CNS Anatomy Exam With Accurate Solutions
Nervous sysytem is divided into 2 groups
1-CNS
2-PNS
PNS is divided into
1-cranial nerve(12 pairs)
2-spinal nerves(31 pairs)
The CNS is divided into 2 groups
1-brain
2-Spinal cord
Brain is divided into
1-Forebrain
2-Midbrain
3-Hindbrain
Each spinal nerve is formed by
the union of the ventral and dorsal roots
pair of spinal nerves (31 segments) consists of
1-8 of the segments are in the cervical region.
2-12 in thoraxes
,3-5 in the lumbar
4-5 in sacral
5-1 in coccygeal
sympathetic and parasympathetic neurons in the spinal cord
Sympathetic neurons of lateral horn T1-L2 - SEGMENTS***
Parasympathetic neurons of lateral horn S2-S4 SEGMENTS***
Length of spinal cord
has nothing to do with height (between 43 and 45 cm)
Spinal cord starts at
foramen magnum
Spinal cord ends at
ends at LI/L2
a)70% of normal population LI/LII
b)T12 or LIII in some other people depending on height
Enlargement of the spinal cord occurs in
1-cervical region
2-lumbar region
Conus medullaris
distal end of the spinal cord
The gray matter of the spinal cord is "H"-shaped with a ventral (anterior) horn and a
dorsal (posterior) horn on each side.
gray commissure
The two halves of the gray matter are joined by a narrow strip connecting the central
canal
, The horn contains
cell bodies of neurons
Neuron can be
motor or sensory
Anterior horn
this is where the cell bodies of the motor neurons whose axons exit the cord through the
ventral roots, travel straight to the muscles
Posterior horn
It houses cell bodies of sensory neurons.
These neurons receive information from the sensory neurons in the dorsal root ganglia
whose axons make the dorsal root of the spinal nerves
Lateral horn
It contains autonomic neurons
It exists only on certain segments of the spinal cord
tracts
= bundles of myelinated nerve fibers
columns
It compromised of tracts that carry sensorimotor information
The white matter of the spinal cord
1-It surrounds the gray matter
2-IT is organized as ventral, lateral, and dorsal columns on each half of the spinal cord.
Nervous sysytem is divided into 2 groups
1-CNS
2-PNS
PNS is divided into
1-cranial nerve(12 pairs)
2-spinal nerves(31 pairs)
The CNS is divided into 2 groups
1-brain
2-Spinal cord
Brain is divided into
1-Forebrain
2-Midbrain
3-Hindbrain
Each spinal nerve is formed by
the union of the ventral and dorsal roots
pair of spinal nerves (31 segments) consists of
1-8 of the segments are in the cervical region.
2-12 in thoraxes
,3-5 in the lumbar
4-5 in sacral
5-1 in coccygeal
sympathetic and parasympathetic neurons in the spinal cord
Sympathetic neurons of lateral horn T1-L2 - SEGMENTS***
Parasympathetic neurons of lateral horn S2-S4 SEGMENTS***
Length of spinal cord
has nothing to do with height (between 43 and 45 cm)
Spinal cord starts at
foramen magnum
Spinal cord ends at
ends at LI/L2
a)70% of normal population LI/LII
b)T12 or LIII in some other people depending on height
Enlargement of the spinal cord occurs in
1-cervical region
2-lumbar region
Conus medullaris
distal end of the spinal cord
The gray matter of the spinal cord is "H"-shaped with a ventral (anterior) horn and a
dorsal (posterior) horn on each side.
gray commissure
The two halves of the gray matter are joined by a narrow strip connecting the central
canal
, The horn contains
cell bodies of neurons
Neuron can be
motor or sensory
Anterior horn
this is where the cell bodies of the motor neurons whose axons exit the cord through the
ventral roots, travel straight to the muscles
Posterior horn
It houses cell bodies of sensory neurons.
These neurons receive information from the sensory neurons in the dorsal root ganglia
whose axons make the dorsal root of the spinal nerves
Lateral horn
It contains autonomic neurons
It exists only on certain segments of the spinal cord
tracts
= bundles of myelinated nerve fibers
columns
It compromised of tracts that carry sensorimotor information
The white matter of the spinal cord
1-It surrounds the gray matter
2-IT is organized as ventral, lateral, and dorsal columns on each half of the spinal cord.
