Lecture 13: CNS Histology

Question 1

What is the name given to support cells in nervous tissue that are involved in conduction speed, repair and NT maintenance?

Answer 1

Glia

Question 2

What is a neuropil?

Answer 2

Dense network of interwoven nerve fibers and their branches and synapses, together with glial filaments

Question 3

What is the distal end of the axon called?

Answer 3

Terminal arborization -> has some branching, collateral branching

Question 4

Ends of axons usually have small telodendria, what is this?

Answer 4

Dilation of branch ends and contact postsynaptic cell

Question 5

An electrical synapse permits direct, passive flow of electrical current from one neuron to another, how does the current flow from one neuron to another?

Answer 5

Via gap junctions

Question 6

The proximal regions of astrocytes are reinforced with intermediate filaments made of what?

Answer 6

Glial fibrillation acid protein (GFAP)

Question 7

What are the functions of astrocytes?

Answer 7

Helps form BBB Regulates interstitial fluid composition Provides structural support and organization to the CNS Assists with neuronal development Replicates to occupy space of dying neurons

Question 8

What are the functions of ependymal cells?

Answer 8

Lines ventricles of brain and central canal of SC Assists in production and circulation of CSF

Question 9

What are the functions of microglial cells?

Answer 9

Phagocytic cells that move through the CNS Protects the CNS by engulfing infectious agents and other potential harmful substances

Question 10

T/F:Schwann cells are unique in the fact that they will entrap axons from multiple neurons

Answer 10

False -> This is true of oligodendrocytes!

Question 11

Ependymal cells are _________________ cells that line the fluid-filled ventricles of the brain and the central canal of the spinal cord

Answer 11

Columnar or cuboidal cells

Question 12

The apical end of ependymal cells have cilia and long microvili. What is the purpose of these structures?

Answer 12

Facilitate movement of CSF Likely involved in absorption

Question 13

T/F: Microglia are less numerous than oligodendrocytes or astrocytes

Answer 13

True

Question 14

What cell type is the major mechanism of immune defense in the CNS, removing any microbial invaders?

Answer 14

Microglia -> they originate from monocytes

Question 15

The choroid plexus is an elaborately folded and highly vascular tissue, found in the roofs of the 3rd and 4th ventricles, and in parts of lateral venticular walls. It contains a thin layer of ____________________ covered by __________________ cells

Answer 15

Well-vascularized pia mater; cuboidal ependymal cells

Question 16

The choroid plexus functions to. Remove __________ from blood and releases it as _______

Answer 16

H2O;CSF

Question 17

Where does the central canal lie in the spinal cord?

Answer 17

In the central commissure of grey matter -> lined by ependymal cells and contains CSF

Question 18

What types of nerve fibers does the white matter of the spinal cord consist of?

Answer 18

Ascending tracts of sensory fibers and descending motor tracts

Question 19

The sharply folded cerebellar cortex is organized into 3 layers. What are they?

Answer 19

Molecular layer Purkinje cells Granular layer

Question 20

What layer of the cerebellar cortex contains various very small, densely packed neurons and little neuropil?

Answer 20

Granular layer

Question 21

What layer of the cerebellar cortex extends dendrites throughout the molecular layer as a branching basket of nerve fibers?

Answer 21

Purkinje cell layer

Question 22

What layer of the cerebellar cortex has much neuropil and scattered neuronal cell bodies?

Answer 22

Molecular layer

Question 23

The neocortex of the cerebral cortex has a variety of cells, divided into 5 different morphological types. What are they?

Answer 23

Pyramidal cells Stellate (granule) cells Cells of martinotti Fusiform cells Horizontal cells of Cajal

Question 24

What cell type found in the cerebral cortex are small and spindle shaped but oriented paralllel to the surface and are the least common?

Answer 24

Horizontal cells of Cajal

Question 25

What cell type found in the cerebral cortex are spindle shaped cells oriented at right angles to the surface of the cerebral cortex?

Answer 25

Fusiform cells

Question 26

What cell type found in the cerebral cortex is small polygonal cells with a few short dendrites?

Answer 26

Cells of martinotti

Question 27

What cells type found in the cerebral cortex has small neurons with a cell body the shape of a star?

Answer 27

Stellate (granule) cells

Question 28

What cell type of the cerebral cortex are huge upper motor neurons of the motor cortex (Betz cells) and have pyramidal shaped cell bodies with the apex directed towards the cortical surface?

Answer 28

Pyramidal cells

Question 29

Biologically older parts of the cortex of the brain are arranged into3 layers and is referred to as the \_\_\_\_\_\_\_\_\_\_\_\_\_. Most of the cortex is called the ____________ and consists of 6 layers

Answer 29

Archicortex; neocortex

Question 30

Which cortical layer is the superficial layer containing dendrites and axons of cortical neurons with sparse neuroglia and horizontal cells of Cajal?

Answer 30

Molecular (plexiform) layer

Question 31

What cortical layer has a dense population of small pyramidal cells and stellate cells, mixed with axons and dendrites from deeper layers?

Answer 31

Outer/external granular layer

Question 32

In what cortical layer do pyramidal cells of moderate size predominate and martinotti cells are also present?

Answer 32

Pyramidal cell layer

Question 33

What cortical layer consists mainly of densely packed stellate cells?

Answer 33

Inner/internal granular layer

Question 34

What cortical layer contans large pyramidal cells and smaller numbers of stellate cells and cells of martinotti?

Answer 34

Ganglionic layer

Question 35

What cortical layer has a wide variety of cell types (small pyramidal cells, cells of martinotti, stellate cels and fusiform cells in the deeper part)?

Answer 35

Multiform cell layer

Question 36

Name this cell type

Answer 36

astrocytes

Question 37

name this cell type

Answer 37

astrocytes

Question 38

name this cell type

Answer 38

oligodendrocytes

Question 39

name this cell type

Answer 39

ependymal cells

Question 40

what is this a pic of?

Answer 40

ependymal cells surrounding the central canal

Question 41

what is this a pic of?

Answer 41

ependymal cells lining a ventricle

Question 42

name this cell type

Answer 42

microglia

Question 43

name this cell type

Answer 43

microglia

Question 44

name this cell type

Answer 44

microglia

Question 45

label the arrows

Answer 45

Question 46

label the arrows

Answer 46

d = dorsal horn l = lateral horn v = ventral horn

Question 47

label ML and M and state where this is

Answer 47

ML = molecular layer M = cerebellar medulla This is in the cerebellar cortex

Question 48

label M and ML and state where this is

Answer 48

m = cerebellar medulla ML = molecular layer this is in the cerebellar cortex

Question 49

label the layers and state where this is

Answer 49

cerebellar cortex

Question 50

label the cell type

Answer 50

pyramidal neurons

Question 51

label the cell type

Answer 51

astrocytes

Question 52

label the layers and state where this is

Answer 52

from top to bottom: I = molecular (plexiform) layer II = outer/external granular layer III = pyramidal cell layer IV = inner/internal granular layer V = ganglionic layer VI = multiform cell layer This is in the cerebral cortex

Question 53

Label E and C

Answer 53

e = ependymal cells C = capillaries this is a choroid plexus