Exercise 15: Histology of Nervous Tissue

Question 0

“nerve glue”; supporting cells; serve the needs of the neuron by bracing and protecting them; these cells are not capable of generating and transmitting nerve impulses; different types depending on the central (CNS) and peripheral (PNS) nervous systems

Answer 0

neuroglia

Question 1

the basic functional units of nervous tissue; cells of the nervous system; specialized to transmit messages (nerve impulses) from one part of the body to another

Answer 1

neurons

Question 2

the 2 principle cell populations in nervous tissue

Answer 2

neurons and neuroglia

Question 3

Neuroglia of the CNS

Answer 3

1. Astrocytes
2. Oligodendrocytes
3. Microglia
4. Ependymal cells

Question 4

In CNS, control the chemical environment around neurons; most abundant

Answer 4

astrocytes

Question 5

In CNS, myelinate cytoplasmic extensions of the neuron to speed up signal conduction

Answer 5

Oligodendrocytes

Question 6

phagocytic; destroys pathogens or cellular debris

Answer 6

Microglia

Question 7

line cerebrospinal fluid-filled cavities to secrete cerebrospinal fluid (a clear liquid that bathes the CNS)

Answer 7

Ependymal cells

Question 8

Neuroglia of the PNS

Answer 8

1. Schwann cells

2. Satellite cells

Question 9

In PNS, myelinate cytoplasmic extensions of the neuron to speed up signal conduction; assist in regeneration of damaged fibers

Answer 9

Schwann cells

Question 10

surround the neurosomas in ganglia of the PNS; provide electrical insulation around the soma; regulate the chemical environment of the neurons

Answer 10

Satellite cells

Question 11

region of the neuron that houses the nucleus and cytoplasm

Answer 11

Cell body (aka neurosoma)

Question 12

The cytoplasm of the neuron is riddled with _____ and ______.

Answer 12

Neurofibrils and Nissil bodies

Question 13

clusters of cell bodies in the CNS; neuron fibers running through the CNS form tracts of white matter

Answer 13

Nuclei

Question 14

clusters of cell bodies outside the CNS; neuron fibers running form the peripheral nerves

Answer 14

Ganglia

Question 15

cytoskeletal elements of the neuron that helps maintain support and intracellular transport functioning

Answer 15

Neurofibrils

Question 16

a type of rough endoplasmic reticulum that is involved with the metabolic activities of the cell

Answer 16

Nissil bodies

Question 17

receptive regions for neurotransmitters released by other neurons; neurons can have many of these

Answer 17

Dendrites

Question 18

nerve fibers that generate and conduct nerve impulses; neurons have only one of these

Answer 18

Axon

Question 19

where the cell body transitions into the axon

Answer 19

Axon hillock

Question 20

form synapses or junctions with neurons or effector cells

Answer 20

Axon terminals (aka synaptic knobs)

Question 21

Each axon terminal is separated from the cell body or dendrites of the next neuron by a ______.

Answer 21

Synaptic cleft

Question 22

gaps or indentations in the myelin sheath

Answer 22

Nodes of Ranvier

Question 23

a fatty material that covers the nerve fibers

Answer 23

Myelin

Question 24

In PNS: axons are myelinated by ____

____ which wrap tightly around the axon in jellyroll fashion; this wrapping is called a ____ ____

Answer 24

1. Schwann cells

2. Myelin sheath

Question 25

the peripheral part of the Schwann cell and its exposed plasma membrane

Answer 25

Neurilemma (aka sheath of Schwann)

Question 26

In CNS: myelination is accomplished by ____; these CNS sheaths do not exhibit ____; myelin insulates the fibers and greatly increases the speed of neurotransmission by ____ ____.

Answer 26

1. Oligodendrocytes
2. Neurilemma
3. Neuron fibers

Question 27

What is neuron classification based upon?

Answer 27

1. Structure (number of processes attached to the cell body)

2. Function

Question 28

one very short process that extends from the cell body; divides into peripheral and central processes; only the most distal portions of the peripheral process act as receptive endings; the rest acts as an axon along with the central process

Answer 28

Unipolar neurons

Question 29

two processes attached to the cell body; rare – found only as part of the receptor apparatus of the eye, ear, and olfactory mucosa

Answer 29

Bipolar neurons

Question 30

many processes that come from the cell body that are all called dendrites; has a single axon

Answer 30

Multipolar neurons

Question 31

neurons carrying impulses from sensory receptors in the internal organs, the skin, skeletal muscles, joints, or special sensory organs; receptive endings are often equipped with specialized receptors that are stimulated by specific changes in their immediate environment; cell bodies found in a ganglion outside the CNS; typically unipolar

Answer 31

Sensory (afferent) neurons

Question 32

neurons carrying impulses from the CNS to the viscera and/or body muscles and glands; often multipolar; cell bodies located in the CNS

Answer 32

Motor (efferent) neurons

Question 33

neurons that help connect sensory and motor neurons; cell bodies located within CNS; multipolar structure

Answer 33

Interneurons (aka association neurons)

Question 34

bundle of neuron fibers (axons) wrapped in connective tissue coverings that extends to and/or from the CNS and visceral organs or structures of the body periphery

Answer 34

Nerve

Question 35

Nerves that transmit impulses toward CNS

Answer 35

Sensory (afferent) nerves

Question 36

Nerves that transmit impulses away from CNS

Answer 36

Motor (efferent) nerves

Question 37

nerves that carry both sensory and motor fibers

Answer 37

Mixed nerves

Question 38

a connective tissue sheath that surrounds each nerve fiber (axon); provides insulation from the other neuron processes adjacent to it; this CT layer is often mistaken for the myelin sheath

Answer 38

Endoneurium

Question 39

connective tissue that surrounds groups of fibers; this forms bundles of fibers called fascicles

Answer 39

Perineurium

Question 40

bundles of fibers formed by the perineurium

Answer 40

Fascicles

Question 41

fibrous connective tissue that surrounds all the fascicles to group them together to make the nerve

Answer 41

Epineurium