Animal Tissue 2

• A tissue is a group of cells which function together to carry out specialized activities.
• There are four types of animal tissue: Epithelial, Connective, Muscular, and Nervous.
• Epithelial tissue consists of cells arranged in continuous sheets, in either single or multiple layers, and is closely packed and held tightly together, covering and lining the body, with a free surface.
• The major functions of epithelial tissue are protection and acts as a barrier.
• Epithelial tissue can be classified according to shape into squamous, cuboidal, and columnar cells.
• Epithelial tissue can also be classified according to arrangement of layers into simple and pseudo-stratified tissues.
• Muscle tissue is classified into three types: skeletal, cardiac, and smooth muscular tissue.
• Muscle tissue consists of elongated cells called muscle fibers or myocytes.
• Nervous tissue is found in the brain, spinal cord, and nerves and is characterized by the ability to conduct electrical signals.
• Nervous tissue consists of neurons (nerve cells), which are the fundamental units of the brain and nervous system, and neuroglia (glial cells), which provide homeostatic support, protection, and defense to the nervous tissue.
• Muscle tissue transports oxygen, hormones, nutrients and waste products and is located within the blood vessel.
• Cells in muscle tissue use ATP to generate force.
• Simple epithelium is found in the lining of blood vessels, heart, glands, surface of ovaries, kidney tubules, stomach, intestines, gall bladder, auditory tubes.
• Stratified epithelium is found in the skin, mouth, throat, larynx, sweat glands, salivary glands, mammary glands ducts, and a portion of the male urethra.
• Transitional epithelium is found in the lining of the urinary bladder, ureters, urethra.
• White blood cells, or leukocytes, are a type of connective tissue.
• Bone tissue is a type of connective tissue.
• Mast cells contain heparin and histamine.
• Loose connective tissue includes areolar, adipose, and reticular tissues.
• Liquid connective tissue includes blood and lymph.
• Embryonic connective tissue also includes mucous connective tissue, which is embryonic tissue from which connective tissues, as well as other tissues, arise.
• Embryonic connective tissue includes mesenchyme and mucous connective tissue.
• Adipose cells, or fat cells, also called adipocytes, store triglycerides.
• Dense connective tissue includes regular and irregular tissues.
• Umbilical cord of newborn; composed of fibroblast-like cells.
• Mature connective tissue includes loose connective tissue, dense connective tissue, cartilage, and bone tissue.
• Cartilage includes hyaline, fibrocartilage, and elastic cartilage.
• Connective tissue consists of relatively few cells scattered through an extracellular matrix and is the most abundant and widely distributed tissues in the body.
• The functions of connective tissue include binding tissues together, supporting and strengthening tissue, transporting blood, storing compounds, and providing protection.
• Connective tissue has three types of fibers: collagenous fibers which provide strength and flexibility, reticular fibers which join connective tissue to adjacent tissues, and elastic fibers which make tissues elastic.
• Dense, regular elastics matrix composed of collagen fibers and elastin fibers.
• Perichondrium protects bones from injury and damage, nourishes cartilage through blood vessels, and facilitates cartilage growth.
• Connective tissue also has three types of cells: blasts which create the matrix, cytes which maintain it, and clasts which break it down for remodeling.
• Fibrocartilage is found where strong support and some flexibility are needed, such as in the rib cage, and chondrocytes are scattered among bundles of collagen fibers within the extracellular matrix, with more collagen than hyaline.
• There are two types of bone: Spongy bone, which has spaces between trabeculae or plates, resembles a sponge, and is characterized by a matrix network called trabeculae (little beam) that gives its spongy appearance, and Compact bone, which forms the hard, dense layer of bones throughout the body and consists of closely packed osteons.
• Blood tissue is a connective tissue with a liquid extracellular matrix called blood plasma.
• Bone is a hard connective tissue that consists of living cells and mineralized matrix, with bone cells, or osteocytes, located within holes in the matrix.
• Chondrocytes, the cartilage cells, produce and maintain the cartilaginous matrix.
• Dense, regular collagenous matrix composed of collagen fibers.
• Hyaline cartilage is the most abundant cartilage in the body and is surrounded by perichondrium, providing flexibility and support.