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1.1 THE TISSUES




















TISSUES: A tissue is a mass of cells each of which performs a similar function. The four types of tissue are epithelial, connective, muscular, and nervous.



ORGANS:An organ is a structure composed of two or more tissues which combine to perform a specific function(s). Examples of organs are the stomach, heart, lungs, skin, etc.




AN ORGAN SISTEM:An organ system is composed of two or more organs which combine to perform a specific function(s). Examples of organs systems are the cardiovascular system, muscular system, skeletal system, nervous system, et







TISSUES IN ANIMALS : TYPES OF TISSUES

Epithelial : Epithelial tissues are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.

CONNECTIVE TISSUES: Connective tissues bind structures together, form a framework and support for organs and the body as a whole, store fat, transport substances, protect against disease, and help repair tissue damage.

MUSCLE TISSUES:Muscle tissue is composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts. The tissue is highly cellular and is well supplied with blood vessels.

NERVOUS TISSUES:
Nervous tissue is found in the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities. It stimulates muscle contraction, creates an awareness of the environment, and plays a major role in emotions, memory, and reasoning. To do all these things, cells in nervous tissue need to be able to communicate with each other by way of electrical nerve impulses.

2. THE ANIMAL CELL

3.THE HUMAN SISTEMS