The Strength Of Muscle Clench Within Dominant And Non Dominant Arm Of An Individual

The anatomy and physiology of the human body explains that muscles are attached to the skeleton. They work like hinges or levers to pull or move particular joints when a muscle contracts, pulling the joint in the direction it is designed to move. Parts of muscles move antagonistically, that is, when one contracts, its opposite member relaxes to allow movement. Muscles can become slack, making movement slower and more difficult.

The more stimuli per second, the greater the force generated by the muscle due to a

This activity is the critical driving force of muscle contraction. The stream of action potentials along the muscle fiber surface is terminated as Acetylcholine at the neuromuscular junction is broken down by acetyl cholinesterase. The release of Calcium ions is ceased. The action of the myosin molecule heads is obstructed because of the change in the configuration of troponin and tropomyosin due to the absence of calcium ions. This will eventually cause the contraction to be ceased. Together with these physical processes, an external stretching force such as gravity pulls the muscle back to its normal length.

Smooth muscle contraction occurs when calcium is present in the smooth muscle cell and binds onto calmodulin to activate myosin light chain kinase (Wilson et al., 2002). Phosphorylation of myosin light chains result in myosin ATPase activity thus cross-bridge cycling occurs causing the muscle to contract (Horowitz et al., 1996). There are two known models of excitation and contraction in smooth muscle, electromechanical coupling (EMC) and pharmomechanical coupling

There are three main types of muscle tissue in the body: Skeletal muscle, smooth muscle and cardiac muscle. Firstly, skeletal muscle has a stripped appearance when it is examined under a microscope so it is sometimes known as striated/stripped muscle. Skeletal muscle is voluntary and this means that it is under conscious control. Secondly, there is smooth muscle which is an involuntary muscle that operates without any conscious control. This muscle is controlled by the nervous system. Smooth muscle can be found in the blood vessels and the walls of the digestive system and it helps to control digestion and blood pressure. Lastly, there is cardiac muscle which is located in in the wall of the heart. Cardiac muscle is involuntary and this means that it is not under conscious control. This is made up of a specialised type of tissue which is striated and it has its own blood supply. The contractions aid the pumping of blood through the blood vessels

As a result of the contractions in the Muscle- Skeletal Longitudinal Section cells and the Muscle- Skeletal Cross Section cells, it allows your muscle to be able to contract in response to nerve stimuli. This means that the movements of most of these muscles are not involuntary, you can control them. Therefore, once the stimulation stops, the muscles relax.

These muscle tissue cells specialised to contract and move parts of the body. It is also capable of responding to stimuli. There are three types of muscle in the body such as: skeletal, cardiac and smooth. Each muscle is created of muscle fibers that are capable of contracting and returning back to original state-relaxation. Contraction causes movement of the skeleton, soft tissue, blood or specific material. Skeletal muscle is attached to the bones of the skeleton. Some facial muscles are attached to the skin. They have direct control over them through nervous impulses from our brain sending messages to the muscle. Contractions can vary to produce fast, powerful movements. These muscles also have the ability to stretch and contract to return to original shape. Cardiac muscles are found in the chambers of the heart such as the atria and ventricles. It is under the control of the automatic nervous system; however, even without nervous input contractions can occur. It is completely different to all the other muscles. Smooth muscles are also known as involuntary due to our inability to control its movement. This muscle is usually found in the walls of hollow organs

There are three types of muscle; skeletal (also known as striated), smooth, and cardiac. Skeletal muscles move the bones, cardiac muscle is found in the heart, and smooth muscles line the organs and blood vessels . Although different in function, the basic structure of each type is similar . The experiment for this investigation was conducted using skeletal muscle, as it is common and easy to access when fresh. Meats that were bought from the butcher were used as they are skeletal muscle.

Martini, F. H., Nath, J. L., and Bartholomew, E. F. “Muscle Tissue.” Anatomy & Physiology. 9th

Motor Unit Recruitment - the successful activation of the same and more motor units with larger strength and voluntary muscle contraction

Smooth muscles are found in the skin, internal organs, reproductive system, major blood vessels, and excretory system. Skeletal muscles are composed of long fibers surrounded by a membranous sheath, the sarcolemma. Since the Skeletal muscles are under control by whom ever they belong to are called voluntary muscles. This muscle is attached to two or more bones which are then attached to the skeleton by tendons. For example, head and neck muscles; contraction of these muscles produces facial expressions and head movements. They are also responsible for speech and swallowing. Skeletal muscles are the main muscles which move your body. Muscles nearly always work in coordinated groups; contraction of one muscle is accompanied by relaxation of another, while other muscles stabilize nearby joints. Then the last of the muscle types is the Cardiac Muscle or the involuntary muscles. Cardiac muscles are not under conscious control they do not react by a persons decision or movement. and are connected to the nervous system which are stimulated by autonomic impulses. Cardiac muscles are found in your internal organs like the heart or the intestine. For example; they include muscles that propel food through the intestine and those that control sweating and blood pressure.

Review Sheet Results 1. Describe how increasing the stimulus frequency affected the force developed by the isolated whole skeletal muscle in this activity. How well did the results compare with your prediction? Your answer: When the stimulus frequency was at the lowest the force was at its lowest level out of all of the experiments. As the stimulus frequency was increased to 130, s/s the force increased slightly but fused tetanus developed at the higher frequency. When the stimulus frequency was increased to the amounts of 146-150 s/s, the force reached a plateau and maximal tetanic tension occurred, where no further increases in force occur from additional stimulus frequency. 2. Indicate what type of force was developed by the isolated skeletal muscle in this activity at the following stimulus frequencies: at 50 stimuli/sec, at 140 stimuli/sec, and above 146 stimuli/sec. Your answer: At 50- Unfused

Denervated muscle undergoes changes that deteriorate the functional outcomes after reinnervation. The main factors are progressive muscle atrophy, loss of functional motor endplates and changes of intramuscular innervation. A denervation period of 6 months leads to a reduced number of muscle fibers, which are smaller in size, and to decreased tetanic force. (Gutmann and Young 1944, Gutmann 1948, Fu and Gordon 1995b) The number of functioning motor endplates after 6 months of denervation is reduced to 75%, which is attributed to atrophy, fibrosis and slow motor endplate regeneration and re-innervation. (Gutmann and Young 1944) Following denervation, intramuscular nerve fibers undergo changes that lead to the outgrowth of axons along the surface of denervated muscle. (Gutmann and Young 1944, Fu and Gordon 1995b) After 8 months of denervation, atrophy results in increasingly poor functional outcomes, as progressive muscle fiber loss occurs. (Gutmann 1948, Irintchev, Draguhn et al. 1990) The loss of muscle satellite cells, which are

Each body part has a specific role within the community of the human body. When working properly, each system is contributing to maintaining homeostasis as well. The purpose of this essay is to discuss the relationship between the muscular system and how it contributes to the overall health and balance of the body it is placed within. The essay will discuss the function of the muscular system, the organization of the system and how it contributes to homeostasis.

Exercise 2: Skeletal Muscle Physiology: Activity 3: The Effect of Stimulus Frequency on Skeletal Muscle Contraction Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. During a single twitch of a skeletal muscle You correctly answered: b. maximal force is never achieved. 2. When a skeletal muscle is repetitively stimulated, twitches can overlap each other and result in a stronger muscle contraction than a stand-alone twitch. This phenomenon is known as You correctly answered: c. wave summation. 3. Wave summation is achieved by You correctly answered: a. increasing the stimulus frequency (the rate of stimulus delivery to the muscle). 4. Wave summation increases the force produced in the muscle.