4 Tissue: The Living Fabric.

4 Tissue: The Living Fabric

Tissue: The Living Fabric
Individual body cells specialized Each type performs specific functions that maintain homeostasis _____________________ Groups of cells similar in structure that perform common or related function Histology Study of ______________________ © 2013 Pearson Education, Inc.

Types of Primary Tissues
Epithelial tissue Covers Connective tissue __________________ Muscle tissue Produces movement Nerve tissue ____________________________ © 2013 Pearson Education, Inc.

Nervous tissue: Internal communication • Brain • Spinal cord • Nerves
Figure 4.1 Overview of four basic tissue types: epithelial, connective, muscle, and nervous tissues. Nervous tissue: Internal communication • Brain • Spinal cord • Nerves Muscle tissue: Contracts to cause movement • Muscles attached to bones (skeletal) • Muscles of heart (cardiac) • Muscles of walls of hollow organs (smooth) Epithelial tissue: Forms boundaries between different environments, protects, secretes, absorbs, filters • Lining of digestive tract organs and other hollow organs • Skin surface (epidermis) Connective tissue: Supports, protects, binds other tissues together • Bones • Tendons • Fat and other soft padding tissue © 2013 Pearson Education, Inc.

Epithelial Tissue (Epithelium)
Form boundaries Two main types (by location) Covering and lining epithelia On external and internal surfaces _______________epithelia Secretory tissue in glands © 2013 Pearson Education, Inc.

Epithelial Tissue Functions
Protection Absorption _____________________ Excretion Sensory reception © 2013 Pearson Education, Inc.

Five Characteristics of Epithelial Tissues
Polarity Specialized ____________________ Supported by connective tissues Avascular, but innervated Can ____________________ © 2013 Pearson Education, Inc.

Characteristics of Epithelial Tissue: Polarity
Cells have polarity _____________________surface (upper free) exposed to exterior or cavity Basal surface (lower, attached) Both surfaces differ in structure and function © 2013 Pearson Education, Inc.

Apical Surface of Epithelial Tissues
May be smooth & slick Most have microvilli (e.g., brush border of intestinal lining) _______________________surface area Some have cilia (e.g., lining of trachea) © 2013 Pearson Education, Inc.

Basal Surface of Epithelial Tissues
Noncellular __________________lamina Glycoprotein and collagen fibers lies adjacent to basal surface Adhesive sheet Selective filter Scaffolding for cell migration in wound ________________ © 2013 Pearson Education, Inc.

Characteristics of Epithelial Tissue: Specialized Contacts
Covering and lining epithelial tissues fit closely together Form continuous sheets Specialized contacts bind adjacent cells Lateral contacts Tight junctions _______________ © 2013 Pearson Education, Inc.

Characteristics of Epithelial Tissue: Connective Tissue Support
______are supported by connective tissue Reticular lamina Deep to basal lamina Network of collagen fibers Basement membrane Basal lamina + ___________ _____________________ Reinforces epithelial sheet Resists stretching and tearing Defines epithelial boundary m conversion- gate01/95/epithelium-in-general jpg?cb= © 2013 Pearson Education, Inc.

Characteristics of Epithelial Tissue: Avascular but Innervated
No blood vessels in epithelial tissue Must be nourished by diffusion from underlying connective tissues Is supplied by ______ __________________ conversion-gate01/95/epithelium-in-general jpg?cb= © 2013 Pearson Education, Inc.

Characteristics of Epithelial Tissue: Regeneration
High regenerative capacity Stimulated by loss of apical-basal polarity and lateral contacts Some exposed to friction Some exposed to _____________substances If adequate nutrients, can replace lost cells by _______________________________ © 2013 Pearson Education, Inc.

Classification of Epithelia
All epithelial tissues have two names One indicates number of cell layers Simple epithelia = single layer of cells Stratified epithelia = two or more layers of cells _____________________can change in different layers One indicates shape of cells Squamous Cuboidal _____________________________ In stratified epithelia, epithelia classified by cell shape in apical layer © 2013 Pearson Education, Inc.

Figure 4.2a Classification of epithelia.
Apical surface Basal surface Simple Apical surface Basal surface Stratified Classification based on number of cell layers. © 2013 Pearson Education, Inc.

Cells of Epithelial Tissues
Flattened and scalelike Nucleus flattened Boxlike Nucleus round Columnar cells Tall; column shaped Nucleus elongated © 2013 Pearson Education, Inc.

Figure 4.2b Classification of epithelia.
Squamous Cuboidal Columnar Classification based on cell shape. © 2013 Pearson Education, Inc.

Classification of Epithelia: Simple Epithelia
Absorption Secretion _________________________ Very thin © 2013 Pearson Education, Inc.

Simple Squamous Epithelium
Cells flattened ____________________ Cytoplasm sparse Function where rapid diffusion is priority i.e., kidney, ________________________ Note description, function, location on next slide © 2013 Pearson Education, Inc.

Figure 4.3a Epithelial tissues.
Simple squamous epithelium Description: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia. Air sacs of lung tissue Nuclei of squamous epithelial cells Function: Allows materials to pass by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae. Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity (serosae). Photomicrograph: Simple squamous epithelium forming part of the alveolar (air sac) walls (140x). © 2013 Pearson Education, Inc.

Simple Squamous Epithelium
Two other locations _______________________________ The lining of lymphatic vessels, blood vessels, and heart The epithelium of serous membranes in the ventral body cavity © 2013 Pearson Education, Inc.

Simple Cuboidal Epithelia
_____________________layer of cells Secretion Absorption Forms walls of smallest ducts of glands and many ___________________tubules Note description, function, location on next slide © 2013 Pearson Education, Inc.

Figure 4.3b Epithelial tissues.
Simple cuboidal epithelium Description: Single layer of cubelike cells with large, spherical central nuclei. Simple cuboidal epithelial cells Nucleus Function: Secretion and absorption. Basement membrane Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface. Connective tissue Photomicrograph: Simple cuboidal epithelium in kidney tubules (430x). © 2013 Pearson Education, Inc.

Simple Columnar Epithelium
Single layer of tall, closely packed cells _______________________ Secretion Note description, function, location on next slide © 2013 Pearson Education, Inc.

Figure 4.3c Epithelial tissues.
Simple columnar epithelium Description: Single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain mucus-secreting unicellular glands (goblet cells). Microvilli Simple columnar epithelial cell Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action. Mucus of goblet cell Location: Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus. Basement membrane Photomicrograph: Simple columnar epithelium of the small intestine mucosa (660x). © 2013 Pearson Education, Inc.

Pseudostratified Columnar Epitheliem
Cells vary in height Cell nuclei at different levels Appears stratified, but is _______________ Secretion Absorption Note description, function, location on next slide © 2013 Pearson Education, Inc.

Figure 4.3d Epithelial tissues.
Pseudostratified columnar epithelium Description: Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia. Cilia Pseudo-stratified epithelial layer Function: Secrete substances, particularly mucus; propulsion of mucus by ciliary action. Location: Nonciliated type in male’s sperm-carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of the upper respiratory tract. Basement membrane Photomicrograph: Pseudostratified ciliated columnar epithelium lining the human trachea (800x). Trachea © 2013 Pearson Education, Inc.

Stratified Epithelial Tissues
__________________________cell layers Regenerate from ___________________ Basal cells divide, cells migrate to surface More durable than simple epithelia Protection is major role © 2013 Pearson Education, Inc.

Stratified Squamous Epithelium
_______________widespread of stratified epithelia Free surface squamous; deeper layers cuboidal or columnar Located for wear and tear Those farthest from basal layer (and therefore nutrients) less ______________ Note description, function, location on next slide © 2013 Pearson Education, Inc.

Figure 4.3e Epithelial tissues.
Stratified squamous epithelium Description: Thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers. Stratified squamous epithelium Function: Protects underlying tissues in areas subjected to abrasion. Nuclei Location: Nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin, a dry membrane. Basement membrane Connective tissue Photomicrograph: Stratified squamous epithelium lining the esophagus (285x). © 2013 Pearson Education, Inc.

Stratified Cuboidal Epithelium
Quite ___________________ Found in some sweat and mammary glands Typically two cell layers thick © 2013 Pearson Education, Inc.

Stratified Columnar Epithelium
Limited distribution in body Small amounts in pharynx, male urethra, and lining some glandular ducts Also occurs at transition areas between two other types of epithelia Only ________________layer columnar © 2013 Pearson Education, Inc.

Transitional Epithelium
Forms lining of hollow urinary organs Basal layer cells are cuboidal or columnar Ability to change _________________with stretch Apical cells vary in __________________ Note description, function, location on next slide © 2013 Pearson Education, Inc.

Figure 4.3f Epithelial tissues.
Transitional epithelium Description: Resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamouslike, depending on degree of organ stretch. Transitional epithelium Function: Stretches readily, permits stored urine to distend urinary organ. Basement membrane Location: Lines the ureters, bladder, and part of the urethra. Connective tissue Photomicrograph: Transitional epithelium lining the bladder, relaxed state (360x); note the bulbous, or rounded, appearance of the cells at the surface; these cells flatten and elongate when the bladder fills with urine. © 2013 Pearson Education, Inc.

Glandular Epithelia Gland Classified by
One or more cells that makes and secretes an aqueous fluid called a __________________ Classified by Site of product release—endocrine or __________________________ Relative number of cells forming the gland unicellular (e.g., goblet cells) or multicellular © 2013 Pearson Education, Inc.

__________________________glands
Endocrine Glands __________________________glands Secretions not released into a duct Secrete (by exocytosis) hormones that travel through lymph or blood to their specific target organs Target organs respond in some characteristic way © 2013 Pearson Education, Inc.

Secretions released onto body surfaces (skin) or into body cavities
Exocrine Glands Secretions released onto body surfaces (skin) or into body cavities More numerous than endocrine glands Secrete products into ________________ Examples include mucous, sweat, oil, and salivary glands © 2013 Pearson Education, Inc.

Unicellular Exocrine Glands
The only important unicellular glands are mucous cells and ________________cells Found in epithelial linings of intestinal and respiratory tracts All produce mucin Dissolves in water to form mucus Slimy protective, lubricating coating © 2013 Pearson Education, Inc.

Figure 4.4 Goblet cell (unicellular exocrine gland).
Microvilli Secretory vesicles containing mucin Golgi apparatus Rough ER Nucleus © 2013 Pearson Education, Inc.

Multicellular Exocrine Glands
Multicellular exocrine glands are composed of a duct and a secretory unit Usually surrounded by supportive connective tissue Supplies blood and nerve fibers Extends into and divides gland into lobes © 2013 Pearson Education, Inc.

Classification of Multicellular Glands
By structure and type of secretion Structure Simple glands (unbranced duct) or compound glands (branched duct) Cells tubular, alveolar, or tubuloalveolal Type of secretion ____________________________– most – secrete products by exocytosis as produced ____________________________– accumulate products within then rupture Apocrine – accumulates products within but only apex ruptures – controversy if exist in humans © 2013 Pearson Education, Inc.

Figure 4.5 Types of multicellular exocrine glands.
Simple duct structure (duct does not branch) Compound duct structure (duct branches) Tubular secretory structure Simple tubular Example Intestinal glands Simple branched tubular Example Stomach (gastric) glands Compound tubular Example Duodenal glands of small intestine Alveolar secretory structure Simple alveolar Example No important example in humans Simple branched alveolar Example Sebaceous (oil) glands Compound alveolar Example Mammary glands Compound tubuloalveolar Example Salivary glands Surface epithelium Duct Secretory epithelium © 2013 Pearson Education, Inc.

Figure 4.6 Chief modes of secretion in human exocrine glands.
Secretory cell fragments Secretory vesicles Merocrine glands secrete their products by exocytosis. In holocrine glands, the entire secretory cell ruptures, releasing secretions and dead cell fragments. © 2013 Pearson Education, Inc.

Most abundant and widely distributed of primary tissues
Connective Tissue Most abundant and widely distributed of primary tissues Four main classes Connective tissue proper _______________________ Bone © 2013 Pearson Education, Inc.

Table 4.1 Comparison of Classes of Connective Tissues (1 of 2)
© 2013 Pearson Education, Inc.

Table 4.1 Comparison of Classes of Connective Tissues (2 of 2)
© 2013 Pearson Education, Inc.

Major Functions of Connective Tissue
Binding and support Protecting _____________________ Storing reserve fuel Transporting substances (blood) © 2013 Pearson Education, Inc.

Characteristics of Connective Tissue
Three characteristics make connective tissues different from other primary tissues Have mesenchyme (an embryonic tissue) as their common tissue of origin Have varying degrees of vascularity (blood vessels) Have extracellular ____________________ Connective tissue not composed mainly of cells Largely nonliving extracellular matrix separates cells So can bear weight, withstand tension, endure abuse © 2013 Pearson Education, Inc.

Structural Elements of Connective Tissue
Three elements Ground substance _________________ Cells Composition and arrangement varies in different connective tissues © 2013 Pearson Education, Inc.

Ground Substance Unstructured material that fills space between cells
Medium through which solutes diffuse between blood capillaries and _____________________ Components ___________________________fluid Cell adhesion proteins ("glue" for attachment) Proteoglycans Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid) Trap water in varying amounts, affecting viscosity of ground substance © 2013 Pearson Education, Inc.

Connective Tissue Fibers
Three types of fibers provide support ______________________ Strongest and most abundant type Tough; provides high tensile strength _________________fibers Networks of long, thin, elastin fibers that allow for stretch and recoil Reticular Short, fine, highly branched collagenous fibers (different chemistry and form than collagen fibers) Branch, forming networks that offer more "give" © 2013 Pearson Education, Inc.

Cells "Blast" cells "Cyte" cells
Immature form; mitotically active; secrete ground substance and fibers Fibroblasts in connective tissue proper __________________________________in cartilage Osteoblasts in bone Hematopoietic stem cells in bone marrow "Cyte" cells Mature form; maintain matrix Osteocytes in bone © 2013 Pearson Education, Inc.

Other Cell Types in Connective Tissues
__________________________cells Store nutrients White blood cells Neutrophils, eosinophils, lymphocytes Tissue response to injury Mast cells Initiate local inflammatory response against foreign microorganisms they detect __________________________ Phagocytic cells that "eat" dead cells, microorganisms; function in immune system © 2013 Pearson Education, Inc.

Cell types Extracellular matrix Ground substance Macrophage Fibers
Figure 4.7 Areolar connective tissue: A prototype (model) connective tissue. Cell types Extracellular matrix Ground substance Macrophage Fibers • Collagen fiber • Elastic fiber • Reticular fiber Fibroblast Lymphocyte Fat cell Mast cell Neutrophil Capillary © 2013 Pearson Education, Inc.

Types of Connective Tissues: Connective Tissue Proper
All connective tissues except bone, cartilage and blood Two subclasses Loose connective tissues __________________________ Adipose Reticular Dense connective tissues (also called fibrous connective tissues) Dense regular Dense irregular © 2013 Pearson Education, Inc.

Areolar Connective Tissue
Support and bind other tissues Universal packing material between other tissues Most widely distributed Provide reservoir of water and salts Defend against _______________________ Store nutrients as ______________________ Fibroblasts Loose arrangement of fibers Ground substance When inflamed soaks up fluid  edema © 2013 Pearson Education, Inc.

Figure 4.8a Connective tissues.
Connective tissue proper: loose connective tissue, areolar Description: Gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells. Function: Wraps and cushions organs; its macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fluid. Elastic fibers Ground substance Location: Widely distributed under epithelia of body, e.g., forms lamina propria of mucous membranes; packages organs; surrounds capillaries. Fibroblast nuclei Collagen fibers Epithelium Photomicrograph: Areolar connective tissue, a soft packaging tissue of the body (340x). Lamina propria © 2013 Pearson Education, Inc.

Adipose Tissue White fat Brown fat
Similar to areolar but greater nutrient storage Cell is __________________________ Stores nutrients Scanty matrix Richly vascularized Shock absorption, insulation, energy storage Brown fat Use lipid fuels to heat bloodstream not to produce ATP © 2013 Pearson Education, Inc.

Figure 4.8b Connective tissues.
Connective tissue proper: loose connective tissue, adipose Description: Matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet. Function: Provides reserve food fuel; insulates against heat loss; supports and protects organs. Nucleus of adipose (fat) cell Location: Under skin in subcutaneous tissue; around kidneys and eyeballs; within abdomen; in breasts. Fat droplet Adipose tissue Photomicrograph: Adipose tissue from the subcutaneous layer under the skin (350x). Mammary glands © 2013 Pearson Education, Inc.

Reticular Connective Tissue
Resembles areolar but fibers are reticular fibers Fibroblasts called ______________________cells Supports free blood cells in lymph nodes, the spleen, and bone marrow © 2013 Pearson Education, Inc.

Figure 4.8c Connective tissues.
Connective tissue proper: loose connective tissue, reticular Description: Network of reticular fibers in a typical loose ground substance; reticular cells lie on the network. Function: Fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages. White blood cell (lymphocyte) Location: Lymphoid organs (lymph nodes, bone marrow, and spleen). Reticular fibers Spleen Photomicrograph: Dark-staining network of reticular connective tissue fibers forming the internal skeleton of the spleen (350x). © 2013 Pearson Education, Inc.

Dense Regular Connective Tissue
Closely packed bundles of collagen fibers running parallel to direction of pull White structures with great resistance to pulling Fibers slightly wavy so stretch a little Fibroblasts manufacture fibers and ground substance _________________cells Poorly vascularized © 2013 Pearson Education, Inc.

Figure 4.8d Connective tissues.
Connective tissue proper: dense connective tissue, dense regular Description: Primarily parallel collagen fibers; a few elastic fibers; major cell type is the fibroblast. Function: Attaches muscles to bones or to muscles; attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction. Collagen fibers Location: Tendons, most ligaments, aponeuroses. Nuclei of fibroblasts Shoulder joint Ligament Photomicrograph: Dense regular connective tissue from a tendon (430x). Tendon © 2013 Pearson Education, Inc.

Dense Irregular Connective Tissue
Same elements but bundles of collagen thicker and irregularly arranged Resists tension from many ____________ Dermis Fibrous joint capsules Fibrous coverings of some organs © 2013 Pearson Education, Inc.

Figure 4.8e Connective tissues.
Connective tissue proper: dense connective tissue, dense irregular Description: Primarily irregularly arranged collagen fibers; some elastic fibers; fibroblast is the major cell type. Nuclei of fibroblasts Function: Withstands tension exerted in many directions; provides structural strength. Location: Fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract. Collagen fibers Shoulder joint Fibrous joint capsule Photomicrograph: Dense irregular connective tissue from the fibrous capsule of a joint (430x). © 2013 Pearson Education, Inc.

Elastic Connective Tissue
Some ___________________very elastic Those connecting adjacent vertebrae Many of larger arteries have in walls © 2013 Pearson Education, Inc.

Figure 4.8f Connective tissues.
Connective tissue proper: dense connective tissue, elastic Description: Dense regular connective tissue containing a high proportion of elastic fibers. Function: Allows tissue to recoil after stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration. Location: Walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes. Elastic fibers Aorta Heart Photomicrograph: Elastic connective tissue in the wall of the aorta (250x). © 2013 Pearson Education, Inc.

Cartilage Chondroblasts and _______________________ Tough yet flexible
Lacks __________________________fibers Up to 80% water - can rebound after compression _______________________________ Receives nutrients from membrane surrounding it Perichondrium Three types of cartilage: Hyaline cartilage Elastic cartilage Fibrocartilage © 2013 Pearson Education, Inc.

Figure 4.8g Connective tissues.
Cartilage: hyaline Description: Amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae. Function: Supports and reinforces; serves as resilient cushion; resists compressive stress. Chondrocyte in lacuna Location: Forms most of the embryonic skeleton; covers the ends of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx. Matrix Costal cartilages Photomicrograph: Hyaline cartilage from a costal cartilage of a rib (470x). © 2013 Pearson Education, Inc.

Figure 4.8h Connective tissues.
Cartilage: elastic Description: Similar to hyaline cartilage, but more elastic fibers in matrix. Function: Maintains the shape of a structure while allowing great flexibility. Chondrocyte in lacuna Matrix Location: Supports the external ear (pinna); epiglottis. Photomicrograph: Elastic cartilage from the human ear pinna; forms the flexible skeleton of the ear (800x). © 2013 Pearson Education, Inc.

Figure 4.8i Connective tissues.
Cartilage: fibrocartilage Description: Matrix similar to but less firm than that in hyaline cartilage; thick collagen fibers predominate. Function: Tensile strength allows it to absorb compressive shock. Location: Intervertebral discs; pubic symphysis; discs of knee joint. Chondrocytes in lacunae Intervertebral discs Collagen fiber Photomicrograph: Fibrocartilage of an intervertebral disc (125x). Special staining produced the blue color seen. © 2013 Pearson Education, Inc.

Bone Also called ________________________tissue
Supports and protects body structures Stores fat and synthesizes blood cells in cavities More collagen than cartilage Has inorganic calcium salts Osteoblasts produce matrix Osteocytes maintain the matrix _________________________– structural units Richly vascularized © 2013 Pearson Education, Inc.

Figure 4.8j Connective tissues.
Others: bone (osseous tissue) Description: Hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae. Very well vascularized. Function: Supports and protects (by enclosing); provides levers for the muscles to act on; stores calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoiesis). Central canal Lacunae Lamella Location: Bones Photomicrograph: Cross-sectional view of bone (125x). © 2013 Pearson Education, Inc.

Most atypical connective tissue – is a fluid
Blood Most atypical connective tissue – is a fluid _____________________blood cells most common cell type Also contains white blood cells and platelets Fibers are soluble proteins that precipitate during blood clotting Functions in _______________________ © 2013 Pearson Education, Inc.

Figure 4.8k Connective tissues.
Connective tissue: blood Description: Red and white blood cells in a fluid matrix (plasma). Red blood cells (erythrocytes) Function: Transport respiratory gases, nutrients, wastes, and other substances. White blood cells: • Lymphocyte • Neutrophil Location: Contained within blood vessels. Plasma Photomicrograph: Smear of human blood (1670x); shows two white blood cells surrounded by red blood cells. © 2013 Pearson Education, Inc.

Muscle Tissue Highly vascularized
Responsible for most types of movement Three types Skeletal muscle tissue Found in skeletal muscle __________________________ Cardiac muscle tissue Found in walls of heart Smooth muscle tissue Mainly in walls of hollow organs other than heart © 2013 Pearson Education, Inc.

Figure 4.9a Muscle tissues.
Skeletal muscle Description: Long, cylindrical, multinucleate cells; obvious striations. Part of muscle fiber (cell) Function: Voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control. Nuclei Location: In skeletal muscles attached to bones or occasionally to skin. Striations Photomicrograph: Skeletal muscle (approx. 440x). Notice the obvious banding pattern and the fact that these large cells are multinucleate. © 2013 Pearson Education, Inc.

Figure 4.9b Muscle tissues.
Cardiac muscle Description: Branching, striated, generally uninucleate cells that interdigitate at specialized junctions (intercalated discs). Intercalated discs Function: As it contracts, it propels blood into the circulation; involuntary control. Striations Location: The walls of the heart. Nucleus Photomicrograph: Cardiac muscle (900x); notice the striations, branching of cells, and the intercalated discs. © 2013 Pearson Education, Inc.

Figure 4.9c Muscle tissues.
Smooth muscle Description: Spindle-shaped cells with central nuclei; no striations; cells arranged closely to form sheets. Function: Propels substances or objects (foodstuffs, urine, a baby) along internal passageways; involuntary control. Nuclei Location: Mostly in the walls of hollow organs. Smooth muscle cell Photomicrograph: Sheet of smooth muscle (720x). © 2013 Pearson Education, Inc.

Nervous Tissue Main component of nervous system
Brain, spinal cord, nerves Regulates and controls body functions _____________________________ Specialized nerve cells that generate and conduct nerve impulses Supporting cells that support, insulate, and protect neurons © 2013 Pearson Education, Inc.

Figure 4.10 Nervous tissues.
Description: Neurons are branching cells; cell processes that may be quite long extend from the nucleus-containing cell body; also contributing to nervous tissue are nonexcitable supporting cells. Nuclei of supporting cells Neuron processes Cell body Axon Dendrites Cell body of a neuron Function: Neurons transmit electrical signals from sensory receptors and to effectors (muscles and glands) which control their activity; supporting cells support and protect neurons. Neuron processes Location: Brain, spinal cord, and nerves. Photomicrograph: Neurons (350x). © 2013 Pearson Education, Inc.

Covering and Lining Membranes
Composed of at least two primary tissue types An epithelium bound to underlying connective tissue proper Are simple organs Three types __________________________membranes Mucous membranes © 2013 Pearson Education, Inc.

Cutaneous Membranes Skin
Keratinized stratified squamous epithelium (__________________________) attached to a thick layer of connective tissue (___________________________) Dry membrane © 2013 Pearson Education, Inc.

Figure 4.11a Classes of membranes.
Cutaneous membrane The cutaneous membrane (the skin) covers the body surface. Cutaneous membrane (skin) © 2013 Pearson Education, Inc.

Mucous Membranes Mucosa indicates location not cell composition
All called ____________________________ Line body cavities open to the exterior (e.g., Digestive, respiratory, urogenital tracts) Moist membranes bathed by secretions (or urine) Epithelial sheet lies over layer of connective tissue called ______________________propria May secrete mucus © 2013 Pearson Education, Inc.

Figure 4.11b Classes of membranes.
Mucous membranes Mucous membranes line body cavities that are open to the exterior. Mucosa of nasal cavity Mucosa of mouth Esophagus lining Mucosa of lung bronchi © 2013 Pearson Education, Inc.

Serous Membranes Serosae—found in closed ventral body cavity
Simple squamous epithelium (mesothelium) resting on thin areolar connective tissue Parietal serosae line internal body cavity walls Visceral serosae cover internal organs ______________________fluid between layers Moist membranes Pleurae, pericardium, peritoneum © 2013 Pearson Education, Inc.

Figure 4.11c Classes of membranes.
Serous membranes Serous membranes line body cavities that are closed to the exterior. Parietal pleura Visceral pleura Parietal peritoneum Parietal pericardium Visceral pericardium Visceral peritoneum © 2013 Pearson Education, Inc.

Necessary when barriers are penetrated Cells must divide and migrate
Tissue Repair Necessary when barriers are penetrated Cells must divide and migrate Occurs in two major ways _______________________________ Same kind of tissue replaces destroyed tissue Original function restored Connective tissue replaces destroyed tissue Original function lost © 2013 Pearson Education, Inc.

Steps in Tissue Repair: Step 1
_________________________sets stage Release of inflammatory chemicals Dilation of blood vessels Increase in vessel permeability Clotting occurs © 2013 Pearson Education, Inc.

Scab Epidermis Vein Blood clot in incised wound Inflammatory chemicals
Figure Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Slide 1 Scab Epidermis Vein Blood clot in incised wound Inflammatory chemicals Migrating white blood cell Artery 1 Inflammation sets the stage: • Severed blood vessels bleed. • Inflammatory chemicals are released. • Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins, and other plasma proteins to seep into the injured area. • Clotting occurs; surface dries and forms a scab. © 2013 Pearson Education, Inc.

Organization restores blood supply The blood clot is replaced with granulation tissue Epithelium begins to ____________________ Fibroblasts produce collagen fibers to bridge the gap Debris is phagocytized © 2013 Pearson Education, Inc.

Organization restores the blood supply:
Figure Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Slide 2 Regenerating epithelium Area of granulation tissue ingrowth Macrophage Budding capillary Fibroblast Organization restores the blood supply: • The clot is replaced by granulation tissue, which restores the vascular supply. • Fibroblasts produce collagen fibers that bridge the gap. • Macrophages phagocytize dead and dying cells and other debris. • Surface epithelial cells multiply and migrate over the granulation tissue. 2 © 2013 Pearson Education, Inc.

Regeneration and fibrosis The _______________________detaches Fibrous tissue matures; epithelium thickens and begins to resemble adjacent tissue Results in a fully regenerated epithelium with underlying scar tissue © 2013 Pearson Education, Inc.

Regeneration and fibrosis effect permanent repair:
Figure Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Slide 3 Regenerated epithelium Fibrosed area 3 Regeneration and fibrosis effect permanent repair: • The fibrosed area matures and contracts; the epithelium thickens. • A fully regenerated epithelium with an underlying area of scar tissue results. © 2013 Pearson Education, Inc.

Regenerative Capacity in Different Tissues
Regenerate extremely well _________________________tissues, bone, areolar connective tissue, dense irregular connective tissue, blood-forming tissue Moderate regenerating capacity Smooth muscle and dense regular connective tissue Virtually no functional regenerative capacity Cardiac muscle and nervous tissue of brain and _____________________________cord New research shows cell division does occur Efforts underway to coax them to regenerate better © 2013 Pearson Education, Inc.

Developmental Aspects
Primary germ layers Superficial to deep: ___________________, mesoderm, and ____________________ Formed early in embryonic development Specialize to form the four primary tissues _________________tissue arises from ectoderm Muscle and connective tissues arise from mesoderm ___________________________tissues arise from all three germ layers © 2013 Pearson Education, Inc.

16-day-old embryo (dorsal surface view) Muscle and connec-
Figure Embryonic germ layers and the primary tissue types they produce. 16-day-old embryo (dorsal surface view) Epithelium (from all three germ layers) Ectoderm Mesoderm Endoderm Inner lining of digestive system (from endoderm) Nervous tissue (from ectoderm) Muscle and connective tissue (mostly from mesoderm) © 2013 Pearson Education, Inc.

Aging Tissues Normally function well through youth and middle age if adequate diet, circulation, and infrequent wounds and infections Epithelia thin with increasing age so more easily breached Tissue repair less efficient Bone, muscle and nervous tissues begin to __________________________ DNA mutations possible  increased cancer risk © 2013 Pearson Education, Inc.

4 Tissue: The Living Fabric.

Similar presentations

Presentation on theme: "4 Tissue: The Living Fabric."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

4 Tissue: The Living Fabric.

Similar presentations

Presentation on theme: "4 Tissue: The Living Fabric."— Presentation transcript:

Similar presentations

About project

Feedback