Animal Cell Types Senior High School PDF

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ATENEO DE DAVAO UNIVERSITY Km 7 Central Park Blvd, Talomo, 8016 Davao City, Philippines Tel No. +63 (82) 221.2411 local 8608 E-Mail: [email protected] * www.addu.edu.ph In Consortium with Ateneo de Zamboanga University and Xavier University SENIOR HIGH SCHOOL a. Learning Content Tissue is composed of a layer of cells that are similar which perform a specific function. ANIMAL CELL TYPES - The basic structural and functional units of animal tissues and organs. They are eukaryotic cells that lack a cell wall and have a true, membrane- bound nucleus along with other cellular organelles. Animal cells come in many different varieties, each with a purpose-specific function. Four types occur in all vertebrate bodies: - o Categories of Animal Tissue ▪ Epithelial - Epithelial tissues form the protective covering and inner lining of the body and organs. Epithelial tissues are characterized by closely-joined cells with tight junctions (i.e., a type of cell modification). Being tightly packed, tight junctions serve as barriers for pathogens, mechanical injuries, and fluid loss. The shape of the cell and layering dictates how the tissue will function Shape o Squamous – generally round, flat, and have a small, centrally located nucleus. Fast absorption and diffusion. o Cuboidal – cube-shaped with a single, central nucleus. Absorbs nutrients; produce secretions 1  o Columnar - taller than they are wide: they resemble a stack of columns in an epithelial layer. Absorbs material from the digestive tract. Layering o Simple – One layer of cells o Stratified – Two or more layers of cells o Pseudostratified – Mostly one layer of cells; cells have different shapes and sizes ▪ Nervous - composed of cells designed to take in and transfer electrical impulses from specific areas of the body and to send them to specific locations in the body. Neurons – Connect to other neurons to receive, send, and transmit electrical impulses or information Glial Cells - provide physical and metabolic support to neurons in the central nervous system and the peripheral nervous system. 2 ▪ Muscle - specialized tissues in animals with a unique capacity to contract and produce force, enabling movement and a range of physiological processes. There are three types of muscle cells: Skeletal – Multinucleate. Occur in parallel arrangements and has striations that run perpendicular to the fibers caused by the arrangement of contractile proteins. It is voluntary and is found in the muscles that move bones Smooth – Single, centrally located nucleus. It lacks striations and appears as short, tapered cells. The action is involuntary and is found in blood vessel walls, tubes of the digestive system, and tubes of the reproductive system. Cardiac – Single, centrally located nucleus. Only found in the heart. It has striations unlike the smooth muscle. It is involuntary but may be influenced by the autonomic nervous system to speed up or slow down. The cells divide and converge with other cardiac cells. An intercalated disc can be found in between cells. 3 ▪ Connective - a type of animal tissue that is predominantly composed of extracellular components such as fibers and intercellular substances. It functions for connection, mechanical support, and surrounding tissues and organs. It is the most abundant tissue type. Loose – The cells are in a loose matrix of elastin and collagen fibers. It holds organs in place and is responsible for attaching the epithelial tissue to underlying tissue. It is found under the skin and between organs. Dense - Cells are in a dense matrix of elastin and collagen fibers. It is the tendon, which connects muscle to bone, and ligament, which connects bone to bone. 4  Adipose – It is composed of adipocytes with few fibers and is in a minimal matrix. It functions for insulation and to store energy in the form of fat. It can be found under the skin, between muscles, around the heart, and joints. Blood – A type of connective tissue composed of blood cells and plasma. It is responsible for the transport of nutrients, oxygen, and waste products throughout the body. Found in arteries, veins, and capillaries. 5  Cartilage – Composed of cells in a matrix of fine collagen fibers. It functions to cushion impact between bones and for flexible support. It is found in the ears, joints, bone ends, and respiratory tract. Bone – Composed of collagen and minerals, such as calcium and phosphorus, in matrix. It provides the structural support of the body and protects internal organs. Bones make up the skeletal system of a vertebrate. 6 7