Internal Anatomy of CNS

Question 1

T/F.. Cutting a motor nerve axon anywhere along it’s axon will have the same clinical presentation.

Answer 1

TRUE

Question 2

What do Nissil stains stain for?

Answer 2

Nerve cells, the nucleic acid will turn dark/blue. Highest in GRAY matter.

Question 3

What do Weigert stains stain for?

Answer 3

Lipids, will turn dark. Highest in WHITE matter.

Question 4

The 3 regions of white matter (dorsal, lateral, ventral) are referred to as?

Answer 4

Funiculi

Question 5

What separates the Dorsal and Lateral Funiculi?

Answer 5

Gray matter

Question 6

Each funiculi are made up smaller units of specific fiber tracts called:

Answer 6

Fasciculi

Question 7

3 spinal cerebellar tracts live in the Lateral Funiculi, which ones carry Ascending information? and which carry descending?

Answer 7

Ascending = Dorsal + Ventral
Descending = Lateral

Question 8

What are the 3 areas of Gray matter? and what are their general functions?

Answer 8

Dorsal = Sensory
Intermediate = Important for ANS
Ventral = Motor

Question 9

The gray matter are further divided into 10 regions known as the:

Answer 9

LAMINA of REXED

Question 10

Which lamina are in the Dorsal horn of gray matter?

Answer 10

L1-L6

Question 11

Which lamina are in the Intermediate zone of gray matter?

Answer 11

L7 and L10

Question 12

Which lamina are in the Ventral horn of gray matter?

Answer 12

L8-L9

Question 13

The close proximity of what 3 features seen on cross-section will tell you that you’re in the Medulla?

Answer 13

Pyramid, Inferior Olivary Nucleus, Medial Lemniscus.

Seen in both caudal and rostral medulla

Question 14

T/F. You can see the 3 distinctive features of the medulla in the Pyramidal Decussation.

Answer 14

FALSE! They are no longer apparent, that’s how you know you’re in that “transition region” and moving into the cervical cord

Question 15

Neurons in the Left-sided motor cortex will end up controlling the right or left side of the body?

Answer 15

RIGHT! Axons cross over at the Pyramidal Decussation

Question 16

On a cross section of the Pons you see a HUGE dark fiber tract surrounding the 4th ventricle, what is that called?

Answer 16

Middle Cerebellar Peduncle

Question 17

Unlike in the medulla, where the Coricospinal tract was on the surface in the pyramids, in the Pons where will we see it?

Answer 17

Deeper, looks like a perfect dark circle

Question 18

What do we expect to happen to the space for the 4th ventricle to do as we move into the Midbrain?

Answer 18

narrows

Question 19

What is the structure that allows communication between the 3rd and 4th ventricle?

Answer 19

Cerebral Aqueduct

Question 20

Name of the nucleus that surrounds the Cerebral Aqueduct?

Answer 20

Periaqueductal Gray

Question 21

How do you know if we’re in the CAUDAL MIDBRAIN vs the Rostal?

Answer 21

1. Inferior Colliculi
2. “wineglass” shaped fiber tract below inferior colliculi
3. Fiber tract below the Periaqueductal gray that is a continuation of the superior cerebellar pedicles

Question 22

How do you know if we’re in the ROSTAL MIDBRAIN vs the Caudal?

Answer 22

1. Superior Colliculi
2. 2 Big spherical “RED nuclei”
3. HUGE fiber tract of Crus Cerebri surround interpedicular fossa

Question 23

In the brain, Axons cross the midline at the:

Answer 23

Corpus Callosum (majority) + Anterior Commisure

Question 24

What are the 3 main nuclei in the brain?

Answer 24

Caudate, Putamen, Thalamus

Question 25

What is the major fiber tract that runs between the nuclei?

Answer 25

INTERNAL CAPSULE

Question 26

What limb of the Internal Capsule separates the Caudate and Putamen nuclei?

Answer 26

ANTERIOR

Question 27

What limb of the Internal Capsule separates the Putamen and Thalamus nuclei?

Answer 27

POSTERIOR

Question 28

What is the name of the bend in the internal capsule between the anterior and posterior limbs?

Answer 28

GENU

Question 29

What area of the brain is prone to Hemorrhagic STROKES?

Answer 29

Internal Capsule

Question 30

Where the Caudate Nuclei lie in comparison to the Lateral ventricle?

Answer 30

Lateral to it