Copyright © 2010 Pearson Education, Inc. TISSUES Ch. 3b

Copyright © 2010 Pearson Education, Inc. Tissues There are four types of tissue in the body Epithelial tissue Connective tissue Muscle tissue Nerve tissue

Copyright © 2010 Pearson Education, Inc. General Characteristics of Epithelial Tissue 1.Cells have: Polarity— apical (unattached/ free) and basal (attached) surfaces Apical surfaces: May bear microvilli /cilia Basal surface: Supported by a basement membrane

Copyright © 2010 Pearson Education, Inc. Characteristics of Epithelial Tissue 2.Composed of closely packed cells 3.Avascular 4.High rate of regeneration

Copyright © 2010 Pearson Education, Inc. Figure 4.2a Stratified Simple Apical surface Basal surface Apical surface Basal surface

Copyright © 2010 Pearson Education, Inc. Classification of Epithelia Ask two questions: 1.How many cell layers? 1 = simple epithelium >1 = stratified epithelium

Copyright © 2010 Pearson Education, Inc. Classification of Epithelia 2.What type of cell? Squamous = flat Cuboidal Columnar # of cell layers followed by cell shape = epithelial classification If E.T. is stratified, name according to the top layers of cells

Copyright © 2010 Pearson Education, Inc. Figure 4.3a (Simple squamous epithelium Description: Single layer of flat cells Function: Diffusion & Filtration Location: Air sacs of lungs Lining of ventral body cavity

Copyright © 2010 Pearson Education, Inc. ( Simple Cuboidal epithelium Location: Glands and ducts Function: Secretion and absorption. Description: Single layer of cubelike cells

Copyright © 2010 Pearson Education, Inc. (Simple Columnar epithelium Description: Single layer of tall cells May have goblet cells Function: Absorption and secretion Location: Lines most of digestive tract

Copyright © 2010 Pearson Education, Inc. Pseudostratified Ciliated Columnar epithelium Trachea Description: Single layer of cells of differing heights on same basement membrane; May have goblet cells Function: Secretion, propulsion of mucus by ciliary action. Location: upper respiratory tract.

Copyright © 2010 Pearson Education, Inc. Stratified squamous epithelium Description: Thick, surface cells squamous Two types: Non-Keratinized: alive Keratinized: surface cells dead & full of keratin Function: Protection in areas subjected to abrasion. Location: Nonkeratinized: Lines cavities which open to exterior Keratinized: forms epidermis

Copyright © 2010 Pearson Education, Inc. Figure 4.3f Transitional epithelium Description: Basal cells cuboidal/columnar Surface cells dome shaped or squamous (depends on degree of stretch) Function: Stretches readily Location: Lines hollow urinary organs

Copyright © 2010 Pearson Education, Inc. Characteristics of Connective Tissue Connective Tissues are the most abundant and widely distributed tissue type C.T. has varying degrees of vascularity C.T. has cells separated by nonliving extracellular matrix (ground substance and fibers)

Copyright © 2010 Pearson Education, Inc. Components of Extracellular Matrix Ground substance Interstitial fluid, Adhesion proteins (“glue”), Large polysaccharides Three Types of Fibers can be found within the ground substance: Collagen Strongest, most abundant type; Provides tensile strength; form thick cables Elastic Long, thin, fibers; allow for stretch Reticular Short, fine, branched fibers that form an internal network (mesh) that is supportive to other cells

Copyright © 2010 Pearson Education, Inc. Cells of Connective Tissue Cell Types “blasts” = Mitotically active and secretory cells “cytes” = Mature cells Fibroblasts in connective tissue proper Chondroblasts and chondrocytes in cartilage Osteoblasts and osteocytes in bone Hematopoietic stem cells in bone marrow

Copyright © 2010 Pearson Education, Inc. Figure 4.8j Osseous tissue Description: Hard, calcified matrix; osteocytes in lacunae; Function: Support, protection, attachment site for muscles. Location: Bones Lacunae Lamella Central canal

Copyright © 2010 Pearson Education, Inc. Connective Tissue: Cartilage Three types of cartilage: Hyaline cartilage Elastic cartilage Fibrocartilage

Copyright © 2010 Pearson Education, Inc. Cartilage: Hyaline Description: most abundant of cartilage types;less hard and more flexible than bone; Chondrocytes in lacunae. Function: Supports,cushions, resists compressive stress. Location: Forms most of embryonic skeleton; articular cartilage; cartilages of nose, trachea, larynx. Costal cartilages Chondrocyte in lacuna Matrix

Copyright © 2010 Pearson Education, Inc. Cartilage: Elastic Function: Also allows great flexibility. Location: E ar, epiglottis. Chondrocyte in lacuna Matrix

Copyright © 2010 Pearson Education, Inc. Cartilage: Fibrocartilage Location: Intervertebral discs Intervertebral discs Chondrocytes in lacunae Collagen fiber

Copyright © 2010 Pearson Education, Inc. Connective tissue proper: Dense regular connective tissue Description: Parallel collagen fibers Function: Withstands tensile stress when pulling force is applied in one direction. Location: Tendons, most ligaments Shoulder joint Ligament Tendon Collagen fibers Nuclei of fibroblasts

Copyright © 2010 Pearson Education, Inc. Connective tissue proper: Dense irregular connective tissue Description: Irregularly arranged collagen fibers Function: Withstands tension exerted in many directions Location: Fibrous capsules of organs,joints; dermis of skin Collagen fibers Nuclei of fibroblasts Fibrous joint capsule

Copyright © 2010 Pearson Education, Inc. Connective tissue proper: Areolar connective tissue Description: Most widely distributed variety of CT Soft, pliable, like cobwebs Function: Wraps and cushions organs Location: Under epithelia of body, universal packaging material Epithelium Lamina propria Fibroblast nuclei Elastic fibers Collagen fibers

Copyright © 2010 Pearson Education, Inc. Connective tissue proper: Adipose connective tissue Description: Closely packed adipocytes Function: Reserve fuel insulation; supports & protects organs. Location: H ypodermis; around kidneys and eyeballs; in abdomen; breasts. Nucleus of fat cell Vacuole containing fat droplet Adipose tissue Mammary glands

Copyright © 2010 Pearson Education, Inc. Connective tissue proper: Reticular connective tissue Description: Network of reticular fibers Function: Fibers form a soft internal skeleton that supports other cells Location: Lymphoid organs (lymph nodes, bone marrow, and spleen). Spleen White blood cell (lymphocyte) Reticular fibers

Copyright © 2010 Pearson Education, Inc. Others: blood Description: Red and white blood cells in a fluid matrix (plasma). Function: Transport of respiratory gases, nutrients, wastes, and other substances. Location: Contained within blood vessels. Neutrophil Red blood cells Lymphocyte Plasma

Copyright © 2010 Pearson Education, Inc. MUSCLE TISSUE

Copyright © 2010 Pearson Education, Inc. (a) Skeletal muscle Description: Long, cylindrical, multinucleate cells; obvious striations. Function: Voluntary movement Location: Skeletal muscles attached to bones or occasionally to skin. Photomicrograph: (approx. 460x). Nuclei Striations Part of muscle fiber (cell)

Copyright © 2010 Pearson Education, Inc. (b) Cardiac muscle Description: Branching, striated, Have intercalated discs. Function: P ropel blood into circulation; involuntary control. Location: Walls of the heart. Photomicrograph: (500X); Intercalated discs Striations Nucleus

Copyright © 2010 Pearson Education, Inc. (c) Smooth muscle Description: Spindle-shaped Cells; no striations; cells form sheets. Function: Propels substances or objects; involuntary control. Location: Mostly in walls of hollow organs. Photomicrograph: Sheet of smooth muscle (200x). Smooth muscle cell Nuclei

Copyright © 2010 Pearson Education, Inc. NERVOUS TISSUE

Copyright © 2010 Pearson Education, Inc. Function: Transmit electrical signals from sensory receptors to effectors. Location: Brain, spinal cord, and nerves. Description: Neurons w/ cell processes that extend from the cell body; Contains supporting cells Dendrites Neuron processes Cell body Axon Nuclei of supporting cells Cell body of a neuron Neuron processes Nervous tissue

Copyright © 2010 Pearson Education, Inc. Steps in Wound Repair Inflammation Increased blood flow with healing components & clotting factors to damaged area (redness, swelling, pain, heat) due to the release of inflammatory chemicals Clot forms and exposed portion forms scab Organization and restored blood supply Granulation tissue forms=new capillaries and phagocytes and fibroblasts Regeneration and fibrosis Surface ET regenerates, scab detaches, underlying scar tissue

Copyright © 2010 Pearson Education, Inc. Scab Blood clot in incised wound Epidermis Inflammatory chemicals Migrating white blood cell Artery

Copyright © 2010 Pearson Education, Inc. Regenerating epithelium Area of granulation tissue ingrowth Fibroblast Macrophage

Copyright © 2010 Pearson Education, Inc. Regenerated epithelium Fibrosed area