Sports Science muscular functions

ATP

Adenosine triphosphate. Energy produced when phosphate breaks off. ATP=ADP+Phosphate+Energy.

Lactc acid pathway/anaerobic glycolysis

Anaerobic (no oxygen) way to make ATP. 2ATP and lactic acid will be produced from a glucose molecule in the cytoplasm.

Aerobic glycolysis

in the presense of oxygen glucose produce 38ATP, water, heat, and carbon dioxide.

glycolysis

Breakdown of glucose to make energy

Lipolysis

fat is used as energy in the mitochondria with oxygen present to make 150 ATP, water, heat, and carbon dioxide.

Mitochondria

powerhouse of a cell

Type 1a

One of the three muscle types, uses oxygen, slow to fatigue, slow twitch, endurance muscle. Has lots of mitochondria and myoglobin. Red colored

Type 2a

One of the three muscle types, fast twitch muscle fiber. It uses oxygen, slow to fatigue, but produces more power. Fast twitch. can be trained into type 1a/2b muscle

Type 2b

Fast twitch glycolytic muscle, one of the three muscle fibers. powerful, fatigues quickly, anaerobic. Produces lactic acid.

Size principle

Type 1a: small bundles, move slower, less power.

Type 2a: medium bundles, move faster than 1a, more power than 1a.

Type 2b: large bundles, moves fastest, most power.

Myoglobin

a protein that stores oxygen in the muscle cells. Found in cardiac and skeletal muscle tissue.

Motor Neurons

Nerves that deliver signals from the central nervous system(CNS) to motor units.

Motor unit

In charge of muscle fibers. When a motor unit is activated, all of its fibers contract

All or None principle

A motor unit engages all of its muscle fibers at once or none at all.

Creatine

a chemical that recharges phosphate in the ATP cycle.

Glucose

A sugar that comes from carbohydrates like potatoes wheat and flour. It is used in lactic acid system(anaerobic glycolysis) and aerobic glycolysis to produce ATP

ATP cycle

ATP drops a phosphate to release energy becoming ADP, the phosphate then is re-energized by creatine to rejoin ADP making ATP

Hypertrophy

Muscle fibers are damaged and grow back bigger with protein causing an increase in size in the muscle and motor units.

Atrophy

Muscle fibers are reabsorbed due to lack of use causing a size reduction in muscle and motor unit.

Isometric Contraction

muscle contracts but does not change the length. (plank, wall sit)

Isotonic Contraction

Muscle moves while contracting

Concentric Contraction

muscle gets shorter while contracting (quadricep in squat, bicep in bicep curl)

Eccentric Contraction

Muscles extend while contracting (hamstring in squat, tricep in bicep curl)

Isokenetic Contraction

Muscle keeps the same tension while moving

Agonist/Prime mover

The main muscle that contracts to bring movement (bicep in bicep curl)

antagonist

The opposite muscle that relaxes as the agonist contracts (tricep in bicep curl)

Reciprocal Inhibition

A reflex process telling antagonist to relax when the agonist contracts.

Insertion

where the muscle attaches to the bone being moved

Origion

the end of muscle attached to a fixed bone

Synergist

A muscle whose contraction helps an agonist (brachialis and brachioradialis in bicep curl)

Fixator

a muscle that stabilizes movement at a joint

Skeletal muscle

attached to a bone, voluntary, will fatigue, and striated muscle.

Smooth muscle

Line the walls of blood vessels and hollow organs. Involuntary, does not fatigue, moves food and helps blood. not striated.

Cardiac muscle

heart muscle, involuntary, striated, does not fatigue, movement of blood.

skeletal movement

One of the functions of muscles. Skeletal muscles contract to exert force on tendons that pull bones causing joint movement.

Substance movement

One of the functions of muscles. move substances for example food (smooth) and blood (cardiac) within the body

stability

One of the functions of muscles. skeletal muscles help stabilize and maintain posture

Thermoregulation

One of the functions of muscle. Regulating temperature by shivering producing heat) and sweating (releasing heat)

Contractility

One of the properties of muscle tissue. the ability of muscles to contract and generate force. When one is contracted, the opposing extends.

Elasticity

One of the properties of muscle tissue. the ability to return to its original resting length after the stretch is removed.

Extensibility

One of the properties of muscle tissue. the ability of muscle to be stretched beyond its normal resting length.

Calcium

a mineral that is key for muscle contraction (Ca++)

Tropomyosin

A protein that wraps around the actin filament

Troponin

A protein that attracts calcium and forces tropomyosin to rotate.

Myosin

The larger filament in the sarcomere that attaches to actin

Action Potential

The electric signal sent by the Central Nervous System to the motor units

synapse

the gap between the motor neuron and the fibers at the neuromuscular junction

Acetylcholine

an organic compound that acts as a neurotransmitter, changing the electric signal to a chemical signal

sodium

a mineral that crosses the synapse to release calcium into the sarcomere

depolarisation

changing polarity of the synapse to allow mineral to cross.

sarcomere

a unit of a myofibril where the contraction takes place

myofibril

made up of sections of sarcomeres that have actin and myosin in them. Lots of them make a fiber

cross bridge

when a myosin head connects to the actin filament

Power stroke

an action powered by ATP where myosin heads pulls the actin towards each other.

motor end plate/ neuromuscular junction

where the motor unit meets the muscle fiber

sarcoplasmic reticulum

an organelle that releases calcium

binding sites

Spots on the actin that myosin heads can attach to

structural difference between slow twitch and fast twitch muscles

slow twitch: more myoglobin, mitochondria

fast twitch: more sarcoplasmic reticulum, bigger muscle fiber bundles