Spinal Cord and Meninges Flashcards
List the boundaries of the vertebral canal
Spinal cord Pia mater Subarachnoid space Arachnoid mater Dura mater Spinal nerves Extradural space Blood vessels
Spinal cord in adults and children
Adults: from foramen magnum to L1/2
Children: from foramen magnum to L3
Spinal cord enlargements
Cervical C4-T1: brachial plexus- innervation of upper limbs
Lumbosacral T11-S1: lumbosacral plexus- innervation of lower limbs
Spinal nerves
8 cervical 12 thoracic 5 lumbar 5 saccral 1 coccygeal
How spinal nerve comes together
Rootlets converge to form roots (posterior roots=sensory, anterior roots=motor), anterior and posterior roots converge to become a spinal nerve (mixed sensory and motor)
Spinal nerves divide into mixed ventral and dorsal rami
Spinal nerves and their corresponding number
Cervical nerves are numbered according to vertebra below
All other spinal nerves are numbered according to vertebra above
Dura Mater
Known as dural sac as it descends vertebral canal
Unattached to bone
Narrows at lower border of S2 and fuses with filum terminale and coccyx
Arachnoid mater
Lines dural sac
Ends at lower border of S2
Connects to pia mater by arachnoid tuberculae
Where is lumbar cistern found and what does it do?
In subarachnoid space- encloses cauda equina
Pia mater
adhered closely to surface of CNS
Becomes filum terminale at inferior end of spinal cord that attaches to coccyx
Attached to arachnoid mater in dural sac by lateral triangular denticulate ligaments
Where is internal vertebral venous plexus found?
Extradural space
Longitudinal arteries
Branches of subclavian artery
2 paired posterior spinal arteries
1 anterior spinal artery (gives off sulcul arteries)
Segmental arteries
Branches of aorta
Give off segmental medullary arteries
Support posterior/anterior spinal arteries
Distinctive characteristic of venous plexi
No valves so blood flows in either direction
Location of internal venous plexus
In extradural fat in extradural space
