What are Tissues?


Tissues can be defined as a group of cells with similar shapes and functions termed tissues. They form a cellular organizational level, intermediate between the cells and organ system. Organs are then created by combining the functional groups of tissues.

Different Types of Animal Tissues

There are four types of animal tissues

  1. Connective Tissue: They help in maintaining the form of the organism’s body as well as its organs. These tissues also provide internal support to the body. They help in holding the organs together.  The composition of all types of connective tissues is similar. They are mainly composed of extracellular fibers, amorphous matrix, and stationery as well as migrating cells. Skeleton in the human body is one example of connective tissue.

Functions of Connective Tissue

Important and major functions of connective tissue in the body are:

  1. Insulating.
  2. Helps in binding the organs together and provides support.
  3. It protects against the invasions of pathogens by their phagocytic activity.
  4. Provides shape to the body, conserves body heat, and also stores energy.
  5. It is involved in the transportation of water,  nutrients, minerals, hormones, gases, wastes, and other substances within the body.

2. Muscle Tissue: These help in the movement of the body. They produce force and generate motion for the movement of the body as well as movement inside organs. There are three types of muscle tissues; mainly, they are skeletal, cardiac, and visceral or smooth muscle tissue. The main functions of muscle tissues include assisting various body movements such as running, lifting, jumping, picking, etc. They help in maintaining the position and postures of the body. They are associated with voluntary as well as involuntary movements. Involuntary muscle tissues play an important role in pumping blood and its regulation in arteries. It also helps in the inhaling and exhaling of air from the body.
Functions of Muscle Tissue

  1. Helps in maintaining an erect position, or posture.
  2. Helps in the constriction of organs and blood vessels.
  3. Involved in both voluntary and involuntary movements.
  4. Involved in pumping blood and regulating the flow of blood in arteries.
  5. Controls respiration by automatically driving the movement of air both into and out of our body.

3. Nervous Tissue: The tissue that is mainly associated with the central nervous system is known as nervous tissue. They are mainly found in the brain and spinal cord. This tissue is responsible for the communication network inside the body. It plays an important part in the processing of information. It is also responsible for the response to stimuli and transmits information inside the body. It plays an important role in managing emotions, reasoning skills, and memory of an organism.
4. Epithelial Tissue: These play a major role in an organism’s body. They perform various functions such as acting as a sensory reception, helping infiltration, and certain other metabolic activities as well. It also helps in various processes like diffusion and secretion. Epithelial tissues protect internal organs from pathogens as well. These tissues help in the secretion of various enzymes, mucus, hormones, and much more.

Animal Tissues VS Plant Tissue

Plant Tissue Animal Tissue
Tissue is organized adhering to the stationary position of plants. Tissue is organized adhering to the mobility of animals.
Tissues are organized more simply. Tissue is organized in a complex way.
There are many dead cells. There are many living cells.
The growth of plant tissues is restricted to certain areas. The growth of animals is not restricted to certain areas.
Less energy is required to maintain tissues. More energy is required to maintain tissues.