Lecture 13: Histology of the CNS

Question 1

Describe the anatomy of a neuron

Answer 1

• Cell body: is large, w/ large nucleus and Nissl substance/bodies
• Numerous dendrites
• Long axons, emerges from axon hillock

Question 2

Label A-D

Answer 2

A) Axon

B) Nissl bodies

C) Nucleolus

D) Nucleus

Question 3

Where are Nissl bodies found and why can this help you histologically?

Answer 3

• Found only in cell body and dendrites of a neuron
• Can help you distinguish the axons from the dendrites

Question 4

What type of neuron is this?

Answer 4

Pyramidal cell - Multipolar neuron

Question 5

Label A-E on this neuron

Answer 5

A) Nissl substance

B) Nucleus

C) Axon Hillock

D) Axon

E) Dendrite

Question 6

What are the 6 layers of cerebral cortex from superficial to deepest?

Answer 6

I: Molecular layer

II: External Granular layer

III: External Pyramidal layer

IV: Internal Granular layer

V: Internal Pyramidal layer

VI: Multiform layer

Question 7

Where is the white matter and gray matter located within the Cerebral Cortex?

Answer 7

Gray matter: outer layer

White matter: inner layer

Question 8

Identify the layers A-F of the cerebral cortex.

Answer 8

A) Molecular layer

B) External granular layer

C) External pyramidal layer

D) Internal granular layer

E) Internal pyramidal layer

F) Multiform layer

Question 9

What strucutre is this and identify layers A-C

Answer 9

• Cerebellar cortex

A) Molecular layer

B) Granular layer

C) Cerebellar medulla (white matter)

Question 10

Identify A-D

Answer 10

A) Molecular layer

B) Purkinje Cell Dendrites

C) Purkinje Cell Body

D) Granular Layer

*This is the cerebellar cortex

Question 11

What are the 4 layers of the Cerebellar cortex from outermost to innermost?

Answer 11

1) Molecular Layer
2) Purkinje Cell Layer
3) Granular Layer
4) Cerebellar medulla (white matter)

Question 12

Identify this cell type

Answer 12

Purkinje Cell

Question 13

Identify this cell type

Answer 13

Purkinje cells

Question 14

Identify A and B; what kind of synapse is this?

Answer 14

• Chemical synapse

A) Pre-synaptic terminal

B) Dendrite

Question 15

Identify A-C

Answer 15

A) Presynaptic Membrane

B) Postsynaptic Membrane

C) Synaptic Cleft

Question 16

Identify this cell type

Answer 16

Astrocyte

Question 17

What is the function of Astrocytes?

Answer 17

• Branching expansions called End-Feet
• Helps form the blood-brain barrier
• Provide structural support and organization to the CNS

Question 18

What does this picture show?

Answer 18

• Astrocytes connected to BV’s by their end-feet
• Producing the BBB

Question 19

What is the main component of the blood brain barrier?

Answer 19

Tight junctions

Question 20

What is the function of Oligodendrocytes and where do they act?

Answer 20

• Provides a myelin sheath to multiple axons!
• Schwann cells of the PNS can only myelinate one axon

Question 21

Identify the structures

Answer 21

Question 22

What is the function of Microglia?

Answer 22

• Migratory, will remove damaged or unactive synapses/other fibrous components (phagocytic cells of CNS)
• Major mechanism of immune defense in the CNS

Question 23

Identify this cell type

Answer 23

Microglia

Question 24

What are Ependymal Cells?

Answer 24

• Columnar or cuboidal cells that line fluid-filled ventricles of the brain and central canal of spinal cord
• Apical end may have cilia and long microvilli

Question 25

Identify A and B?

Answer 25

A) Ependymal cells

B) Ventricle

Question 26

Identify the arrows from top to bottom

Answer 26

Top: Dorsal Horn

Middle: Lateral Horn

Bottom: Ventral Horn

Question 27

Identify A and B

Answer 27

A) Fasciculus Cuneatus

B) Fasciculus Gracillis

Question 28

Identify A and B

Answer 28

A) Choroid Plexus

B) Ependymal Cells