spinal cord

Question 1

spinal cord

Answer 1

derived from embryonic neural tube
located in vertebral canal within vertebral column
invested by meninges (Dura, arachnoid and pia)
Dura encloses cord and cauda and ends at S2, it contains loose areolar tissue and internal vertebral venous space

Arachnoid also end at S2 on filum terminale

Pia mater- vascular membrane, thickened on either side between nerve roots to form denticulate ligaments ends at filum terminale

Question 2

overview of spinal cord organization

Answer 2

Extends from medulla at foramen magnum to lower border of L1, conus medullaris at L1 and L2 vertebrae so lumbar puncture at L4 L5
Filum terminale= pia mater from conus medullaris to the coccygeal ligament

Question 3

spinal cord segmentation

Answer 3

31 segments with 31 pairs of nerves, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

C1-C7 exits above matched vertebrae, C8 and beyond exits below matched vertebrae

Question 4

spinal cord indentation

Answer 4

anterior median fissure (anterior spinal artery and vein)
Posterior median sulcus/septum
Posteriolateral sulcus (hugs the H, entry of dorsal roots)
Anterolateral sulcus (hus the H, exit of ventral roots)
Posterior intermediate sulcus (at cervical and uppthoracic levels ony separation between 2 major ascending tracts

Question 5

internal structures gray matter

Answer 5

dorsal horn (Sensory, recieves input, mediates synapses, gives rise to ascending sensory paths, the sustantia gelatinosa is for pain and temp and lissauers tract is the thin line)
ventral horn (motor, houses alpha, gamma and interneurons
Lateral horns (intermediolateral cell column (T1-L23, thoraco

Question 6

white matter regions

Answer 6

Posterior white column (Fasciculus gracilus is medial and cuneatus is laterl)
Lateral white column
Anterior White column

Alpha motoneurons are extrafusal and gamma is for intrafusal