What contraction involves a change in muscle tension, but not muscle length?
Isometric contraction (iso=same metric=length). ex. holding a book in your hand, then adding another book but not moving it.
What contraction involves a change in muscle length, but not tension (weight on muscle)?
Isotonic contraction (iso=same tonic=tension)
What are the two forms/directions of isotonic contractions?
Concentric (muscle shortens) ex. arm curls
Eccentric (muscle extends) ex. lowering arms
Sources of ATP: What is Aerobic respiration?
With enough oxygen; glucose is converted into ATP
Sources of ATP: What is Anaerobic respiration?
Without enough oxygen, backup systems are used: Creatine phosphate contributes to conversion of ADP to ATP. Also oxygen is taken from myoglobin. These need to be replenished after exercise
Stored ATP is also a source of ATP
What are some reasons for muscle fatigue?
ATP synthesis slows, ability of sodium-potassium pump to regulate RMP drops
Lactic acid lowers pH of sarcoplasm
What is maximum oxygen uptake?
The peak/plateau of a person’s oxygen consumption
What are type one slow-twitch fibers?
Fatigue resistant fibers, darker color
Relies on aerobic respiration and has a long twitch
Ex. postural muscles of back
What are type two fast-twitch fibers?
Paler appearance due to lack of capillaries and other nutrient-giving bodies
Uses glycogen for energy and rapid ATP use.
Ex. Calf muscles (though is a mix with slow-twitch)
What is resistance training?
Muscle contraction against a load
Muscles synthesize more myofilaments, making muscles bigger
What is endurance training?
Improves fatigue resistant muscles, makes slow twitch fibers make more mitochondria which means more ATP