click below
click below
Normal Size Small Size show me how
Anatomy & Physiology
Chapter 4
Question | Answer |
---|---|
Define Tissue | a group of cells that have a common embryonic origin and function together to carry out specialized activities. |
What are the 3 consistencies of tissue? | Hard (bone), semisolid (fat), or liquid (blood). |
Define Histology | the science that deals with the study of tissues. |
Define Pathologist | is a physician who specializes in laboratory studies of cells and tissue for diagnoses. |
Name the 4 types of tissues | Epithelial, connective, muscular, nervous. |
Describe Epithelial Tissue | covers the body surfaces and lines hollow organs, body cavities, duct, and forms glands. |
Describe Connective Tissue | Protects, supports, and binds organs. Stores energy as fat, and provides immunity. |
Describe Muscular Tissue | Generates the physical force needed to make body structures move and generate body heat. |
Describe Nervous Tissue | Detects changes in the body and responds by generating nerve impulses. |
What are the 3 primary germ layers from which tissues of the body develop? | Ectoderm, Endoderm, and Mesoderm. |
What tissue develops from all three germ layers? | Epithelial tissue |
What tissue develops from Mesoderm? | All connective tissue and most muscle tissue. |
What tissue develops from Ectoderm? | Nervous tissue. |
What are Cell Junctions? | contact points between the plasma membranes of tissue cells. |
What are the five most common types of Cell Junctions? | Tight junctions, adherens junctions, desmosomes, hermidesmosomes, and gap junctions. |
What are Tight Junctions? | consist of web-like strands of transmembrane proteins that fuse cells together and seal off passageways between adjacent cells. |
Where are Tight Junctions located in the body? | They are common in epithelial tissues of the stomach, intestines, and urinary bladder. |
What is the function of Tight Junctions? | they help to retard the passage of substances between cells and prevent the contents from leaking into the blood or surrounding tissues. |
What are Adherens Junctions and what are their functions? | contain plaque which is a dense layer of protein. They help resist separation of cells during contractile activities. |
Where are Adherens Junctions located in the body? | located inside of the plasma membrane attached to both membrane proteins and microfilaments of the cytoskeleton. |
What are Cadherins? | They are transmembrane glycoproteins that insert into the plaque and join cells. |
What are Adhesion Belts? | |
Describe Desmosomes | contain plaque and Cadherins that extend into the intercellular space to attach adjacent cells together. Desmosome plaque attaches to intermediate filaments that contain a protein called Keratin. |
What are Hemidesmosomes? | They resemble half of a desmosome. They do not link adjacent cells but anchor cells to the basement membrane. |
What does a Hemidesmosome consist of? | it contains a transmembrane glycoprotein called integrin. Integrins attach to intermediate filaments and the protein Laminin present in the basement membrane. |
What are Gap Junctions? | They connect neighboring cells via tiny fluid-filles tunnels called Connexons. |
What do Gap Junctions consist of? | They contain membrane proteins called Connexins. Plasma membranes of Gap Junctions are separated by a very narrow intercellular gap (space). |
What is Epithelial Tissue? | It consists of cells arranged in continuous sheets, in either single or multiple layers. The cells are closely packed and held tightly together. It forms coverings and linings in the body. It always has a free surface. |
What are the 3 major functions of Epithelial Tissue? | Selective barrier that regulates the movement of materials in/out of the body, secretory surfaces that release products onto the free surface, protective surfaces against the environment. |
What are the various surfaces of Epithelial Cells? | Apical (free), Lateral, and Basal. |
Describe Apical Surface | Faces the body surface, body cavity, lumen, or duct. |
Describe Lateral Surface | Faces adjacent cells. |
Describe Basal Surface | Opposite of apical layer and adhere to extracellular materials. |
Describe Basement Membrane | A thin double extracellur layer that serves as the point attachment and support for overlying Epithelial Tissue. |
What are the 2 layers that make up the Basement Membrane? | Basal lamina and Reticular lamina. |
Describe Basal lamina | It is closer to and secreted by epithelial cells. It contains laminin, collagen, glycoproteins, and proteoglycans. |
Describe Reticular lamina | It is closer to the underlying connective tissue. It contains collagen secreted by the connective tissue cells. |
What type of tissue has its own nerve supply? | Epithelial Tissue |
Epithelial Tissues are ________________ or lacks its own blood supply. | Avascular |
Epithelial Tissues have a high rate of __________________ for renew and repair. | Cell division |
What in the connective tissue brings in nutrients and eliminate waste. | Blood vessels |
What are the numerous roles that Epithelial Tissues play in the body? | Protection, filtration, secretion, absorption, and excretion. |
What are the 2 types of Epithelial Tissues? | Covering and lining epithelium and Glandular epithelium. |
Describe Covering and lining epithelium. | Is the outer covering of skin and some internal organs. |
Describe Glandular epithelium. | Is the secreting portion of glands. (i.e. thyroid, adrenal, & sweat glands. |
What are the 2 characteristics that classify Covering and Lining Epithelium? | Arrangement of cells into layers and shapes of cells. |
What are the names of the 3 layers of Covering and Lining Epithelium? | Simple, pseudostratified, and stratified. |
Describe Simple epithelium | Single layer of cells that function in diffusion, osmosis, filtration, secretion, or absorption. |
Describe Pseudostratified epithelium | Appear to have multiple layers because cell nuclei are at different levels; all cells do not reach the apical surface. |
Describe Stratified epithelium | Two or more layers of cells that protect underlying tissues in areas of wear and tear. |
What are the 4 cell shapes of Covering and Lining Epithelium? | Squamous, cuboidal, columnar, and transitional. |
Describe squamous cells | Thin cells, arranged like floor tiles , allows for rapid passage of substances. |
Describe cuboidal cells | As tall as they are wide, shaped like cubes or hexagons, may have microvilli, function in secretion or absorption. |
Describe columnar cells | Much taller than they are wide, like columns, may have cilia or microvilli, specialized function for secretion and absorption. |
Describe transitional cells | Cells change shape, transition from flat to cuboidal. Organs such as urinary bladder stretch to larger size and collapse to a smaller size. |
What are the 4 types of Simple Epithelium? | Simple squamous, simple cuboidal, simple columnar (nonciliated & ciliated), and pseudostratified columnar (nonciliated & scilated). |
Describe Simple Squamous Epithelium | Single layer of cells that resembles a tiled floor on the surface. The nucleus is centrally located and appears flattened oval or sphere. Is found at sites for filtration or diffusion. |
What is Endothelium? | Is simple squamous epithelium that lines the heart, blood vessels, and lymphatic vessels. |
What is Mesothelium? | Is simple squamous epithelium of serous membranes such as the pericardium, pleura, or peritoneum. |
What type of Simple Squamous Epithelium are derived from embryonic mesoderm? | Endothelium and Mesothelium. |
Describe Simple Cuboidal Epithelium | Cuboidal shaped cells, cell nuclei are usually round and centrally located, found in the thyroid gland and kidneys, and functions in secretion and absorption. |
Describe Simple Columnar Epithelium | Column shaped cells with oval nuclei near the base, exists in 2 forms: nonciliated and ciliated. |
Describe Nonciliated Simple Columnar Epithelium | Contains columnar cells with microvilli at their apical surface and goblet cells. |
What are Goblet Cells? | Goblet shaped cells within the Simple Columnar Epithelium that secrete mucus which serves as a lubricant for the lining of the digestive, respiratory, reproductive, and urinary tracts. This mucus also prevents the destruction of the stomach lining by acid |
Describe Ciliated Simple Columnar Epithelium | They are columnar epithelial cells with cilia at the apical surface. |
Where are Ciliated Simple Columnar epithelium located? | In respiratory tract, goblet cells are interspersed among ciliated columnar epithelia. |
What is microvilli? | Fingerlike cytoplasmic projections. |
Describe Pseudostratified Columnar Epithelium | Appear to have several layers due to nuclei of cells at various depths. All cells are attached to the basement membrane in a single layer but some do not extend to the apical surface. |
What are ciliated cells? | cells that secrete mucus and bear cilia. |
What are nonciliated cells? | cells that lack cilia and goblet cells. |
What is Stratified Epithelium? | Two or more layers of cells. |
What are the 4 types of Stratified Epithelium? | Stratified squamous, stratified cuboidal, stratified columnar, and trasitional. |
What is Stratified Squamous Epithelium? | Several layers of cells that are flat in the apical layer. Cells of the deep layers vary in shape from cuboidal to columnar. |
Describe the process of Stratified Squamous Epithelium | As cells grow they are pushed up toward the apical layer. As cells move further from the blood supply they dehydrate, harden, and die. |
What are the 2 types of Stratified Squamous Epithelium? | Keratinized and nonkeratinized. |
What is Keratinized Stratified Squamous Epithelium? | It contains the fibrous protein Keratin. It forms the superficial layer of the skin. |
What is Nonkeratinized Stratified Squamous Epithelium? | It does not contain Keratin and is found in the mouth and esophagus. |
What is Stratified Cuboidal Epithelium and what is its function? | Fairly rare type of epithelium in which the apical layers are cuboidal. It functions in protection. |
What is Stratified Columnar Epithelium and what is its function? | A very uncommon epithelium. Contains columnar cells in the apical layer only, basal layers has shorten, irregular shaped cells. It functions in protection and secretion. |
What is Transitional Epithelium? | Found only in the urinary system and has a variable appearance. In relaxed state, cells appear cuboidal. Upon stretching, cells become flattened and appear squamous. Ideal for hollow structures subjected to expansion such as the bladder. |
Describe a Gland | may consist of a single cell or a group of cells that secrete substances into ducts (tubes), onto a surface, or into the blood. |
What are the 2 classifications of Glands? | Endocrine and Exocrine. |
What are the structural classifications of Exocrine Glands? | Unicellular and multicellular. |
What are the 2 criteria that categorize Multicellular Glands? | Whether the ducts are branched or unbranched, and the shape of the secretory portion of the gland. |
If the duct of the gland does not branch it is? | a Simple Gland. |
If the duct of the gland branches it is? | a Compound Gland. |
Tubular Glands are | Glands with tubular secretory parts. |
Acinar Glands are | Glands with rounded secretory parts. |
Tubuloacinar Glands are | Glands with both tubular and rounded secretory parts. |
What is the structural classification of a Simple Tubular Exocrine Gland? | The secretory portion is tubular (shaped like a balloon with no air) and attaches to a single unbranched duct. |
What is the structural classification of a Simple Branched Tubular Exocrine Gland? | The secretory portion is tubular (shaped like a ballon with no air), is branched, and attaches to a single unbranched duct. |
What is the structural classification of a Simple Coiled Tubular Exocrine Gland? | The secretory portion is tubular (shaped like a balloon with no air), is coiled, and attaches to a single unbranched duct. |
What is the structural classification of a Simple Acinar Exocrine Gland? | The secretory portion is round and attaches to a single unbranched duct. |
What is the structural classification of a Simple Branched Acinar Exocrine Gland? | The secretory portion is round, is branched, and attaches to a single unbrached duct. |
What is the structural classification of a Compound Tubular Exocrine Gland? | The secretory portion is tubular (shaped like a balloon with no air) and attaches to a branched duct. |
What is the structural classification of a Compound Acinar Exocrine Gland? | The secretory portion is round and attaches to a branched duct. |
What is the structural classification of a Compound Tubuloacinar Exocrine Gland? | The secretory portion is both round and tubular and attaches to a branched duct. |
What are Unicellular Exocrine Glands? | Single-celled - such as Goblet Cells. |
What are Multicellular Exocrine Glands? | Composed of many cells that form a distinctive microscopic structure or macroscopic organ. |
The functional classification of Exocrine Glands is based on what? | How their secretions are released. |
If the secretions of a particular gland are synthesized on ribosomes attached to rough ER; then sent through the Golgi complex; and released from the cell in secretory vesicles via exocytosis it is what type of gland? | Merocrine Gland |
Most Exocrine Glands of the body are? | Merocrine Glands |
If the secretions of a particular gland are accumlated at the apical surface of a cell and that portion of the cell pinches off from the rest of the cell to release the secretion it is what type of gland? | Apocrine Gland |
If the secretions of a particular gland accumlate in its cytosol; cell matures; then ruptures and becomes the secretory product it is what type of gland? | Holocrine Gland |
Describe Endocrine Glands | Its secretory products (hormones) diffuse into the blood after passing through interstitial fluid (the portion of the extracellular fluid that fills the microscopic spaces between cells of tissues). |
What is the function of Endocrine Glands? | To produce hormones that regulate various metabolic and physiological body activities to maintain homestasis. |
What are some examples of where Endocrine Glands are located? | Pituitary gland at base of brain, pineal gland in brain, thyroid and parthyroid glands near larynx, adrenal glands superior to kidneys, pancreas near stomach, ovaries in pelvic cavity, testes in scrotum, thymus in thoracic cavity. |
Describe Exocrine Glands | Secretory products are released into ducts that empty onto the surface of the epithelium. |
What is the funtion of Exocrine Glands? | Produces substances such as sweat, oil, earwax, saliva, mucus, or digestive enzymes. |
What are some examples of where Exocrine Glands are located? | Sweat, oil, and earwax glands of the skin, digestive glands such as salivary glands which secrete into mouth cavity, pancreas which secretes into the small intestine. |
What is Connective Tissue? | It is the most abundant and widely distributed tissue in the body. |
What are the functions of Connective Tissue? | It binds tissues together, supports and strengthens tissue, protects and insulates internal organs, compartmentalizes structures and serves as a major transport system within the body, is a primary location of stored energy reserves (fat tissue), and is t |
What are the general features of Connective Tissue? | Extracellular Matrix and cells. |
What is Extracellular Matrix? | Is the material located between the cells. Consist of protein fibers and ground substances. |
Connective Tissue is/is not highly vascular. | Yes - Is |
True or False: Connective Tissue is supplied with nerves? | True - with exception to cartilage and tendon. Both have little or no blood supply and no nerves. |
What are the 6 types of Connective Tissue? | Fibroblasts, Adipocytes, Mast cells, White blood cells, Macrophages, and Plasma cells. |
What is the function of Fibroblasts? | They secrete fibers and components of ground substances. |
What is the function of Adipocytes (fat cells)? | The store triglycerides (fat). |
What is the function of Mast cells? | To produce histamine. |
What is the function of White blood cells? | Are an immune response. Are categorized as either Neutrophil or Eosinophils. |
What is the function of Macrophages? | To engulf bacteria and cellular debris by phagocytosis. |
What is the function of Plasma cells? | To secrete antibodies. |
What are the 2 major components of Extracellular Matrix in Connective Tissue? | Ground substance and Fibers. |
What is Ground Substance? | Is the component between cells and fibers. It is either fluid, semifluid, gelatinous, or calcified. It contains a complex combination of proteins and polysaccharides. |
What is the function of Ground Substance? | Functions to support and bind cells, store water, and allow exchange between blood and cells. |
What are the 3 types of Fibers in the Extracellular Matrix of Connective Tissue? | Collagen, Elastic, and Reticular. |
What makes up Collagen Fibers? | Collagen proteins in parallel bundles. |
What makes up Elastic Fibers? | Elastin proteins & glycoprotein fibrillin. |
What makes up Reticular Fibers? | Collagen in fine bundles w/glycoprotein coating. |
What is the function of Glycosaminoglycans or GAGs? | They trap water, making the ground substance more jellylike. |
What is Hyaluronic Acid? | Is a viscous, slippery subtance that binds cells together, lubricates joints, and helps maintain the shape of the eyeballs. |
What is the function of Chrondroitin Sulfate? | Provides support and adhesiveness in cartilage, bone, skin, and blood vessels. |
What are Adhesion Proteins? | They are present in the ground substance. They are responsible for linking components of the ground substance to one another and to the surfaces of cells. |
What is Fibronectin? | It is the main adhesion protein of connective tissue. It binds to both collagen fibers and ground substance, linking them together. |
What are the 2 major subclasses of Connective Tissue? | Embryonic and Mature. |
What are the 2 classifications of Embryonic Connective Tissue? | Mesenchyme and mucous. |
What are the 5 classifications of Mature Connective Tissue? | Loose, Dense, Cartilage, Bone, and Liquid. |
What are the 3 subclasses of tissue within the Mature Loose Connective Tissue? | Areolar, adipose, and reticular. |
What are the 3 subclasses of tissue within the Mature Dense Connective Tissue? | Dense regular, dense irregular, and elastic. |
What are the 3 subclasses of tissue within the Mature Cartilage Connective Tissue? | Hyaline cartilage, Fibrocartilage, and Elastic cartilage. |
What are the 2 subclasses of tissue within the Mature Liquid Connective Tissue? | Blood and Lymph. |
What are the functions of a Desmosome? | The prevent epidermal cells from separating under tension and cardiac muscle cells from pulling apart during contraction. |
What are the functions of a Gap Junction? | They allow communication of cells; ions, nutrients, waste, chemical and electrical signals travel through the connexons from one cell to another. |
What are the functions of Ciliated Simple Columnar Epithelium? | Secreted mucus on the surface traps inhaled froeign particles. Beating ciliam moves particles to the throat for removal by coughing, swallowing, or sneezing. Cilia also move oocytes to the uterine tubes. |
Describe Mesenchyme | Gives rise to all other connective tissues and is located exclusively in the embryo. |
Where is Mucous Connective Tissue (Wharton's Jelly) found in the body? | Unbilical cord of the fetus. |
What is Cartilage? | A dense network of Collagen fibers and Elastic fibers firmly embedded in Chondroitin Sulfate. |
What are Chrondrocytes? | Cells of mature cartilage found in the spaces called lucunae. |
What is Percondrium? | Covering of dense irregular connective tissue that surround the cartilage. |
What are the 2 layers of Percondrium? | Outer fibrous layer and inner cellular layer. |
True/False: Cartilage has no blood vessels or nerves, except in the pericondrium. | True |
True/False: Cartilage grows slowly | True |
When cartilage is injured or inflamed its repair is slow due to its what? | Avascular nature. |
What are the 2 patterns of Cartilage growth? | Interstitial and Appositional. |
What is Interstitial growth? | Growth from within the tissue. |
What is Appositional growth? | Growth at the outer surface of the tissue. |
What are bones? | Organs composed of several different connective tissues. |
What are the 2 classifications of bone? | Compact or spongy. |
What is the basic unit of Compact bone? | Osteon or haversian system. |
Spongy bone lacks osteons. They have columns called what? | Trabeculae. |
What is Lamellae? | Concentric mineral salt rings of extracellular matrix which give bone its hardness and collagen fibers, which give bone its strength. |
What is Lacunae? | Small spaces between Lamellae that contain mature bone cells called Osteocytes. |
What is Canaliculi? | Networks of minute canals containing the processes of osteocytes. |
What does the Central Haversian system contain? | Blood vessels and nerves. |
What are 2 types of Liquid Connective tissue? | Blood tissue and Lymph. |
What is Blood tissue? | Connective tissue with liquid extracellular matrix called Blood Plasma. Suspended in the blood plasma are formed elements: RBCs, WBCs, and platelets. |
What is Blood Plasma? | A pale yellow fluid that consists mostly of water with a wide variety of dissolved substances. |
What is Lymph? | Extracellular fluid that flows in lymphatic vessels. |
What is the function of Red Blood cells? | Transport oxygen to body cells and remove some carbon dioxide from them. |
What is the function of White Blood cells? | Involved in phagocytosis, immunity, and allergic reactions. |
What is the function of Platelets? | They participate in blood clotting. |
What are membranes? | Flat sheets of pliable tissue that cover or line a part of the body. |
What are the 2 major divisions of Membranes? | Epithelial and Synovial. |
What are Epithelial Membranes? | A combination of and epithelial layer and an underlying connective tissue layer. |
What are Synovial Membranes? | They line joints and contain connective tissue but not epithelium. |
Where are Mucous Membranes (Mucosa) located in the body? | The line a body cavity that opens directly to the exterior. Line entire digestive, respiratory, and reproductive tracts, and much of the urinary tract. |
What do Mucous Membranes consist of? | Epithelial layer is important for the body's defense against pathogens. Connective tissue layer is areolar connective tissue and is called Lamina Propria. |
What is the function of the Lamina Propria. | Supports the epithelium, binds it to the underlying structures, and allows some flexibility of the membrane. It also holds blood vessels in place and affords some protection for underlying structures. |
Where are Serous Membranes or Serosa located in the body? | Lines a body cavity (thoracic & abdominal) that does not open directly to the exterior. Also covers the organs that lie within the cavity. |
What do Serous Membranes consist of? | Areolar Connective tissue covered by mesothelium (simple squamous epithelium) that secrete a serous fluid for lubrication. |
What are the 2 layers of Serous Membranes? | Parietal and Visceral. |
What is the Parietal layer? | Layer attached to and lining the cavity wall. |
What is the Visceral layer? | Layer that covers and adheres to the organs within the cavity. |
What is the Serous Membrane that lines the lungs? | Pleura |
What is the Serous Membrane that lines the heart cavity and covering heart? | Pericardium |
What is the Serous Membrane that lines the abdominal cavity and covering abdominal organs? | Peritoneum |
What is Serous Fluid? | A watery lubricant that allows organs to glide easily over one another or to slide against the walls of cavities. |
Describe Cutaneous Membrane | Skin. Covers entire surface of the body. |
What are the 2 portions of the Cutaneous Membrane? | Epidermis and Dermis. |
What is Epidermis? | Is the outer (superficial), thinner portion, composed of epithelial tissue. Protects underlying tissues. It is keratinized stratified squamous epithelium. |
What is Dermis? | Is the inner (deeper), thicker connective tissue portion. Consists of areolar connective tissue & dense irregular connective tissue. |
Describe Synovial Membranes | Line the cavities of freely movable joints. They lack epithelium and are composed of discontinuous layer of cells called synoviocytes. |
What is the function of Synovial Fluid? | Lubricates and nourishes the cartilage covering the bones at movable joints and contains macrophages that remove microbes and debris from the joint cavity. |
Describe Muscular Tissue | Consists of elongated cells called muscle fibers or myocytes that can use ATP to generate force. |
What are the 4 functions of Muscle Tissue? | Produces body movements, maintains posture, generates heat, provides protection. |
What are the 3 classifications of Muscular Tissue? | Skeletal, Cardiac, and Smooth Muscular Tissue. |
Describe Skeletal Muscle Tissue | Attached to bones of the skeleton, has striations, has Voluntary movement or contracts by conscious control. Fibers can vary in length and are roughly cylindrical in shape. |
Describe Cardiac Muscle Tissue | Has striations, has Involuntary movement or contraction is not consciously controlled. Consists of Intercalated Disc unique to cardiac muscle tissue. |
Describe Smooth Muscle Tissue | Located in the walls of hollow internal structures such as blood vessels, airways of lungs, stomach, and intestines. Is nonstriated and usually involuntary control. |
What 2 principle types of cells exists in Nervous Tissue? | Neurons or nerve cells and Neuroglia. |
What is the function of Neurons or nerve cells? | Convert stimuli into electrical signals called action potentials (nerve impulses) and conduct these action potentials to other neurons, to muscle tissue, or to glands. |
What is the function of Neuroglia? | Participates in activities of nervous tissue (ex. astrocytes). |
What are Dendrites? | Tapering, highly branched, and usually short cell processes (extensions). They are the major receiving or input portion of a neuron. |
What is a Axon? | Single, thin, cylindrical process of a neuron that may be very long. Is the output portion of the neuron, conducting nerve impulses toward another neuron or to some other tissue. |
What are Excitable Cells? | Exhibit electrical excitability. The ability to respond to certain stimuli by producing electrical signals such as action potentials. |
What 2 types of cells are considered Excitable cells? | Neurons and Muscle Fibers. |
What is the function of Excitable Cells? | Action potentials propagate along a nerve or muscle plasma membrane to cause a response. There is a release of neurotransmitters and then muscle contraction. |
What is Tissue Repair? | The replacement of worn-out, damaged, or dead cells. |
What is the process of Tissue Repair? | New cells originate by cell division from the stroma, the supporting connective tissue, or from the parenchyma, cells that constitute the functioning part of the tissue or organ. |
What are the 3 major events that occur in Tissue Repair? | Fibroblast divide rapidly, new collogen fibers are manufactured, and new blood capillaries supply materials for healing. |
The 3 processes of Tissue Repair create an actively growing connective tissue called what? | Granulation Tissue |
What is Stroma? | Supporting connective tissue. |
What is Parenchyma? | Cells that constitute the functioning part of the tissue or organ. |
True/False: Tissue heal faster in young adults? | True |
True/False: Surgery of a fetus normally leaves scars? | False |
True/False: Young tissues have a better nutritional state, blood supply, and higher metabolic rate? | True |
True/False: Extracellular components of tissues also change with age. | True |
True/False: Changes in the body's use of glucose, collagen, and elastic fibers contribute to the aging process? | True |
What is Atrophy? | A decrease in the size of cells, with a subsequent decrease in the size of the affected tissue or organ. |
What is Biopsy? | The removal of a sample of living tissue for microscopic examination to help diagnose disease. |
What is Hypertrophy? | Increase in the size of a tissue because its cells enlarge without undergoing cell division. |
What is Tissue Rejection? | An immune response of the body directed at foreign proteins in a transplanted tissue or organ. |
What is Tissue Transplantation? | The replacement of diseased or injured tissue or organ. |
What is Xenotransplantation? | The replacement of a diseased or injured tissue or organ with cells or tissue from an animal. |
What is the Integumentary System composed of? | Skin, hair, oil, sweat glands, nails, and sensory receptors. |
What is the function of the Integumentary System? | Helps maintain a constant body temperature, protects the body, and provides sensory information about the surrounding environment. |
What is Dermatology? | Medical specialty that deals with the diagnosis and treatment of integumentary system disorders. |
Describe the Skin (cutaneous membrane) | Covers the external surface of the body and is the largest organ of the body in both surface area and weight. |
What is the Subcutaneous layer of the skin? | Deep to the dermis, but not part of the skin, consists of areolar and adipose tissue. Fibers extend from the dermis and anchor the skin to the subcutaneous layer. |
What is the function of the Subcutaneous layer of the skin? | Serves as a storage depot for fat and contains large blood vessels that supply the skin. Contains nerve endings called pacinian corpuscles that are sensitive to pressure. |
What are the 4 principle types of cells of the Epidermis? | Keratinocytes, melanocytes, langerhans cells, and merkel cells. |
What are Keratinocytes? | Epidermal cells which are arranged in 4 or 5 layers and produce the protein keratin. |
What is the function of Keratinocytes? | They produce lamellar granules, which release a water-repellent sealant that decreases water entry and loss and inhibits the entry of foreign materials. |
What are Melanocytes? | Epidermal cells which develop from the ectoderm of a developing embryo and produce the pigment melanin. |
What is Melanin? | A yellow-red or brown-black pigment that contributes to skin color and absorbs damaging ultraviolet light. |
What are Langerhans cells? | Arise from red bone marrow and migrate to the epidermis. Participate in immune responses mounted against microbes that invade the skin, and are easily damaged by UV light. |
What is the function of Langerhans cells? | Their role in the immune response is to help other cells of the immune system reorganize and invading microbe and destroy it. |
What are Merkel cells? | Least numerous of the epidermal cells, located in the deepest layer of the epidermis. They detect touch sensations. |
In most regions of the body what are the 4 layers of epidermis? | Stratum basale, stratum spinosum, stratum granulosum, and a thin stratum corneum. Referred to as Thin Skin. |
Where exposure to friction is greatest, what are the 5 layers of epidermis? | Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and a thick stratum corneum. Referred to as Thick Skin. |
What is Stratum Basale? | Deepest layer of the epidermis, composed of a single row of cuboidal or columnar keratinocytes. Contains some stem cells and its role is in forming new cells. Melanocytes, Merkel Cells and Merkel discs are scattered amoung Kerotinocytes of this layer. |
What is Stratum Spinosum? | Superficial to the stratum basale, arranged in 8-10 layers of many-sided keratinocytes fitting closely together. Provides both strength and flexability to the skin. Layer contains Langerhans Cells and projections of Melanocytes. |
What is Stratum Granulosum? | Located around the middle of the epidermis, consists of 3-5 layers of flattened keratinocytes that are undergoing apoptosis. |
What is Apoptosis? | An orderly, genetically programmed cell death in which the nucleus fragments before the cells die. |
What is Stratum Lucidum? | Present only in the thick skin. Consists of 3-5 layers of flattened, clear, dead keratinocytes that contain large amounts of keratin and thickened plasma membranes. |
What is Stratum Corneum? | Consists on average of 25-30 layers of flatttened dead keratinocytes. Cells are continuously shed and replaced by cells from the deeper strata. |
What is Epidermal Growth Factor? | Hormone-like proteins. |
What is the excessive amount of keratinized cells that shed from the skin of the scalp? | Dandruff. |
What is the Dermis? | The second, deeper part of the skin, composed of strong connective tissue containing collagen and elastic fibers. The outer papillary region consists of areolar connective tissue containing thin collagen and elastic fibers. |
What are the 2 regions of the dermis? | Papillary and Reticular. |
What are Dermal Papillae? | Small, fingerlike structures that project into the undersurface of the epidermis. |
What are Capillary Loops? | Blood vessels. |
What are Meissner Corpuscles? | Tactile receptors, nerve endings that are sensitive to touch. |
What are Free Nerve Endings? | Dendrites that lack any apparent structural specialization. |
Different free nerve endings initiate signals that give rise to what? | Sensations of warmth, coolness, pain, tickling, and itching. |
What is Extensibility? | Ability to stretch. |
What is Elasticity? | Ability to return to original shape after stretching. |
What is striae? | Small tears in the dermis, or stretch marks, visible as red or silvery white streaks on the skin surface. |
What are Epidermal Ridges? | A series of ridges and grooves on the surfaces of the palms, fingers, soles, and toes which reflect contours of the underlying dermal papillae and form the basis for fingerprints. |
What makes up Fingerprints? | Ducts of sweat glands open on the tops of the epidermal ridges as sweat pores, the sweat and ridges form fingerprints upon touching a smooth object or surface. |
What is Dermatoglyphics? | The study of the pattern of epidermal ridges. |
What are the 3 pigments that impart of wide variety of colors to skin? | Melanin, hemoglobin, and carotene. |
What is a Nevus (mole)? | Round, flat, or raised area that represents a benign localized overgrowth of melanocytes. |
What is Melanosome? | |
What is Hemoglobin? | Oxygen-carrying pigment in red blood cells. |
What is Carotene? | Yellow-orange pigment that gives egg yolk and carrots their color. Is a precursor of vitamin A, which is used to synthesize pigments needed for vision. |
What is Albinism? | The inherited inability of an individual to produce melanin. |
What is Vitiligo? | The partial or complete loss of melanocytes from patches of skin produces irregular white spots. |
What are the 3 accessory structures of the skin? | Hair, skin glands, and nails. |
Describe the anatomy of Hair | Composed of columns of dead, keratinized epidermal cells bonded together by extracellular proteins. |
What are the 10 structures that makeup the anatomy of hair? | Shaft, root, hair follicle, epithelial root sheath, dermal root sheath, bulb, papilla of the hair, hair matrix, arrector pili, and hair root plexuses. |
What is the Shaft of hair? | Superficial portion which projects above the surface of the skin. |
What is the root of hair? | Portion of the hair deep to the shaft that penetrates into the dermis, and sometimes into the subcutaneous layer. |
What is the Hair Follicle? | Surrounds the root of the hair, which is made up of external and internal root sheaths. |
What is Epithelial Root Sheath? | Refers to the combination of the external and internal root sheaths. |
What is the Dermal Root Sheath? | Dense dermis surrounding the hair follicle. |
What is the bulb of hair? | Onion-shaped struture which is the base of each hair follicle and its surrounding dermal root sheath. |
What is the Papilla of the hair? | Nipple-shaped indentation, which contains areolar connective tissue and many blood vessels that nourish the growing hair follicle. |
What is the Hair Matrix? | Germinal layer of cells within the bulb. Responsible for the growth of existing hairs, and they produce new hairs when old hairs are shed. |
What is Arrector Pili? | Smooth muscle which extends from the superficial dermis of the skin to the dermal root sheath around the side of the hair follicle. |
What are Hair Root Plexuses? | Dendrites of neurons that are sensitive to touch. They generate nerve impulses if the hair shaft is moved. |
What are the 3 stages that a hair follicle goes through during growth? | Growth, regression, and resting. |
What happens during the Growth (anagen) stage in hair? | Cells of the hair matrix divide. New cells are added to the base of the hair root and existing cells are being pushed upward. They become keratinized and die. |
What happens during the Regression (catagen) stage in hair? | When the cells of the hair matrix stop dividing, the hair follicle atophies (shrinks) and the hair stops growing. |
What happens during the Resting (telogen) stage in hair? | The hair follicle enters the resting stage for about 3 months then a new growth cycle begins. The old hair root falls out or is pushed out of the follicle, and a new hair begins to grow in its place. |
What is Alopecia? | The partial or complete lack of hair. |
What are the 3 types of hairs on the body? | Lanugo, terminal, and vellus. |
What is Lanugo hair? | Very fine, nonpigmented, downy hairs that cover the body of the fetus. |
What is Terminal hair? | Long, coarse, heavily pigmented hairs which replace the lanugo hair of the eyebrows, eyelashes and scalp prior to birth. |
What is Vellus hair? | Short, fine, pale hairs that are barely visible to the naked eye. It replaces the lanugo of the rest of the body. |
What determines hair color? | Color is determined by the amount and type of melanin in its keratinized cells. |
What are Sebaceous Glands (oil glands)? | Simple, branched acinar glands. With few exceptions they are connected to hair follicles. |
What is Sebum? | An oily substance that is secreted by Sebaceous Glands. |
What is the function of Sebum? | Coats the surface of hairs and helps keep them from drying and becoming brittle. Also prevents excessive evaporation of water from the skin. |
What are Sudoriferous Glands? | Sweat Glands |
What is the function of Sudoriferous Glands? | Release sweat, or perspiration, into hair follicles or onto the skin surface through pores. |
What are the 2 main types of Sweat Glands? | Eccrine and apocrine. |
What are Eccrine (Merocrine) Sweat Glands? | Simple, coiled tubular glands that are much more common than apocrine. |
Where are Eccrine (Merocrine) Sweat Glands located in the body? | Distributed throughout the skin of most regions of the body, especially in the skin of the forehead, palms, and soles. |
What is the function of Eccrine (Merocrine) Sweat Glands? | Help regulate body temperature through evaporation. |
What is Thermoregulation? | The homeostatis regulation of body temperature. |
What is Thermoregulatory Sweating? | The role of Eccrine (Merocrine) Sweat Glands in helping the body to achieve thermoregulation. |
What is Insensible Perspiration? | Sweat that evaporates from the skin before it is perceived as moisture. |
What is Sensible perspiration? | Sweat the is excreted in larger amounts and is seen as moisture on the skin. |
What is Emotional Sweating (Cold Sweat)? | Sweat glands release sweat in response to an emotional stress such as fear or embarrassment. |
What are Apocrine Sweat Glands? | Simple, coiled tubular glands. |
Where are Apocrine Sweat Glands located in the body? | Found mainly in the skin of the axilla (armpit), groin, Areolae (nipples) of the breasts, and bearded regions of the face in adult males. |
What is the appearance of Apocrine Sweat? | Slightly viscous, appears milky or yellowish in color. Apocrine sweat is odorless, but when sweat interacts with bacteria on the skin surface, the bacteria metabolize, causing Apocrine Sweat to have a musky odor that is often referred to as body odor. |
What are Ceruminous Glands? | Modified sweat glands in the external ear that produce a waxy lubricating secretion. |
What is Cerumen? | A yellowish secretion of the combined ceruminous and sebaceous glands. |
What is the function of Cerumen? | Together with hairs in the external auditory canal, provides a sticky barrier that impedes the entrance of foreign bodies and insects. It also waterproofs the canal and prevents bacteria and fungi from entering cells. |
Describe nails | Are plates of tightly packed, hard, dead, keratinized epidermal cells that form a clear, solid covering. |
What are the 3 things that each nail consists of? | Nail body, free edge, and nail root. |
What is the nail body (plate)? | The visible portion of the nail. |
What is the Free Edge of the nail? | The part of the nail body that may extend past the distal end of the digit. |
What is the Nail Root? | Portion of the nail that is buried in a fold of skin. |
What is the Lunula of the nail? | Whitish, crescent-shaped area of the proximal end of the nail body. |
What is the Hyponychium of the nail? | Area beneath the free edge which is a thickened region (nail bed) which secures the nail to the fingertip. |
What is the Eponychium of the nail? | (Cuticle) a narrow band of epidermis that extends from and adheres to the margin of the nail wall. |
What is the Nail Matrix? | The proximal portion of the epithelium deep to the nail root where cells divide by mitosis to produce nail growth. |
What are the 2 major types of skin? | Thin (hairy) skin and thick (hairless) skin. |
What are the 6 functions of the skin? | Thermoregulation, storage of blood, protection, cutaneous sensations, excretion and absorption, and synthesis of vitamin D. |
What are the 2 ways that the skin contributes to thermoregulation? | By liberating sweat at its surface and by adjusting the flow of blood in the dermis. |
How does the skin act as a Blood Reservoir? | The dermis houses an extensive network of blood vessels that carry 8-10% of the total blood flow in a resting adult. |
What are the ways skin provides Protection to the body? | Keratin protects underlying tissues, lipids released by lamellar granules inhibit evaporation of water from the skin surface; thus guarding against dehydration; |
What are Cutaneous Sensations? | Tactile sensations - touch, pressure, vibration, and tickling; thermal sensations - warmth and coolness; also pain, usually is an indication of impending or actual tissue damage. |
True/False: Skin normally has a small role in Excretion and Absorption. | True |
Describe Synthetis of Vitamin D | Synthethis requires activation of a precursor molecule in the skin by UV rays in sunlight. Enzymes in the liver and kidneys then modify the activated molecule, finally producing Calcitriol, the most active form of vitamin D. |
What are the 2 types of Skin Wound Healing? | Epidermal and deep wound. |
What are the 4 phases that Deep Wound Healing occurs? | Inflammatory, migratory, proliferative, and maturation. |
What occurs during the Inflammatory Phase? | A blood clot forms in the wound and loosely unites the wound edges. This phase involves inflammation. |
What is inflammation? | Vascular and cellular response that helps eliminate microbes, foreign material, and dying tissue in preparation for repair. |
What occurs during the Migratory Phase? | Clot becomes a scab, and epithelial cells migrate beneath the scab to bridge the wound. Fibroblasts migrate along fibrin threads and begin scar tissue, and damaged blood vessels begin to regrow. Tissue filling the wound is called granulation tissue. |
What occurs during the Proliferative Phase? | Characterized by extensive growth of epithelial cells beneath the scab, deposition by fibroblasts of collagen fibers in random patterns, and continued growth of blood vessels. |
What occurs during the Maturation Phase? | Scab sloughs off once the epidermis has been restored to normal thickness. Collagen fibers become more organized, fibroblasts decrease in number, and blood vessels are restored to normal. |
What is Fibrosis? | Process of scar tissue formation. |
What is a Hypertrophic Scar? | A scar that remains within the boundaries of the original wound. |
What is a Keloid (Cheloid) Scar? | A scar that extends beyond the boundaries into normal surrounding tissues. |
In development of the Integumentary System the Epidermis is derived from what? | The Ectoderm which covers the surface of the embryo. |
What is Rosacea? | A skin condition that affects mostly light-skinned adults. Is characterized by redness, tiny pimples, and noticeable blood vessels, usually in the central area of the face. |
What is the function of Topical Products? | Bleach the skin to tone down blotches and blemishes or decrease fine wrinkles and roughness. |
What is the function of Microdermabrasion? | The use of tiny crystals under pressure to remove and vacuum the skin's surface cells to improve skin texture and reduce blemishes. |
What is the function of a Chemical Peel? | Application of a mild acid to the skin to remove surface cells to improve skin texture and reduce blemishes. |
What is Laser Resurfacing? | Use of a laser to clear up blood vessels near the skin surface, even out blotches and blemishes, and decrease fine wrinkles. |
What are Dermal Fillers? | Injections of collagen from cows, hyaluronic acid, or calcium hydroxylapatite that plumps up the skin to smooth out wrinkles and fill in furrows. |
What is Fat Transplantation? | Fat from one part of the body is injected into another location such as around the eyes. |
What is botulinum toxin or Botox? | Diluted version of a toxin that is injected into the skin to paralyze skeletol muscles that the skin to wrinkle. |
What is Radio Frequency Nonsurgical Facelift? | Use of radio frequency emissions to tighten the deeper layers of the skin og the jowls, neck, and sagging eyebrows and eyelids. |
What is a Facelift, Browlift, or Necklift? | Invasive surgery in which loose skin and fat are removed surfically and the underlying connective tissue and muscle are tightened. |
What is a Threadlift? | Noninvasive surgical facelift in which threads that have tiny barbs are inserted into sagging facial tissues to gently lift and reposition them into a more vertical and youthful position. |
What is Keratin? | a tough fibrous protein that helps protect the skin and underlying tissues from heat, microbes, and chemicals. |
What is Keratinization? | Newly formed cells in the stratum basale are slowly pushed to the surface. As the cells move from one epidermal layer to the next, they accumulate more and more keratin. Process takes about 4 wks. |
What are line of cleavage? | Tension lines in the skin which indicate the predominant direction of underlying collagen fibers. |
The deeper Reticular Region of the dermis consists of what? | Dense irregular connective tissue containing collagen and elastic fibers, adipose cells, hair follicles, nerves, sebaceous (oil) glands, and sudoriferous (sweat) glands. |