anatomy dr. gamal

Question 1

what is the length of SC
at birth?
adult?
how many pairs of spinal nerves?
characteristic of them?
where are the enlargements?

Answer 1

45 cm
reaches L3 at birth
to L1 
31 pairs
mixed, not uniform in diameter 
- cervical(for upper limbs)& Lumbar (for lower limbs) enlargements

Question 2

what is conus medullaris?

what is cauda equana?

Answer 2

tapered inferior end , btwn L1&L2 ,triangular in shape

-origin of spinal nerves extending
inferiorly from conus
medullaris.

Question 3

meninges of the spinal cord;

Answer 3

1-Dura mater: outermost layer;
continuous with epineurium of the
spinal nerves

2- Arachnoid mater: thin and wispy,Continuous with the cerebral arachnoid above, it traverses the foramen magnum and descends to about the S2 vertebral level

3- Pia mater: bound tightly to surface
◼ Forms the filum terminale
◼ Anchors spinal cord to coccyx

◼ Forms the denticulate ligaments
that attach the spinal cord to the dura

Question 4

spaces in meninges;

Answer 4

Epidural: external to the dura Anesthetics injected here

Subdural space: serous fluid

Subarachnoid: between pia and arachnoid, filled with CSF

Question 5

at which level is the lumbar puncture inserted?

position?

Answer 5

below canus medullaris(L1) and as the subarachnoid space continues to S2,
-inserted btwn vertebral lamina

-lying or sitting(most common)

Question 6

cross section of spinal cord, 
fissures/sulcus?
GM ?
WM?
commisures?
roots?

Answer 6

-Anterior median fissure and posterior median sulcus:
Deep clefts partially separating left and right halves

◼ Gray matter: neuron cell bodies, dendrites, axons.

• Divided into horns:
  1. Posterior (dorsal) horn
  2. Anterior (ventral) horn
  3. Lateral horn

◼White matter:
 Myelinated axons
- Divided into three
columns (funiculi):
1. Ventral
2. Dorsal
3. lateral
# Each of these divided into sensory or motor tracts

◼Commissures:
connections between
left and right halves
1. Gray with central
canal in the center
2. White

◼Roots:
Spinal nerves arise as
rootlets then combine to form dorsal and ventral roots
-Dorsal (Sensory) and
Ventral (Motor) roots
merge laterally and
form the spinal nerve

Question 7

Blood Supply to Spinal Cord;
what supply it?
where they travel?
anastomoses via?

Answer 7

• by 3 arteries :anterior spinal a. + R &L posterior spinal a. and by branches from aorta
• travel in the subarachnoid space
• via anterior and posterior segmental arteries
• Supply blood up to cervical segments