Animal tissue is a collection of cells thatconnected by intercellular substance and intended for a specific purpose. It is divided into many types, each of which has its own characteristics. Animal tissue under a microscope may look completely different, depending on the type and purpose. Let's take a closer look at the different types.
Animal tissue: varieties and characteristics
There are four main types: connective, epithelial, nervous and muscular. Each of them is divided into several types, depending on the location and some distinctive features.
Connective animal tissue
It is characterized by a large numberintercellular substance - it can be both liquid and solid. The first type of this type of tissue is bone. The intercellular substance in this case is solid. It consists of mineral substances, mainly salts of phosphorus and calcium. Also the connective type is cartilaginous animal tissue. It differs in that its intercellular substance is elastic. It, in turn, is subdivided into such species as hyaline, elastic, and fibrous cartilage. The most common in the body is the first type, it is part of the trachea, bronchi, larynx, large bronchi. Elastic cartilages form the ears, medium-sized bronchi. Fibrous part of the structure of the intervertebral discs - they are located at the junction of the tendons and ligaments with hyaline cartilage.
The connective tissue also includes adipose tissue, inwhich are stored nutrients. In addition, this includes blood and lymph. The first of these is characterized by specific cells called blood cells. They are of three types: red blood cells, platelets and lymphocytes. The former are responsible for the transport of oxygen throughout the body, the latter are responsible for blood clotting in case of injuries of the skin, and still others perform an immune function. Both of these connective tissues are special in that their intercellular substance is liquid. Lymph is involved in the process of metabolism, it is responsible for the return of various chemical compounds from the tissues back to the blood, such as all sorts of toxins, salts, and some proteins. Fibrous fibrous, dense fibrous and reticular tissues are also connective. The latter is distinguished by the fact that it consists of collagen fibers. It acts as a basis for such internal organs as the spleen, bone marrow, lymph nodes, etc.
Epithelium
This type of tissue is characterized by the fact that the cellsarranged very closely to each other. The epithelium mainly performs a protective function: the skin consists of it, it can line the organs both outside and inside. It can be of many types: cylindrical, cubic, single-layer, multi-layered, ciliated, ferruginous, sensitive, flat. The first two are so called because of the shape of the cells. Ciliated has small villi, it lines the intestinal cavity. The following type of epithelium consists of all the glands that produce enzymes, hormones, etc. The sensitive one plays the role of a receptor, it lines the nasal cavity. The squamous epithelium is located inside the alveoli, the vessels. Cubic is found in organs such as the kidneys, eyes, and the thyroid gland.
Nervous Animal Tissue
It consists of spindle-like cells - neurons.They have a complex structure, built of a calf, an axon (long process) and dendrites (several short ones). These formations of the cells of the nervous tissue are interconnected, signals are transmitted through them, as if by wires. Between them there is a lot of intercellular substance that supports neurons in the right position and nourishes them.
Muscle tissue
They are divided into three types, each of whichhas its own characteristics. The first one is smooth muscle animal tissue. It consists of long cells - fibers. This type of muscle tissue lines the internal organs such as the stomach, intestines, uterus, etc. They can contract, but the person (or animal) is unable to control and manage these muscles independently. The next type is a striated fabric. It is reduced several times faster than the first one, since it contains more actin and myosin proteins, due to which this happens.
