic motor output from primary motor cortex
Descend the spinal cord in an anterior corticospinal tract
Synapses with lower motor neuron in a motor nucleus of an anterior gray horn.
Lower motor neurone:
exist the spinal cord via ventral root.
steps of spinal reflex
Reception (skin) Sensory neuron Reflex center Motor neuron Effector (muscle or gland)
what does damage to posterior grey horns or sending sensory tracts within the posterior lateral or anterior white columns
loss of sensation
damage to anterior grey horns or corticospinal tracts within lateral and anterior white columns
spastic or flaccid paralysis
whats spastic paralysis
occurs when upper motor neurons within the corticospinal tracts (or primary motor cortex) are damaged.
loss of voluntary movement
Reflex activity intact (may exhibit signs of hyperreflexia)
whats flaccid paralysis
occurs when the lower motor neurones of the anterior grey horns (or ventral nerve roots) are damaged
loss of voluntary movement and reflex activity to muscle atrophy.
whats a complete transection of spinal cord result
in a total loss of sensation and paralysis in body regions below the level of the lesion.
normal reflex activity below the level of the lesion
whats a transection between T1-L1 causes
paraplegia
whats a transection in the cervical region
quadriplegia
whats spinal cord shock
a transient period of complete sensory loss, paralysis, and a loss of all reflexes (somatic and autonomic) below the level of the lesion.
Reflexes activity gradually returns, can last few hours to few months.
