Spinal Cord Stuff Flashcards
How many parts of spinal nerves?
31
The spinal cord terminates where?
The conus medullaris (L2)
A small central canal in the spinal cord extends rostrally into where?
The 4th ventricle
At which spinal segments is there also a small lateral horn?
T1-L2 (where the sympathetic chain is)
What are the 2 ascending tracts (sensory)?
1) Dorsal column
2) Spinothalamic tract
What is the dorsal column responsible for?
Where do the fibres cross?
For fine touch and propriopception
The fibres cross in the medulla.
What is the spinothalamic tract responsible for?
Where doe the fibres cross?
Pain, crude touch, and temperature.
Fibres cross segmentally.
Corticospinal tract is also referred to as what?
What is it responsible for?
Also known as the PYRAMIDAL TRACT.
Resonsible for fine precise movements of distal limb muscles. E.g. digits.
Where do the fibres of the corticospinal tract cross?
About 85% of the fibres cross in the medulla. (Forms visible ridges known as the pyramids)
Crossed fibres form the lateral corticospinal tract.
Uncrossed fibres form the ventral CST, which cross segmentally.
A CVA of where can result in a lack of descending control of the corticospinal tract?
A CVA of the internal capsule, results in decorticate posturing; hyperflexion of upper limbs.
What is the tectospinal tract responsible for?
Thought to mediate reflex head and neck movements due to visuals stimuli. Mainly input to cervical segments.
Reticulospinal tract function?
Forms the central core of the brain stem. Fibres originate in areas of the reticular formation in pons and medulla.
Fibres originating in PONS facilitate EXTENSOR. (PE)
How does an upper motor neurone lesion present?
Increased tone.
Muscle wasting Not marked.
No fasciculation
Hyper-reflexia
Lower motor neurone lesion presentation
Decreased tone.
Muscle wasting
Fasciculation
Diminished reflexes.
Is the spinothalamic tract contralateral or ipsilateral?
It is contralateral because it decussates at spinal level
