Spinal Cord Flashcards
Somite subdivisions
From Superficial to Deep
- Dermatome
- Myotome
- Sclerotome
Somite Cells that migrate ANTERIORLY give rise to what?
- Muscles
- Limbs
- Trunk (hypaxial muscles)
- Associated Dermis
Somite Cells that migrate POSTERIORLY give rise to what?
- Intrinsic muscles of the BACK
- Associated Dermis
Part of each somite gives rise to what?
- Skeletal muscle
- Dermis of the skin
Upper Limb bud vertebral segments
C5 - T1
Lower Limb bud vertebral segments
L2 - S2
Dermatome
The area of the skin supplied with AFFERENT nerve fibers (Towards the CNS) by a Single POSTERIOR spinal Root.
Myotome
- All the muscles that are innervated by a Single EFFERENT Anterior Root.
T/F: Most muscles are composed of only one myotome.
False
Most are composed of MORE than one myotome
Somatic Innervation
Arises SEGMENTALLY along the Developing CNS in association with Somites
Spinal cord enlargements occur where?
- Cervical region
&
- Lumbar region
How many spinal nerves in total
31
How many CERVICAL nerves?
8
- But 7 vertebrae
How many THORACIC nerves?
12
- The most of any nerve subset
How many LUMBAR nerves?
5
Same as Sacral
How many SACRAL nerves?
5
- Same as Lumbar
How many COCCYGEAL nerves?
1
Lowest number
How many Plexuses are there?
3 total
- Cervical
- Brachial
- Lumbo-sacral
“LBC”
What nerve is the location where the nerves switch from being ABOVE the bone to being BELOW?
C8
Cauda Equina is Latin for what?
Horse’s Tail
What is the Cauda Equina?
A bundle of nerves at the end of the spinal cord
What shape does the gray matter have in the spinal cord?
An ‘H’ shape
The Post. Horns have a ____ shape and the Ant. Horns have a ____ shape.
- Pointed/Triangular
- Blunt/Square
Which matter is Myelinated?
White matter
- It contains the axons
What region of the Spinal Cord are the LATERAL horns located?
- Thoracic
&
- Upper Lumbar
Characteristics of the ANTERIOR horns?
Aka VENTRAL Horns
- Site of of the CELL BODIES of the Alpha Motor Neurons to the Skeletal Muscle fiber
How many types of columns exist in the White matter?
3 Total
- Posterior (Dorsal)
- Anterior (Ventral)
- Lateral
Which Root type also has associations with a Root GANGLION?
Dorsal root
- Carries Cell bodies from the AFFERENT neurons
White Ramus Communications
Carries PRE-ganglionic fibers from LATERAL horns (Gray matter)
Gray Ramus Communications
Carries POST-ganglionic fibers from Paravertebral ganglia
Dura Mater
Tough Outer layer of the Spinal Cord
Arachnoid Mater
Web-like MIDDLE layer of the spinal cord
Pia Mater
Delicate Innermost Layer of the Spinal cord
Outer Layers of the spinal chord from Sup to Deep
- Dura Mater
- Arachnoid Mater
- Pia mater
“DAP”
What is contained in the Subarachnoid space?
CSF
The nerves exit the spinal cords through what opening?
The MENINGES
