Overview of Myasthenia Gravis

Overview of Myasthenia Gravis

Introduction

The movement of body is made possible with the help of the assortment of different tissues and they compose a muscular system. The human body performs different activities like running, walking and many more. All of these activities of the organisms are made possible with the help of the two processes of the muscles that are contraction and relaxation. The involuntary movements of the body are also performed by the muscular system (faqs.org 2013).

Discussion

Anatomy of the muscular system

Muscular system of human beings is composed of three groups of tissues and they are skeletal tissues, visceral tissues, and the cardiac tissues.

Cardiac muscles

Heart is an organ which pumps the blood in the entire body and it is composed of cardiac muscles and the cardiac muscles are composed of the striated cells. They are also the involuntary muscles of the body and these muscles are linked together by intercalated disks which can tolerate the increased level of blood pressure (innerbody.com).

Visceral muscles

They are the most sensitive tissues of the muscular system and they are present around the internal organs of the body. They cannot be controlled consciously hence; they are controlled by the brain and are called as the involuntary muscles. These muscles are also called as smooth muscles because of their smooth appearance (innerbody.com).

Skeletal muscles

These muscles can be controlled by the humans themselves therefore they are called as the voluntary muscles. The organs are brought closer to the bones by the contraction of the skeletal muscles and these small cells collectively from the multi nucleated and long tissues.

The fibers of muscles are enclosed in a membrane which is called as sarcolemma. Sarcolemma produces the impulses that are required for the generation of muscle stimulation. Sarcolemma is further connected along with the T tubules and they assist in transferring of the impulses to the fibers of muscles. Calcium ions are also stored in sarcolemma that is required for the contraction of muscles. Sarcomeres are the functional unit of the muscles and they combine to make up the myofibrils. Energy is provided to the muscle cells in the form of ATP through mitochondria (innerbody.com).

Physiology of muscle contraction

Motor neurons activate the muscles and the activation results in the contraction of muscles. The contraction of muscles starts at the neuromuscular junction and here the neurotransmitters are released. They are joined with the motor end ...