Spinal Cord/Spinal Nerves Flashcards
Neural plate forms
Neural tube
When do tissues fold, converge, change structure and start to differentiate?
4th week
What vitamin is important for healthy development of neural tube and preventing defects?
Folate (B vitamin)
Neural plate border separates ectoderm from
Neural plate
Neural plate bends and joins together at neural plate borders, now forming
Neural crest
Neural crest differentiates into
PNS
Notocord differentiates and persists as
Nucleus pulposus of IV discs
Precursors of axial skeleton and skeletal muscle
Somites
Spina bifida
Two sides of vertebral arches (usually lower) fail to fuse during development
Spina bifida occulta
-L5-S1
-10% of individuals
-Asymptomatic with tuft of hair
Severe forms of spina bifida
-Outpouching of meninges
-Meningocele: just CSF
-Myelomeningocele: Portion of spinal cord
Spinal nerves
-Originate at spinal cord
-Connect PNS to CNS
-31 pairs
How many spinal nerves in each region
-Cervical: 8
-Thoracic: 12
-Lumbar: 5
-Sacral: 5
-Coccygeal: 1
How do spinal nerves exit?
Between 2 adjacent vertebrae
-C1 goes between skull and C1
-C7 exits between C6 and C7
C8 exits between C7 and T1
Ventral Rami
Innervate ventral body wall, extrinsic back and all limbs
Dorsal rami
Innervate skin and deep muscles of back
C5 Myotome Actions
Shoulder flexion, ER, abduction, scaption
C6 Myotome Actions
Shoulder: IR, adduction, extension
Elbow: Flexion
Wrist: Extension
Supination
C7 Myotome Actions
Shoulder: IR, adduction, extension
Elbow: Extension
Wrist: Flexion
Digital extension
C8 Myotome Actions
Shoulder: IR, adduction, extension
Digital flexion
Pronation
T1 Myotome Actions
Digit abduction/adduction
Spinal cord terminates between
L1/L2
Spinal dural sac terminates at
S2
Spinal meninges from superficial to deep
Epidural space, dura mater, subdural space, arachnoid mater, subarachnoid space (CSF), pia mater
