Cutting human organs: features
Everyone knows that due to the presence of muscle tissue, it is possible to move the human body and its individual parts in space. But in our body there are also contracting organs. All of them perform irreplaceable functions for normal functioning.
What are the bodies of
First, let's look at what is an organ in general. This part of the body, which occupies a certain position, has a characteristic structure and performs one or a number of functions. A very important feature of any organ is that several tissues are included in its composition.
There are four of them in the human body: epithelial, connective, muscular and nervous. All of them are formed by cells that are similar in structure and function.
The contracting organs of a person
The composition of contracting organs necessarily includes muscle tissue or cells that are close to it by properties. For example, collagen fibers are located in the skin. Due to this structure it is capable of stretching and does not interfere with the implementation of various movements. All cutting organs can change their volume and length, and then return to the standard state.
Features of the structure of the muscular tissue
Muscle tissue consists of individual contractile fibers, called myofibrils. The latter are formed by the filaments of special proteins, actin and myosin. Between each other they are connected by means of transverse bridges. Nerve impulses excite muscle fibers, and they begin to contract. The essence of this process is that threads of actin with the help of transverse bridges are drawn between the myoson. The length of the muscle fiber in this case decreases.
Defined muscular tissue
There are several types of muscle tissue. What cutting organs form a striated or striated tissue? These are mimic and skeletal muscles, diaphragm, larynx, tongue, upper part of the esophagus. The fibers of this type of fabric are long and multi-core. Under a microscope, they look like alternating dark and light strips.
Defined muscle tissue is characterized by a high rate of contraction and relaxation, which are realized consciously. After all, man himself controls the movement of the limbs and changes his facial expression.
Heart muscle tissue
The heart is a special organ. He is constantly at work, because the life of a person depends on the frequency of his contractions. Therefore, this organ is formed and a special kind of striated tissue, which is called - cardiac. It has special areas in which individual fibers are joined together. This structure ensures a simultaneous reduction of the whole organ. Conduction is very important property of the cardiac muscle. It consists in spreading the excitement that has arisen in one area, throughout the body. In special cells of the heart periodically there are impulses that spread throughout the heart muscle and regulate the rhythm of its contractions. This property is called automatism.
Unclear muscle tissue
Internal cutting organs mainly consist of smooth, or undistorted tissue. This is the gastrointestinal tract, bladder, bronchi and lungs, the walls of the blood and lymphatic vessels. Spindle-shaped cells of smooth tissue are mononuclear and look uniform under a light microscope. Their characteristic sign is a rather slow contraction and relaxation. Their activity is involuntary and does not depend on the will of man. For example, we can not stop contractions of the stomach or intestines.
So, the contracting human organs have in their structure one of the varieties of muscle tissue. The coordinated automatic operation of the heart provides a special type of striated fibers. Smooth muscle tissue contracts slowly and involuntarily, forming the walls of internal organs. The movement of the body and its individual parts is ensured by striated fibers. They shrink quickly and are controlled by humans.