Internal Anatomy of CNS Flashcards
T/F.. Cutting a motor nerve axon anywhere along it’s axon will have the same clinical presentation.
TRUE
What do Nissil stains stain for?
Nerve cells, the nucleic acid will turn dark/blue. Highest in GRAY matter.
What do Weigert stains stain for?
Lipids, will turn dark. Highest in WHITE matter.
The 3 regions of white matter (dorsal, lateral, ventral) are referred to as?
Funiculi
What separates the Dorsal and Lateral Funiculi?
Gray matter
Each funiculi are made up smaller units of specific fiber tracts called:
Fasciculi
3 spinal cerebellar tracts live in the Lateral Funiculi, which ones carry Ascending information? and which carry descending?
Ascending = Dorsal + Ventral Descending = Lateral
What are the 3 areas of Gray matter? and what are their general functions?
Dorsal = Sensory Intermediate = Important for ANS Ventral = Motor
The gray matter are further divided into 10 regions known as the:
LAMINA of REXED
Which lamina are in the Dorsal horn of gray matter?
L1-L6
Which lamina are in the Intermediate zone of gray matter?
L7 and L10
Which lamina are in the Ventral horn of gray matter?
L8-L9
The close proximity of what 3 features seen on cross-section will tell you that you’re in the Medulla?
Pyramid, Inferior Olivary Nucleus, Medial Lemniscus.
Seen in both caudal and rostral medulla
T/F. You can see the 3 distinctive features of the medulla in the Pyramidal Decussation.
FALSE! They are no longer apparent, that’s how you know you’re in that “transition region” and moving into the cervical cord
Neurons in the Left-sided motor cortex will end up controlling the right or left side of the body?
RIGHT! Axons cross over at the Pyramidal Decussation
On a cross section of the Pons you see a HUGE dark fiber tract surrounding the 4th ventricle, what is that called?
Middle Cerebellar Peduncle
Unlike in the medulla, where the Coricospinal tract was on the surface in the pyramids, in the Pons where will we see it?
Deeper, looks like a perfect dark circle
What do we expect to happen to the space for the 4th ventricle to do as we move into the Midbrain?
narrows
What is the structure that allows communication between the 3rd and 4th ventricle?
Cerebral Aqueduct
Name of the nucleus that surrounds the Cerebral Aqueduct?
Periaqueductal Gray
How do you know if we’re in the CAUDAL MIDBRAIN vs the Rostal?
- Inferior Colliculi
- “wineglass” shaped fiber tract below inferior colliculi
- Fiber tract below the Periaqueductal gray that is a continuation of the superior cerebellar pedicles
How do you know if we’re in the ROSTAL MIDBRAIN vs the Caudal?
- Superior Colliculi
- 2 Big spherical “RED nuclei”
- HUGE fiber tract of Crus Cerebri surround interpedicular fossa
In the brain, Axons cross the midline at the:
Corpus Callosum (majority) + Anterior Commisure
What are the 3 main nuclei in the brain?
Caudate, Putamen, Thalamus
What is the major fiber tract that runs between the nuclei?
INTERNAL CAPSULE
What limb of the Internal Capsule separates the Caudate and Putamen nuclei?
ANTERIOR
What limb of the Internal Capsule separates the Putamen and Thalamus nuclei?
POSTERIOR
What is the name of the bend in the internal capsule between the anterior and posterior limbs?
GENU
What area of the brain is prone to Hemorrhagic STROKES?
Internal Capsule
Where the Caudate Nuclei lie in comparison to the Lateral ventricle?
Lateral to it
