Histology Of The Brain

Front 1

What are nissl bodies?

Back 1

1. Clusters of basophilic RER

2. Found in neuron soma

Front 2

What are phagosomes?

Back 2

1. Waste-containg vacuoles that fuse with primary lysosomes to form secondary lysosomes

Front 3

What is a dense body?

Back 3

1. Tertiary lysosome

2. Contains lipofuscin

Front 4

What are neurofilaments?

Back 4

1. Specialized form of intermediate filament

2. NF-L, NF-M, and NF-H subtypes

3. NF+ neurons contain these filaments

Front 5

What is the orientation of microtubules in dendrites?

Back 5

1. Mixed--- plus to minus and minus to plus

2. Plus end points away from axons

Front 6

What are dendritic spines?

Back 6

1. Small evagination of the neuronal membrane

Front 7

What is the prevalence of nissl bodies as you move away from the soma?

Back 7

1. Highly concentrated in soma

2. Less so as you move distal

Front 8

What is a neuropil?

Back 8

1. Interconnected and interwoven processes of dendrites, axons, and glia

2. "Neuronal environment"

Front 9

How do you distinguish between axons and dendrites histologically?

Back 9

1. Dendrites-- homogenous collection of microtubules, unmyelinated

2. Axons-- clumped microtubules, myelinated, synaptic vesicle

Front 10

What is anterograde transport?

Back 10

1. Movement away from the soma toward the axon terminal

Front 11

What is fast anterograde transport?

Back 11

1. Majority of protein transport

2. Products made in RER

Front 12

What is slow anterograde transport?

Back 12

1. Proteins synthesized in free polysomes in soma

Front 13

What is dynamin?

Back 13

1. Microtubule motor protein that functions in slow-component A

Front 14

What is the function of calcium-dependent proteases in anterograde transport?

Back 14

1. Disassemble the structure so that proteins can be utilized at their destination

Front 15

What is retrograde transport?

Back 15

1. Movement towards the soma

Front 16

What is transported in retrograde transport?

Back 16

1. NGF
2. Neurotoxins

3. Viruses

Front 17

What is the role of dyne in retrograde transport?

Back 17

1. Moves from plus to minus end of microtubules

Front 18

What are Golgi type I axons?

Back 18

1. Long axons

2. Seen in PNS

Front 19

What are Golgi type II axons?

Back 19

1. Short axons

2. CNS

Front 20

What are unipolar neurons?

Back 20

1. Single process that may give rise to many branches

Front 21

What are bipolar neurons?

Back 21

1. Single axon and single dendrite

Front 22

What are pseudounipolar neurons?

Back 22

1. Single process coming off a stem attached to soma

Front 23

What are multipolar neurons?

Back 23

1. Multiple axons and dendrites

Front 24

What is layer 1?

Back 24

1. Molecular layer

2. Few cells

3. Synaptic center for incoming axons

Front 25

What are layers 2 and 3?

Back 25

1. Smaller pyramidal neurons

2. Form association and commissural fibers

Front 26

What is layer 4?

Back 26

1. Primary input center for cerebral cortex

Front 27

What is layer 5?

Back 27

1. Pyramidal neurons that project to subcortical areas

Front 28

What is layer 6?

Back 28

1. Pyramidal neurons that project to the thalamus

Front 29

How are cells in the six layers organized?

Back 29

1. Columns

Front 30

What interconnect the columns of the six layers?

Back 30

1. Association fibers

Front 31

How do neuroglia differ from neurons?

Back 31

1. Ability to proliferate

2. Can't transmit AP

3. Lack neurofilaments

Front 32

What intermediate filaments do astroyctes contain?

Back 32

1. GFAP

Front 33

What part of the astrocyte forms the BBB?

Back 33

1. Perivascular feet

Front 34

What is the function of astrocytes?

Back 34

1. Supportive

2. Insulate synapse

3. Regulate extracellular pH, K

4. BBB

Front 35

What is the glial limitans?

Back 35

1. Structural barrier formed on deep surface of meninges by astrocytes

Front 36

What are fibrous astrocytes?

Back 36

1. Prominent in white matter

2. Thin processes, few branches

Front 37

What are protoplasmic astrocytes?

Back 37

1. Prominent in grey matter

2. Shorter, thicker processes with more branches

Front 38

What is a Bergmann glial cell?

Back 38

1. Found in cerebellum

2. Processes that extend to pia membrane

3. Astrocyte

Front 39

What is a Muller cell?

Back 39

1. Astrocyte found in retina

2. Similar to astrocyte and ependymal cells

Front 40

What is gliosis?

Back 40

1. Astrocyte response to disease in brain

2. Increase GFAP concentration

3. Form glial scar

Front 41

What is the function of microglial cells?

Back 41

1. Eliminate toxic debris

2. Facilitate neural stem cell migration

Front 42

What are satellite cells?

Back 42

1. Squamous cells that form a single layer around neuron soma

2. Similar to Schwann cells

3. Help from BBB in PNS

Front 43

What is the origin of oligodendrocytes?

Back 43

1. Neuroectoderm

Front 44

What are interfascicular oligodendrocytes?

Back 44

1. Oligodendrocytes found along and in between axons they myelinate

Front 45

What are satellite oligodendrocytes?

Back 45

1. Found in grey matter of CNS

Front 46

What is the origin of Schwann cells?

Back 46

1. Neuroectoderm

Front 47

What is the mesaxon?

Back 47

1. Forms when edge of the plasma membrane abuts another plasma membrane

Front 48

What is the incisor of Schmidt-Lanterman?

Back 48

1. Clumps of cytoplasm trapped in layers of plasma membrane

Front 49

What is the major dense line?

Back 49

1. Fusion of two cytoplasmic faces (inner) of lipid bilayer

Front 50

What is the inter-period line?

Back 50

1. Fusion of two extracellular faces of lipid bilayer

Front 51

What is the internode?

Back 51

1. Myelinated regions between nodes of Ranvier

2. Large if formed by oligodendrocytes

3. Small if formed by Schwann cells

Front 52

What is a paranode?

Back 52

1. Region next to node of Ranvier

Front 53

What is the function of connexin32?

Back 53

1. Links cytoplasmic layers together through tight junctions

Front 54

What is the order of the BBB?

Back 54

1. Inner--->outer

2. Capillary endothelium--- basement membrane--- astrocyte end-feet

Front 55

What is the morphology of ependymal cells?

Back 55

1. Cuboidal or low columnar with microvilli

Front 56

What are tanycytes?

Back 56

1. Basal processes found interdigitating with ependymal cells

2. Contain GFAP

3. Transporter molecules

Front 57

What is the average CSF production per day? How much is found in an average adult?

Back 57

1. 500 mL/d

2. 100-150 mL in adult

Front 58

What is the function of CSF?

Back 58

1. Transport glucose and other products to CNS

2. Remove waste products and drugs

3. support and cushion CNS

4. Carries hormones from hypothalamus

Front 59

What are the properties of CSF?

Back 59

1. pH=7.33

2. Isotonic

3. Lower concentration of glucose and protein than in serum

Front 60

How does CSF return to the venous system?

Back 60

1. Arachnoid granulations