Cells and Tissues Chapter 3 PDF

Cells and Tissues Chapter 3  Types of tissues and their origins 4 basic types – Epithelial tissue – Connective tissue – Muscular tissue – Nervous tissue  Types of tissues and their origins Epithelial tissue – Covers body surfaces – Lines hollow organs, body cavities, and duct...

Cells and Tissues Chapter 3  Types of tissues and their origins 4 basic types – Epithelial tissue – Connective tissue – Muscular tissue – Nervous tissue  Types of tissues and their origins Epithelial tissue – Covers body surfaces – Lines hollow organs, body cavities, and ducts – Forms glands – Internal and external surfaces  Types of tissues and their origins Connective tissue – Protects and supports the body and organs – Diversity in function Bind organs together Provides flexibility Store energy Provide immunity Provide structural support  Types of tissues and their origins Muscular tissue – Contraction and generation of force and heat Nervous tissue – Detect internal and external changes – Generation of nerve impulses – Activates muscle contractions and glandular excretions  Cell Junctions Contact points between two plasma membranes  Cell Junctions Tight junctions – Transmembrane proteins fuse together adjacent cells – Prevent fluids from leaking through cell wall  Cell Junctions Tight junctions – Transmembrane proteins fuse together adjacent cells – Prevent fluids from leaking through cell wall – Line the stomach, intestine, and urinary bladder  Cell Junctions Adherens junctions – Rows of cadherens (transmembrane glycoproteins) on external surface of epithelial cell – Attach to plaque w/ parallel rows of actin (microfilaments) – Connect to adhesion belt – wraps periphery of cell – Aid epithelial cells in resisting separation  Cell Junctions Desmosomes – Rows of cadherens (transmembrane glycoproteins) on external surface of epithelial cell – Attach to plaque embedded with keratin (intermediate filaments) – Aid epithelial and cardiac cells in resisting separation under tension  Cell Junctions Hemidesmosome – Rows of integrins (transmembrane glycoproteins) on external surface of epithelial cell – Attach to plaque embedded with keratin (intermediate filaments) – Connect to laminin of basement membrane – Anchor cells to basement membrane  Cell Junctions Gap junctions – Connexins form tunnels – Transports ions, small molecules, and fluid  Epithelial Tissue Arranged in sheets Closely packed Little intercellular space Many cell junctions Always has a apical (free) surface – Serves a barrier – Secretory surface  Epithelial Tissue 4 surfaces – Apical Lines body cavity, duct, surface, or lumen (interior space of organ) – Basal (basement membrane) Contain cell junction – Lateral Contain cell junctions  Epithelial Tissue Classification – Layer Simple Stratified – Shape Sqamousal Cuboidal Columnar Transitional (change from squamousal and cuboidal)  Simple Squamous Epithelium Form: – Single layer of thin flat cells with broad thin nuclei Function: – Filtration, diffusion, osmosis – Covers surfaces Location: – Alveoli – Capillaries  Simple Cuboidal Epithelium Form: – Single layer of cube-shaped cells with centrally located spherical nuclei Function: – Secretion and absorption Location: – Kidney tubules – Glands: salivary, thyroid, pancreas, liver  Non-Ciliated Simple Columnar Epithelium Form: – Nuclei near base of cells – Cells have microvilli Function: – Secretion and absorbtion Location: – Lines gastrointestinal tract (from stomach to anus, gallbladder  Ciliated Simple Columnar Epithelium Form: – Single layer of elongated cells whose nuclei are located at the basement membrane Function: – Absorption, secretion, protection Location: – Fallopian tubes, uterus, digestive tract Pseudostratified ciliated Columnar Epithelium Form: – Single layer of cells that appear layered because of the placement of the nuclei – May have cilia Function: – Protection, secretion, movement of mucus Location: – airways Stratified Squamous Epithelium Form: – Multiple layers of relatively thick cells that continuously divide pushing older layers outward forming a flattened outer layer – May have keratin Function: – Protection Location: – Outer layer of skin – Mouth, throat, vagina, and anal canal  Stratified Cuboidal Epithelium Form: – Multiple layers of cube-shaped cells Function: – Protection Location: – Female and male reproductive systems  Stratified Columnar Epithelium Form: – Multiple layers of elongated cells with a basal layer of cube shaped cells Function: – Protection, secretion Location: – Male urethra and vas deferens – Pharynx  Transitional Epithelium Form: – Similar to nonkeratinized stratified squamous epithelium – Except: rounded rather than flat surface cells Function – Elasticity Location – Walls of ureters, part of urethra, urinary bladder, uterus  Glandular Epithelial Tissue Gland – Secrete substances into ducts or tubes – Endocrine Secrete into bloodstream – Exocrine Secrete into ducts or tubes and surfaces  Glandular Epithelial Tissue Merocrine Exocrine Gland – Gland releases secretion into duct/tube – Salivary glands – Pancreatic glands – Certain sweat glands  Glandular Epithelial Tissue Apocrine Exocrine Gland – Gland releases secretion and apical surface of cell – Mammary glands  Glandular Epithelial Tissue Holocrine Exocrine Gland – Gland releases whole cell when matured – Sebaceous (oil) gland  Connective Tissue Diverse and abundant body tissue Has relatively few cells Consists of extracellular matrix – Protein fibers – Ground substance  Embryonic Connective Tissue Mesenchymal cells – Present in embryo – Differentiate into –blast cells – Have capacity for cell division – Secrete extracellular matrix specific to cell type  Embryonic Connective Tissue Mesenchymal cells – Fibroblast Found in loose and dense connective tissue – Chondroblasts Found in cartilage – Osteoblast Found in bone  Mesenchyme Form: – Irregularly shaped mesenchymal cells embedded in a semifluid ground substance that contains reticular fibers Function: – Forms almost all other types of connective tissue Location: – Under skin and along developing bones of embryo  Mature Connective Tissue Present in newborn Arise from mesenchyme cells  Mature Connective Tissue Loose connective tissue – Areolar, Adipose, Reticular Dense connective tissue – Regular, Irregular, Elastic Cartilage – Hyaline, Fibrocartilage, Elastic Bone Liquid – Blood, lymph  Areolar Connective Tissue Form: – Thin membranes Function: – Connects skin to underlying organs Location: – Beneath skin, between muscles, beneath epithelial tissues  Adipose Connective Tissue Form: – Large cloud like cells that crowd other cells Function: – Protects, stores fat, insulates Location: – Beneath skin, around kidneys, behind eyeballs, surface of heart  Reticular Connective Tissue Form: – Network of interlacing reticular fibers and reticular cells Function: – Forms stroma or organs; binds together smooth muscle tissue cells, filters and removes worn-out blood cells in the spleen and microbes in lymph nodes Location: – Stroma of liver, spleen, lymph nodes, red bone marrow,  Dense Regular Connective Tissue Form: – Extracellular matrix looks shiny white, consists mainly of collagen fibers regularly arranged in bundles Function: – Provides strong attachment between various structures Location: – Forms tendons, most ligaments, and aponeuroses Dense Irregular Connective Tissue Form: – Randomly arranged collagen fibers and a few fibroblasts Function: – Provides strength Location: – Fascia, reticular region of dermis, fibrous pericardium of heart, periosteum of bone  Elastic Connective Tissue Form: – Freely branching elastic fibers, fibroblasts are present in spaces between fibers Function: – Allows stretching of various organs Location: – Lung tissue, walls of elastic arteries, trachea, bronchial tubes, suspensory ligament of penis  Hyaline Cartilage Form: – Chondrocytes located in lacunae which is surrounded by extracellular matrix Function: – Supports, protects, provides framework Location: – Found on ends of bones – Soft part of nose – Rings of trachea  Fibrocartilage Form: – Chondrocytes in lacunae surrounded by large collagenous fibers in its extracellular matrix Function: – Supports, protects, absorbs shock Location: – Between bony parts of spinal column – Parts of the pelvic girdle and knee  Elastic Cartilage Form: – Chondrocytes in lacunae surrounded by elastic fibers in its extracellular matrix Function: – Supports, protects, provides flexible framework Location: – Framework of external ear and parts of larynx  Compact Bone Form: – Most rigid connective tissue – Deposition of mineral salts – calcium phosphate and calcium carbonate – Contains bone marrow Function: – Support, protect, provides framework Location: – Bones of skeleton  Blood Form: – Biconcave disks of RBC, WBC, and platelets Function: – Transport substances, helps maintain stable internal environment Location: – Throughout body within a closed system of blood vessels and heart  Membranes Flat sheets of pliable tissue Covers/lines parts of the body Composed of epithelial and connective layers  Membranes Mucous membrane (mucosa) – Line body cavities that open to exterior of body – Basement membrane attaches to areolar lamina propria (CT) – Has tight junctions – Goblet cells secrete mucous – Glandular cells secrete enzymes  Membranes Serous membrane (serosa) – Lines body cavities that do not open to the exterior Parietal layer – Lines organs within the cavity Visceral layer – Secretes serous fluid Reduces friction  Membranes Serous membrane (serosa) – Pleura Thoracic cavity and organs – Pericardium Mediastinum and heart – Peritoneum Abdominal cavity and visceral organs  Membranes Cutaneous membrane (skin) – Covers entire surface of body – Superficial Epidermis Keratinized epithelium – Deep Dermis Dense irregular and areolar CT  Membranes Synovial membrane – Line freely moveable joint cavities – Lack an epithelial layer – Apical side is composed of synoviocytes – Basal side is composed of areolar and adipose CT – Synovial fluid lubricates and nourishes cartilage covering bones at moveable joints  Muscular Tissue Elongated cells Use ATP to generate force Produces body mvmt, maintains posture, generates heat, provides protection  Skeletal Muscle Tissue Form: – Striated muscle fibers with many nuclei Function: – Voluntary movements of skeletal parts Location: – Muscles usually attached to bones  Cardiac Muscle Tissue Form: – Branched and interconnected striated cells joined end to end by intercalated discs Function: – Heart movements (involuntary) Location: – Heart muscle  Smooth Muscle Tissue Form: – Spindle-shaped cells with centrally located nucleus. Function: – Involuntary movements of internal organs Location: – Walls of hollow internal organs  Nervous Tissue Highly specialized tissue Composed of neurons – Axons – Dendrite – Cell body Composed of neuroglial cells – Accessory functions Table 3.6