The muscular system contains six hundred muscles and they result in movement and in carrying out daily physiological processes. “Through their functions, muscles can be categorized into three classes which are skeletal that aid in movement, cardiac that pump blood, and smooth that support blood vessel contractions and other tracts (Sherwood, 2008, p. 133)”. However, muscles cannot expand or elongate but they move through contraction and relaxation. The origin of the movement is basically either voluntary or involuntary with reflex categorized as voluntary movement. Voluntary contractions are further classified into twitch and titanic in accordance to duration stimulations. The molecular theory that explains muscular movement is the sliding-filament theory. The theory states that a myosin head which is in a high energy state makes the thin filament slide onto a thick filament that contains 350 myosin heads (Turley, 2008). The thick filament attaches and detaches from the thin filament at a rate of 5 times per second resulting to movement of muscles (Premkumar, 2004).
Bones are living things that contain both inorganic and organic material and are classified according to their shape, that is long, short, flat, irregular, and sesamoid (Turley, 2008). Bones are formed in the foetal stage through intermembranous and endochondrial processes. The specific term of bone formation is ossification. After formation, bones elongate and thicken with the help of osteoblasts that deposit bone cells and osteoclasts that reabsorb the cells (Premkumar, 2004). The process is in equilibrium resulting in constant body mass in humans between ages of 25 and 40. The shift in equilibrium occurs in humans who are not in the specified years.
Nerve transmission is facilitated by the nervous system in humans which contain millions of cells called neurons. Neurons are specially designed for their function and they transmit information through nerve impulses. Signals in a neuron originate from an electrical impulse while transmission of the signal is done by chemical impulses (Sherwood, 2008). The process of nerve transmission is a four step procedure entailing: neurotransmitter synthesis, release into synaptic cleft, recognition by specific receptors, and inactivation of the neurotransmitters (Sherwood, 2008)
Premkumar, K. (2004). The Massage Connection: anatomy and physiology (2nd ed.). Pp. 176-183
Sherwood, L. (2008). Human Physiology: from cells to systems (7th ed.). Ohio: Cengage Learning. Chapt. 5 and 8
Turley, S. (2008). Medical Language: Immerse Yourself. New Jersey: Pearson Apprentice. Chapters 8, 9, and 10