Glossary Flashcards
(405 cards)
A-Band
The region of the sarcomere where myosin filaments are predominantly seen with minor overlap of the actin filaments.
Abduction
A movement in the frontal plane away from the midline of the body.
Acceleration
When a muscle exerts more force than is being placed on it, the muscle will shorten; also known as a concentric contraction or force production.
Acidosis
The accumulation of excessive hydrogen that causes increased acidity of the blood and muscle.
Actin
One of the two major myofilaments, actin is the “thin” filament that acts along
with myosin to produce muscular contraction.
Action Potential
Nerve impulse that allows neurons to transmit information.
Active Flexibility
The ability of agonists and synergists to move a limb through the full range of motion while their functional antagonist is being stretched.
Active-Isolated Stretch
The process of using agonists and synergists to dynamically move the joint into a range of motion.
Adduction
Movement in the frontal plane back toward the midline of the body.
Adenosine Diphosphate (ADP)
A high-energy compound occurring in all cells
from which adenosine triphosphate (ATP) is formed.
Adenosine Triphosphate (ATP)
Energy storage and transfer unit within the cells of
the body.
Adequate Intake (AI)
A recommended average daily nutrient intake level, based on observed (or experimentally determined) approximations or estimates of nutrient intake that are assumed to be adequate for a group (or groups) of healthy people; this measure is used when an RDA cannot be determined.
Afferent Neurons
(Also known as sensory neurons) They gather incoming sensory information from the environment and deliver it to the central nervous system.
Agonist
Muscles that are the primary movers in a joint motion; also known as prime movers.
Alarm Reaction
The first stage of the General Adaptation Syndrome (GAS), the initial reaction to a stressor.
Altered Reciprocal Inhibition
The concept of muscle inhibition, caused by a tight agonist, which inhibits its functional antagonist.
Amortization Phase
The electromechanical delay a muscle experiences in the transition from eccentric (reducing force and storing energy) to concentric (producing force) muscle action.
Anaerobic Threshold
The point during high-intensity activity when the body can no longer meet its demand for oxygen and anaerobic metabolism predominates; also called lactate threshold.
Anatomic Position
The position with the body erect with the arms at the sides and the palms forward. The anatomic position is of importance in anatomy because it is the position of reference for anatomic nomenclature. Anatomic terms such as anterior and posterior, medial and lateral, and abduction and adduction apply to the body when it is in the anatomic position.
Antagonist
Muscles that act in direct opposition to agonists (prime movers).
Anterior
(or Ventral) On the front of the body.
Aortic Semilunar Valve
Controls blood flow from the left ventricle to the aorta going to the entire body.
Appendicular Skeleton
Portion of the skeletal system that includes the upper and lower extremities.
Arteries
Vessels that transport blood away from the heart.