Muscle Vertebrates

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.

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.

to contract, which then allows body movements and functions? There are two types of muscles in

These muscles are under control of will. These muscles are controlled by the central nervous system. i.e. Coraco brachialis muscle. This is found in the upper part of the arm and flexes the shoulder joint.

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.

Introduction: According to the “Human Physiology Laboratory Manual “,BIOL 282 ,page 31 , the reason of performing this experiment is to learn how the muscle contraction occurs based on the molecular level and what kind of factors are involved .As a matter of fact, skeletal muscles contain a lot of nuclei because of the cell fusion while being developed and are made of cylindrical cells that have myofibrils. The myofibrils contain sarcomeres and the

Antagonistic Pairs are a pair of muscles working together to allow coordinated movement of the skeletal joints. Muscles can only exert a force and do work by contracting. An example is the antagonistic pair of muscles used in bending and straightening the arm. To bend the arm requires the biceps to contract, while the triceps relax. If the arm is to be straightened, the reverse happens. The individual components of antagonistic pairs can be classified into extensors and

Oxygen and nutrients the body requires for function are pumped around this complex network of blood vessels by the heart. At roughly the size of a human fist, the heart is a four-chambered muscle and performs two functions of circulation simultaneously and continuously. Systemic and pulmonary circulation. The heart is made up from three separate layers of cardiac tissue; the outer layer called the pericardium, which is a double sac-like outer covering with serous fluid inside to keep the middle layer, the myocardium from adhering to the outer layer. This middle layer of the heart is the heart muscle which is thicker on the left side, to aid with the pressure needed to sustain systemic circulation. The inner layer of the heart is the endocardium. It’s lining is smooth to help prevent the blood which circulates around the inside of the heart from clotting. The heart is the human body’s in-built pacemaker, and the electrical signals sent through the it cause the heart to contract and relax. This process is triggered by the autonomic nervous system and the contraction and relaxing cycle is

Thirdly our muscular system also allows blood circulation which is controlled by the heart. The muscular pump is a skeletal muscle group that help to assist the heart in the circulation of blood to all the muscles around the body.

Muscle is formed with a long and thin tissue called muscle tissue which moves the organs and organisms, and the muscle tissue is made out of a group of cells called the muscle fibers. There are three types of muscle: skeletal muscle, smooth muscle, and cardiac muscle. Skeletal muscle is the muscle who moves the bones, it has much longer fibers than the smooth muscles. Smooth muscle forms the walls of organs, for example, the wall of a stomach. Cardiac muscle is the muscle that forms the heart. From the cross-section view of a muscle, it shows that there is a layer of muscle sheath around the outermost layer of the muscle. The blood vessels that brings glucose and oxygen to the muscle are weaved in the fibers, and there is a layer of epithelial cells around the muscle to keep the fibers together.Muscle tissue can repair itself, but with round scar tissue instead of long, stretchy fibers. Skeletal

There are two different types of cells in the heart- conducting cells, which carry the heart’s electrical signals and muscle cells, which are responsible for the contractions of the heart. A specific group of cells located near the top of the heart are known as the pacemaker of the heart because the rate

• pacemaker cells- are specialized cells that cause involuntary muscles and tissues to contract or dilate.

Agonist muscles are the main muscles responsible for isotonic contractions; as they are predominantly responsible for producing a specific movement they are also referred to as “prime movers”. Antagonist muscles control a movement and also return limbs back to the original position. If a movement is performed in reverse the antagonist and agonist muscle switch roles, therefore one muscle can be both an agonist and an antagonist depending on

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.