SEER Training Modules: The Nervous System

The nervous system is composed of

The various activities of the nervous system can be grouped together as three general, overlapping functions:

A measure of acidity and alkalinity of a solution. The measure is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity. On the scale, each unit of change represents a tenfold change in acidity or alkalinity.

A substance that, when dissolved in a suitable solvent or when fused, becomes an ionic conductor.

two main types of cells in nerve tissue

Each neuron has three basic parts:

What does the cell body lack?

cytoplasmic extensions, or processes, that project from the cell body

carries impulses away from the cell body

An axon may have infrequent branches called

Many axons are surrounded by a segmented, white, fatty substance called

what makes up the white matter in the CNS?

What makes up the gray matter within the CNS?

The unmyelinated regions between the myelin segments are called

In the peripheral nervous system, the myelin is produced by

The plasma membrane surrounding a Schwann cell of a myelinated nerve fiber and separating layers of myelin.

In the CNS, oligodendrocytes produce myelin, but there is no

neurons that carry impulses from peripheral sense receptors to the CNS

neurons transmit impulses from the CNS to effector organs such as muscles and glands.

are located entirely within the CNS in which they form the connecting link between the afferent and efferent neurons.

cells do not conduct nerve impulses, but instead, they support, nourish, and protect the neurons.They are capable of mitosis.

benign tumors of the peripheral nervous system which commonly occur in their sporadic, solitary form in otherwise normal individuals

fairly common benign nerve growth and begins when the outer coating of a nerve in your foot thickens

The nervous system as a whole is divided into two subdivisions:

Organs of the central nervous system:

The organs of the peripheral nervous system are the

The peripheral nervous system is further subdivided into an

the efferent or motor division is again subdivided into

supplies motor impulses to the skeletal muscles

supplies motor impulses to cardiac muscle, to smooth muscle, and to glandular epithelium

The innermost layer of meninges

tumors of the nerve tissue covering the brain and spinal cord

The brain is divided into the

The great band of commissural fibers uniting the cerebral hemispheres of higher mammals including humans.

Each cerebral hemisphere is divided into five lobes:

The diencephalons is centrally located and is nearly surrounded by the cerebral hemispheres. It includes the

a small region below the thalamus, which plays a key role in maintaining homeostasis because it regulates many visceral activities

the most dorsal portion of the diencephalons. This small gland is involved with the onset of puberty and rhythmic cycles in the body.

The brain stem consists of three parts:

most superior portion of the brain stem

bulging middle portion of the brain stem

extends inferiorly from the pons;ascending (sensory) and descending (motor) nerve fibers connecting the brain and spinal cord pass through this

the second largest portion of the brain, is located below the occipital lobes of the cerebrum

Three paired bundles of myelinated nerve fibers form communication pathways between the cerebellum and other parts of the central nervous system

The spinal cord extends from the_______ to the ________

refers to tumors that arise from the support cells of the brain

These tumors are the most common primary brain tumors

consists of the nerves that branch out from the brain and spinal cord

The peripheral nervous system is further subdivided into the

consists of nerves that go to the skin and muscles and is involved in conscious activities

consists of nerves that connect the CNS to the visceral organs such as the heart, stomach, and intestines. It mediates unconscious activities.

contains bundles of nerve fibers, either axons or dendrites, surrounded by connective tissue

A connective tissue sheath that surrounds each nerve is called

Each bundle of nerve fibers is called a _______and is surrounded by a layer of connective tissue called the ________

Within the fasciculus, each individual nerve fiber, with its myelin and neurilemma, is surrounded by connective tissue called the

Either of the 10th pair of cranial nerves that arise from the medulla and supply chiefly the viscera especially with autonomic sensory and motor fibers

benign fibrous growths that arise from the balance nerve, also called the eighth cranial nerve or vestibulocochlear nerve.

is a visceral efferent system, which means it sends motor impulses to the visceral organs.

The autonomic nervous system has two parts