Spinal Cord Flashcards
what is the segmentation of the spinal cord
- Cervical – 8 (but 7 cervical vertebrae bones) o Thoracic – 12 o Lumber – 5 o Sacral – 5 o Coccygeal – 1
total segments- 31
Each segment gives rise to a _____ of spinal nerves
pair
What is the lower limit of the spinal cord in adults and infants
New born infants- L3/L4 vertebrae
Adults- L1/L2 border
describe the passing of spinal nerves in relation to their vertebrae
C1-7 pass through the intervertebral foramen above their vertebrae
C8 – Coc1 pass through the intervertebral foramen below their vertebrae
what is the upper limit of the spinal cord
at junction with the medulla oblongota of the brainstem
what embryological sturcure is the spinal cord formed by
Neural Tube
how is neural tube formed
develops from a flat plate of cells called
the neuro-ectoderm
how is a tube of neuroectoderm formed
Edges of plate rise up and meet each other in midline- forming a central canal
WHat is the central canal of the neuroectoderm tube surrounded by
nervous tissue (grey and white matter)
The neural tube has two different plates of cells. what does the alar plate form
Dorsal grey matter (sensory)
What does the basal plate form
Ventral grey matter (motor)
how does spina bifida occurs
due to the failure of neural tube closure in the caudal area
Describe the types of spina bifida severities
- Occulta- least severe with no outwards sign
- Lipo-meningocele- spinal cord attached to fatty growth- can be outward signs
- Meningocele
- Myelomeningocele
Both 3 and 4 can be severely affected by paralysis, loss of sensation and other defects below level of deformity
what does the grey matter of the spinal cord include
Dorsal Horn
Intermediate Horn
Ventral Horn
Transverse section- grey matter is towards the central part of the spinal cord
(see pics)
what does the white matter of the spinal cord include
Dorsal Funiculus
Lateral Funiculus
Ventral Funiculus
Transverse section- white matter is towards the peripheral part of the spinal cord
(see pics)