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PowerPoint® Lecture Slides prepared by Vince Austin, University of Kentucky Tissue: The Living Fabric Human Anatomy & Physiology, Sixth Edition Elaine N. Marieb Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 4 Tissues Groups of cells similar in structure and function The four types of tissues Epithelial Connective Muscle Nerve Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelial Tissue covers exposed surfaces (including skin), lines internal passageways and chambers (respiratory, reproductive, urinary), and forms glands. Epithelia – layers of cells that cover internal or external surfaces Glands – structures that produce fluid secretions – either attached or derived from epithelia Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelial Tissue Five important characteristics: cellularity – composed almost entirely of cells bound closely together by cell junctions. polarity – there are structural and functional differences between the exposed and attached surfaces. The exposed surface of cells is called apical, and the attached basal. attachment – the base of an epithelium is bound to a thin basal lamina (basement membrane). Avascularity – epithelia lack blood vessels. They must obtain their nutrients by diffusion or absorption from the exposed or attached surface. Regeneration – Very high level of regeneration since these cells are constantly lost or damaged. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Four essential functions of epithelia physical protection from the external environment and from dehydration control permeability of items into and out of the body sensation to stimuli specialized secretion through gland cells to provide protection (ex. Mucus) or act as chemical messengers. Glandular epithelium is when most or all of the epithelial cells produce sections. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia The cell is divided into two functional groups: apical surface – where the cell is exposed to internal or external surface basolateral surface – includes both the base and the sides of the cell Many epithelial cells have microvilli on their exposed surfaces. These are abundant where absorption and secretion take place (digestive and urinary tract). Cilia are also found on some epithelium cells. They line the respiratory tract to move mucus. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Maintaining the integrity of epithelia To be effective as a barrier, an epithelium must form a complete cover or lining. Three factors help maintain the physical integrity: 1. intercellular connections cells are firmly attached to one another and the basal lamina large areas of opposing cell membranes are interconnected by transmembrane proteins called cell adhesion molecules (CAMs) which bind to each other and to extracellular materials. The membrane of adjacent cells may be bonded by intercellular cement. This is a thin layer of proteoglycans that contain hyaluronan (hyaluronic acid) Cell junctions are specialized areas of the cell membrane that attach a cell to another cell or to extracellular materials. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of cell junctions: Tight Junction a. tight junction – lipid portions of the two cell membranes are tightly bound together by interlocking membrane proteins. This attachment is so tight they prevent the passage of water and solute between cells. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Tight Junction Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of cell junctions: Gap Junction a. Gap junction – two cells are held together by interlocking junctional proteins call connexons. These proteins are channel proteins and allow small molecules and ions pass from cell to cell. They allow for rapid intercellular communication. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of cell junctions: Gap Junction Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of cell junctions: Desmosome Desmosome – durable interconnections that allow for stretching, bending, twisting, or compression. Two types: Button desmosomes – function as cross-braces to stabilize the shape of the cell Hemidesmosomes – attaches a cell to extracellular filaments in the basal lamina to help stabilize the position of the cell and anchor it to underlying tissues. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three types of cell junctions: Desmosome Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Factors that maintain physical integrity 2. Attachment to the basal lamina Epithelia hold onto to each other and are first connected to the rest of the body by attaching to the basal lamina. It is made of two parts: Lamina lucida – layer closer to the epithelium. It acts as a barrier that restricts the movement of proteins and other large molecules from the underlying connective tissue into the epithelium. Lamina densa – the deeper layer of the basal lamina. It gives the basement membrane its strength, and acts as a filter to determine what substances can diffuse between adjacent tissues and the epithelium. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Factors that maintain physical integrity 3. Epithelial maintenance and repair The epithelium is replenished by the continual division of stem cells (germinative cells) located near the basal lamina. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Epithelia Epithelia can be sorted into categories based on the cell shape and the number of cell layers between the base and exposed surface of the epithelium Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Epithelia – cell shape Squamous, cuboidal, or columnar Figure 4.1b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Epithelia – cell layers Simple or stratified Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 4.1a Squamous Epithelium -thin, flat, and somewhat irregular in shape -resemble the look of fried eggs -nucleus occupies the thickest portion of each cell Two types: Simple squamous Stratified squamous Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Simple Squamous Single layer of flattened cells with disc-shaped nuclei and sparse cytoplasm Functions Diffusion and filtration Provide a slick, friction-reducing lining in lymphatic and cardiovascular systems Present in the kidney glomeruli, lining of heart, blood vessels, lymphatic vessels, and alveoli Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Simple Squamous Figure 4.2a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Stratified Squamous Thick membrane composed of several layers of cells Function in protection of underlying areas subjected to abrasion Forms the external part of the skin’s epidermis (keratinized cells), and linings of the esophagus, mouth, and vagina (nonkeratinized cells) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Stratified Squamous Thick membrane composed of several layers of cells Function in protection of underlying areas subjected to abrasion Forms the external part of the skin’s epidermis (keratinized cells), and linings of the esophagus, mouth, and vagina (nonkeratinized cells) Figure 4.2e Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cuboidal Epithelium Resemble hexagonal boxes or squares Spherical nuclei are near the center of each cell Distance between adjacent nuclei is rough equally to the height of the epithelium Two types: Simple cuboidal Stratified cuboidal Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Simple Cuboidal Single layer of cubelike cells with large, spherical central nuclei Function in secretion and absorption Present in kidney tubules, ducts and secretory portions of small glands, and ovary surface Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Simple Cuboidal Single layer of cubelike cells with large, spherical central nuclei Function in secretion and absorption Present in kidney tubules, ducts and secretory portions of small glands, and ovary surface Figure 4.2b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Stratified Cuboidal Quite rare in the body Found in some sweat and mammary glands Typically two cell layers thick Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Transitional Several cell layers, basal cells are cuboidal, surface cells are dome shaped Stretches to permit the distension of the urinary bladder Lines the urinary bladder, ureters, and part of the urethra Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Transitional Several cell layers, basal cells are cuboidal, surface cells are dome shaped Stretches to permit the distension of the urinary bladder Lines the urinary bladder, ureters, and part of the urethra Figure 4.2f Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Columnar Epithelia Appear rectangular under the microscope Elongated nuclei are crowded into a narrow band close to the basal lamina The height of the epithelium is several times the distance between adjacent nuclei Three types Simple columnar Stratified columnar Pseudostratified columnar Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Simple Columnar Single layer of tall cells with oval nuclei; many contain cilia Goblet cells are often found in this layer Function in absorption and secretion Nonciliated type line digestive tract and gallbladder Ciliated type line small bronchi, uterine tubes, and some regions of the uterus Cilia help move substances through internal passageways Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Simple Columnar Figure 4.2c Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Pseudostratified Columnar Single layer of cells with different heights; some do not reach the free surface Nuclei are seen at different layers Function in secretion and propulsion of mucus Present in the male sperm-carrying ducts (nonciliated) and trachea (ciliated) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Pseudostratified Columnar Single layer of cells with different heights; some do not reach the free surface Nuclei are seen at different layers Function in secretion and propulsion of mucus Present in the male sperm-carrying ducts (nonciliated) and trachea (ciliated) Figure 4.2d Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Stratified Columnar Limited distribution in the body Found in the pharynx, male urethra, and lining some glandular ducts Also occurs at transition areas between two other types of epithelia Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelia: Glandular A gland is one or more cells that makes and secretes an aqueous fluid Classified by: Site of product release – endocrine or exocrine Relative number of cells forming the gland – unicellular or multicellular Two types: Endocrine and Exocrine glands Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Endocrine Glands release secretions into the interstitial fluid secretions are hormones which enter the bloodstream for distribution throughout the body Examples include thyroid gland, pituitary gland Called ductless because they do not use ducts. Their secretions are released directly into interstitial fluid Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Exocrine Glands More numerous than endocrine glands Release secretions into ducts that open onto an epithelium Examples include mucous, sweat, oil, and salivary glands The only important unicellular gland is the goblet cell Multicellular exocrine glands are composed of a duct and secretory unit Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Exocrine Glands – Modes of Secretion Merocrine – products are secreted by exocytosis (e.g., pancreas, sweat, and salivary glands), most common mode of secretion Apocrine – loss of cytoplasm as well as the secretory product (eg. Milk production – apocrine and merocrine) Holocrine – products are secreted by the rupture of gland cells (e.g., sebaceous glands), destroys the cell Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Modes of Secretion Figure 4.4 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Exocrine gland structure There are two types of gland structure: Unicellular glands Independent, scattered gland cells Only ones in body are goblet cells (secrete mucins) Multicellular glands Include glandular epithelia and aggregations of gland cells that produce exocrine or endocrine secretions. Three ways to describe: Structure of the duct Shape of the secretory portion of the gland Relationship between ducts and the glandular area Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of Multicellular Exocrine Glands Figure 4.3a-d Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of Multicellular Exocrine Glands Figure 4.3e-g Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Found throughout the body; most abundant and widely distributed in primary tissues Connects the epithelium to the rest of the body Never exposed to the external environment Major types of connective tissue are: Connective Tissue proper Fluid Connective Tissue Supporting Connective Tissue Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Three basic components of connective tissue Ground substance – unstructured material that fills the space between cells Fibers – collagen, elastic, or reticular Cells – fibroblasts, chondroblasts, osteoblasts, and hematopoietic stem cells Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Functions of Connective Tissue Binding and support Protection Insulation Transportation Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Characteristics of Connective Tissue Connective tissues have: Mesenchyme as their common tissue of origin Varying degrees of vascularity Nonliving extracellular matrix, consisting of ground substance and fibers Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue: Embryonic Mesenchyme – embryonic connective tissue Gel-like ground substance with fibers and starshaped mesenchymal cells Gives rise to all other connective tissues Found in the embryo Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue: Embryonic Figure 4.8a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper Contains extracellular fibers, viscous ground substance, and various cells Commonly referred to as the “packing materials” of the body because they fill spaces between organs, cushion and stabilize, and support. Components of Connective Tissue proper 1. Cells Fibroblasts Most abundant permanent resident and always present in it Secrete hyaluronan (polysaccharide derivative) and proteins that make the ground substance viscous Macrophages Large amoeboid cells scattered throughout the matrix that engulf pathogens or damaged cells Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cells (cont) of Connective Tissue Proper -Adipocytes Adipose cells (fat cells) They contain a single, enormous liquid droplet. All cells parts are squeezed to the side making it look like a class ring. Mesenchymal Cell Stem cell present in may connective tissues Respond to local injury by dividing to produce daughter cells that differentiate into other cells Melanocytes Synthesize and store the brown pigment melanin Play a large role in skin color Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cells (cont) of Connective Tissue Proper Mast cells Filled with granules containing histamine and heparin which stimulate local inflammation Lymphocytes They travel throughout the body, but their numbers increase where tissue is damaged May develop into plasma cells which produce antibodies Microphages Phagocytic blood cells that move throughout the connective tissue in small numbers. Attracted by chemicals released by macrophages and mast cells Examples are neutrophils and eosinophils Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Components of Connective Tissue Proper - Fibers 2. Connective Tissue Fibers Formed by fibroblasts Three types of fibers A. Collagen Fibers Long, straight, and unbranched Most common fibers in connective tissue proper Consists of a bundle of fibrous protein subunits wound together like rope Flexible but strong Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Components of Connective Tissue Proper - Fibers B. Reticular fibers Thinner than collagen fibers Form a branching, interwoven framework (stroma) that stablizes the functional cells (parenchyma) Tough, flexible, and resist forces from many directions C. Elastic Fibers Contain the protein elastin Branched and wavy Only one that will return to original length after stretching Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Comp of Conn Tissue Proper – Ground Substance C. Ground Substance Fills the spaces between cells and surrounds connective tissue fibers Dense enough so bacteria have trouble moving through it Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper There are two types of CT Proper Loose Dense Regular Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Commonly referred to as “the packing materials” of the body because they fill spaces between organs, cushion and stabilize specialized cells in many organs, and support epithelia. Different types include: Areolar Adipose Reticular Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Areolar connective tissue Gel-like matrix with all three connective tissue fibers Fibroblasts, macrophages, mast cells, and some white blood cells are found in Areolar CT Wraps and cushions organs Widely distributed throughout the body Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Figure 4.8b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Adipose connective tissue Matrix similar to areolar connective tissue with closely packed adipocytes Reserves food stores, insulates against heat loss, and supports and protects Found under skin, around kidneys, within abdomen, and in breasts Local fat deposits serve nutrient needs of highly active organs. When nutrients are scarce, adipocytes deflate like collapsing balloons. They are not destroyed when you lose weight. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Figure 4.8c Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Reticular connective tissue Loose ground substance with reticular fibers Reticular cells lie in a fiber network Forms a soft internal skeleton, or stroma, that supports other cell types Found in lymph nodes, bone marrow, and the spleen Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Loose Figure 4.8d Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Dense Often called collagenous tissues because collagen fibers are the dominant type of fiber in them. Contain variable amounts of elastic fibers. Two main types of Dense Connective Tissue Dense Regular Dense Irregular Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Dense Regular Parallel collagen fibers with a few elastic fibers Major cell type is fibroblasts Good for movement in one direction Attaches muscles to bone or to other muscles, and bone to bone Found in tendons, ligaments, and aponeuroses (fibrous membrane) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Dense Regular Figure 4.8e Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Dense Irregular Irregularly arranged collagen fibers with some elastic fibers Major cell type is fibroblasts Withstands tension in many directions providing structural strength Found in the dermis, submucosa of the digestive tract, and fibrous organ and joint capsules Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Connective Tissue Proper: Dense Irregular Figure 4.8f Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 2. Fluid Connective Tissue 2nd main classification of connective tissue Blood and lymph are examples Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fluid Connective Tissue: Blood the watery matrix is called plasma which contains blood cells and fragments of cells called formed elements. There are three types of formed elements: a. red blood cells (erythocytes) account for about half the volume of blood responsible for the transport of oxygen Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fluid Connective Tissue: Blood b. white blood cells (leukocytes) includes phagocytic microphages (neutrophils and eosinophils), basophils, lymphocytes, and monocytes important component of the immune response c. platelets made of tiny membrane-enclosed packets of cytoplasm function in the clotting response that seals breaks in the endothelial lining Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fluid Connective Tissue: Blood Figure 4.8k Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fluid Connective Tissue: Lymph Forms as interstitial fluid enters lymphatic vessels Gets circulated around the body and helps identify injury or infection Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 3. Supporting Connective Tissue Third main type of connective tissue Provides a strong framework that supports the rest of the body Examples include bone and cartilage Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue- Cartilage The matrix is a firm gel that contain polysaccharide derivates called chondroitin sulfates. Chondrocytes (cartilage cells) are the only cells in the cartilage matrix. They are found in small chambers called lacunae. Blood vessels do not grow into cartilage because of a chemical produced by chondrocytes. Cartilage is set apart from surrounding tissues by a fibrous perichondrium. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue- Cartilage The perichondrium consists of two layers: Outer fibrous region - made dense irregular connective tissue – provides mechanical support and protection and attaches the cartilage to other structures. Inner cellular level – important to the growth and maintenance of cartilage Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue- Cartilage Cartilage Growth occurs by two mechanisms: 1. interstitial growth Cartilage enlarges from within Chondrocytes in the cartilage matrix undergo cell division, and the daughter cells produce additional matrix. Begins in embryonic development and continues through adolescence. Not found in adults. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue- Cartilage 2. appositional growth new layers of cartilage are added to the surface Fibroblasts in the cellular layer of the perichondrium differentiate into chondrocytes Begins in embryonic development and continues through adolescence. Only found in adults in unusual circumstances such as cartilage damage or excessive stimulation by growth hormone from the pituitary gland. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Cartilage There are three types of cartilage: 1. Hyaline cartilage Most common type found Supports, reinforces, cushions, and resists compression Surrounded by a dense perichondrium in most places Contains tightly packed collagen fibers which make it somewhat flexible Found in connections between the ribs and sternum, nasal cartilages, covers the end of long bones Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Hyaline Cartilage Figure 4.8g Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Elastic Cartilage 2. Elastic Cartilage Contains many elastic fibers which make it resilient and flexible Form the external flab of the outer ear, the epiglottis, the auditory tube, and part of the larynx Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Elastic Cartilage Similar to hyaline cartilage but with more elastic fibers Maintains shape and structure while allowing flexibility Supports external ear (pinna) and the epiglottis Figure 4.8h Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Fibrocartilage 3. Fibrocartilage Extremely durable and tough, resists compression and absorbs shock Has little ground substance and its matrix is dominated by densely interwoven collagen fibers Found between spinal vertebrae, between pubic bones of the pelvis, and around tendons Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Fibrocartilage Matrix similar to hyaline cartilage but less firm with thick collagen fibers Provides tensile strength and absorbs compression shock Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint Figure 4.8i Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Bone (Osseous Tissue) Contain calcium salts and collagen fibers which make bone strong, somewhat flexible and highly resistant to shattering. Osteocytes (bone cells) are found in lacunae in the matrix. The lacunae are organized around blood vessels that branch through the matrix. Canaliculi are long, slender passageways in the matrix that allow for communication between bone cells and blood vessels. Most bone surfaces are sheathed by a periosteum which contains a fibrous (outer) and cellular (inner) layer. Its function is to attach the bone to a surrounding tissue, tendons, and ligaments Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Supporting Connective Tissue: Bone (Osseous Tissue) Figure 4.8j Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Tissue - Muscle Muscle Tissue specialized for contraction There are three types: skeletal, cardiac, and smooth muscle Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue: Skeletal Cells are long, cylindrical, striated, and multinucleate (more than one nuclei) The cells are called muscle fibers because they are so long and slender Muscle fibers are incapable of dividing, but new ones are produced through the divisions of satellite cells (stem cells that persist in adult muscle skeleton) Striations are caused by myosin and actin organized in repeating groups Found in skeletal muscles (ones you can move) and are called striated voluntary muscle Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue: Skeletal Long, cylindrical, multinucleate cells with obvious striations Initiates and controls voluntary movement Found in skeletal muscles that attach to bones or skin Figure 4.11a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue: Cardiac Only found in the heart Smaller than a skeletal muscle cell One centrally positioned nucleus Contain striations Possess intercalated discs (place where cardiac cells are interconnected) Called striated involuntary muscle because you do not have voluntary control of the heart muscle Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue: Cardiac Branching, striated, uninucleate cells interdigitating at intercalated discs Propels blood into the circulation Found in the walls of the heart Figure 4.11b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue: Smooth Located in the walls of blood vessels and around hollow organs A smooth muscle cell is a small, spindle-shaped cell with tapering ends and a single, oval nucleus Do not contain striations Called nonstriated involuntary muscle Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscle Tissue: Smooth Figure 4.11c Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Nervous Tissue Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Tissue - Nervous carries information throughout the body in the form of electrical impulses specialized for the conduction of electrical impulses from one region of the body to another Most is located in the brain and spinal cord Contains two basic types of cells: neurons (carry nerve impulses) and neuroglia (support and repair neural tissue and supply nutrients to neurons) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Tissue - Nervous Tissue Neurons consist of the following parts: Cell body – contains nucleus and major organelles Dendrites – extend from the cell body and possess branches. Pick up nerve impulses Axon – conducts the nerve impulse to other cells. Also called nerve fiber PLAY InterActive Physiology®: Nervous System I: Anatomy Review Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Nervous Tissue Figure 4.10 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranes Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranes Membranes form a barrier or interface. Epithelia and connective tissues combine to form membranes that cover and protect other structures and tissues. The four types of membranes are mucous, serous, cutaneous, and synovial. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranes - Muscous A. Mucous membranes line cavities that communicate with the exterior contain areolar tissue called lamina propia. must be kept moist to reduce friction and to facilitate absorption or secretion. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelial Membranes Mucous – lines body cavities open to the exterior (e.g., digestive and respiratory tracts) Serous – moist membranes found in closed ventral body cavity Figure 4.9b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranes - Serous B. Serous membranes line the body’s sealed internal cavities form a fluid called a transudate which is used to reduce friction. Three types of serous membranes are the pleura (lines the pleural cavities and covers the lungs), peritoneum (lines the peritoneal cavity and covers the surfaces of the enclosed organs), and the pericardium (lines the pericardial cavity and covers the heart). Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelial Membranes Figure 4.9c Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranes - Cutaneous C. Cutaneous membranes known as skin. It covers the body surface. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epithelial Membranes Cutaneous – skin Figure 4.9a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranes - Synovial D. Synovial membranes forms an incomplete lining within the cavities of synovial joints. Produce fluid within the joint Example is the knee Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Connective Tissue Framework of the Body Internal organs and systems are tied together by a network of connective tissue proper. Fasciae are connective tissue layers and wrappings that support and surround organs. Fasciae can be divided into three layers: superficial fascia, deep fascia, subserous fascia Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Connective Tissue Framework of the Body Superficial fascia Also known as the subcutaneous layer or hypodermis Layer of areolar tissue and fat Separates the skin from underlying tissues and organs, provides insulation and padding, and lets the skin and underlying structures move independently. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Connective Tissue Framework of the Body Deep fascia Made of dense irregular connective tissue The fibers in each layer run in the same direction, but the orientation of the fibers changes from layer to layer. Resist forces applied from many directions Bound to tendons, capsules, ligaments Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The Connective Tissue Framework of the Body Subserous fascia Layer of areolar tissue and lies between the deep fascia and the serous membranes that line the body cavities. Movements of muscles or muscular organs do not distort this lining Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings