Chapter 10- Nervous system I: Basic structure and function

Indicate the four types of neuroglia (glial cells) in the central nervous system.

Astrocytes Oligodendrocytes Microglia Ependyma

Where are axon terminals located?

At the ends of axons

Select examples of effectors that can be stimulated by motor impulses.

Autonomic

The motor division of the nervous system is subdivided into _____ and _____ nervous systems

Autonomic Somatic

The part of a neuron that sends out nerve impulses is the _____.

Axon

Which three items are parts of a neuron?

Axon Cell body Dendrites

A neuron has no more than one _____, but can have many _____.

Axon; dendrites

The process called _____ transport involves the passage of proteins, organelles and other materials along an axon.

Axonal

Where is a synaptic cleft located?

Between a synapti knob and another cell

Neurons that have only two processes, one axon and one dendrite, are called _____ neurons.

Bipolar

The enlarged part of the neuron (within the circle) is the cell _____.

Body

Select examples of effectors that can be stimulated by motor impulses.

Cardiac muscle Glands Skeletal muscle

Arrow A indicates a _____. Whereas arrow B indicates a _____.

Cell body; dendrite

Within neurons, dendrites are processes extending from the _____. They function to carry signals _____ the cell body.

Cell body; toward

Structures called tracts are bundles of axons occurring within the _____ nervous system.

Central

What is the source of new neurons in the CNS?

Central nervous system stem cells

The two main divisions of the nervous system are the _____ nervous system and the _____ nervous system.

Central, peripheral

The gap between the two neurons is called the synaptic _____.

Cleft

What is the term for branches off of an axon?

Collaterals

What is a function of the nervous system?

Coordinate all other body functions

What type of process is typically more abundant in a neuron?

Dendrite

Neurons have processes called _____ that receive signals from other neurons.

Dendrites

Within a neuron, the _____ are highly branched cellular processes that carry signals toward the cell body of the neuron.

Dendrites

A neuron includes a cell body with its organelles, and cell processes called _____ and _____.

Dendrites; axons

Mature neurons _____divide.

Do not

Muscles and glands, located outside of the central nervous system, function as _____, responding to motor impulses.

Effectors

The chromatophilic substance (Nissl bodies) of a neuron is a modification of what cellular organelle?

Endoplasmic reticulum

True or false: If an axon in the CNS is damaged, it regenerates after a short period of time.

False- Regeneration is unlikely because the CNS lack neurilemma; oligodendrocytes do not proliferate after injury.

A mass of neuron cell bodies located outside the brain and spinal cord is called a(n) _____.

Ganglia

_____ matter consists of _____ axons, dendrites, and neuron cell bodies.

Gray; unmyelinated

Indicate three functions of astrocytes.

Helps repair nervous tissue Aids in the metabolism of substances (ie glucose). Forms the blood brain barrier.

The axon _____ is the region of a neuron where the axon originates.

Hillock

Sensory signals come into the central nervous system where _____ occurs. Then, signals are sent out to the body using _____ neurons.

Integration; motor

The _____ function of the nervous system is to gather _____ information and make decisions that affect _____ functions.

Integrative; sensory; motor

What is the meaning of the prefix "multi-"?

Many

Name the cell in nervous tissue that provides physical support, insulation, and nutrients for other cells.

Neuroglia

What are the two cell types in neural tissue?

Neuroglia Neurons

In the central nervous system, cells called _____ outnumber the cells called _____.

Neuroglia; neurons

Schwann cells and satellite cells are types of _____ found in the _____ nervous system.

Neuroglia; peripheral

Mature _____ do not divide.

Neurons

What is the term for biological messenger molecules that transmit a signal between two neurons?

Neurotransmitters

What is the name of the gaps found between segments of myelin along an axon?

Nodes of Ranvier

In the CNS, myelin is produced by cells called _____. In the peripheral nervous system, myelin is made by cells called _____.

Oligodendrocytes; Schwann cells

What prefix means "all around"?

Peri-

The somatic nervous system and autonomic nervous system are subdivisions of the _____ nervous system.

Peripheral

In what branch of the nervous system do the Schwann cells wrap around axons creating myelin sheaths?

Peripheral nervous system

Schwann cells are neuroglia that produce myelin in the _____.

Peripheral nervous system

What division of the nervous system consists of cranial and spinal nerves?

Peripheral nervous system

The ability of damage axons to regenerate in the _____ nervous system may be due to the neuroglia cell called the _____.

Peripheral; Schawnn cell

Sensory neurons carry electrical signals from the _____ to the _____.

Periphery; central nervous system

Indicate three general functions of neuroglia.

Produce components of myelin. Provide structural support of neurons. Carry out phagocytosis.

Axonal transport is the movements of _____ up and down the _____.

Proteins and organelles; axon

What is the source of myelin, found around large axons of the peripheral nervous system?

Schwann cell membranes tightly wound around axons.

The cells that are responsible for wrapping around axons, creating myelin sheaths in the PNS, are _____.

Schwann cells

List three functions of the nervous system.

Sense the environment Integrate incoming signals Initiate changes in effectors

Nerve impulses are conducted via the _____ neurons from peripheral body parts into the brain and spinal cord.

Sensory

_____ receptors detect changes in internal and external body conditions.

Sensory

Match the neuron type with its function.

Sensory (afferent) neuron- Located in PNS; carry impulses toward the CNS Motor (efferent) neuron- Located in PSN; carry impulses away from the CNS Interneuron- Located in the CNS; integrate sensory signals

What class of neurons transmit information from the periphery to the central nervous system?

Sensory neurons

Somatic motor neurons control _____ muscles. Autonomic motor neurons control _____ muscles.

Skeletal; smooth

In the central nervous system, severed axons degenerate _____ compared to the PNS and are _____ to regenerate.

Slower; unlikely

The _____ division of the peripheral nervous system handles voluntary motor activites.

Somatic

The _____ division of the peripheral nervous system handles voluntary motor activities.

Somatic

What organs make up the peripheral nervous system?

Spinal nerves Cranial nerves

Which three of the following describe the autonomic nervous system?

Subdivision of the peripheral nervous system Controls smooth and cardiac muscle Effectors are under involuntary control

A(n) _____ is the location at which a neuron and the cell with which it communicates meet (without directly touching).

Synapse

Which two characteristics apply to cells called interneurons (or association neurons)?

They are multipolar neurons They link sensory neurons to motor neurons

The meaning of the prefix "bi" is _____.

Two

Nodes of Ranvier are narrow gaps between what two structures?

Two myelin sheath

What prefix means "one"?

Uni-

Gray matter consists of what three structures?

Unmyelinated axons Neuron cell bodies Dendrites

Within the central nervous system, tissue called _____ matter consists of bundles of _____ axons.

White; myelinated

In the peripheral nervous system, severed axons _____ regenerate under certain conditions.

May

Huntington's disease may be caused by cells of the brain called _____ releasing toxins. Cells called _____may release toxins that may be related to amyotrophic lateral sclerosis (ALS), a neurodegerative disorder.

Microglia; astrocytes

Neurons that send signals away from the central nervous system to effectors, such as a muscle (skeletal, cardiac and smooth) and glands are called _____ neurons.

Motor

What type of neuron would stimulate an effector?

Motor neurons

Nervous system damage to _____ neurons would affect skeletal muscle contration (movement); difficulty in feeling touch or pain is caused by damage to _____ neurons.

Motor; sensory

A patient is diagnosed with brain lesions caused by an immune system attack against myelin sheaths. What is most likely the diagnosis?

Multiple sclerosis

Neurons are structurally classified as unipolar, bipolar, or _____.

Multipolar

What gives white matter of the central nervous system its white color?

Myelin

The winding of Schwann cells around an axon results in the formation of what feature of a neuron?

Myelin sheath

A neurilemma surrounds the _____ and contains most of the _____.

Myelin sheath; Schwann cell cytoplasm

Myelinated axons have _____, and transmit impulses more _____ than unmyelinated axons.

Myelin sheaths; quikly

Structures within the peripheral nervous system called _____ are bundles of axons wrapped in connective tissue.

Nerves

What is the term for bundles of axons within the peripheral nervous system?

Nerves

Feeling, thinking and moving are functions of which organ system?

Nervous