Bell work 102711 Please answer the bell work

Bell work 10/27/11 Please answer the bell work question of the day! Thank you! 1. What are three most abundant connections between cells in the superficial layers of the skin? 2. How are epithelial tissues classified? Describe each classification.

Essentials of Anatomy & Physiology, 4 th Edition Martini / Bartholomew 4 The Tissue Level of Organization Power. Point® Lecture Outlines prepared by Alan Magid, Duke University Slides 1 to 64 Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Overview of Tissue Science An Orientation to the Tissues of the Body Figure 4 -1

Overview of Tissue Science Histology- the study of tissues Four Basic Tissue Types: • • Epithelial Connective Muscular Neural Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Overview of Tissue Science Key Note Tissues are collections of cells and extracellular material that perform a specific but limited range of functions. The four tissue types, in varying combinations, form all of the structures of the human body. Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Epithelia ( sing. Epithelium) An avascular layer of cells that forms a barrier that covers internal or external surfaces Glands Secretory structures derived from epithelia Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Characteristics of Epithelia • Cells closely packed • Apical cells exposed to external or internal surface • Cells attached to basement membrane • Lack blood vessels ( avascular condition) • Cells continually replaced Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Functions of Epithelia • Physical protection- ex: skin; abrasion, dehydration and destruction • Permeability control- impermeable & permeable to large proteins • Sensation trigger-detect changes in the environment and relays information • Produce specialized secretions- ex: sweat and milk Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Gland cells- are epithelial cells that produce secretions, which are typically scattered among other cell types. v v In glandular epithelium, most of the cells actively produces secretions

Epithelial Tissue Two Classes of Glandular Secretion: • Exocrine secretion—Secretion onto a body surface. Examples: enzymes entering the digestive tract, perspiration of the skin, milk produced by mammary glands • Endocrine secretion—Secretion (of hormones) into neighboring tissues and blood and produced in organs such as pancreas, thyroid and pituitary glands Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Intercellular Connections Figure 4 -2

Epithelial Tissue Importance of Intercellular Connections of epithelial tissues Ø to be effective barrier to other tissue vwhen connections are broken or damaged , it will no longer become effective q examples are damaged by burning or an abrasion where a bacteria may enter

Epithelial Tissue Cell Adhesion Molecules ( CAM) specialized transmembrane proteins that held together the epithelial cell membrane to form effective barriers Intercellular Cement- a thin layer composed of a protein – polysaccharide mixture CAM’s bind together cytoskeletal filaments to each other and to extracellular materials and form specialized attachment sites known as cell junctions or intercellular junctions. Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

3 types of Cell junctions: Tight junctions Gap junctions Desmosomes v. Tight Junctions Ø the lipid layers of adjacent cell membranes are bound together by interlocking membrane proteins ØIt prevents the passage of water and solutes between cells ØIt is common between epithelial cells expose to harsh chemicals or powerful enzymes like in the digestive tracts

Epithelial Tissue v Gap Junctions Ø two cells are held together by embedded proteins ( channel proteins) , which forms a narrow openings that lets small molecules and ions to pass from cell to cell Ø most abundant in cardiac muscle and smooth muscle tissue and are essential to the coordination of muscle contractions v Desmosomes Øthe cell membrane of the two cells are locked together by intercellular cement and by membrane proteins, they form two disc called button desmosomes Øabundant between cells in the superficial layer of the skin

Epithelial Tissue The Epithelial Surface Apical surface of the epithelia has: § Microvilli • Abundant on transport cells • Dramatically increase surface area • Found in intestinal lining, kidney tubule Ciliated Epithelium has: § Cilia • Beat in coordinated fashion • Move fluid along surface • Found in airways, oviduct Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue The Surfaces of Epithelial Cells Figure 4 -3

Epithelial Tissue The Basement Membrane ü firmly connect the epithelial cells to the rest of the body ü lies between the epithelium and the underlying connective tissues üResists passage of large molecules üStrengthens against distortion Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Epithelial Renewal and Repair § An epithelium must repair and renew itself § Epithelium cells survived only for a day or two because they are lost or destroyed by exposure § Stem cells or germinative cells are unspecialized cells that continues cell division , found in the basement membrane Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Classifying Epithelia Number of layers • Simple (one cell thick) • Stratified (multiple cells thick) Cell shape • Squamous (flat) • Cuboidal (cubic) • Columnar (tall columns) Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Epithelial Tissue Table 4 -1

Epithelial Tissue Simple Epithelium • single layer of cells • Thin, fragile, limited mechanical protection • Found in areas that are protected like the lining internal compartments, passageways including body cavities, the heart chambers and blood vessels

Epithelial Tissue Stratified Epithelium • provides greater degree of protection • several layers of cells above the basement membrane • Found in areas subject to mechanical stress or chemical stress like the surface areas of the skin and the linings of the mouth and anus

Epithelial Tissue Simple Squamous Epithelium Figure 4 -4(a)

Epithelial Tissue Simple Squamous Epithelia • found in protected regions where absorption takes place or where slippery surface reduces friction • examples: portion of the kidney, surface of the lungs lining of the ventral body cavities lining of the blood vessels inner surfaces of the heart.

Epithelial Tissue Simple Cuboidal Epithelium Figure 4 -4(b)

Epithelial Tissue Simple Cuboidal Epithelia • provides limited protection and occurs where secretion and absorption takes place • secretes enzymes and buffers in the pancreas and salivary glands • Lined the portion of the kidney tubules involved in the production of urine

Epithelial Tissue Simple Columnar Epithelium Figure 4 -4(c)

Epithelial Tissue Simple Columnar Epithelia • provides some protection and may also occur in areas of absorption or secretion • lines the stomach, intestinal tract and many excretory ducts

Epithelial Tissue Pseudostratified Ciliated Columnar Figure 4 -5(a)

Epithelial Tissue Pseudostratified Columnar Epithelia • it looks stratified but it’s not • found in portion of the respiratory tract, which includes a mixture of cell types • possess cilia • line most of the nasal cavity, the trachea ( windpipe) and bronchi, and portion of the male reproductive tract

Epithelial Tissue Transitional Epithelium Figure 4 -5(b)

Epithelial Tissue Transitional Epithelia withstands considerable stretching • it lines the uterus and urinary bladder, where large changes in volume occur •

Epithelial Tissue Stratified Squamous Epithelium Figure 4 -5(c)

Epithelial Tissue Stratified Squamous Epithelia is found where mechanical stress occurs like the surface of the skin lining of the mouth and tongue , esophagus and anus •

Epithelial Tissue Glandular Epithelia – contains cells that produce secretion both exocrine and endocrine

Epithelial Tissue Classification of exocrine secretions according to mode of secretions: § Merocrine- product is released from secretory vesicles by exocytosis example of secretion is the mucin , which forms mucus when mixed with water, an effective lubricant, protective barrier and a sticky trap foreign particles and microorganisms Copyright ©

Epithelial Tissue involves the loss of both cytoplasm and the secretory product and example is milk production in the mammary glands § Apocrine Secretions- § Holocrine Secretions- does not leave the cell intact , it is packed with secretions and then bursts apart and die sebaceous glands, associated with hair follicles , provide oily hair coating by means of holocrine secretions

Epithelial Tissue Types of Secretions: 1. Serous- secrete a watery solution containing enzymes 2. Mucous – secretes mucins that form a thick slippery mucus 3. Mixed- contain more than one type of gland cell and may produce two different exocrine secretions , one serous and other mucus

Epithelial Tissue Mechanisms of Glandular Secretion PLAY Glandular Secretions Figure 4 -6

Bell work 10/31/11 1. Describe a pseudo stratified ciliated columnar epithelium. What makes it different from other epithelial tissues?

Connective Tissues vmost diverse tissues of the body v bone, blood, fat – familiar connective tissues, with different functions and properties v distributed throughout the body but never exposed v highly vascular vcontain receptors ( pain, pressure, temperature)

Connective Tissues Components • Specialized cells Matrix surrounds the • Protein fibers cell, accounts for the volume of connective • Fluid phase tissue Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissues Functions • Support and protection ü structural framework üTissue interconnection üPhysical protection for organs • Transport of materials üfluid and solute transport • Storage of energy reserves ü fat stored called adipose cells • Defense of the body ü by microorganisms and antibodies Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissues Major Category of Connective Tissues 1. Embryonic Connective Tissue Type: Mesenchyme 2. Connective Tissue Proper Types: Areolar connective tissue Adipose tissue Reticular connective tissue Dense regular connective tissue Dense irregular connective tissue Elastic tissue 3. Solid Connective Tissue ( Supporting Tissue) Types: Cartilage, Bone 4. Fluid Connective Tissue Type: Blood

Connective Tissues Major Types of Connective Tissue Figure 4 -7

Connective Tissue Embryonic connective tissue- the first connective tissue form in the developing embryo and gives rise to all other types of connective tissue TYPE: Mesenchyme- gel like substance with fine protein fibers and immature cells; gives rise to all other connective tissue. It is located in the embryo/fetus

Connective Tissues Connective tissue proper § Contains varied cell populations and fiber types surrounded by a syrupy ground substance Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissues Connective Tissue Proper ØCell are considered resident and migrating cells ØMajor cell types in Connective Tissues: • Fibroblasts • Macrophages • Fat cells • Mast cells • Other white cells Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissue Major Cell type in connective tissues; 1. Fibroblasts Ø most abundant Ø permanent resident Ø producing and maintaining connective tissue fibers and ground substance 2. Macrophages Ø big eater cells Ø engulf or phagocytize damaged cells or pathogens Ø release chemicals that mobilize immune system Ø tissue defense Ø fixed and free macrophages

Connective Tissue 3. Fat Cells ( adipose cells or adipocytes ) ü permanent resident ü contains large droplets of lipids ü numbers vary from one region to another and among individuals 4. Mast Cells ü small ü mobile connective tissue cells , found near the blood vessels ü defense against injury and infections

Connective Tissues Fibers in Connective Tissue Proper ØFormed protein fibers • Collagen fibers- long straight, unbranched , strong but flexible, most common üProvides toughness • Reticular fibers- contain protein elastin, branched , wavy üSupports cells • Elastic fibers ( network)- least common, thin branched üProvides resilience Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissues Cells and Fibers of Connective Tissue Proper Figure 4 -8

Connective tissue proper: 1. Areolar connective tissue- gel like substance with collagen and elastic fibers; cell types include fibroblasts , macrophages, mast cells and white blood cells; separates the skin from underlying muscle provides padding and movement Location: Between cells and underlying muscles; between muscles; directly beneath most epithelial layers; between adjacent organs

Connective Tissue 2. Adipose tissue or fat-specialized cells for fat storage; a loose connective tissue, contains large numbers of fat cells or adipocytes, it is a loose connective dominated by fat cells, provides padding, shock absorptions, insulation that slows down heat loss energy storage. Location/s: deep skin layers; walls of organs; spaces between joints; bone cavities

Connective Tissue 3. Reticular Connective Tissue- gel like substance ; has network of reticular fibers with intervening reticular cells. It is located in the walls of lymphatic organs.

Connective Tissue Dense regular connective tissue- fibroblasts arranged in parallel rows between densely packed bundles of collagen fibers. 2 Types are : TENDONS- attached skeletal muscles to bones LIGAMENTS – attached bone to another

Two types of dense connective tissues: Ø Tendons cords of dense regular connective tissue that connects skeletal muscles to the bones. Ø Ligaments resembles tendons but it connects bone to one another often contains elastic fibers as well as collagen fibers and therefore can tolerate a modest amount of stretching

Connective Tissue Dense Irregular Connective Tissue- irregularly arranged collagen and elastic fibers with intervening fibroblasts; interwoven meshwork of collagen. It gives skin its strength and supports from stress. It is located in the dermis of the skin; capsules around the organs; covering around the brain; spinal cord and nerves

Connective Tissue Elastic Tissue- parallel bundles of elastic fibers with fibroblasts interspersed between them. It is mostly located in the ligaments between vertebrae

Connective Tissue Solid Connective Tissue ( Support Connective Tissue)generally supports the body Types: 1. Cartilage- chondrocytes cells within cavities called lacunae; lacunae separated by a solid matrix with varying amounts of collagen and elastic fibers; three types of cartilage: hyaline cartilage, elastic cartilage, fibrocartilage Cartilage are avascular. Mostly covered by fibrous perichondrium

Types of Cartilage Hyaline Cartilage Ø glassy Ø most common type of cartilage Ø collagen fibers are closely packed , making it tough but flexible ØConnects the ribs to the sternum ( breastbone) Ø supports the conducting passageways of the respiratory tracts Ø covers the opposing bone surface within the joints

Connective Tissue Elastic Cartilage Ø contains numerous elastic fibers that makes it extremely resilient and flexible Ø forms external flap of the outer ear ( auricle or pinna) Ø epiglottis Ø airway to the middle ear ( auditory tube)

Connective Tissue Fibrocartilage Ø has a little ground substance and the matrix is dominated by collagen fibers Ø interwoven, making it extremely durable and tough Ø lies between spinal column Ø pubic bones of the pelvis Ø surrounds few joint and tendons Ø resists compression , absorbs shock, prevent damaging bone to bone contact

Connective Tissues Bone (Osseous Tissue)- osteocytes within lacunae; lacunae separated by solid matrix containing collagen fibers and calcium salts • Matrix provides unique properties • Collagen fibers resist bending • Calcium salts resist compression • Diffusion through canaliculi nourishes osteocytes ( bone cells), found in lacunae • Covered by periosteum • Highly vascular Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissues Fluid Connective Tissues Ø Cells + a liquid ground substance ( interstitial fluid) 1. Blood- compose ü RBCs- account for half the volume of the blood, transport oxygen ü WBCs- small amount but importance for immune system ü Platelets- cell fragments , function for blood clotting ü Plasma (watery matrix) Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Connective Tissue 2. Lymph ü interstitial fluid which surrounds the body cells ü enters small passage ways or lymphatic vessels ü Lymphocytes + lymph fluid

Connective Tissues Loose Connective Tissue Figure 4 -9(a)

Connective Tissues Adipose Tissue Figure 4 -9(b)

Connective Tissues Dense Connective Tissues Figure 4 -9(c)

Connective Tissues Elastic Cartilage Figure 4 -10(b)

Connective Tissues Bone Figure 4 -11

Connective Tissues Hyaline Cartilage Figure 4 -10(a)

Connective Tissues Fibrocartilage Figure 4 -10(c)

Membranes Figure 4 -12

Membranes Properties of Membranes • Barrier or interface • Cover and protect • An epithelium plus connective tissue Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Membranes Types of Membranes ØMucous membranes or mucosae • Lines cavities that communicate with the exterior • Mucus moistens surface • Examples: oral cavity, airways • contains connective tissue portion called the lamina propria • mucous that are line by simple epithelia perform absorptive and secretory functions Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Membranes 2. Serous Membranes Ø lined the sealed , internal subdivisions of the ventral body cavity

Membranes 3 types of Serous membranes : 1. Pleura ( ribs) – lined the pleural cavities, covers the lungs has two types called visceral and parietal pleura 2. Peritoneum- lines the peritoneal ( abdominal) cavity and covers the surfaces of enclosed organs 3. Pericardium- lines the pericardial cavity and covers the heart

Membranes Types of Membranes (continued) ØCutaneous • Covers body surface • Dry surface waterproofs the body • Example: the skin ØSynovial • Lines joints ( associated with movable joints) • Secretes slippery synovial fluid • Lubricates joints • Examples: knee, elbow Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Muscle Tissue Properties of Muscle Tissue • Capable of contraction w/c involves the cytoskeleton proteins • Actin filaments • Myosin filaments • Three types of muscle tissue • Skeletal muscle • Cardiac muscle • Smooth muscle Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Muscle Tissue Skeletal Muscle Tissue • Contains elongated cells (fibers) very large, long and slender • 100 um ( 1/25, 000 in) diameter and 25 cm ( 10 in) long • Fibers tied together by loose connective tissue • Possesses microscopic striations • Contains many nuclei ( multinucleated) • Controlled by voluntary nervous system ( also called striated voluntary muscle) • Moves and stabilizes the skeleton Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Muscle Tissue Skeletal Muscle Tissue Figure 4 -13(a)

Muscle Tissue Cardiac Muscle Tissue • • • Only in heart Short, branched fibers Single nucleus Striated and Involuntary contraction Also called striated involuntary muscle It has intercalated disc (attachment sites w/c contains gap junctions and desmosomes) • Blood circulation • Blood pressure Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Muscle Tissue Cardiac Muscle Tissue Figure 4 -13(b)

Muscle Tissue Smooth Muscle Tissue • • • Short, tapering cells No striations Involuntary contraction Also called nonstriated involuntary muscle Found mostly in walls of hollow organs • Blood vessels • Urinary bladder • Digestive organs • Uterus Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Muscle Tissue Smooth Muscle Tissue Figure 4 -13(c)

Neural Tissue v also known as nervous tissue or nerve tissues v mostly concentrated in the brain and spinal cord ( 98%) Properties of Neural Tissue • Conduct electrical impulses • Transfer, process, and store information • Comprises neurons and neuroglia Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Neural Tissue Neurons Ø Longest cell in the body ( 39 in long), cannot divide under normal cicumstances Ø Communicate through electrical events that effect the cell membranes • Dendrites • Information entry • Cell body ( soma) • Information integration • Axon (nerve fibers) • Information transmission • Synaptic terminals • Information transfer Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Neural Tissue Neuroglia ( supporting cells) • Several types of neuroglia • Provide physical support • Maintain extracellular chemistry • Supply nutrients • Defend against infection Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Neural Tissue Figure 4 -14

Tissue Injuries and Repair • An injury harms multiple tissues simultaneously ( sequence of events is initiated by our body) • Tissues make coordinated response • Responses restore homeostasis • Two response types to maintain homeostasis ( tissue repair) ØInflammation ØRegeneration ( restoration of damage tissues) Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Tissue Injuries and Repair Inflammation ( Inflammatory response) - body’s natural response that occurs immediately following tissue damage - Main function is to defend the body against harmful substances , dispose of dead or dying tissue and to promote renewal of normal tissue • Isolation of injured area • Cleanup of damaged tissue • Mast cells release chemicals ( histamine and heparin) causes blood vessels to dilate and become more permeable, increase blood Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Four signs of inflammation 1. Pain ( due to chemicals release by damaged cells) 2. Swelling or Edema ( due to influx of fluid into the damaged region) 3. Redness ( widening of blood vessels and bleeding in the joint) 4. Heat ( warmth) due to increase in blood flow) 5. Loss of function ( due to swelling)

Tissue Injuries and Repair Regeneration • Repair/replacement of damaged tissue • Restoration of tissue function • Scar tissue from fibroblast activity • Complete, partial, or no regeneration • Tissue fibrosis common outcome Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Tissues and Aging Tissues Change with Age • • • Healing slows Epithelia become thinner Connective tissues become more fragile Bones weaken, become brittle Neuron and muscle fiber losses accumulate • Lifestyle interventions slow decline Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings

Tissues and Aging and Cancer Incidence • 25% develop cancer • Cancer risk rises with age • After heart disease, cancer second leading cause of death • Smoking linked to 40% of cancers • 75% caused by environment Copyright © 2007 Pearson Education, Inc. , publishing as Benjamin Cummings