Exercise 15: Histology of Nervous Tissue

Lakukan tugas rumah & ujian kamu dengan baik sekarang menggunakan Quizwiz!

What are the six types of neuroglia (glial cells), and what nervous system are they apart of?

1. Astrocytes: Central 2. microglial cells: Central 3. ependymal cells: Central 4. Oligodendrocytes: Central 5. Satellite cells: Peripheral 6. Schwann cells: Peripheral

Describe how the Schwann cells form the myelin sheath encasing the nerve fibers.

A Schwann cell becomes apposed to an axon and envelopes it in a trough. It then begins to rotate around the axon, wrapping it loosely in successive layers of its plasma membrane.

efferent neuron

Neuron that conducts impulses away from the CNS to muscles and glands.

afferent neuron

Neuron that conducts impulses toward the CNS from the body periphery.

What is a nerve?

a bundle of axons wrapped in connective tissue

interneuron

a neuron serving as part of the conduction pathway between sensory and motor neurons

Amyotrophic lateral sclerosis is a neurodegenerative disease in which motor neurons are progressively destroyed. Excess levels of the neurotransmitter glutamate have been implicated in this process. Which type of neuroglia would play a role in controlling glutamate levels in the chemical environment of neurons?

astrocytes because they control the chemical environment of neurons.

nerve

bundle of axons in PNS

tract

bundle of axons in the CNS

Neurotransmitters

chemicals released by neurons that stimulate or inhibit other neurons or effectors

ganglion

collection of nerve cell bodies in the PNS

Nucleus

collection of neuron cell bodies found within the CNS

chromatophilic substance

essentially rough endoplasmic reticulum, important metabolically

peripheral nervous system

ganglia and spinal and cranial nerves

Axon

impulse generator and transmitter

myelin sheath

insulates the nerve fibers

neurofibril

involved in the transport of substances within the neuron

snaptic cleft

junction or point of close contact between neurons

What type of neuron is multipolar?

motor neuron

Peripheral neuropathy has a variety of causes. Worldwide, the most common cause is leprosy, also known as Hansen's disease. Would you expect peripheral neuropathy to cause damage to tracts or to nerves? Why?

nerves because leprosy affects the skin and skin is part of the PNS

What substance is found in synaptic vesicles of the axon terminal?

neurotransmitters

Where is the endoneurium located?

on the outside of the myelin

Dendrite

receptive region of a neuron

axon hillock

region of the cell body from which the axon originates

axon terminal

secretes neurotransmitters

What type of neuron is unipolar?

sensory neuron

cell body

site of the nucleus and most important metabolic area

Neuroglia

specialized supporting cells in the nervous system

Where is the perineurium located?

surrounds a bundle of axons

central nervous system

term for the brain and spinal cord collectively

what anatomical characteristic determines whether a particular neuron is classified as unipolar, bipolar, or multipolar?

the number of processes that extend from the cell body

What is the function of the connective tissue wrappings found in a nerve?

to protect and insulate nerve fibers

The basic functional unit of the nervous system is the neuron. What is the major function of this cell type?

to send messages from one part of the body to another

microglial cells

type of neuroglia that act as a phagocyte in the CNS

Astrocytes

type of neuroglia that controls the chemical environment around neurons in the CNS

Oligodendrocytes

type of neuroglia that forms the myelin sheath in the CNS

Schwann cells

type of neuroglia that forms the myelin sheath in the PNS

ependymal cells

type of neuroglia that lines CSF-filled cavities

sattelite cells

type of neuroglia that surrounds the cell body of a neuron found in the PNS


Set pelajaran terkait

Political Science, Chapter 9 mindtap

View Set

Tennessee Life Insurance Chapter 1: Completing the Application, Underwriting, and Delivering the Policy

View Set

Chapter 8 Fibrous Joints Characteristics

View Set