unit 10 review

Annie's muscles fatigued after repetitive stimulation because there might be a short in the nerve pathway. This would lead to a closer look at Annie's central nervous system for possible causes.

1. Predict if healthy muscle or muscle with MH will contract with the most force.

during these movements, the angles of those joints, as well as the muscles involved during the

The fibers in both cells are striated, and the fibers are long and each muscle cell is fused to one another. This is why so many nuclei are included. Also, the fibers are almost threadlike, with dark and light colored striations.

Myofibrils are made up of long proteins that include myosin, titin, and actin while other proteins bind them together. These proteins are arranged into thin and thick filaments that are repetitive along the myofibril in sectors known as sarcomeres. The sliding of actin and myosin filaments along each other is when the muscle is contracting. Dark A-bands and light I-bands reappear along myofibrils. The alignment of myofibrils causes an appearance of the cell to look banded or striated. A myofibril is made up of lots of sarcomeres. As the sarcomeres contract individually the muscle cells and myofibrils shorten in length. The longitudinal section of skeletal muscle exhibits a unique pattern of alternating light and dark bands. The dark staining, A-bands possess a pale region in the middle called the H-zone. In the middle of the H-zone the M-line is found, that displays filamentous structures that can join the thick filaments. The light-staining bands also known as I-bands are divided by thin Z-line. These striated patterns appear because of the presence of myofibrils in the sarcoplasm (IUPUI, 2016).

1. How is there a lower metabolic cost but with the higher forces during eccentric contraction?

In final consideration, I think the symptoms Annie is experienced are due primarily to muscles fatigue. Factors that generate muscle weakness are vary based on the standard of the muscle activity. It depends on the blood vessel accumulation, amount of myoglobin, myosin molecules that burst ATP at an accelerated rate. Low ATP and high lactic acid can decrease twitch fibers that release acetylcholine. In fact, physical fatigue may occur because of a disorder sickness, such as pain, anemia or other health dilemmas. In addition, Each of that thing is taken into attention when thinking out how Annie's muscle gets tired. On the contrary, muscle fatigue has its negative and positive outcomes. Weakness can occur in the decline of muscle force. It

The process begins while a muscle is relaxed in its resting state. “In the resting state,

Actin and myosin are contractile proteins that are essential for muscle contraction (Powers). A contraction is triggered by a series of events called the crossbridge cycle. In a muscle fiber, the functional unit of contraction is called a sarcomere (Powers). A sarcomere contains myofibrils, which consist of actin and myosin myofilaments. The sarcomere shortens when myosin heads and thick myofilaments form crossbridges with actin molecules and thin myofilaments. The formation of a crossbridge is initiated when calcium ions released from the sarcoplasmic reticulum bind to troponin. An action potential triggers this release of these ions. The binding of calcium ions causes troponin to change shape. Tropomyosin moves away from the myosin binding cites on actin, allowing the myosin head to bind actin and form a crossbridge. When ATP on the myosin head has not been hydrolyzed yet, the myosin head is inactivated, or in the uncocked position. The myosin head has to be activated before a crossbridge cycle can begin (Powers). This occurs when ATP binds to the myosin head and is hydrolyzed to Adenosine Diphosphate (ADP) and an inorganic phosphate. The enzyme that breaks this ATP down is called myosin ATPase, which is located on the myosin head. The energy from the hydrolysis activates the myosin head putting it into the cocked position. The activated myosin head binds to actin forming a crossbridge. Then inorganic

Muscles are specialised tissues which respond to nervous stimulation by contracting, which means that the muscle shortens and thickens. Muscle tissue is also elastic, which means that it can be stretched by weight, and when the weight is removed the muscle will return to its normal length.

Because there is not enough ATP being produced to allow the muscle to contract that many times and for the length of time.

This is because once a contraction has started, the action potential has already fired, stimularing the muscle fibers. Once they

twitch muscles. Fast twitch muscles have a fast form of myosin ATP and are very

When combined, the ATP-PC system can sustain maximum exercise for up 10-15 seconds. It is at this stage that the potential rate for the power output is at its greatest. It must then rely on other energy system.

Both of these muscles expand and contract as they have complex structures so it is essential how they do this. The cardiac muscle needs the contractions to occur in order to pump blood out of the atria and into the ventricles and round the circulatory system so the structure of this muscle shows the systole of the heart. The contractions of the skeletal muscle also depend on its structure. The binding and releasing of two strands of sarcomere is how the repeated pattern of contractions occurs. ATP is used to prepare myosin for binding to allow the contractions to happen. The skeletal and cardiac muscle also both has elasticity. The elasticity is used to restore the muscles back to their original lengths which enable them to resume back to their original length once they have contracted and been stretched.