Structure of the cell INTRODUCTION Cells are basic units of life. All living organisms are com- posed of many blocks of cells. Each single has all the characteristics of life. Cell is defined as structural and functional unit of the living body. The space outside the cell is called extracellular space. General Characteristics of Cell Each cell in the body: 1. Needs nutrition and oxygen. 2. Produces its own energy necessary for its growth, repair and other activities. 3. Eliminates carbon dioxide and other metabolic wastes. 4. Maintains the medium, i.e, the environment for its survival. 5. Shows immediate response to the entry of invaders such as bacteria or toxic substances into the body. 6. Reproduces by division. There are some exceptions such as neuron, which do not reproduce. TISSUE Tissue is defined as the group of cells having similar function. There are many types of tissues in the body. All the tissues are classifie
Internal structure of the kidneys seen on a dissected specimen INTRODUCTION The closely packed structure and numerous functions of the kidney illustrate the beautiful workmanship of our creator. It not only applies to the kidney but to each and every part of our body. Synonyms The kidney are also called renes from which we have the derivative renal and nephros from which we have the terms nephron, nephritis, etc Definition Kidneys are a pair of excretory organs located on the posterior abdominal wall, one on each side of the vertebral column, behind the peritoneum. They remove waste products of metabolism and excess of water and salts from the blood, and maintain its pH. Location Location of the kidneys The kidneys occupy the epigastric, hypochondriac. lumbar and umbilical regions. Vertically they extend from the upper border of twelfth thoracic vertebra to the center of the body of third lumbar vertebra. The right kidney is slight