Transcript Chapter 4
Anatomy and Physiology, Sixth Edition Rod R. Seeley Idaho State University Trent D. Stephens Idaho State University Philip Tate Phoenix College Chapter 04 Lecture Outline* *See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. 4-1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 Histology: The Study of Tissues 4-2 Tissues and Histology • Tissue Level of Organization – – – – Epithelial Connective Muscle Nervous • Histology: Microscopic Study of Tissues 4-3 Embryonic Tissue • Germ layers – Endoderm • Inner layer • Forms lining of digestive tract and derivatives – Mesoderm • Middle layer • Forms tissues as muscle, bone, blood vessels – Ectoderm • Outer layer • Forms skin and neuroectoderm 4-4 Epithelium Characteristics • Consists almost entirely of cells • Covers body surfaces and forms glands • Has free and basal surface • Specialized cell contacts • Avascular • Undergoes mitosis 4-5 Functions of Epithelia • • • • • Protecting underlying structures Acting as barriers Permitting the passage of substances Secreting substances Absorbing substances 4-6 Classification of Epithelium • Simple – Squamous, cuboidal, columnar • Stratified – Squamous, cuboidal, columnar • Pseudostratified – columnar • Transitional – Cuboidal to columnar when not stretched and squamouslike when stretched 4-7 Types of Epithelium 4-8 Types of Epithelium 4-9 Types of Epithelium 4-10 Types of Epithelium 4-11 Types of Epithelium 4-12 Types of Epithelium 4-13 Types of Epithelium 4-14 Types of Epithelium 4-15 Functional Characteristics • Cell layers and shapes – Diffusion, Filtration, Secretion, Absorption, Protection • Cell surfaces – Microvilli: Increase surface area absorption or secretion – Cilia: Move materials across cell surface • Cell connections – Desmosomes, tight, gap • Glands – Exocrine: Have ducts – Endocrine: Have no ducts 4-16 Cell Connections • Functions – Bind cells together – Form permeability layer – Intercellular communication • Types – Desmosomes – Tight – Gap 4-17 Exocrine Glands • Unicellular – Goblet cells 4-18 Multicellular Exocrine Glands 4-19 Exocrine Glands and Secretion Types • Merocrine – Sweat glands • Apocrine – Mammary glands • Holocrine – Sebaceous glands 4-20 Connective Tissue • Abundant • Consists of cell separated by extracellular matrix • Diverse • Performs variety of important functions 4-21 Functions of Connective Tissue • Enclosing and separating as capsules around organs • Connecting tissues to one another as tendons and ligaments • Supporting and moving as bones • Storing as fat • Cushioning and insulating as fat • Transporting as blood • Protecting as cells of the immune system 4-22 Connective Tissue Cells • Specialized cells produce the extracellular matrix – Suffixes • -blasts: create the matrix • -cytes: maintain the matrix • -clasts: break the matrix down for remodeling • Adipose or fat cells • Mast cells that contain heparin and histamine • White blood cells that respond to injury or infection • Macrophages that phagocytize or provide protection • Stem cells 4-23 Extracellular Matrix • Components – Protein fibers • Collagen which is most common protein in body • Reticular fill spaces between tissues and organs • Elastic returns to its original shape after distension or compression – Ground substance • Shapeless background – Fluid 4-24 Connective Tissue Categories • Embryonic or mesenchyme • Adult – – – – – – Loose Dense Connective tissue with special properties Cartilage Bone Blood 4-25 Loose Connective Tissue • • • • Also known as areolar tissue Loose packing material of most organs and tissues Attaches skin to underlying tissues Contains collagen, reticular, elastic fibers and variety of cells 4-26 Dense Connective Tissue • Dense regular – Has abundant collagen fibers • Tendons: Connect muscles to bones • Ligaments: Connect bones to bones • Dense regular elastic • Ligaments in vocal folds • Dense irregular • Scars • Dense irregular collagenous • Forms most of skin dermis • Dense irregular elastic • In walls of elastic arteries 4-27 Dense Regular Connective Tissue 4-28 Dense Irregular Connective Tissue 4-29 Connective Tissue with Special Properties • Adipose tissue – Consists of adipocytes – Types • Yellow (white) – most abundant, white at birth and yellows with age • Brown – found only in specific areas of body as axillae, neck and near kidneys • Reticular tissue – Forms framework of lymphatic tissue – Characterized by network of fibers and cells 4-30 Adipose Tissue 4-31 Reticular Tissue 4-32 Cartilage • Composed of chondrocytes located in spaces called lacunae • Next to bone firmest structure in body • Types of cartilage – Hyaline – Fibrocartilage – Elastic 4-33 Hyaline Cartilage • Found in areas for strong support and some flexibility – Rib cage and cartilage in trachea and bronchi • Forms most of skeleton before replaced by bone in embryo • Involved in growth that increases bone length 4-34 Fibrocartilage • Slightly compressible and very tough • Found in areas of body where a great deal of pressure is applied to joints – Knee, jaw, between vertebrae 4-35 Elastic Cartilage • Rigid but elastic properties – External ears, epiglottis 4-36 Bone • Hard connective tissue that consists of living cells and mineralized matrix • Organic and inorganic • Types – Cancellous or spongy bone – Compact bone 4-37 Bone 4-38 Blood • Matrix between the cells is liquid • Hemopoietic tissue – Forms blood cells – Found in bone marrow • Yellow • Red 4-39 Bone Marrow 4-40 Muscle Tissue • Characteristics – Contracts or shortens with force – Moves entire body and pumps blood • Types – Skeletal • Striated and voluntary – Cardiac • Striated and involuntary – Smooth • Nonstriated and involuntary 4-41 Skeletal Muscle 4-42 Cardiac Muscle 4-43 Smooth Muscle 4-44 Nervous Tissue • Found in brain, spinal cord and nerves • Ability to produce action potentials • Cells – Nerve cells or neurons • Consist of dendrites, cell body, axons • Consist of multipolar, bipolar, unipolar – Neuroglia or support cells 4-45 Neurons 4-46 Neuroglia 4-47 Membranes • Mucous – Line cavities that open to the outside of body – Secrete mucus • Serous – Line cavities not open to exterior • Pericardial, pleural, peritoneal • Synovial – Line freely movable joints – Produce fluid rich in hyaluronic acid 4-48 Inflammation • Response when tissues damaged or with an immune response • Manifestations – Redness, heat, swelling, pain, disturbance of function • Mediators – Include histamine, kinins, prostaglandins, leukotrienes – Stimulate pain receptor and increase blood vessel permeability 4-49 Tissue Repair • Substitution of viable cells for dead cells • Skin repair – Primary union: Edges of wound close together • • • • • • Wound fills with blood Clot forms Scab Pus Granulation tissue Scar – Secondary union: Edges of wound not close • Clot may not close gap • Inflammatory response greater • Wound contraction occurs leading to greater scarring 4-50 Tissue Repair 4-51 Tissues and Aging • Cells divide more slowly in older than younger people • Tendons and ligaments become less flexible and more fragile • Arterial walls become less elastic • Rate of blood cell synthesis declines in elderly • Injuries are harder to heal in elderly 4-52