ANIMAL TISSUES Animal tissues are of 4 types: 1. Epithelial Tissues 2. Connective Tissues 3. Muscular Tissues and 4. Nervous Tissues. 1.EPITHELIAL TISSUES; It forms the covering on the surface of the body. It covers outside and inside Organs eg. Skin and Inner lining of Digestive system Glands are produced. Based on the shape of cells there are five types of Epithelial Tissues: 1.Squamous Epithelium - Flat Cells 2. Cuboidal Epithelium - Cube like cells 3. Ciliated Epithelium - Cilia (hair like projections ) 4. Columnar Epithelium - Cylindrical & long 5. Simple Epitelium - Single layer
Simple SquamousSimple CuboidalSimple Columnar So thin that it offers almost no protection; it functions to allow materials to pass through. This offers some protection, but it is more prevalent when material must be secreted & absorbed. Although only a simple epithelium, this offers some protection of underlying tissue. It is found where some protection is necessary and where secretion occurs. Stratified SquamousStratified CuboidalPseudostratified This tissue is usually made up of so many layers of cells that it offers the most protection to the underlying tissue (that's why we find it in skin). This is typically only found in areas where secretion is important (like in glands), but where a little bit more protection is needed than just simple cuboidal. This tissue offers protection and is usually found in places where mucus must get secreted, since it has many mucus- secreting cells called goblet cells.
PROTECTION as a barrier between the outer world (or inner spaces) and our bodies. SECRETION when our bodies need to release material, like hormones into the blood, this tissue has to allow for such material to pass through. Often, it is the cells within the epithelial tissue that make the material for secretion. ABSORPTION epithelial tissue facing our digestive tract has to be very good at absorbing nutrients from the digestive tract lumen in order for us to get what we need from what we eat. EXCRETION epithelial tissue even lines the excretory lumina, like the tracts from the kidneys through to the urethra. FUNCTION S OF EPITHELIAL TISSUES:
ANIMAL TISSUES Connective Tissues; It helps in binding the other tissues & organs & provides a framework & support to various organs of in the body. It plays a major role in the transport of material from one tissue to another tissue. It also helps in body defence, body repair, & in the storage of fat. There are seven types in connective tissue. They are ; 1.Areolar 2.Cartilage 3.Bone 4.Ligament 5.Tendon 6.Adipose 7.Blood
ANIMAL TISSUES Aerolar Tissue: It joins different tissues. It helps in packing tissues & they helps to keep the organs in place. Cells called “fibroblasts” are the major components in this type of connective tissue. These cells secrete fibrous material which holds the other tissues in position. These cells also helps in repair of the tissues when they are injured. Cartilage : It is the type of connective tissue found in the joints of bones, tip of ribs, tip of nose, external ears & in trachea. Embryos of the several vertebrates do not have bone but have cartilage. The entire skeleton of fishes like shark is made up of cartilage.
Bone: It is made up of calcium + phosphate + calcium carbonate. This salts are secreted by the cells called “osteocytes”. These cells are present in the central hollow portion of the bone called “bone marrow”. It is the major component of the skeletal system of several vertebrates. Ligament: [Bone-Bone] It connects bones at the joints & holds them in position. It is made up of large no. of fibres. These fibres are made up of protein called “collagen”. Tendon: [Bone-Muslce] The tendon joins the muscle to the bone. It is also made up of Collagen Fibres