Bio Unit D: Muscular System

trigger and control muscle contractions

provides muscle fibres with nutrients and oxygen (for cell resp) and removes cellular waste

• 1.Muscles: lie along the bone, attached at both ends by a tendon
• 2.Muscle Fibre Bundle: Muscle fibres held by layers of connective tissue, Blood vessels and nerves run between the tissue
• 3.Muscle Fibre: A long string bound by a membrane called sarcoma, this string is made from Myofibril
• 4.Myofibril: an organised bundle of myofilaments that are used in muscle contraction, they repeat along the myofibril
• 5.Myofilament: Two types, thick and thin, they each contain their own protein for muscle contraction. Protein is called Actin and Myosin

Muscles cause movement of bones at a joint, they can only pull, not push, muscles can contract, and stretch when they are at rest. Lastly, muscles come in pairs every action has one muscles doing the action, and another doing the opposite.

The stimulation of a muscle fibre usually results in an all or nothing contraction. The contraction can vary based on how far the contraction must go.

muscle twitches that contract fast, but fatigue will happen sooner. they have light colour as there is little myoglobin with mitochondria and blood vessels

muscle twitches that contract slowly and are only used when the fuel is gone, for endurance this muscle will have darker colour because of many blood vessels and mitochondria in the myoglobin,

A infection that will cause a muscle twitch to last long than it should, keeping the twitch in the contraction phase.

A movement of a muscle in a second can be broken into three parts, Latent period: the time before the contraction. Contraction Period: the muscle contracts. Relaxation Period: the muscle returns to normal.

A electrical impulse from the nervous system that will make muscles contract, this is only for a single contraction for a second that is known as a muscle twitch

provides ATP without any oxygen needed. glucose and ADP combine to make lactate acid and ATP. The build up of lactate will cause muscles to work less efficiently and oxygen must return to clear the cells

Glucose and Oxygen combine with ADP to create carbon dioxide, water and ATP energy. This method creates the most ATP for the body

Creatine Phosphate is a high energy compound that builds up when a muscle is resting. It combines with ADP to make creatine and ATP energy, this is the fastest way to make ATP but the ATP it creates burns out quickly and needs to be rebuilt

A long filament composed of protein that blocks myosin from bonding with actin

Normal myosin cannot bond to actin as tropomyosin floats on top of actin and acts as a lock or cover. Calcium will be released from the sarcoplasmic reticulum and reposition the tropomyosin allowing the bond to happen, When Calcium returns to the Sacroplasmic Reticulum the tropomyosin returns to its original place.

Each actin is anchored to a striated muscle tissue called the z line at one end, when the actin moves, it pulls the z line along with it. Once the z line comes into contact with the myosin this is the end of the line and the actin cannot move anymore (the point where you cannot contract muscles anymore)

The contraction a dead body can become stuck in as, you need ATP to unflex but since your dead, you cannot produce ATP

Myosin head attach to actin through chemical binding, then the myosin heads pull back a few nanometers, pulling the actin as well. ATP provides energy for the myosin to detach from the actin and reset it's position. The myosin then attaches further along the actin again

Think myofliaments of two strands of protein wrapped around each other, one end has a long rod called a "head"

Thin myofliaments that consist of protein that wrapped around each other, two of them sandwich myosin

• -Skeletal: Striated and tubular have voluntary moment, attached to skeleton bone
• -Smooth: non-striated, contract involuntary found in walls of internal organs
• -Cardiac: Striated, tubular and branched, involuntary and in the walls of heart