Nervous Tissue

Question 1

most numerous of the neuroglial cells

Answer 1

Astrocytes

Question 2

have a euchromatic nucleus that is considerably smaller than that of the neurons. Their principal role is to clear neurotransmitters from within the synaptic cleft, and to that end, their attenuated processes surround every synaptic junction in the CNS.

Answer 2

Astrocytes

Question 3

Their processes contribute to the blood-brain barrier and surround all penetrating blood vessels and all the free surfaces of the brain and spinal cord.

Answer 3

Astrocytes

Question 4

The extensive network of astrocytes and their processes is integrated by ___ _____, and they signal each other using _____.

Answer 4

gap junctions; calcium

Question 5

enlarge and form the scar that follows damage to areas of nervous tissue.

Answer 5

Astrocytes

Question 6

The three main types of glial cells; location?

Answer 6

Astrocytes, oligodendrocytes, microglia

CNS

Question 7

small cells with a heterochromatic nucleus that form and maintain central myelin for axons in the central nervous system

Answer 7

Oligodendrocytes

Question 8

small cells with a heterochromatic nucleus. They perform functions similar to those of the macrophage. They are mobile within the brain and can multiply when the brain is damaged

Answer 8

Microglia

Question 9

What are the origins of all three neuroglia

Answer 9

Oligodendrocytes and astrocytes - ectodermal tissue

microglial - hematopoietic stem cells; mesodermal tissue

Question 10

Which of the neuroglia has the smaller more heterochromatic nuclei?

Answer 10

Oligodendrocyte and microglia

Question 11

Which of the neuroglia has the larger more euchromatic nuclei?

Answer 11

Astrocytes

Question 12

Expand to form the glial limitans

Answer 12

astrocytes

Question 13

List the supporting cells of the PNS

Answer 13

Schwann cells

Question 14

What are the origins of Schwann cells?

Answer 14

They originate in the neural crest of the developing embryo and migrate throughout the body in parallel with the developing peripheral nervous system.

Question 15

What is the relationship between neurons and Schwann cells?

Answer 15

Every surface of a neuron in the periphery is in contact with a Schwann cell.

Question 16

The cell bodies of the ganglion cells are encapsulated by a layer of Schwann cells, known classically as ___________ in that location.

Answer 16

Satellite cells

Question 17

envelop bundles of unmyelinated axons, providing physical support and protection

Answer 17

Schwann cells

Question 18

Following damage to axons, __________ phagocytose the debris of degenerating fibers and establish guidance paths for axon regeneration

Answer 18

Schwann cells

Question 19

the endoneurium consists of _____ and _______ of the nerve fiber

Answer 19

reticular fibers and the external lamina

Question 20

Describe the perineurium

Answer 20

is a fiber-reinforced layer of fibroblast-like cells that surrounds fascicles of axons

Question 21

Describe the epineurium; what is it made up of?

Answer 21

outer covering that binds the multiple nerve fascicles into a larger peripheral nerve.

The epineurium is a dense irregular connective tissue with many collagen fibers arranged in parallel to the fascicle.

Question 22

The presence of a perineurium is one way to differentiate between _____________, ____________________, and peripheral nerve in a light microscope tissue section.

Answer 22

smooth muscle, dense regular connective tissue

Question 23

In some neurons, the cytoplasm may contain _____ _____. These are also
called ‘age pigment’ because they increase in number and prominence with age;

Answer 23

lipofuscin granules

Question 24

What are the three types of neurons and how do they differ?

Answer 24

Multipolar neurons are characterized by mutiple dendrites
emerging from the cell body and a single axon, bipolar neurons have two dendritic processes
(one serves as an input process, the other as an output process), and unipolar (also
known as pseudounipolar) neurons have one process.