Neuroanatomy 2 Flashcards
Where are the 2 enlargements of the spinal cord found?
in the cervical region and lumbar region
Why are there enlargements in the spinal cord?
relate to the innnervation of the upper and lower limbs
What do roots pass through to reach their intervertebral foramen?
subarachnoid space
What is the posterior root enlarged by as it passes through the intervertebral foramen?
posterior root ganglion
What is the end of the spinal cord called?
conus medullaris
What is the thin spinal cord extension of connective tissue that is anchored to the coccyx?
filum terminale
What is the name of the collection of roots that extend from the conus medullaris to reach the sacrum and coccyx called?
cauda equina
What suspends the spinal cord in the canal?
denticulate ligaments
What are the denticulate ligaments formed of?
pial and arachnoid tissue
What is the small central canal in the spinal cord connected to superiorly?
the 4th ventricle
What forms the horizontal part of the H of grey matter in the psinal cord?
anterior and posterior commisures which surround the central canal
From which levels of the spinal cord are lateral horns found?
T1 to L2
What is found within the lateral horns of the spinal cord?
preganglionic sympathetic neurons
What are the 3 types of arteries supplying the spinal cord?
longitudinal; segmental and radicular
What are the longitudinal arteries derived from?
the vertebral arteries
What are the longitudinal arteries?
one anterior and two posterior
What arteries are the segmental arteries derived from?
vertebral, intercostal and lumbar
Where are the radicular arteries found?
travel along the dorsal and ventral roots (radicular= root associated)
Where is the venous plexus within the spinal cord found?
within the epidural spaces
What is found within the epidural spaces?
adipose tissue and venous plexuses
How is the pimary somatosensory cortex arranged?
somatotopically, body is mapped onto the cortex
How does the proportion of white matter within the spinal cord change as your descned?
white matter occupies a smaller proportion of the cord
What is the dorsal column and medial lemniscus system invovled in?
fine touch and proprioception
Where do the fibres of the dorsal column cross over?
arcuate fasciculus
What are the two sections of the dorsal column?
fasciculus gracilis and fasciculus cuneatus
What does the fasculus gracilis carry?
nerves from the lower limbs
What does the fasciculus cuneatus carry?
nerves from the upper limbs
Where do fibres from the dorsal column first synapse?
medulla
Where is the second synapse of the dorsal column/medial lemniscus system?
thalamus
Where do the third order neurons of the dorsal column travel?
from the thalamus to the cortex
What does the spinothalamic tract carry?
pain, temperature and deep pressure
Where do fibres from the spinothalamic tract cross over?
segmentally at the level they enter the spinal cord
Where is the pimrary motor cortex situated?
pre-central gyrus
What is the funciont of the corticospinal tract?
fine, precise movement of distal limb muscles
What forms the lateral CST?
crossed fibres
What forms the ventral CST?
uncrossed fibres
Where do the lateral CST fibres cross over?
caudal medulla
Where do ventral CST fibres cross over?
segmentally
What other name is the CST known by?
pyramidal tract
What are motor systems outwith the CST known as?
the extrapyramidal system
Where does the tectospinal tract begin?
tectum of the midbrain
Where does the tectospinal tract end?
cervical segments
What is the function of the tectospinal tracts?
reflex head and neck movement from visual stimuli
What forms the central core of the brainstem?
reticular formation
Where do fibres of the reticulospinal tract originate?
areas of reticular formation in pons and medulla
What is the general function of reticulospinal fibres originating in the pons?
facilitate extensor movements and inhibit flexor movements
What is the general function of reticulospinal fibres originating in the medulla?
facilitate flexor movements and inhibit extensor movements
Where do fibres of the vestibulospinal tract originate?
vestibular nuclei of pons and medulla
Where do the fibres of the vestibulospinal tract end?
cervical and lumbar segments
What is the function of the vestibulospinal tract?
excite limb extensor muscles
