Human muscles can be divided into three categories, namely smooth muscle, cardiac muscle and skeletal muscle. Each has different features and functions.
Smooth muscle exists in other internal organs other than the heart, such as the gastrointestinal tract, urinary tract, respiratory tract, and reproductive system ducts, etc. This type of muscle not only has its special shape under the observation of the microscope, but also is not affected by the individual in most cases. It is controlled by the subjective consciousness, but is regulated by the autonomic nervous system of the viscera itself and the hormones in the blood.
The Heart Muscles
is limited to the heart chamber, and it is also not subject to subjective consciousness. Its regular pulsation forms the heartbeat; the heartbeat is going on every minute and every second of the human body’s existence. The origin of this rhythm comes from a group of special and specialized cardiomyocytes in the right atrium, medically known as pacemakers. The pacemaker cells alternately change the concentration of sodium, potassium and other electrolytes inside and outside the cell to form a pulsed electric current. These currents then spread to other parts of the myocardium through special conducting tissue in the myocardium. For more research click here.
Due to the abnormally fast transmission speed of the current in the heart, the myocardium in the two chambers of the left and right ventricles receives the nerve impulse signal almost at the same time, thus producing a consistent contraction, and the blood in the ventricle is pumped out strongly and effectively. The chambers of the right and left atria beat together when the next nerve impulse arrives. The heartbeat is followed by a very short time to relax the heart muscle, and then a new round of the beat cycle is performed, and the cycle goes on and on.
The biggest feature of skeletal
muscle is that the time, amplitude and intensity of contraction can be controlled by individual consciousness, and the size of such muscle can change significantly with the degree of training and use; other factors that affect muscle thickness include Genetic factors, nutrition, hormones, etc.
The function of skeletal muscle is to complete various activities of the human body by contracting and moving the bone to which it is attached. According to the speed of muscle fiber contraction, skeletal muscle can be divided into two types: fast muscle and slow muscle. For more health tips visit our site ArticlesHubs.
Slow muscle is the so-called red muscle. Because of its rich microvascular distribution and less glycogen and mitochondria in muscle cells, it mainly relies on the energy generated by aerobic respiration and metabolism to supply muscle contraction. These muscles contract slowly and have poor explosive power, but they can last longer and are less prone to fatigue. They are the main muscle groups for activities of daily living.
Fast muscle is also known as white muscle. There are more glycogen and mitochondria in muscle cells, while micro blood vessels are relatively lacking. It mainly performs contraction activities through the energy generated by anaerobic respiration and metabolism, so it can be used in a very short time. Rapid movement within the body produces a huge explosive force, but it is more prone to fatigue and cannot be endured for a long time. These muscles are commonly used in sprinting, long jumps, weightlifting, shot put, etc. In daily life sports, it is specially used for fine and sensitive movements, such as hand muscles and eye muscles.
This article is reviewed by the consultant doctor of this site. May you can see about Exercise Physiology – Understanding Breathing.