Zoology Lecture Bio Tissue PDF

ZOOLOG Y ANIMAL TISSUES table of 02 contents: 03 Parts of Animal Tissue Function of Animal Tissue...

ZOOLOG Y ANIMAL TISSUES table of 02 contents: 03 Parts of Animal Tissue Function of Animal Tissue 01 Classification of Animal 04 Tissues 05 Anatomical Terms Animal Classification levels of  organization tissue A group of cells that have similar structure and function together as one unit HISTOLOGY - The study of the microscopic anatomy of cells and tissues. 4 Basic types of tissue Connective tissue Epithelial tissue Muscle tissue Nervous tissue epithelial tissues Cover body surfaces, form glands and line hollow organs, body cavities and ducts. Classified based on 2 ways: Layers and Shape 1 layer - simple; more than one - stratified  Special classification - pseudo means false (false layer) ·Flat – squamous; cuboidal- same width and height; if it is longer than the wide – columnar. epithelial tissues Epithelia are named according to the shape of their cells, and the thickness or arrangement of their layers (of cells) simple squamous pseudostratified squamous stratified squamous simple cuboidal pseudostratified cuboidal stratified cuboidal simple columnar pseudostratifiedcolumnar stratified columnar transitional simple squamous epithelium the kidney Function: Diffusion of gases in the Composed of a single layer of flat cells lungs and easy transport of found: molecules. In the air sacs of lungs In the lining of blood vessels, the heart, and lymphatic vessels In all capillaries, including those of  simple cuboidal epithelium Forms a single layer of column-like cells cilia, microvilli, mucus (goblet cells). Composed of a single layer of cube Goblet cells (wine like shape) are shaped cells. simple columnar cells that have ·It is often found lining the tubules of differentiated to acquire the ability to the kidneys and many other glands secrete mucus. (Found in small and Function: For absorption, secretion large intestines) Function: Absorption, transport and secretion pseudostratified squamous epithelium Appears to have layers, due to nuclei which are at various depths. In reality, all cells are attached to the basement membrane in a single layer, but some do not extend to the simple columnar epithelium apical surface. Ciliated tissue has goblet cells that secrete  mucous (nose, pharynx, larynx); trachea Has Globular cells, Cilia Function: Protection from any foreign Locations: Upper respiratory tract material like dust particles so you form mucous or you cough. stratified squamous epithelium Has more than one layer of flat cells has an apical surface that is made up of squamous (flat) cells. The other layers have different shapes, but the name is based on the apical layer. The many layers are ideal for protection against strong friction forces. Location: Skin Function: Protection especially from friction and forces. Layers of the skin – stratum corneum, S. Lucidum, S. granulosum, S. Spinosum, S. Basale/Germinativum stratified cuboidal epithelium Has an apical surface made up of two or more layers of cube-shaped cells. ·Locations: include the sweat glands and part of the male urethra stratified columnar epithelium A rare type of epithelial tissue composed of column-shaped cells arranged in multiple layers Locations: Conjunctiva, pharynx, anus, and male urethra. It also occurs in embryo. transitional epithelium The cells of this epithelium change shape depending on the state of stretch in the tissue. In a full bladder, the cells are flattened. 700- 800 mL capacity of the urinary bladder It became squamous when it is full then become cuboidal when empty.  epithelial tissues Although epithelia are found throughout the body, certain ones are associated with specific body locations. Stratified squamous epithelium is a prominent feature of the outer layers of the skin. Simple squamous makes up epithelial membranes and lines the blood vessels, alveolar sacs, serous membrane like peritoneum, pleura, or pericardium. Columnar is common in the digestive tract. Pseudostratified ciliated columnar is characteristic of the upper respiratory tract (from pharynx, larynx trachea). Transitional is found in the urinary bladder. Cuboidal lines ducts and sweat glands and male urethra. connective tissues Connective Tissues are the most abundant and widely distributed tissues in the body – they are also the most heterogeneous of the tissue groups. They perform numerous functions: Bind tissues together Support and strengthen tissue Protect and insulate (work of fats or adipose tissue) internal organs Compartmentalize certain structure and transport (blood) Energy reserves (fats store triglycerides) and immune responses (antibodies) Collagen is the main protein of C.T. and the most abundant protein in the body, making up about 25% of total protein content. Helps stretching of the skin that’s why the wrinkles fade.  Common cells of connective tissues Blast – immature (monoblast) Cyte – mature (monocyte) 1.Fibroblasts are the most numerous cell of  connective tissues. These cells secrete protein fibers (collagen, elastin, & reticular fibers) and a “ground substance” which varies from one C.T. to another. 2. Chondrocytes make the various cartilaginous C.T. Chondro - cartilage 3. Adipocytes store triglycerides 4. Osteocytes - make bones 5. Blood Cells connective tissues Embryonic Connective Tissue  Mesenchyme Mucous Connective Tissue Germ Cell layer that us the source of connective Tissue Mature connective tissue Loose connective tissue (Areolar, Adipose, Reticular) Dense connective tissue (Irregular, Regular, Elastic) Cartilage (Hyline, Fibrocartilage, Elastic) Bone loose connective tissues areolar connective tissue Is the most widely distributed in the body. It contains several types of cells and all three is located in the subcutaneous layer deep to fiber types. the skin and around organs and joints. It reduces heat loss and serves as padding It is used to attach skin and underlying and as an energy source. tissues, and as a packing between It serves as energy source glands, muscles, and nerves. Glycogenesis: formation of glycogen from The cells are separated, there are spaces glucose. in between and have different fibers. Glycogenolysis: breakdown of glycogen to form adipose tissue glucose. loose connective tissues RETICULAR connective tissue Last connective tissue; is a network of interlacing reticular fibers and cells. It forms a scaffolding used by cells of lymphoid tissues such as the spleen and lymph nodes. It fights the invading germs in the blood by the process of filtration. dense connective tissues DENSE IRREGULAR CONNECTIVE consists predominantly of fibroblasts and TISSUE collagen fibers randomly arranged in different directions. Provides strength when forces are pulling from many different directions. Like the skin, there is a part that has dense comprise tendons, ligaments, and other irregular connective tissue because the strong attachments where the need for skin is being pulled in different directions strength along one axis is mandatory (a ·a muscle pulling on a bone). DENSE REGULAR CONNECTIVE tissue Arranged regularly. dense connective tissues elastic CONNECTIVE TISSUE  consists predominantly of fibroblasts and freely branching elastic fibers. It allows stretching of certain tissues like the elastic arteries (the aorta). cartilage tissues hyaline cartilage is the most abundant type of cartilage; it covers the ends of long bones and parts of the ribs, nose, trachea, bronchi, and larynx. It provides a smooth surface for joint movement In elderly patients, the hyaline cartilage starts to fade because the bones starts to touch each other like the tibia and the fibula. fibrocartilage with its thick bundles of collagen fibers, is a very strong, tough cartilage. Fibrocartilage discs in the intervertebral spaces and the knee joints support the huge loads up and down the long axis of the body. Found in the areas of the body that uses so much load like intervertebral spaces (backbones- atlas, axis, c2 c3 c4 c5 are joined together by the cartilage) cartilage tissues elastic cartilage Consists of chondrocytes located in a threadlike network of elastic fibers. It makes up the malleable part of the external ear and the epiglottis (it prevents food and drink from entering the windpipe). There are 2 tubes: the tube going to lungs (front) and the tube where the food passes through (back). When you swallow, the epiglottis covers the tube in front so that food will slide down at the back. bones Is a connective tissue with a calcified intracellular matrix. In the right circumstances, the chondrocytes of cartilage are capable of turning into the osteocytes that make up bone tissue. Initially, it is chondrocytes and as the patient ages, it becomes osteocytes to make up the bone tissue. Haversian canal- middle The whole thing there (all canaliculi, lacunae/ space or osteocytes) makes up the Haversian System blood and lymp As we have seen, blood has many cells. It also has fibers (such as fibrin that makes blood clot). Leukocyte – WBC Erythrocyte – RBC Platelets Plasma summary of mature ct Muscle and nerve tissues ·Muscles and nerve tissues are the last of the 4 basic tissue types. Neurons and muscle fibers are  considered excitable cells because they exhibit electrical excitability, the ability to respond to certain stimuli by producing electrical signals such as action potentials. Action potentials can propagate (travel) along the plasma membrane of a neuron or muscle fiber due to the presence of specific voltage-gated ion channels. Muscular tissues Skeletal – striated, they have more than one nucleus, multinucleated. Nucleus are located eccentrically meaning it is in the periphery, not in the middle. Cardiac – striated but nucleus is located centrally. In one muscle fiber, it is only single. It has intercalated discs, and it is branching Visceral – no striation and has only one centrally located nucleus and tapers at both  ends. nervous tissues Neurons gather information at dendrites and process it in the dendritic tree and cell body. Then they transmit the information down their axon to the axon terminals. 2 TYPES OF CELL IN THE NERVOUS SYSTEM: 1. NEURONS- main nerve cells 2. NEUROGLIA- supporting nerve cells Dendrites- receives impulses towards the cell body Axon- receives impulses away from the cell body stratified columnar epithelium A rare type of epithelial tissue composed of column-shaped cells arranged in multiple layers Locations: Conjunctiva, pharynx, anus, and male urethra. It also occurs in embryo. transitional epithelium The cells of this epithelium change shape depending on the state of stretch in the tissue. In a full bladder, the cells are flattened. 700- 800 mL capacity of the urinary bladder It became squamous when it is full then become cuboidal when empty.