Histology of the Central Nervous System

Question 1

Answer 1

1. Axon
2. Mitochondrion
3. Neurotubules
4. Golgi Apparatus
5. Nissl Bodies
6. Nucleolus
7. Nucleus
8. Glial Cells
9. Nissl Body (Free ribosomes and rough ER)

Question 2

Answer 2

1. Axon
2. Axon Hillock (Lighter Staining area)
3. Soma
4. Dendrites

Question 3

What is the name of the structures in the neuron soma that will stain? Where are they absent?

Answer 3

• Nissl Bodies
• ABSENT in the Axon Hillock

Question 4

Answer 4

1. Soma (With Nissl Bodies)
2. Axon Hillock (NO nissl bodies)

Question 5

What type of neuron is this? Where is it normally found?

Answer 5

BIPOLAR neuron

• Retina, Olfactory Epithelium, Vestibular and Auditory Systems

Question 6

What type of Neuron is in the image? Where is it typically found?

Answer 6

PSEUDOUNIPOLAR neuron

• Sensory Ganglia of Cranial and Spinal Nerves

Question 7

What type of neurons are in the image? Where would you typically find each of them?

Answer 7

MULTIPOLAR neurons

• Pyramidal cell: Found in Cerebral Cortex
• Purkinje Cell: Found in Cerebellar Cortex

Question 8

What type of Neuron is in the image?

Answer 8

Multipolar PYRAMIDAL Cell

Question 9

What type of neuron is in the image?

Answer 9

Multipolar PIRKINJE cell

Question 10

List the layers that make up the grey matter in the Cerebral Cortex. (From outside –> in)

Answer 10

1. Molecular Layer
2. External Granular Layer
3. External Pyramidal Cell Layer
4. Internal Granular Layer
5. Internal Pyramidal Layer
6. Multiform Cell Layer
   - White Matter

Question 11

Answer 11

CEREBRAL CORTEX

1. Molecular Layer (Dendrites)
2. External Granular Layer
3. External Pyramidal Cell Layer
4. Internal Granular Layer
5. Internal Pyramidal Layer
6. Multiform Cell Layer

Question 12

Answer 12

CEREBELLUM

1. Molecular Layer (Dendrites)
2. Purkinje Cell Layer
3. Granular Layer
4. White Matter

Question 13

Answer 13

1. Molecular Layer
2. Purkinje Cell Dendrites
3. Purkinje Cell Bodies
4. Granule Cell Layer

Question 14

Describe the two main types of channels and their location in the neuron.

Answer 14

• Voltage Gated Channels (“Presynaptic”)
• Ligand Gated Channels (“Postsynaptic”)

Question 15

Answer 15

1. Synaptic Vesicles
2. Presynaptic Membrane
3. Postsynaptic Membrane
4. Synaptic Cleft
5. Dendrite
6. Mitochondrion

Question 16

Differentiate between the 4 different types of Synapses.

Answer 16

1. AXOSOMATIC: Axon Terminal –> Soma
2. AXOAXONIC: Axon Terminal –> Axon Terminal
3. AXODENDRITIC: Axon Terminal –> Dendrite
4. AXOSPINOUS: Axon Terminal –> Dendritic Spine

Question 17

Answer 17

1. Soma
2. Dendritic Spine
3. Dendritic Shaft

Question 18

Answer 18

1. Perivascular End-Feet Area
2. Blood Capillary
3. Astrocyte

Question 19

Answer 19

Astrocytes

Question 20

Answer 20

Astrocytes

Question 21

What is the “job” of the Blood-Brain Barrier? What are the different components?

Answer 21

Keep blood away from the Neural Tissue

1. Endothelial Cell
2. Basal Lamina
3. TIGHT JUNCTIONS
4. Perivascular Astrocyte End-Feet

Question 22

Which substances can move across the Blood-Brain Barrier?

Answer 22

WATER, Gases, and LIPID-Soluble molecules can diffuse across ENDOTHELIAL cells

Question 23

Which cells make the myelin in the CNS?

Answer 23

Oligodendrocytes (can myelinate MULTIPLE axons)

Question 24

Answer 24

Oligodendroglia (Oligodendrocytes)

Question 25

Answer 25

1. Oligodendroglia 2. Nucleus 3. Axon 4. Myelin

Question 26

Answer 26

Oligodendroglia (Oligodendrocytes)

Question 27

Differentiate between the myelination process and structure of the CNS and PNS.

Answer 27

CNS: Oligodendrocytes make the myelin; ASTROCYTIC end-foot is going to be located between the myelin PNS: Schwann Cells make the myelin; NODE of RANVIER is going to be located between the myelin

Question 28

Answer 28

Node of Ranvier (PNS)

Question 29

What is the name of these cells? What is their purpose?

Answer 29

Microglia Cells function as the Phagocytic Cells of the CNS - Require SPECIAL staining techniques

Question 30

Answer 30

1. Choroid Plexus 2. Choroid Epithelium (Cuboidal Cells linked by TIGHT junctions; Produce CSF) 3. Ependymal Epithelium (Cuboidal Cells linked by Desmosomes) 4. Lumen of the 3rd Ventricle

Question 31

Differentiate between Tanycytes and Ependymal Cells.

Answer 31

Tanycytes: Linked together by TIGHT junctions, can penetrate the Blood-Brain Barrier and communicate with blood vessels; typically found in the THIRD VENTRICLE Ependymal Cells: Linked together by BELT-DESMOSOMES

Question 32

Answer 32

Ependymal Cell

Question 33

Answer 33

Central Canal (Brainstem) lined by Ependymal Cells, **NO TANYCYTES!!!!**

Question 34

Answer 34

Ependymal Cell with CILIUM

Question 35

In which ventricles does most of the Choroid Plexus reside?

Answer 35

LATERAL ventricles

Question 36

Answer 36

Choroid Plexus

Question 37

What is the "job" of the Arachnoid-CSF Barrier?

Answer 37

Keeps CSF off of the Dura mater and is responsible for draining CSF back out into the blood stream - Taking CSF out of the Subarachnoid space and draining it into the Dural Venous Sinus

Question 38

What is the "job" of the Blood-CSF Barrier?

Answer 38

Getting fluid out of the blood (ultrafiltrate of plasma) and into the Ependymal cells via fenestrated capillaries to PRODUCE CSF!

Question 39

List the different layers of Meninges. (Inside --\> Out)

Answer 39

1. Pia Mater (Directly on the Brain) 2. Arachnoid Mater 3. Dura Mater

Question 40

Answer 40

1. Arachnoid Mater 2. Pia Mater

Question 41

What is the structure that is responsible for getting CSF out of the Arachnoid Mater? Describe its structure.

Answer 41

ARACHNOID VILLUS Part of the Arachnoid Mater that will protrude up into the Dura Mater INTO the Dural VENOUS SINUS!

Question 42

Answer 42

1. White Matter 2. Arachnoid Mater 3. Pia Mater 4. Dura Mater