Human Physiology

Lesson 07 : Tissues


Human body is a complex organism made of trillions of cells of different types. All cells differ extensively in shape, size, characteristics and functions. Cells grouped together constitute a tissue and several tissues form an organs, several organs makes a system and several systems makes entire human body. Cell with the help of its organelles like cell membrane, endoplasmic reticulum, golgi bodies, mitochondria, vacuoles, lysosomes etc. performs various functions like synthesis of bio molecules, secretions, contraction, body defence, gas transport and so on.

Cells grow by multiplication. Mitotic division produces cells of own kind and occurs in all somatic cells. Mitotic division is important for tissue growth, tissue repair and replenishing non-functional cells. Meiotic cell division occurs in gametic cells that participate in sexual reproduction and maintains uniform chromosomal number through generations.

Epithelial, connective, muscular and nervous tissues are four basic types of tissues present on different organs of the body.

Last modified: Tuesday, 10 April 2012, 5:54 AM