Lesson 6 Cell Types In The Human Body PDF

 What happens when cells group together to perform a common function?  It results in tissue formation, since the cell is the fundamental unit of any tissue, it determines the type, nature, and function of the tissues, which ultimately affects the organs and organ...

 What happens when cells group together to perform a common function?  It results in tissue formation, since the cell is the fundamental unit of any tissue, it determines the type, nature, and function of the tissues, which ultimately affects the organs and organ systems.  An assembly of similar types of cells forms tissues; one or more types of tissues form organs; and organs that work in coordination with each other build the organ systems.  If any tissue is injured, both the cells and the cell structure in the organ are also damaged. These damaged cells decide the fate of the entire tissue (i.e., either to recover or die). Epithelial cells These are cells found in the largest organ of the body the skin. These protect the body from the external environment and also cover the internal organs. Muscle cells Primarily intended for movement, the muscle cells (also known as myocytes) are mostly long. They are classified according to their texture, attachments, and ability to respond. Muscle cells 1. Striated muscle cells, also called skeletal muscle cells, are those which perform locomotory functions such as exercising, and are connected to long bones that move through muscle contraction.  Muscle cells 2. Smooth muscle cells make up the muscle of the internal organs. Muscle cells 3. Cardiac muscle cells are considered to be the most powerful of all cells as they are responsible in pumping blood to different body parts. Bone cells Also called as osteocytes, the bone cells are the most resilient body cells as they are bound together by calcium and phosphate. Bone cells They give strength, support, and framework to the body by enclosing the organs. Bone cells These cells form the bones. Together with the striated muscle cells, osteocytes enable humans/animals to perform locomotion. Cartilage cells These cells are also known as chondrocytes. They function similarly to bone cells but they are composed of chondroitin sulfate that makes them softer and more flexible compared with those of bone cells. The cartilage cells are surrounded by spaces called lacuna, which makes them freely bendable. They are present in the ears and cover the ends of the human body's long bones to lessen the friction when bones rub on each other at the joints. Nerve cells Nerve cells or neurons are the most versatile because they work every second of a human's lifetime. They are present all over the body, enabling a person to think, feel, and respond to his/her environment. Nerve cells They appear very long and have many branches at both ends. They can even grow sometimes as long as a few meters long. They consist of dendrites which receive signal from other neurons; and the axon, which in turn conveys the message to other neurons. Nerve cells Nerve cells make up the brain. They are also found abundantly in the spinal cord. They never multiply in one's lifetime. Secretory cells These cells are found in glands which function as organs of secretion. These secretions can be in the form of sweat, oil, and the like- -which play important roles in the body. Adipose cells Adipose cells are more aptly known as fat cells. They are ring-like in form and function to store fat. Each adipose cell contains a droplet of lipid that is surrounded by the cytoplasm. Specially seen in the abdomen and buttocks, these cells reduce friction and help cushion the body. Blood cells These cells are further divided into red blood cells (erythrocytes), which transport and supply oxygen to the different body parts; white blood cells (lymphocytes, monocytes, neutrophils, eosinophils, and basophils), which protect the body from infection; and thrombocytes (platelets) which help in the process of blood clotting to prevent blood loss. Reproductive cells Reproductive cells, or gametes, have a single set of chromosomes and become active at puberty stage. The nucleus of the spermatocyte (male gamete) unites with the nucleus of the oocyte (female gamete), allowing fertilization to form a new organism.