Advertisement Upgrade to remove ads

The Nervous System

It is a conglomeration of billions of cells forming nerves that are specifically designed to provide a communication network within the human body

What are the three primary functions of the nervous system?

Sensory, Integrative, and Motor Function.

Sensory Function

The ability of the nervous system to sense changes in either the internal or external environment.

Integrative Function

The ability of the nervous system to analyze and interpret the sensory information to allow for proper decision making and produce the appropriate response.

Motor Function

The neuromuscular response to the sensory information, such as causing the muscle to initially contract when stretched.

The Neuron

The functional unit of the nervous system.

Cell Body, Axon, and Dendrites.

The three main parts of the neuron.

Sensory, Interneurons, Motor

The three main functional classifications of neurons.

Sensory Neurons

Transmit nerve impulses from effector sites via receptors to the brain and spinal cord.


Transmit nerve impulses from one neuron to another.

Motor Neurons

Transmit nerve impulses from the brain and spinal cord to the effector sites such as muscles or glands.

Central Nervous System

Consists of the brain and the spinal cord. Serves mainly to interpret information.

Peripheral Nervous System

Consists of 12 cranial nerves, 31 pairs of spinal nerves and sensory receptors.

Two Functions of Peripheral Nerves

1. They provide a connection for the nervous system to activate different effector sites such as muscles. 2. Relay information from the effector sites back to the brain via sensory receptors providing a constant update on the relationship between body and environment.

Sensory Receptors

Specialized structures that are designed to transform environmental stimuli (heat, light, sound, taste, motion) into sensory information that the brain and spinal cord can interpret and produce a response.

Mechano Receptors

Specialized structures that are responsible for sensing distortion in tissues.

Muscle Spindles

The major sensory organs of the muscle and sit parallel to the muscles fibers. They are sensitive to change in length and rate of length change.

Golgi Tendon Organs

At the point where the muscle and tendon meet and are sensitive to changes in muscular tension and rate of the tension change.

Kinetic Chain

Made up of three systems. The Muscular, Nervous and Skeletal systems.

The Skeletal System

A framework for our structure and movement.


Form junctions that are connected by muscles and connective tissue.


Sites where movement occurs as a result of muscle contraction.

Axial Skeleton

Made up of the skull, the rib cage, and the vertebral column. 80 Bones.

Appendicular Skeleton

The upper and lower extremities as well as the shoulder and pelvic girdles. 126 Bones.

Number of joints in the body


Bone Depressions

Flattened or indented portions of the bone that are attachment sites for the supraspinatus and infraspinatous muscles, respectively.

Bone Processes

Projections protruding from the bone to which muscles, tendons, and ligaments can attach.


Joint motion with three major motion types. Roll, slide and spin.

Classifications of Joints

Synovial and Nonsynovial.


Comprising 80% of the joints in the body and are most associated with movement and have the greatest capacity for movement. (The Knee)


No joint cavity and fibrous connective tissue; Little or no movement.

Gliding Joint

No axis of rotation; Moves by sliding side-to-side or back and forth. (Carpals of the hand)

Condloid Joint

Formed by fitting of condyles of one bone into elliptical cavities of another; moves predominantly in one plane. (Knee)


Uniaxial; moves in one plane of motion - sagittal (Elbow)


One bone fits like a saddle on another bone; moves predominantly in two planes - sagittal frontal (Joint of the thumb)


Only one axis; moves in one plane of motion - transverse (radioulnar)

Ball and Socket

Most mobile of joints; Moves in all three planes of motion (Shoulder)


Made up of collagen and is the primary connective tissue for a joint. Connect bone to bone and provide static and dynamic stability.

The Muscular System

Muscles generate internal tension that, under the control of the nervous system, manipulates the bones of our body to produce movements.


Structures that attach muscles to bone and provide the anchor from which the muscle can exert force.

The Epimysium

Layer of connective tissue that is underneath the fascia and surrounds the muscle.


A plasma membrane that encases muscle fibers.


The functional unit of muscle that produces muscular contraction and consists of repeating sections of actin and myosin.

Neural Activation

The contraction of a muscle generated by neural stimulation

Motor Unit

A motor neuron and all the muscle fibers it innervates


Chemical messengers that cross synapses to transmit electrical impulses from the nerve to the muscle.

Type 1 (slow twitch)

Muscle fiber with; -More Capillaries, mitochondria and myoglobin -Increased Oxygen delivery -Smaller in size -Less force produced -Slow to fatigue

Type II (fast twitch)

Muscle Fiber: -Fewer capillaries, mitochondria, and myoglobin -Decreased oxygen delivery -Larger in size -More force produced -Quick to fatigue

Four Muscle Types

- Agonist - Synergist - Stabilizer - Antagonist


Muscles that are the primary movers in a joint motion. Also known as Prime Movers.


Muscles that act in direct opposition to agonists


Muscles that assist Prime Movers (agonists) during functional movement patterns


Muscles that support or stabilize the body while the prime movers and the synergists perform the movement patterns.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!



Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom


Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording