spinal cord and pathways Flashcards
rootlets are found in what area
sub arachnoid space
spinal cord terminates in cone shape called the…
conus medullaris
conus modularis in turn, continues as a thin connective tissue cord called the ____ which is anchored to the ___ of the coccyx.
filum terminals anchored to dormsum of coccyx
The spinal cord is suspended in the canal by a ribbon of tissue on the ____ aspects of the cord called the _____.
lateral aspect called denticulate ligament
the denticulate ligament is made up of? this connects to what and where
Pial and arachnoid tissue, connect to dura at points along length of the cord
what is found at very middle of spinal cord
central canal
white matter of cord is said to be made up of …
posterior, anterior and lateral FASCICULI
at what spinal levels are there lateral horns
T1 > L2
lateral horns contain which fibres
preganglionic sympathetic firbres
3 types of arteries that supply cord
- longitudinal
- segmental
- radicular
how many longitudinal arteries
3
the 3 longitudinal arteries are:
1 x anterior
2 x posterior
longitudinal arteries arise from ____
vertebral arteries
segmental arteries arise from ____
vertebral, intercostal and lumbar arteries
radicular arteries travel along ___
dorsal and ventral roots
how does dura in cord differ from cranial cavity
it is not attached to periosteum like in brain, leaving a gap (epidural space)
epidural space contains what
fat and anterior and posterior epidural venous plexuses
do sensory fibres cross
yes
primary somatosensory cortex is located where
postcentral gyrus
which sensory fibres DO NOT travel in spinal cord
scalp and face
spinal cord terminates at what level
L1 - L2
white matter occupies less of cord as you ____
descend
ascending tracts include
dorsal funiculus (dorsal column) and spinothalamic tract
dorsal funiculus is made up of which 2 parts
funiculus graciis and funiculus cunealus
cuneate fasciculus carries input from
upper half of the body
gracile fasciculus carries input from
lower half of the body
dorsal column/medial lemiscus pathway has how many neurones
3
dorsal column/medial lemiscus conveys what type of info
sensory: fine touch, vibration, two-point discrimination, proprioception
dorsal column/medial lemiscus info from where
skin and joints
dorsal column/medial lemiscus first order neurones reside in ____
dorsal root ganglion
dorsal column first order neurones make contact with second order neurones where
at gracile and cuneate nuclie in lower medulla
dorsal column/medial lemiscus second order neurone send axons to ____
thalamus
dorsal column/medial lemiscus 3rd order neurones travel from ____ to ____
thalamus to postcentral gyrus
when 2nd order neurones of dorsal column decussate in medulla they are called ____
internal arcuate fibres
crossing of the internal arcuate fibres form the ___
medial lemiscus
spinothalamic tract carry what info
Carries pain, temperature, deep pressure.
spinothalamic tract fibres cross in what how?
segmentally (decussates at level of spinal cord)
motor cortex located where
precentral gyrus
motor cross over?
yes
