Spinal Cord Flashcards
Extent of Spinal Cord
Foramen Magnum -> Lower border of L1 Vertebra/Upper Border of L2
Length Spinal Cord
45 cm Males
43 cm Females
Origin of Dorsal Root Ganglion and Autonomic Ganglion
Neural Crest
At Birth where does spinal cord end?
L3
In Adults where does the spinal cord end?
Lower Border L1/Upper Border L2
Surgery and Spinal taps are usually at what vertebra onward?
L3
How many spinal nerves?
How are they distributed?
8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal
31 Pairs Total
Cervical Nerves all exit where?
What’s the exception?
How about the rest of the spinal nerves?
They usually exit ABOVE the corresponding vertebra
C8 exits BENEATH the C7 vertebrae
The rest exit below the vertebrae
Spinal cord is flattened where?
Dorsoventrally
Define: Conus Medullaris
Conical termination of spinal cord at the level of L1
Location: Conus Medullaris
S2-S4 Cord Segments
Located between L1 and L2 Vertebrae
Location: Cauda Equina
S5-L2 Segments
Function: Filum Terminale
Anchors end of the spinal cord by inserting at dorsum of coccyx
Function: Denticulate Ligaments
Shelves of pia mater that attach the spinal cord to the vertebrae laterally
How many neurons in a spinal cord?
1 Billion
Funiculi : White Matter :: Grey Matter : ?
Horn
[White Matter]
Ascending tracts carry?
Sensory fibers from Spine -> Brain
[White Matter]
Descending tracts carry?
Motor impulses from Brain -> Spine
Define: Thecal Sac
Membrane of Dura Mater that surrounds the spinal cord and cauda equina
Termination Point of Thecal Sac
S1
Termination Point of Filum Terminale
S1
[Grey Matter]
4 Major Parts
Posterior Gray Horn
Anterior Gray Horn
Lateral Gray Horn
Gray Commissures
What types of nuclei are found in the Posterior Gray Horn?
Somatic and Visceral Sensory Nuclei
What types of neurons are found in Anterior Gray Horn?
Lateral Gray Horn?
A: Somatic Motor Control
L: Visceral Motor Control
Spinal Cord is divided into how many Laminae?
10
[Spinal Cord Laminae]
Which are Dorsal?
Which are Ventral?
D: Lamina 1-6
V: Lamina 7-10
Function: Lamina 6
Receives proprioceptive input and sensory information
Sites of origin of ascending projections to higher centres
Function: Lamina 9
Contains motor neurons supplying limbs
