Tissue vs Organ
All organisms are made up of either a single cell or numerous cells. The cell is the smallest structural and functional unit that is alive. A single cell is capable of growth and development, gaining nutrition, respiration, excretion, recognizing and acting on stimulations as well as reproduction. When consider the animal kingdom, all organisms except protozoans are multicellular. Most of the time, the cells in a multicellular organism are specialized to perform different functions. This specialization of the cells has enabled the functions of the body more efficient. The tissues and organs are both such kind of organizational units of cells in a multicellular organism’s body. The organ is of a higher level of organization than a tissue.
Similar cells operate collectively and become specialized functionally to form a tissue. This is called differentiation or division of labour within the organism, and it may be extensive. The advantage of this is that tissues generally perform specific tasks more efficiently than individual cells. The cells in a tissue are not always identical, but they are of the same embryonic dermal origin. They also are specialized to do the same function. The study of tissues is called histology. The main techniques used to recognize and differentiate different components of a tissue are embedding, sectioning, and staining. There are four basic types of animal tissues; they are connective, muscle, nervous, and epithelial. They make up all the systems and the whole body of an animal.
Cellular activity in a tissue is coordinated so that the cells collectively function as a unit. A number of tissues may work together as an organ. Organs perform major collective functions of a multicellular animal such as pumping blood by the heart and screening blood off urea by the kidney. In an organ, there can be many types of tissues. But there is usually the main tissue and the sporadic tissue. The main tissue for the skin is epithelial tissue while connective tissues, nerves and blood are sporadic tissues. An organ can be described as a hollow organ when it takes a shape of a tube or has a cavity within it.
What is the difference between Tissue and Organ?
• The tissues are made of cells, and the organs are made up of tissues.
• The general size of a tissue is smaller than that of an organ.
• A tissue is always specialized to perform a specific function such as the myocardium or heart muscle tissue, which causes the heart to contract.
• But, an organ can perform various bodily functions like the heart itself which pumps blood throughout the body, receives deoxygenated blood and sends blood for oxygenation to the lung.
• Organs are always components of organ systems, which complete one whole survival function such as digestion by the digestive tract and excretion by the urinary tract.
• Organs can be hollow in structure, but the tissues are always even in shape without gaps between cellular components.
• The tissues are hence, the major structural component of an organ, and the organ is the major functional component of an organ system.