A And P Chapter 13a Spinal Cord Flashcards
What is the dural sheath
Dura mater from brain extended to spinal cord called dural sheath. Outermost meninges of spinal cord
Describe epidural space
Sits outside dural sheath (epi). Fatty and vascularized space.
Where are epidurals performed
Epidural space
What is the conus medullaris
Cone shaped ending of spinal cord at L2
What is the filum terminale
Extension of the Pia mater. From ending of spinal cord (conus medullaris) and anchors on coccyx.
What are denticulate ligaments
Pia mater extensions that attach spinal cord to the vertebral walls. Entire length of cord
What is the cauda equina
Horse tail shaped. Nerve roots in inferior vertebral canal, distal to conus medularis. the collection of these nerves at the end of the spinal cord. These nerves send and receive messages to and from the lower limbs and pelvic organs
How many pairs of spinal nerves
31
What are cervical and lumbar enlargements
Where nerves serving upper and lower limbs shoot out
Where is the lateral horn seen and what does it contain
T2 to L1. Contains neurons of sympathetic NS
Why is there no enlargement of thoracic spine
Need space for sympathetic NS which arises from lateral horn
Name the order of the meninges from superficial to deep
Dural sheath, arachnoid mater, Pia mater
Where to motor neurons emerge
Ventral horns of gray matter to ventral root of spinal nerve
Where do sensory neurons emerge from and their continuing path
Dorsal horn to dorsal root to dorsal root ganglion to spinal nerve
Where is the body of sensory neurons located
Outside of CNS in dorsal root ganglion
Where are the bodies of motor neurons located
In CNS in ventral horn
Where are interneurons located
In CNS in dorsal horn
What is the gray commisure
Connects right and left sides of gray matter butterfly and contains the central canal
What are ependymal cells and where are they found
Line ventricles in brain and central canal of spinal cord. Make CSF fluid
What is the function of white matter in the spinal cord
Bundles of axons that course up and down cord providing communication to different levels of CNS. Tracts or funicculi
What do ascending spinal tracts do
Carry sensory info up
What do descending spinal tracts do
Carry motor info down
What is decussation in regard to spinal tracts
Crossing of the midline that occurs in many tracts. Brain senses and controls opposite side of body
What is contralateral in regard to spinal tracts
When origin and destination of tract are on opposite sides of body
What is ipsilateral in regard to spinal tracts
When origin and destination of a tract are on the same side of the body
What are funicculi
White matter columns that contain ascending and descending fiber tracts in spinal cord
Where does decussation occur in ascending spinal tracts
A lot of places
Where does decussation occur in descending spinal tracts
Somatic efferent fibers cross at the decussation of pyramids in the brain stems medulla
What is relay in regard to spinal tracts
Most tracts have 2-3 neurons minimum that synapse and pass along the signal through the pathway
What is the function of the thalamus
Is the gateway to the brain. Interprets signals and sends them to where they need to go in brain
Describe spinocerebellar tracts
From spinal cord to cerebellum. Proprioception (unconscious muscle sense)
Describe spinothalamic tracts
From spinal cord to thalamus and cerebral cortex. Aware of crude sensation like touch and temp
Describe fasciculus gracilis and fasciculus cuneatus tracts
To cerebral cortex. Proprioception and discriminative touch
What is more important motor output or sensory input
Motor function
What receives all conscious stimuli in brain
Thalamus
In regard to descending spinal tracts (motor) where is the upper motor neuron from and what does it communicate with
Originates in cerebrum motor cortex and communicates with lower motor neuron
In regard to descending spinal tracts (motor) where is the lower motor neuron originating and what is its purpose
Ventral horn motor neurons that originate in brain stem or spinal cord. Axons leave CNS to target organs or somatic muscle
What are corticospinal tracts (pyramidal)
From upper motor neuron to lower motor neuron for voluntary motor control
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