Zoology Lecture Notes on Bio Tissues PDF

ZOOLOGY ANIMAL TISSUES table of 01 02 contents: Classification of Animal Function of Animal Tissue Tissues 03 04 Parts of Animal Tissue Anatomical Terms 05 Animal Cl...

ZOOLOGY ANIMAL TISSUES table of 01 02 contents: Classification of Animal Function of Animal Tissue Tissues 03 04 Parts of Animal Tissue Anatomical Terms 05 Animal Classification  levels of organization  tissue 4 Basic types of 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. 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 pseudostratified columnar stratified columnar transitional simple squamous epithelium simple cuboidal epithelium Composed of a single layer of flat cells Composed of a single layer of cube found: shaped cells. In the air sacs of lungs ·It is often found lining the tubules of In the lining of blood vessels, the the kidneys and many other glands heart, and lymphatic vessels Function: For absorption, secretion In all capillaries, including those of the kidney Function: Diffusion of gases in the lungs and easy transport of molecules. simple columnar epithelium pseudostratified squamous epithelium Appears to have layers, due to nuclei which are Forms a single layer of column-like cells at various depths. In reality, all cells are cilia, microvilli, mucus (goblet cells). attached to the basement membrane in a single layer, but some do not extend to the Goblet cells (wine like shape) are apical surface. simple columnar cells that have Ciliated tissue has goblet cells that secrete differentiated to acquire the ability to mucous secrete mucus. (Found in small and Has Globular cells, Cilia large intestines) Locations: Upper respiratory tract (nose, pharynx, larynx); trachea Function: Absorption, transport and Function: Protection from any foreign secretion material like dust particles so you form mucous or you cough. stratified squamous epithelium stratified cuboidal epithelium Has more than one layer of flat cells Has an apical surface made up of two or more has an apical surface that is made up of layers of cube-shaped cells. squamous (flat) cells. ·Locations: include the sweat glands and part of The other layers have different shapes, but the the male urethra 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 columnar epithelium transitional epithelium A rare type of epithelial tissue composed of The cells of this epithelium change shape depending on the state of stretch in the tissue. column-shaped cells arranged in multiple In a full bladder, the cells are flattened. layers 700- 800 mL capacity of the urinary bladder It became squamous when it is full then become cuboidal when empty. Locations: Conjunctiva, pharynx, anus, and male urethra. It also occurs in embryo.  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 Collagen is the main protein of C.T. and the most abundant protein in the body, making up about 25% of total protein Connective Tissues are the most content. abundant and widely distributed Helps stretching of the skin that’s tissues in the body – they are also the why the wrinkles fade. 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)  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 adipose tissue Is the most widely distributed in the body. It is located in the subcutaneous layer deep to contains several types of cells and all three the skin and around organs and joints. fiber types. It reduces heat loss and serves as padding and as an energy source. It is used to attach skin and underlying It serves as energy source tissues, and as a packing between glands, Glycogenesis: formation of glycogen from muscles, and nerves. glucose. The cells are separated, there are spaces Glycogenolysis: breakdown of glycogen to form in between and have different fibers. 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 DENSE REGULAR CONNECTIVE TISSUE tissue consists predominantly of fibroblasts and collagen fibers randomly arranged in different directions. comprise tendons, ligaments, and other strong attachments where the need for Provides strength when forces are pulling strength along one axis is mandatory (a ·a from many different directions. Like the muscle pulling on a bone). skin, there is a part that has dense Arranged regularly. irregular connective tissue because the skin is being pulled in different directions  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 fibrocartilage is the most abundant type of cartilage; it with its thick bundles of collagen fibers, is a covers the ends of long bones and parts of very strong, tough cartilage. Fibrocartilage discs in the intervertebral the ribs, nose, trachea, bronchi, and larynx. spaces and the knee joints support the huge It provides a smooth surface for joint loads up and down the long axis of the body. movement Found in the areas of the body that uses so In elderly patients, the hyaline cartilage much load like intervertebral spaces starts to fade because the bones starts to (backbones- atlas, axis, c2 c3 c4 c5 are joined touch each other like the tibia and the together by the cartilage) fibula.  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 blood and lymp Is a connective tissue with a calcified intracellular matrix. In the right circumstances, As we have seen, blood has many cells. It also the chondrocytes of cartilage are capable of has fibers (such as fibrin that makes blood clot). turning into the osteocytes that make up bone Leukocyte – WBC tissue. Erythrocyte – RBC Initially, it is chondrocytes and as the patient Platelets ages, it becomes osteocytes to make up the Plasma bone tissue. Haversian canal- middle The whole thing there (all canaliculi, lacunae/ space or osteocytes) makes up the Haversian System 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 transitional epithelium A rare type of epithelial tissue composed of The cells of this epithelium change shape depending on the state of stretch in the tissue. column-shaped cells arranged in multiple In a full bladder, the cells are flattened. layers 700- 800 mL capacity of the urinary bladder It became squamous when it is full then become cuboidal when empty. Locations: Conjunctiva, pharynx, anus, and male urethra. It also occurs in embryo.