Muscle Tissue

Sarcomere

Contractile unit of the cell.

Fast Twitch

Skeletal single stimulation, single contraction of a motor unit

Slow Twitch

Cardiac, smooth muscles single contraction of a motor unit

Cross Bridging

Ca++ released by SR bind to tropin this will move tropomyosin and allow cross bridging between actin & myosin

Power Stroke

ADP + P as fuel myosin head grabs G-Actin and slide it to the middle & myosin spins allowing head to reach & pull actin closer (Sarcomere shortens).

Detachment

ATP is consumed; ATP bind myosin head & triggers release of myosin from actin.

Reactivation

ATP is oxidized releasing energy & moves myosin into ‘cocked’/ready position

Parts of a Twitch

Latent Phase, contraction phase, relaxation phase

Latent Phase

Depolarization & repolarization last 2-3 milliseconds

Contraction Phase

Calcium release, cross bridge cycle lasts 30-180ms

Relaxation Phase

10-30ms

Complete/fused Tetanus

High frequency and buid up of Ca++ in the motor untit

Body Recruitment

The stronger the stimuli the more info propriceptors send to the cerebellum to alternates the motor units stimulated

ATP Production

Direct Phosphorylation, Anaerobic Respiration, Aerobic Respiration,

Direct Phosphorylation

ATP is burned and becomes ADP; ADP reacts to Creatine Phosphate and donates P group making it ATP again takes 15 sec.

Anaerobic Respiration

Undergoes Glycolisis, lack oxygen produce 2 ATP per glucose, but lacks oxygen Pyruvic Acid turn to Latic acid

Latic Acid

Only heat muscle, liver, kidneys, can use the term for energy, skeletal muscle builds up and needs to be removed

Smooth Muscle

Found in hollow organs (visceral) no visible striations, arrangement of myofilaments, relies on Extra Cellular Calcium

Extra Cellular Calcium

Calcium attaches Calmodulin

Smooth Muscle Types

Single unit, Multi unit

single Unit

Visceral muscle found in organ innervated by PSNS, contains gap junctions to allow wave like contraction, stress relaxation response, spontaneously contracts contain Varicosities

Varicosities

Nerve endings that release ACh

Multi Unit

Controlled by SNS, motor units produce control, acts like skeletal muscle than NMJ found in skin (arrector pili) and blood vessels (blood flow changes in blood)

Cramps

Painful tetanus caused by Dehydration and a loss of Potassium in the cells due to Aldosterone

Muscle Growth

Cause by adding to the filament GH, and testosterone

Muscle Fatigue

Caused by oxygen debt, muscle need to replenish stores O2 removal lactic acid caused by anaerobic respiration requires movement and plenty of water

Development of Tension

Changes in frequency can be stimulated muscle fibers contraction increased, impulses sent are called wave summation.