Biology Tissues PDF

ANAPHY: TISSUES Columnar – column-like Tissues SIMPLE EPITHELIUM - Groups of specialized cells and the - Concerned with absorption, extracellular substances surrounding secretion, and...

ANAPHY: TISSUES Columnar – column-like Tissues SIMPLE EPITHELIUM - Groups of specialized cells and the - Concerned with absorption, extracellular substances surrounding secretion, and filtration them - Consists of single layer and are usually very thin Histology - Protection is NOT one of their - Study of tissue (histo, tissue; ology, specialities study) SIMPLE SQUAMOUS Epithelial tissue - Single layer of flat cells - found virtually everywhere, both - Usually forms membranes inside and outside the body. - Lines body cavities - Primarily a cellular tissue - Lines lungs and capillaries - Very little extracellular material - Function: Allow passage of materials between cell by diffusion and filtration Characteristics - Cellularity: Composed of closely packed cells with little extracellular material between - Specialized contacts: Adjacent epithelial cells are bound together to form continuous sheets by specialized contacts such as desmosomes and tight junctions - Polarity: exhibits polarity by having an apical surface and a lower attached basal surface; all epithelia exhibit polarity SIMPLE CUBOIDAL Classification - Single layer of cube-like cells - Common in glands and their ducts Simple – one layer - Forms walls of kidney tubules and Stratified - more than one layer ducts - Covers the ovaries Shapes of cells: - Function: secretion and absorption Squamous - flattened Cuboidal – column-like  STRATIFIED EPITHELIUM - Contains two or more cell layers - Main function is protection - Regenerate from below; basal cells divide and push apically to replace the older surface cells - Stratified squamous epithelium is composed of several layers - Transitional epithelium - PESUDOSTRATIFIED COLUMNAR - Single layer, but some cells are shorter than others SIMPLE COLUMNAR - Often looks like a double cell layer - Single layer of tall cells - Often includes goblet cells, which produce mucus - Non-ciliated type: digestive tract, gallbladder and excretory ducts of some glands - Ciliated type: small bronchi, uterine tubes and some regions of the uterus - Function: absorption, secretion of mucus, enzymes and other substances; ciliated type propels mucus (or reproductive cells) by FUNCTION ciliary action - Non-ciliated type (male’s sperm- carrying ducts and ducts of large glands) - Ciliated type (line the trachea, most of the upper respiratory tract) STRATIFIED SQUAMOUS - Thick membrane composed of several cell layers  - Basal cells: cuboidal or columnar (metabolically active) - Surface cells: squamous Function: protects underlying tissues in CONNECTIVE TISSUES areas subjected to abrasion - Primary tissue that makes up part of Types (based on location): every organ in the body - Common origin; mesenchyme - Keratinized: epidermis of the skin; a - Extracellular matrix; non-living dry membrane material that surrounds living cells - Non-keratinized: moist linings of the esophagus, mouth and vagina STRUCTURAL ELEMENTS OF CONNECTIVE TISSUE STRATIFIED COBOIDAL - Cells (Blasts, cytes, clasts) - Rare - Extracellular matrix; Ground - Mostly found in the ducts of some of subtances, protein fibers; collagen, the larger glands (sweat glands and reticular, elastic mammary glands) 4 main classes of connective tissue - Connective tissue proper - Cartilage - Bone Tissue - Blood AREOLAR - Closely packed bundles of collagen fibers, makes up tendons and - Gel-like matrix with all three fiber ligaments types, fibroblasts, macrophages, mast cells and some white blood Dense irregular connective tissue cells - Contains thick bundles of collagen FUNCTION fibers arranged in an irregular fashion and is found in the dermis - Wraps and cushions organs - Its macrophages phagocytize REGULAR bacteria - Important role in inflammation - Primarily parallel collagen fibers - Holds and conveys tissue fluid - Few elastic fibers - Widely distributed under epithelia - Fibroblast: major cell type of the body FUNCTION RETICULAR - Attaches muscle to bone or to - Network of reticular fibers in a muscles; attaches bones to bones typical loose ground substance - Tendons, ligaments, aponeuroses FUNCTION IRREGULAR - Fibers from internal skeleton - Primarily irregularly arranged (stroma) that supports other cell collagen fiber types (WBC, mast cells and - Some elastic fibers macrophages) - Fibroblast: major cell type - Location: lymphoid organs FUNCTION ADIPOSE - Able to withstand tension exerted in - Tissues consists of fat cells, contain many directions the large amounts of lipids for - Provides structural strength energy storage; composed of large - Dermis, submucosa of digestive cell tract, fibrous capsule of organs and - Acts as a thermal insulator; of joints protecting organs ELASTIC - Subcutaneous organs - Composed of collagen and elastin Dense regular connective tissue fibers FUNCTION - Provides elasticity - Maintains the shape of a structure - Capable of stretching and recoiling while allowing great flexibility with strength in the direction of the - External ear (pinna), epiglottis fiber orientation. - Dorsal aspect of the neck, vocal Cartilage Fibrocartilage cords and blood vessels - Matrix similar to but less firm than CARTILAGE that in hyaline cartilage: thick collagen fibers predominate - Stands up to both tension and compression FUNCTION - Ground substance varies from a fluid to a viscous gel - Tensile strength with the ability to absorb compressive shock 3 varieties of cartilage: - Intervertebral discs, pubic symphysis, discs of knee joint Hyaline BONE (osseous tissue) Elastic - Ability to support and protect body Fibrocartilage structures due to hardness - Determined by the additional collagen fibers and calcium salts Cartilage Hyaline (gristle) founds in extracellular matrix - MATRIX: similar to cartilage but is - Most abundant cartilage harder and rigid because of the - Chondroblasts produce matrix abundant collagen fibers, bone has - Chondrocytes lie in lacunae an added matrix element – inorganic calcium salts (bone salts) FUNCTION - Fat storage, synthesis of blood cells - Osteoblasts: immature bone cells - Supports and reinforces - Osteocytes: mature bone cells; lie in - Has resilient cushioning properties lacunae - Resists comprehensive stress - Lacunae (cavity in bone or cartilage) Cartilage Elastic FUNCTION - Most abundant cartilage similar to - Bone supports and protects hyaline cartilage but more elastic - Provides levers for the muscle to act fibers in matrix on FUNCTION  - Site for cell formation SKELETAL (Hematopoeisis) - Stores calcium and other minerals - long cylindrical, multinucleate cells, and fat obvious striations Blood FUNCTION - Red and white blood cells in fluid - transmit electrical signals from matrix (plasma) sensory receptors and to effectors - Most atypical connective tissue (muscle and glands) voluntary - Fluid within blood vessels movement - locomotion FUNCTION - facial expression - in skeletal muscles attached to bones - Transport gases, nutrients, waste and occasionally to skin - Within the blood vessels CARDIAC NERVOUS TISSUE - branching, striated generally - Main component of nervous system uninucleate cells that interdigitate at - Two types of cells specialized junctions (intercalated NEURONS discs) - Specialized cells that generate and FUNCTION conduct electric impulses - propels blood into circulation SUPPORTING CELLS - involuntary control - walls of the heart - Nonconductive cells that support, insulate and protect the neurons SMOOTH MUSCLE TISSUE - spindle-shapes cells with central nuclei - Highly cellular, well-vascularized - no striations tissues responsible for movement - cells arranged closely to form sheets - Muscle cells (muscle fibers) possess myofilaments: FUNCTION - Elaborate versions of the actin and - propels substances or objects along myosin filaments that bring about internal passageways movement or contraction in all - involuntary control muscle cell types - mostly in the walls of hollow organs REGENARATION OF TISSUES Tissues that regenerate easily - Epithelial tissue - Fibrous connective tissue and bone Tissue that regenerate poorly - Skeletal muscle - Cartilage Tissues that are replaced with scar tissue - Cardiac muscle - Nervous tissue within the brain and spinal cord PATHOPHYSIOLOGY - HYDROCEPHALUS (CSF build up in the brain) - Bacterial vaginosis; Gardnerella vaginosis; presence of clue cells - CELIAC DISEASE (celiac spure or gluten-sensitive enteropathy) - DUCTAL CARCINOMA (cancer in the breast)