Ch. 5 - Terms

The Nervous, Skeletal, & Muscular System

Human movement system (HMS)

The collective components and structures that work together to move the body: muscular, skeletal, and nervous systems.

Kinetic Chain

A concept that describes the human body as a chain of interdependent links that work together to perform movement.

nervous system

the network of nerve cells and fibers that transmits nerve impulses between parts of the body.

Neuron

a nerve cell; the basic building block of the nervous system

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Effector sites

A part of the body, such as a muscle or organ, that receives a signal from a neuron to produce a physiological response.

Central Nervous System (CNS)

consists of the brain and spinal cord

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

afferent pathway

Pathway of receptor to control center

efferent pathway

Pathway of control center to effector

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

Mechanoreceptors

Specialized structures that respond to mechanical forces (touch and pressure) within tissues and then transmit signals through sensory nerves.

somatic nervous system

nerves that connect to voluntary skeletal muscles and to sensory receptors

autonomic nervous system (ANS)

the part of the peripheral nervous system that controls internal biological functions

sympathetic nervous system

A subdivision of the autonomic nervous system that activates nerves, glands and visceral muscles in times of stress or threat (prepares the body for action)

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

Proprioception

The body's ability to naturally sense its general orientation and relative position of its parts.

Integrative function

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

motor function of nervous system

The neuromuscular response to the sensory information

muscle spindles

receptors sensitive to change in length of the muscle and the rate of that change

stretch reflex

the contraction of a muscle in response to stretch of that muscle

Golgi tendon organs

Receptors sensitive to change in tension of the muscle and the rate of that change

Neuroplasticity

the ability of the nervous system to change in response to experience or the environment

axial skeleton

Portion of the skeletal system that consists of the skull, rib cage, and vertebral column

appendicular skeleton

Bones of the limbs and limb girdles that are attached to the axial skeleton

osteoclasts and osteoblasts

are responsible for bone remodeling

Wolff's Law

A bone grows or remodels in response to forces or demands placed upon it

Neutral Spine Position

The balance of vertebrae in the three naturally occurring curves; two slight anterior curves at the neck and low back and one slight posterior curve in the thoracic region.

Arthrokinematics

joint motion

fascia

a band or sheet of fibrous connective tissue that covers, supports, and separates muscle

Glycogen

Storage form of glucose

Actin

thin filaments of a muscle fiber

Myosin

thick filament in a muscle fiber; has bump-like projections

neuromuscular junction

point of contact between a motor neuron and a skeletal muscle cell

motor unit

A motor neuron and all of the muscle fibers it innervates

alpha motor neurons

The fibers that carry action potentials to cause skeletal muscle to contract are

sliding filament theory

theory that actin filaments slide toward each other during muscle contraction, while the myosin filaments are still

Adenosine Triphosphate (ATP)

compound used by cells to store and release energy

Type 1 muscle fibers

slow-twitch, smaller and slower to produce maximal tension, more resistant to fatigue.

Type 2 muscle fibers

fast-twitch, larger in size, quick to produce maximal tension and fatigue more quickly

all or nothing principle

The principle that once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.

Capillaries

Microscopic vessel through which exchanges take place between the blood and cells of the body