A&p NERVOUS TISSUE 1&2

List the fundamental physiological properties of neurons.

1) excitability, 2) conductivity, and 3) secretion

The nervous system plays an important role in maintaining homeostasis. List, in order, the basic steps that describe how the nervous system carries out this task.

1. Information received by sensory receptors is transmitted to the CNS. 2. Information is processed and an appropriate response is determined. 3. A command is issued to effectors such as muscles or glands.

What is the approximate ratio of glial cells to neurons?

10:1

Axon hillock Axoplasm Axolemma Axon collateral

A mound located on one side of the soma from which the axon originates Cytoplasm of the axon Plasma membrane of the axon Branch that originates from an axon

The visceral motor division of the PNS is also called the autonomic division. Which of the following are functions of this division?

Accelerating or decreasing heartbeat Controlling gland secretion Stimulating or inhibiting digestion

Sensory (afferent) neurons do which of the following?

Carry signals to spinal cord and brain

Which are functions of astrocytes?

Form blood-brain barrier Secrete nerve growth factors Regulate chemical composition of tissue fluid Convert blood glucose to lactate for neurons to use for fuel

Which correctly describe axonal transport?

It is bidirectional (retrograde and anterograde transport). It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma).

Which are usually found inside the cell body (or soma) of a mature neuron?

Mitochondria, Nucleus, rough endoplasmic reticulum

Which types of glial cells are found in the central nervous system?

Oligodendrocytes Microglia Ependymal cells Astrocytes

The sensory and motor divisions of the peripheral nervous system are further split into which two subdivisions?

Somatic and visceral

What is the primary function of the myelin sheath?

To increase the speed of signal conduction in the axon

Which term is another name for the autonomic nervous system?

Visceral motor division

Another term for sensory division is ______ division.

afferent

Which term describes all neurons that carry signals towards the CNS?

afferent

Which type of cell plays a role in the establishment of the blood-brain barrier?

astrocytes

Name the area of the neuron indicated by the arrow labeled A.

axon collateral

Which term applies to the small swellings at the distal end of the axon of a neuron that contain synaptic vesicles?

axon terminals

Which term refers to the passage of proteins, organelles and other materials along an axon?

axonal transport

Neurons that have one axon and one dendrite, such as olfactory cells, certain neurons of the retina, and sensory neurons of the inner ear, are classified as which of the following?

bipolar

What type of neuron is shown in the image?

bipolar (looks like a mermaid)

A neuron with one axon and one dendrite is structurally classified as a

bipolar neuron

What are the two major anatomical subdivisions of the nervous system?

central and peripheral nervous system

The brain and spinal cord are components of the ______ nervous system, while the nerves and ganglia are components of the ______ nervous system.

central, peripheral

Which fundamental physiological property of neurons allows them to send signals quickly over long distances?

conductivity

The processes that branch from the somas of most neurons are called ______.

dendrite

are the processes of a neuron that usually receive signals from other neurons.

dendrites

Motor, or , neurons carry signals away from the CNS and they lead to effectors (muscle and gland cells).

efferent

Choose the name of the thin layer of fibrous connective tissue found around myelin in nerve fibers of the peripheral nervous system.

endonuerium

Two organ systems are dedicated to internal coordination, communication between the other systems, and maintaining the overall homeostasis of the body. They are the system, which communicates by means of hormones, and the system which sends quick electrical and chemical messages from cell to cell.

endrocrine, nervous

The glial cells that line cavities of the brain and spinal cord and secrete and circulate cerebrospinal fluid are ______.

ependymal cells

Which glial cell produces and helps circulate cerebrospinal fluid?

ependymal cells

The plural form of ganglion is ______.

ganglia

The knotlike swelling in a nerve where neuron cell bodies are found is called a(n) .

ganglion

______ cells protect the neurons and help them function.

glial

The trigger zone includes the axon hillock and the segment, a region between the axon hillock and the first glial cell.

initial segment

Which term refers to the segment of an axon between the axon hillock and the first glial cell?

initial segment

The arrow labeled A is pointing to which type of neuron in this diagram?

interneuron

Which type of neuron lies entirely within the CNS and carries out the integrative function of the nervous system?

interneuron

Between the nodes of Ranvier are myelin-covered segments of axon encircled by Schwann cells. Which term refers to these segments?

internodes

The myelin sheath is composed mostly of which of the following?

lipids

Neuroglial cells that act as macrophages within the CNS are ______.

microglia

Which cell is indicated by the arrow labeled A?

microglial cell

Which division of the PNS carries signals from the CNS to glands and muscle cells?

motor

Neurons with numerous dendrites and a single axon are structurally classified as which of the following?

multipolar

The picture shows the most common structural type of neuron. It contains one axon and multiple dendrites, and it is classified as a(n) ______ neuron.

multipolar

The neurons indicated by a letter "A" are structurally classified as ______ neurons. The neurons indicated by a letter "B" are structurally classified as ______ neurons.

multipolar, bipolar

Which two organ systems are primarily responsible for coordinating the other bodily systems so as to maintain homeostasis?

nervous, endocrine

Which term refers to the thick outermost coil of a Schwann cell?

neurillema

Sensory, association and motor are the three classes of what

neurons

Sensory, association and motor are the three classes of what?

neurons

The ______ (the cell body of a neuron) gives rise to branch-like processes called ______, which are the primary sites for receiving signals from other neurons.

neursoma, dendrites

Which glial cell insulates nerve fibers from extracellular fluids and speeds up signal conduction in the brain?

oligodendrocyte

In the CNS, myelin is produced by glial cells called .

oligodendrocytes

Taken together, the sensory and motor subdivisions make up which of the following?

peripheal nervous system

Which factors influence the speed of nerve signal conduction?

presence of myelin and diameter of axon

Choose the characteristics of neuroglia.

protects and binds

______ cells are glial cells in the peripheral nervous system that surround somas of neurons in the ganglia, provide electrical insulation, and regulate the chemical environment of neurons.

satellite

Identify the type of cell indicated by the arrow labeled A.

schwann (looks like russian finger twist

Which type of glial cell produces the myelin sheath in the PNS?

schwann cells

Which two types of neuroglia are found only in the peripheral nervous system?

schwann, satellite

Afferent neurons are ______ neurons.

sensory

Which terms refers to the part of the PNS that carries signals from various receptors to the CNS?

sensory division

Which type of neuron begins in most body organs and carries information toward the central nervous system?

sensory neuron

List the three functional classes of neurons.

sensory, interneurons, motor

Which is true about a neuron with a large diameter, myelinated axon as compared to a neuron with a small diameter, unmyelinated axon?

signal conduction

Which are names for the cell body of a neuron?

soma, neurosoma

The motor division of the PNS is further subdivided into the ______ motor division that carries signals to the skeletal muscles and the ______ motor division (also known as the autonomic nervous system), which carries signals to glands, cardiac muscle, and smooth muscle.

somatic, visceral

Which part of the neuron is indicated by the arrow labeled A?

terminal aborization

The axon hillock and initial segment play an important role in initiating a nerve signal. They are collectively called the zone.

trigger zone

The region that plays an important role in initiating a nerve signal and is formed by the axon hillock and the initial segment is the ______.

trigger zone

True or false: Unmyelinated nerve fibers (axons) in the PNS are enveloped in Schwann cells.

true

Which lists the structural categories of neurons?

uni,bi,multi,anaxonic

Neurons with a single process extending from the soma, such as the neurons that carry sensory signals to the spinal cord, are classified structurally as ______ neurons.

unipolar

The type of neuron shown here is ______.

unipolar (looks like a long line with an eyeball)

An axon lacking a myelin sheath is said to be ______.

unmyelinated