Muscle Anatomy and Physiology- Oxygen Supply / Cellular Respiration, Muscular Responses/Interaction

Sarcomere

a repeating pattern of myofibril units along each muscle fiber; creates the light and dark striations that we see

Thick filaments

aka myosin filaments they are responsible for force generation during muscle contraction

Thin filaments

aka actin filaments a key component of muscle contraction in striated muscle include tropomyosin and troponin

Motor unit

specialized nerve cells that control voluntary movements, such as walking, talking, and breathing. 

ADP/ATP cycle

the cellular mechanism for storing and releasing energy

Creatine phosphate

involved in the ATP/CP System stores energy that quickly converts ADP to ATP; made by Mitochondria for storage in the muscle

ATP/CP cycle

aka phosphagen system a rapid, anaerobic energy system that provides energy for short bursts of high-intensity exercise, primarily lasting up to about 10 seconds. It relies on the breakdown of creatine phosphate (CP) to rapidly replenish ATP.

Aerobic respiration

the process by which cells convert glucose and oxygen into ATP (energy), carbon dioxide, and water produces more ATP

Myoglobin

O₂ binding site in muscle

Oxygen debt

the amount of extra oxygen the body needs after strenuous exercise to restore itself to a resting state. This occurs because during intense activity, the body's oxygen supply can't keep up with its demand, leading to a buildup of lactic acid. 

Fatigue

an inability to contract commonly caused from:

1. accumulation of lactic acid 

2. psychological loss of desire 

3.  decreased blood flow

4.  ion imbalances across the sarcolemma from heavy use

fast twitch

white (b/c they have less blood& o2) muscle fibers that contract rapidly and generate powerful movements, but fatigue faster

slow twitch

red (b/c they have more blood& o2) muscle fibers highly efficient at using oxygen to produce energy for sustained, low-intensity activities good for endurance as they fatigue slower

red fibers

slow twitch b/c they have more blood& o2 (aerobic) most hemoglobin

white fibers

fast twitch b/c they have less blood& o2 (anaerobic) less hemoglobin

Isometric contraction

muscle contracts but does not change length; generally against immovable objects

isotonic contraction

muscle contracts and changes length; against movable objects

Tone

continuous state of partial contraction; often gives muscles a sculpted look 

1 degree lever

2 degree lever

3 degree lever

Calculate Work

force x distance

Calculate Power

work / time

hemoglobin

O₂ binding site in blood