4-1 Anatomy and Physiology, Sixth Edition Rod R. Seeley Idaho State University Trent D. Stephens Idaho State University Philip Tate Phoenix College Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. *See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Chapter 04 Lecture Outline *

4-2 Chapter 4 Histology: The Study of Tissues

4-3 Tissues and Histology Tissue Level of Organization –Epithelial –Connective –Muscle –Nervous Histology: Microscopic Study of Tissues

4-4 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

4-5 Epithelium Characteristics Consists almost entirely of cells Covers body surfaces and forms glands Has free and basal surface Specialized cell contacts Avascular Undergoes mitosis

4-6 Functions of Epithelia Protecting underlying structures Acting as barriers Permitting the passage of substances Secreting substances Absorbing substances

4-7 Classification of Epithelium Simple –Squamous, cuboidal, columnar Stratified –Squamous, cuboidal, columnar Pseudostratified –columnar Transitional –Cuboidal to columnar when not stretched and squamouslike when stretched

4-8 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 Types of Epithelium

4-16 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

4-17 Cell Connections Functions –Bind cells together –Form permeability layer –Intercellular communication Types –Desmosomes –Tight –Gap

4-18 Exocrine Glands Unicellular –Goblet cells

4-19 Multicellular Exocrine Glands

4-20 Exocrine Glands and Secretion Types Merocrine –Sweat glands Apocrine –Mammary glands Holocrine –Sebaceous glands

4-21 Connective Tissue Abundant Consists of cell separated by extracellular matrix Diverse Performs variety of important functions

4-22 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

4-23 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

4-24 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

4-25 Connective Tissue Categories Embryonic or mesenchyme Adult –Loose –Dense –Connective tissue with special properties –Cartilage –Bone –Blood

4-26 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

4-27 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

4-28 Dense Regular Connective Tissue

4-29 Dense Irregular Connective Tissue

4-30 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

4-31 Adipose Tissue

4-32 Reticular Tissue

4-33 Cartilage Composed of chondrocytes located in spaces called lacunae Next to bone firmest structure in body Types of cartilage –Hyaline –Fibrocartilage –Elastic

4-34 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

4-35 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

4-36 Elastic Cartilage Rigid but elastic properties –External ears, epiglottis

4-37 Bone Hard connective tissue that consists of living cells and mineralized matrix Organic and inorganic Types –Cancellous or spongy bone –Compact bone

4-38 Bone

4-39 Blood Matrix between the cells is liquid Hemopoietic tissue –Forms blood cells –Found in bone marrow Yellow Red

4-40 Bone Marrow

4-41 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

4-42 Skeletal Muscle

4-43 Cardiac Muscle

4-44 Smooth Muscle

4-45 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

4-46 Neurons

4-47 Neuroglia

4-48 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

4-49 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

4-50 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

4-51 Tissue Repair

4-52 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