Muscles are contractile tissues that aid in the movement of the body. They have the ability to provide the necessary motion for the body. They also give the stamina that is required for the internal organs of the body. Muscles enable the body to have sufficient energy for various activities. The body muscles keep the body upright. Nervous system acts as the main controller of the muscles.
Purpose of Study
There are three main types of the muscles in the body. These are: skeletal, cardiac, and smooth muscles. These muscles are classified according to their functions and locations. They also appear in different shapes and sizes. For instance: spindle-shaped, flat shaped and circular. This paper seeks to explore different types of muscles, their composition as well as structure.
Skeletal muscles are responsible for the support of skeleton. Body builder often do exercises so as to strengthen their skeletal muscles. In other words, skeletal muscles help in the motion of the body. Skeletal muscles constitute fifty percent of the body mass. Skeletal muscles join different skeletons by the help of tendons. These muscles are voluntary and consciously controlled. Usually, when a person decides to make any movement like running or jumping, this information is sent to the nervous system by the brain which then commissions the muscle to act accordingly. If it contracts, then a movement is made in the area that receives the information from the nervous system.
The muscles have diverse sizes and shapes. This enables them to do different functions in the body. Some of the skeletal muscles include biceps that are used to bend arms, rectus abdominis found at the stomach, and frontalis located at the forehead. They are located at different parts of the body depending on the degree of their work. Skeletal muscles are made of long cylindrical cells known as fibers. The fibers contain myosin and actin proteins. These fibers are packed in bundles by a skin known as perimysium. They are the most developed muscles of all the three types. The fibers are greatly interconnected in all directions.
These muscles require oxygen to normally function. They consume a lot of energy. This energy is normally made by the adenosine triphosphate (ATP). When work load drastically increases in an individual, the amount of oxygen in the blood decreases. This is due to the increased consumption of oxygen. This may cause fatigue and muscle cramps in any individual. Over exercising is also harmful as it leads to accumulation of harmful chemical like lactic acid. These may make the muscles very painful.
Cardiac muscles are another type. These are found in the heart. They are involuntary in there nature. Their activities are not controlled by the brain. They determine when and when not to act. Cardiac muscles are very important in any body. They are the thick muscles at the heart that pump blood to the whole body. When they contract, they pump oxygenated blood to all parts of the body. When they relax, they allow deoxygenated blood back into the heart. The heart is able to systemically beat throughout by the help of these muscles. They contract similarly as the skeletal muscles. They have a regular arrangement as skeletal muscles but are less developed than the former. Their regular fibers are connected at the branches unlike the skeletal muscles which are regular and parallel. When stimulated, the striated muscles contracts and relaxes in short and intense bursts.
Smooth muscles are found in the stomach, bladder and also in the digestive system. These are also involuntary in nature. When one eats, their contraction and relaxation help the food move into the stomach for digestion. After digestion, they also allow the nutrients to move to different parts of the body. These muscles are also able to push food out of the esophagus from the stomach. This normally occurs when one is sick. This clearly shows the importance of these muscles as without them, ingesting food would be difficult.
Moreover, what help us hold urine until we reach the toilet are these muscles. Without them, urine could be passing out without control. Most importantly, the noble task of these muscles is seen during the process of giving birth. They help the expectant mothers push out the babies. When an object tries to enter your eyes, it automatically closes thanks to the smooth muscles which are involuntarily at work. These muscles are not as developed as the skeletal muscles. They only bundles of thick and thin filaments. When they contract, the shortening takes place in all directions. At this time, the thin filaments slide past thick filaments. The intermediate filaments help in drawing them together. The contractions are controlled by calcium ions and are longer and sustained than all other muscles.
In conclusion, the importance of the muscles can never be over emphasized. They control almost all the activities of the body. They respond accordingly as per the stimulus. This has enabled the efficiency of their work. It should be taken into consideration that these muscles require energy. Therefore, proper feeding of the body with foods that provide calories is very essential. They use the oxygen from the blood to breakdown glucose into energy. This the energy used to respond to different stimulations. Over straining the muscles are also not advisable. This expends all the glucose thereby depriving the muscles the required energy for action. This is a major problem for the skeletal muscles that use much energy. This table shows an experiment on the threshold stimulus when different workloads are applied on different skeletal muscles. The results show different outcomes for each the muscles. Every muscle exhibits a different figure. This shows that as the workload increases on the skeletal muscles, the threshold stimulus also increases at different rates. In this case volts stand for the threshold of stimulation.
An increase in workload increases the skeletal stimulation. But there is a limit that the skeletal muscle can withstand. At the maximum load of 80 grams, lower forelimb and calf muscles are indicated ‘NONE’. This shows an overload to these muscles. They cannot withstand these loads. The stimulation does not produce any effect. Thigh muscles are the strongest here as they can be stimulated by a higher load. The breakdown of ATP produces the necessary energy for muscle to act.
Example of attenuation of ΔVo2/ΔW above the ventilatory threshold (VT) in one subject after the six week electrical stimulation (ES) programme. ΔVo2/ΔW is the slope of the relation between oxygen uptake (Vo2) and power output.