Spinal Cord, Nerves, and Reflexes for Final EXAM Flashcards
State the function of the spinal cord
conduction
neural integration
locomotion
reflexes
the three parts of the meninges
Dura mater
Arachnoid mater
Pia mater
Explain the location and function
Dura Mater
location: the large venous channels (dural sinuses) arachnoid
function: carrying blood from the brain toward the heart.
Explain the location and function
Arachnoid Mater
location: connect the dura mater to the pia mater
function: plays an important protective role by acting as a shock absorber.
Explain the location and function
Pia mater
location: innermost layer between arachnoid meter and brain
supply your brain tissue with blood. It also helps contain cerebrospinal fluid
carry motor information down
descending spinal tracts
carry sensory information up
ascending spinal tracts
types of neurons in ascending tracts
First-order neurons
Second-order neurons
Third-order neurons
what does Ascending tracts do
carry sensory signals up the spinal cord
name the ascending spinal tracts
-Anterior spinothalamic tract
-Lateral spinothalamic tract
-Spinoreticular tract
-Spinocerebellar tract
type of sensation that is carried by spinothalamic tract
carries signals for pain, pressure, temperature, light touch, tickle, and itch
the first, second, and third order neuron, where it crosses and synapses for
spinothalamic tract
- First-order neurons end in posterior horn
of spinal cord - Second-order neurons start in posterior
horn, then decussate and form the
spinothalamic tract - Third-order neurons continue from there
to cerebral cortex
state the type of sensation that is carried from the Spinoreticular tract
Carries pain signals resulting from tissue injury
the first, second, and third order neuron, where it crosses and synapses for Spinoreticular tract
- First-order neurons enter posterior horn and immediately synapse with second-
order neurons - Second-order neurons decussate to opposite anterolateral system; ascend the cord and end in reticular formation: loosely organized core of gray matter in the medulla and pons
- Third-order neurons continue from the pons to the thalamus
- Fourth-order neurons complete the path to the cerebral cortex
state the type of sensation that is carried from the Spinocerebellar tract
Carry proprioceptive signals from limbs and trunk up to the cerebellum
the first, second, and third order neuron, where it crosses and synapses for
Spinocerebellar Tracts
- First-order neurons originate in the muscles and tendons and end in posterior horn
of the spinal cord - Second-order nerves ascend spinocerebellar tracts and end in cerebellum providing it with feedback needed to coordinate movements
- Posterior spinocerebellar tract stays ipsilateral
- Anterior spinocerebellar tracts cross over and travel up contralateral side, but cross
back to end in ipsilateral cerebellum
what does Descending tracts do?
carry motor signals down brainstem and spinal cord
what neurons does the descending spinal tracts use
upper motor neuron
lower motor neuron
originates in cerebral cortex or brainstem and terminates on a lower motor neuron.
upper motor neuron
neurosoma is in brainstem or spinal cord. Axon leads to muscle or other target organ.
Lower motor neuron
name the descending spinal tracts
Corticospinal tract: Anterior and Lateral
Reticulospinal tract
Tectospinal tract
Corticobulbar tract
Vestibulospinal tract
what does the Corticospinal tract do?
carry signals from cerebral cortex for precise, finely coordinated
movements
where does the upper motor neuron cross for corticospinal tracts
at the pyramids (ridges on anterior surface of medulla oblongata formed from fibers of this system)
state the upper, and lower motor neuron, where it crosses and synapses for Lateral corticospinal tract
UMN (from the primary motor cortex) crosses: over at the pyramids of the medulla oblongata
UMN Synapses: lower motor neuron of anterior gray horn of spinal cord
LMN synapses: with the skeletal muscle
