Epithelial Tissue A sheet of closely adhering cells one or more cells think with the upper surfacce usually exposed to the environment or to an internal space in the body Avascular covers the body surface lines body cavities and many organs inside outside constitutes most gland tissue Functions Protection invasion injury infection acid enzymes Secretion mucus sweat enzymes hormones Excretion wastes CO2 bile Absorption nutrients Filtration nutrients wastes Sensation touch irritation Basement membrane anchors epithelium to the connective tissue below it Regulates the exchange of materials and binds growth factor Simple Epithelia single layer of cells Simple squamous Simple cuboidal Simple columnar Pseudostratified columnar Fried egg shape Lines with a minimum space needed Square or round pyramidal in glands Round nuclei in center Microvilli some kidney tubules Cilia bronchioles of lungs Tall narrow Oval nuclei usually in basal half of cell Often secretory vesicles microvilli sometimes cilia May have goblet cells Looks mutilayered All cells reach basement membrane Nuclei at several levelsin depper half Often cilia Often goblet cells Allows rapid diffusion or transport of substances through membrane Secretes lubricating serous fluid Absorption secretion Production of protective mucous coat Movement of respiratory mucous Absorption Secretion of mucus etc Movement of egg and ambryo in uterine tube Secretes and propells mucus Lungs alveoli Bronchioles Kidneys some tubules glomerular capsules Kidneys most tubules Kidneys some tubules Respiratory tract nasal cavity pharynx trachea bronchi Heart and blood vessels inner lining Stomach intestines ect serous membranes Stomach intestines gallbladder uterus uterine tubes inner lining Liver thyroid and other glands secretory cells Pleura pericardium peritoneum and mesenteries surface mesothelium Stratified Epithelia 2 layers Only deepest layer is attached to the basement membrane Portions of male urethra Stratified squamous Most widespread Stratified cuboidal Stratified columnar rare minor imp Transitional epithelium Surface cells square or round Seen only in places where two other epithelial types meet Columnar or cuboidal in its deepest layers but flatten twrd the surface Keratinized keratin coated with water repellent glycolipid Non k moist and slippery Resists abrasion and penetration Keratinized retards water loss Non k moist and slippery resists stress Sweat secretion Secretes ovarian hormones Produces sperm Resembles stratifies squamous BUT surface cells are rounded 5 6 cells thick when relaxed Can have 2 nuclei Stretches to allow filling of urinary tract K epidermis Sweat gland ducts Mostly glands Non k tongue esophagus vagina anal canal few other internal membranes Follicles of ovaries Seminiferous tubules of testis Limited regoins of larynx pharynx Anal canal Male urethra Urinary tract part of kidney ureter bladder part of urethra Umbilical cord Connective Tissue The most abundant widely distributed and histologically variable of the primary tissues Rule cells occupy less space than the extracellular matrix Fibrous tissue adipose tissue cartilage bone and blood Functions Immune protection attack and battlefield Binding of organs tendons ligaments fat fibrous tissue Support bones cartilage fibrous tissue Physical protection cranium ribs sternum fatty cushions Movement bones cartilages Storage fat bones Heat production metabolism of brown fat Transport blood Mesenchyme a form of embryonic connective tissue Fibrous Connective Tissue Cells Fibers Types The most diverse type Conspicuous fibers Components Fibrobalsts produce fibers large fusiform Macrophages phagocyte detect antigens and activate immune system Leukocytes WBC attack and react against bacteria Plasma cells detect foreign agents and synthesize antibodies Mast cells secrete heparin inhinits clotting and histamine dilate Adipocytes small clusters Collagenous fibers tough flexible resist stretching tendons ligaments dermis 3 collagen a chains tropocollagen fibrils fibers Reticular fibers thin collagen coated with glycoprotein Spongelike framework Elastic fibers thinner than collagenous branch and rejoin Recoil back Fibroblasts secrete polypeptide chains network Ground substance Glucosaminoglycans GAG absorb and hold water Chondroitin stiffness of cartilage linked by hyaluronic acid Proteoglycans form thick colloids Create structural bonds Adhesive glycoproteins bind all the components of tissue together mark pathways Interstitial fluid Loose Dense Areolar Reticular Regular Irregular Loosely org zed fibers abundant blood vessels a lot of empty space All cell types fibers Mesh of reticular fibers and fibroblasts Supportive stroma for lymphatic organs Lymph nodes Spleen Thymus Bone marrow Binds epithelia Provides nutrition removes waste Arena for immune defense Underlying epithelia Srrounds blood vessels nerves esophagus and trachea Fascia b w muscles Mesenteries Visceral layers of pericardium and pleura Fibers are parallel to each other Most of the time fibroblasts only Few blood vessels Transfer muscular tension to bones Bind bones resist stress Tendons Ligaments Elastic elastic fibers more fibroblasts with larger nuclei Densely packed collagen fibers random directions Few open space cells or blood vessels Resists unpredictable stress Vocal cords Suspensory ligament of the penis Some ligaments of the vertebral column Arteries Protective capsule around kidneys liver testes spleen Perichondrioum periosteum Deeper dermis Adipose Tissue Primary energy reservoir triglycerides White fat adults Functions Single large central globule of triglyceride cytoplasm is a thin layer nucleus pushed against the edge of the cell Thermal insulation Anchors and cushions eyes kidneys etc Brown fat fetuses infants children Multiple globules Not linked to ATP all energy released as heat unusual abundance of blood vessels and certain enzymes in mitochondria Cartilage Types Chondroblasts secrete matrix trapped in lacunae become chondrocytes Rarely exhibit blood vessels nutrition and waste removal diffusion through matrix rich in GAGs and collagen fibers Hyaline Elastic Fibrocartilage Clear glassy matrix Fibers are usually not visible Cell nests Usually covered by perichondrium Joint movement Holds airways open moves vocal cords Precursor of bone in the fetal skeleton Weblike mesh of elastic fibers Always covered by perichondrium Provides flexible elastic support Movable joints at the ends of the long