Importance of Tissues
A tissue is a collection of linked cells that have a shared function within the body of an organism. All animals, including the human body, have four basic types of tissue in their bodies. They cover all of the organs, structures, and other components of the body of an organism. Animals and plants have a higher level of organization when we compare them with other unicellular microorganisms. They have a complex structure formation in which a collection of a lot of cells perform the functions in a structured and consistent manner. Cells are grouped together in animals and plants, which lead to the formation of tissues. These tissues vary from each other in structure, function, and organism.
Epithelial Tissue
All the organs in the body are covered with a collection of tissues called epithelial tissues, which is commonly referred to as epithelium. The surface of all internal and external organs is covered by the group of epithelial tissues. The epithelial tissue seems to be rather highly permeable. It, therefore, plays a major role in the interchange of substances in and out of cells and helps to maintain the osmoregulation. The epithelium has been classified based on the number of cell layers it comprises into the basic epithelium and compound epithelial tissue. Protection, secretion, absorption, and sensation are some of the main functions of epithelial tissue. Let us now look at the types of epithelial tissues.
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Simple Epithelial Tissue
This type of epithelial cell consists of a single layer of cells that are mainly present as the linings of ducts, tubes, and other cavities in the body. The three types of simple epithelial tissues are as follows:
Squamous Epithelium
The simple squamous epithelium is a single-layered epithelium tissue. It is made of cells that are flat and have irregular boundaries. It forms the alveoli and the lining of blood vessels.
Cuboidal Epithelium
This tissue is made of cells that are of the shape similar to a cuboid or a cube. It forms the salivary gland ducts as well as the tubules of the kidney.
Columnar Epithelium
The cells which form this tissue are long, tall, and column-shaped. The lining of the intestines and stomach is formed by this tissue.
Compound Epithelial Tissue
The compound epithelium is a multi-layered tissue. Protection is the main function of the compound epithelial tissue. It has a minimal role in secretion. Skin is formed by compound epithelial tissue that serves as a shield against chemical and mechanical stress on our skin from the activities of the outside world.
Connective Tissues
As the name suggests, the connective tissues bind and aid the tissues, organs, and different parts of the body. Among the different types of animal tissues, connective tissues are the most prominent and abundant in the animal body. The connective tissue cells are loosely organized in a matrix structure, which is distributed widely throughout the body. Let us have a look at the types of connective tissue and their functions: -
Loose Connective Tissues
Areolar Connective Tissue
This connective tissue is usually found around nerves and blood vessels, as well as underneath the skin. The tissue is composed of fibroblasts, mast cells, and macrophages.
Adipose Tissue
This tissue is found in the skin and organs. The tissue has fat storages and is also composed of globules of fat. It is helpful in providing insulation to the body due to the presence of fat.
Hard Connective Tissues
Bone
It is structured as a rigid matrix made up of collagen and calcium. It offers protection, support, and facilitates the movement of the body parts. It is also a site for the production of blood cells.
Cartilage
It is formed of chondrocytes, which are flexible and dense intercellular materials. Cartilages in most vertebrates get replaced in embryos by bones when the embryo matures. Cartilage tissue sites in our body include the tip of ears, vertebral column, bronchi in lungs, etc.
Fluid Connective Tissue
Blood
It is the only fluid connective tissue formed of blood cells. The main functions include defense, blood clotting, and transportation.
FAQs on Epithelial Tissue and Connective Tissue
1. How Many Types of Animal Tissue are There?
There are in total four types of animal tissue, which are named as epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Two of them have already been explained above. The other two are explained briefly as:
Muscle Tissue
Muscle tissue consists of cells containing contractile filaments that pass past each other and adjust the diameter of the cell. There are three main categories of muscle tissue. They are:
1) Smooth Muscle: located in the inner lining of the organs
2) Skeletal Muscle: It is connected to the bone and moves the body
3) Cardiac Muscle: It is present only in the heart.
Nervous Tissue
Nervous tissue is among the four main animal tissue types. The central nervous system and the peripheral nervous system are the locations in our body where the nervous tissue can be found out. This specialized tissue consists of neurons and other supporting cells, which can be collectively called neuroglia. The nervous system is responsible for the supervision and coordination of the body and its parts.
2. What are The Functions of Muscle Tissue and Nervous Tissue?
Functions Performed By The Muscle Tissue
The functions of muscle tissue include facilitating movement in the body, maintaining the body posture, heat generation through the contraction of muscles, constriction of organs and blood vessels, and pumping blood through blood vessels to reach all the organs of the body.
Functions Performed By The Nervous Tissue
The two main functions performed by the nervous tissue are communication and integration. Nervous tissue contains two types of cells — neuroglia and neurons. Neurons are highly advanced nerve cells which produce and manage nerve impulses in our body.
