Spinal Cord Ascending and Descending Tracts Flashcards
- The spinal cord is a —— structure, giving rise to —– paired spinal nerves
- There are two enlargements - —– (upper limb) and —– (lower limb)
segmental
31
cervical
lumbar
Explain the Spinal nerve roots?
- At each segment a series of rootlets emerge from the dorsal and ventral aspects of each segment of the cord and coalesce to form a posterior and anterior root respectively
- These roots pass through the subarachnoid space until they reach the appropriate intervertebral foramina
- As they pass through the formaina the posterior root is enlarged by the posterior root ganglion
- The roots fuse to form the mixed spinal nerve, which produces posterior and anterior rami
The spinal cord terminates in a cone-shape called the ——- which in turn continues as a thin connective tissue cord called the ——, which is anchored to the dorsum of the coccyx.
conus medullaris
filum terminale
- The spinal meninges are continuous with the cranial meninges via the foramen magnum
- Include all 3 layers (dura, arachnoid, pia)
- The spinal cord is suspended in the canal by a ribbon of tissue called the —— ligament
- As with the brain, the —— space is filled with CSF
denticulate
subarachnoid
A small —— extends the length of the spinal cord. what is it?
- Rostrally (toward the oral or nasal region) opens into —–
- Caudally is —–
central canal
The central canal (also known as spinal foramen or ependymal canal) is the cerebrospinal fluid-filled space that runs through the spinal cord.The central canal lies below and is connected to the ventricular system of the brain, from which it receives cerebrospinal fluid, and shares the same ependymal lining. The central canal helps to transport nutrients to the spinal cord as well as protect it by cushioning the impact of a force when the spine is affected.
4th ventricle
blind ending
Spinal cord: Outer —- & Inner —- matter
white
gray
White matter of spinal cord?
- The white matter consists of longitudinally oriented nerve fibres (axons), glial cells and blood vessels
- The white matter is described as being made up of posterior, lateral, and anteiror fasciculi, each containing a variety of fibre sizes
- White matter occupies a smaller proportion of the cord as you descend the cord
Grey matter of spinal cord?
- The grey matter contains neuronal soma (nucleus), cell processes, synapses, glia and blood vessels
- It is divided into 4 parts, left and right posterior and anterior horns, that correspond to the 4 vertical segments that make up the letter ‘H’
- The horizontal part of the ‘H’ represents the dorsal and ventral grey commisures, which surround the central canal
- At spinal segments T1-L2 there is also a small lateral horn which contains the preganglionic sympathetic neurons
the arteries of the spinal cord?
Spinal Cord Lamina?
what structure is found in white matter of spinal cord?
Funiculus?
contain unmyelinated to large myelinated fibres
venous drainage of the spinal cord?
In cranial cavity: —- mater attached to —- of skull bone
In vertebral canal; space exits between —– and bone: —– space
—– space: contains adipose tissue and epidural venous plexus; Utilized for —– anaesthesia
Dura
periosteum
dura
Epidural (x3)
Location of primary somatosensory cortex and how is it ‘arranged’?
Cord is larger in —- and —– regions.
—— matter occupies a —— proportion of the cord as you descend the cord.
cervical
lumbar
White
smaller
How does the information from the periphery reach the somatosensory cortex?
The Dorsal Column/Medial Lemniscus System?
Brainstem slices?
Spinothalamic tract?
How do the motor commands reach the appropriate muscles?
Corticospinal Tract?
Pyramidal tract?
extrapyramidal system?
There are a number of motor systems outside of the pyramidal tract and these are referred to collectively as the “extrapyramidal system”.
Tectospinal Tract?
Reticulospinal Tract?
Vestibulospinal Tract?
Summary of major descending motor pathways.
Brown-Séquard’s Syndrome?
