What Is Muscle Metabolism?

Muscle metabolism is the set of chemical reactions that occur in your body's muscles. All the muscles in your body have biochemical specialization. This specialization allows your muscles to perform specific physiological functions. For example, your eyeball muscles must contract quickly and precisely while the muscles in your back and buttocks have a fuel economy dynamic.

What is Metabolism?

Chemical reactions occur constantly throughout your entire body. The medical term used for this process of chemical change is metabolism. Metabolism includes the synthesis and breakdown of organic molecules required for appropriate cell structure and function. Metabolism also includes the release of chemical energy used for cell functions. Cells can gain energy through anaerobic or aerobic metabolism of glucose. The anaerobic process is moderately efficient. The aerobic cycle takes place in a specific organelle of the cell known as mitochondria and results in the greatest release of energy.

Types of Vertebrate Muscle

There are three basic types of vertebrate muscle. Your voluntary skeletal muscle is under conscious or voluntary control. Each fiber is big and has multiple nuclei. Cardiac muscle, on the other hand, is not under conscious control. Cells are much smaller and are mono-nucleate with a striated pattern. The final type of vertebrate muscle, smooth muscle, has slower contractions than voluntary skeletal muscle. Smooth muscle is found in your blood vessels, gut, skin, eye pupils, urinary and reproductive tracts.

Muscle Metabolism

Approximately 40 percent of your body is skeletal muscle and approximately 10 percent of your body is smooth and cardiac muscle. Muscle tissue also makes up most of your mass. In general, slow muscle contraction uses economical fibers with a fat-based aerobic metabolism. On the other hand, the more expensive high-speed fibers use carbohydrate as an energy source. Smooth muscle is economical because it has a low myosin, which means a lower consumption of the energetic molecule ATP and lower contraction speed.

Muscle Contraction

The initiation and execution of muscle contractions occur in a sequence. An electrical impulse travels along a motor nerve terminating at the end of the muscle fiber. The nerve secretes the neurotransmitter substance acetylcholine. Acetylcholine opens multiple acetylcholine-gated channels. This opening allows large quantities of sodium ions to enter the muscle cell. This initiates an action potential at the membrane. As a consequence, calcium ions initiate attractive forces between the actin and myosin, the principal muscle proteins, causing them to slide along side each other.