Human Physiology and Physics

These flashcards cover key vocabulary terms and definitions related to human physiology, muscle contraction, and fundamental physics concepts.

Motor Unit

A motor unit consists of a neuron and muscle fibers that connect to the central nervous system, sending messages to initiate muscle contraction.

Acetylcholine (ACh)

A neurotransmitter that facilitates the transmission of impulses across the synapse, converting electrical impulses into chemical signals to trigger muscle contraction.

Cholinesterase

An enzyme that breaks down acetylcholine, enabling the muscle to relax by preventing further sodium entry.

Slow Twitch Fibers

Type I muscle fibers that use aerobic respiration for long-term endurance, characterized by high numbers of blood vessels and myoglobin.

Fast Twitch Fibers

Type II muscle fibers that utilize anaerobic respiration for quick, short-duration contractions, characterized by fewer blood vessels and lower myoglobin content.

Delayed Onset Muscle Soreness (DOMS)

Muscle pain that arises after strenuous or unfamiliar exercise, typically accompanied by microtears in muscle fibers.

Scalar Quantity

A physical quantity defined by its magnitude only, without direction.

Vector Quantity

A physical quantity that has both magnitude and direction.

Center of Mass

The point at which the mass of an object is distributed; can be manipulated by body position.

Fulcrum

The support point or pivot of a lever.

First Class Lever

A lever where the fulcrum is situated between the effort and the load.

Second Class Lever

A lever where the load is located between the fulcrum and the effort.

Third Class Lever

A lever where the effort is placed between the fulcrum and the load.

Newton’s First Law of Motion

An object will remain at rest or in uniform motion unless acted upon by an external force.

Newton’s Second Law of Motion

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

Newton’s Third Law of Motion

For every action, there is an equal and opposite reaction.

Impulse-Momentum Relationship

The change in momentum of an object is equal to the impulse applied to it.

Angular Velocity

The rate of rotation of an object around its axis.

Moment of Inertia

The resistance of an object to changes in its rotational motion, dependent on mass distribution relative to its axis of rotation.

Angular Momentum

The product of an object's moment of inertia and its angular velocity, conserved in a closed system.

Distance

Scalar

Displacement

Vector

Force

Vector

Speed

Scalar

Velocity

Vector

Acceleration

Vector

Momentum

Vector

Impulse

Vector