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144 Cards in this Set
- Front
- Back
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A tissue is
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a group of similar cells and their intercellular substance which work together to perform a specialized activity.
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Tissue is characterized by
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i.Similar morphology or structure ii. Common embryonic origin iii. function together with extracellular fluid to perform a specialized activity
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Histology is the science which
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deals with the tissues
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Pathologists are physicians who
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specialize in studying cells and tissues used in the accurate diagnosis of disease or disorders
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A biopsy is the
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surgical removal of cells or tissues for examination under a microscope by pathologists.
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There are four basic tissue types classified by function and structure
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CMEN 1.Connective 2.Muscle 3.Epilithial 4.Nervous
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All four types of tissues are derived from
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one of the three primary germ layers in human embryo
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The three primary germ layers in human embryo are
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Ectoderm, Endoderm and Mesoderm
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Ectoderm gives rise to
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eplithial and nervous tissue
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Endoderm gives rise to
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eplithial tissue
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Mesoderm gives rise to
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epilithial, connective and muscle tissue
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The points of contact between adjacent cells are called
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cell junctions.
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There are 3 types of cell junctions classified by function
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tight, gap and anchoring junctions
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i.tight junctions provide
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tight continuous seal which prevent the passage of fluids across the cell membranes. Usually found between epilithial tissues ex. Include urinary, stomach, gallbladder, stomach
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Gap (communicating) junctions occur between adjacent cells which
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require rapid and direct connections between cells.
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Gap junctions are
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composed of connexons.
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Gap junction connexons are tiny fluid-filled tunnels where
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ions and small molecules move from the cytosol of one cell to the cytosol of the adjacent cell after passing through a gap in the cell membrane.
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Gap junction connexons assist in
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coordinated cellular function and development
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Connexons penetrate
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the intercalated discs of cardiac muscle fibers
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Connexons penetration promotes
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rapid conduction of impulses within the heart by conducting electrically charged ions between the fibers. (keeps muscle cells pulsing together
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Hormones secreted by glandular tissues are
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released in bursts.
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Connexon linkages allow for
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near simultaneous secretion of hormones in response to release signals.
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Anchoring junctions fasten
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cells to one another or to extracellular materials.
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3 types of anchoring junctions
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adherence, desmosomes, hemidesmosomes
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adherence junctions connect
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cytosolic structures with each other by way of the internal microfilaments and also with extracellular materials. (find them in muscles to tendons, epithelial cells, stomach small intestine)
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desmosomes form firm attachments
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between cells. Stronger than adherence junctions. (Think spot weld – or rebar that reinforces the connection)
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Hemidesmosomes resemble half of a desmosome. They anchor
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the bottoms of epithelial cells to extracellular materials.
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Epithelial Tissue – Characteristics: Cells which are
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arranged in continuous sheets in either single or multiple layers with nerves but no blood vessels meaning they are avascular
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Epithelial Tissue – Characteristics: Cells are closely
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packed with little or no interstitial space or materials.
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Epithelial Tissue - Characteristics: Possess several surfaces which
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vary in structure and function.
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Epithelial Tissue - Apical (free) surface
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covers or lines body cavities and ducts and enters into the formation of specialized structure called glands. Functions in absorption, filtration, secretion and protection. May contain extensions of apical surface:
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Epithelial Tissue - Cilia are short
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hair-like structures which move substances across the surface of the cell. (example structures that contain cilia are respiratory system and fallopian tubes where the cilia help move disease and mucus)
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Epithelial Tissue - Microvilli are small
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finger-like projections which are responsible for increasing the absorptive area of the exposed surface. (find a lot in small intestine)
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Epithelial Tissue - Lateral surface faces
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cells adjacent on either side and may contain tight junctions, gap junction, adherens junction and desmosomes
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Epithelial Tissue - Basal surface is
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the surface opposite the apical surface and adheres to extracellular materials such as basement membrane.
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Epithelial Tissue – basal surface - Basement membrane is a thin extracellular layer which
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anchors and stabilizes the epithelial tissue to maintain the position of individual cells and attach to underlying connective tissue. Consists of two layers:
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Epithelial Tissue – basal surface - Basal Lamina is
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secreted by epithelial cells and contains the proteins collagen and laminal fibers/laminin which adheres to the hemidesmosomes.
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Epithelial Tissue – basal surface - Reticular Lamina lies close to
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underlying connective tissue which secretes reticular fibers for points of attachment and support for overlying epithelial tissue.
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Epithelium may be divided into 2 subtypes
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Covering and Lining epithelium and Glandular epithelium.
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Epithelial Tissue – Covering and lining epithelium tissues are
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classified on the basis of their arrangement in cell layers and cell shapes
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Epithelial Tissue – Layer Classification simple epithelium is arranged
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in single layer in areas of no wear and tear;
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Epithelial Tissue – Layer Classification simple epithelium functions
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in diffusion, osmosis, filtration, secretion and absorbtion.
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Epithelial Tissue – Layer Classification stratified epithelium is arranged
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in mulitiple layers with thin cells on top and thick on the bottom. Occurs is areas of considerable wear and tear
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Epithelial Tissue – Layer Classification stratified epithelium functions
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in protecting underlying tissues.
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Epithelial Tissue – Layer Classification Psuedostratified epithelium is
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arranged in single layer that appears to have multiple layers; not all cells appear to reach the surface, which gives a multilayered appearance.
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Epithelial Tissue – Shape Classification squamous cells are
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flat or scale-like which allows for rapid exchange of substances.
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Epithelial Tissue – Shape Classification Cuboidal cells appear
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cubed and may have microvilli.
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Epithelial Tissue – Shape Classification Cubodial cells Function in
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secretion or absorbtion
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Epithelial Tissue – Shape Classification Columnar cells are
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columnar
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Epithelial Tissue – Shape Classification columnar cells - may be classified as
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i.ciliated ii. columnar
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Epithelial Tissue – Shape Classification columnar cells -ciliated columnar epithelium have
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cilia along the apical surface.
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Epithelial Tissue – Shape Classification columnar cells - Columnar epithelium have
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microvili along apical surface in which case the tissue is said to have a brush border. Small intestine
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Epithelial Tissue – Shape Classification - Transitional epithelium has
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a variable appearance with shapes ranging from squamous (when stretched) to cuboidal (when relaxed).
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Epithelial Tissue – Shape Classification - Transitional epithelium Is found
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i. Where one type of tissue meets another ii. In rapidly growing tissues iii. In tissues that stretch
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Epithelial Tissue – Combining the two characteristics results in nine types of epithelium:
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i. Simple Squamous, ii. Simple Cuboidal, iii. Simple Columnar – ciliated and non ciliated, iv. Simple Columnar – non ciliated, v. Psuedostratified Columnar, vi. Stratified Squamous – keratinized and moist, vii. Stratified Cuboidal, viii. Stratified Columnar, ix. Transitional
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Epithelial Tissue – Glandular epithelium are classified according to
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method of secretion
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Epithelial Tissue – Glandular epithelium - A gland is
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a single cell or group of cells that secrete substances into ducts, surface or directly into the blood
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Epithelial Tissue – Glandular epithelium - Three types of glands:
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i. endocrine, exocrine, heterocrine
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Epithelial Tissue – Glandular epithelium - Endocrine glands are
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ductless glands whose hormones are transported by the blood to maintain homeostasis. (Adrenal, thymus, pituitary, far reaching glands)
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Epithelial Tissue – Glandular epithelium - Exocrine glands secrete
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products into ducts that empty onto the surface of a covering and lining epithelium.
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Epithelial Tissue – Glandular epithelium exocrine glands - Holocrine glands in which
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cells accumulate secretory products in the cytosol, upon maturity the cell ruptures, and the secretory product is discharged.
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Epithelial Tissue – Glandular epithelium exocrine glands - Merocrine (eccrine) glands discharge
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cellular secretory products without alteration to the gland. (salivary glands) (uses vesicles and exocytosis to release fluid)
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Epithelial Tissue – Glandular epithelium exocrine glands - Apocrine glands pinch off
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a portion of the each secretory cell containing the secretory product. The remaining portion of cell repairs itself and continues the process. (mammary glands)
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Epithelial Tissue – Glandular epithelium - Heterocrine glands are
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a combination of both edocrine and exocrine glands (ex. Ovaries, testes) (exocrine glands are localized to an area endocrine go throughout the body)
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Connective Tissue – is
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The abundant tissue type in the body.
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Connective Tissue – Functions in
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i. Binds together various organs, ii. Support (Bone), iii. Protection, iv. Separation of structures, v. Storage of energy reserves, vi. Delivery of nutrients (blood), vii. Main source of immune response
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Connective Tissue DOES NOT
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occur on body surface.
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Connective Tissue – IS Richly supplied by
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vascularized and innervated except the cartilage.
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Connective Tissue – cells are
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widely scattered within a relatively large quantity of intracellular material or ground substance called the extracellular matrix
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Connective Tissue – EXTRACELLULAR MATRIX is
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nonliving and varies in consistency from fluid (plasma), to gel-like (nerves) to solid (bone).
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Types of Cells in Connective Tissue
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FIBROBLASTS, MACROPHAGES, PLASMA CELLS, MAST CELLS, ADIPOCYTES, WHITE BLOOD CELLS
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Cells in Connective Tissue - fibroblasts secrete
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fibers and ground substance of extracellular matrix.
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Cells in Connective Tissue - Macrophages engulf
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bacteria and cellular debris by phagocytosis
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Cells in Connective Tissue - Plasma cells secrete
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antibodies that attack or neutralize foreign substances in the body.
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Cells in Connective Tissue - Mast cells produce
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histamine which dilates blood vessels during inflammatory response.
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Cells in Connective Tissue - Adipocytes (fat cells) store
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triglycerides.
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Cells in Connective Tissue - White blood cells migrate from
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blood into connective tissue.
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Components of Extracellular Matrix
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i. ground substance, ii. fibers
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Components of Extracellular Matrix - Ground substance is
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the component between cells and fibers
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Components of Extracellular Matrix - Fibers are
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embedded in extracellular matrix between cells and function to strengthen and support connective tissue.
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Components of Extracellular Matrix - Three types of common fibers
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collagen, elastic & reticular
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Components of Extracellular Matrix - Collagen fibers resist
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pulling forces allowing tissue flexibility
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Components of Extracellular Matrix - Elastic fibers branch
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and join together to form a network within a tissue and provide the ability to return to return to original shape after being stretched.
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Components of Extracellular Matrix - Reticular fibers form
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a network around cells in some tissues which help form basement membrane.
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the cells and matrix distinguish
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the kinds of connective tissues and their functions.
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KINDS of connective tissues and their functions - Embryonic connective tissue is found
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in the developing embryo (first 2 months) and in the fetus
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KINDS of connective tissues and their functions - Mesenchyme is a primordial cartilage from
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which all other connective tissues arise.
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KINDS of connective tissues and their functions - Embryonic- Mucous connective tissue (Wharton’s jelly) is located
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inside the umbilical cord.
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KINDS of connective tissues and their functions - Adult connective tissue includes:
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i. Loose connective, ii. Dense connective, iii. Cartilage, iv. Osseous, v. vascular (blood)
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KINDS of connective tissues and their functions - Loose connective tissue is
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loosely woven with many cells that provide strength, elasticity and support.
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KINDS of connective tissues and their functions - 3 types of loose connective
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i. areolar, ii. Adipose, iii. reticular
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KINDS of connective tissues and their functions - Areolar contains
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fibrous stands of randomly arranged connective tissue that are widely distributed throughout the body.
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KINDS of connective tissues and their functions - Adipose is
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fat tissue. Cells, adipocytes, are filled with triglycerides instead of cytoplasm.
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KINDS of connective tissues and their functions – adipose tissue nucleus and organelles are
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pushed to the outer edges of the cell and the inner space of the cell resembles a fish egg.
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KINDS of connective tissues and their functions - Adipose tissues functions as
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a source of stored energy and for protection
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KINDS of connective tissues and their functions - Reticular fiber resembles
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a fine, lacy, dispersed network of reticular fibers that form the stroma (framework) of certain organs such as the lymphnodes, spleen and liver.
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KINDS of connective tissues and their functions - Dense connective tissue contains
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large quantities of the collagen fibers and possesses the ability to withstand great pulling forces without stretching.
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KINDS of connective tissues and their functions - 3 types of dense connective tissue:
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dense regular, dense irregular, dense elastic
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KINDS of connective tissues and their functions - Dense regular connective tissue consists of
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collagen fibers arranged in orderly and parallel bundles that may microscopically resemble wavy hair.
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KINDS of connective tissues and their functions – dense regular connective tissue is Found in:
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i. tendons, ii. Ligaments, iii aponeuroses
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KINDS of connective tissues and their functions - Tendons attach
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muscle to bone
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KINDS of connective tissues and their functions - Ligaments attach
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bone to bone
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KINDS of connective tissues and their functions - Aponeuroses attach
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muscle to muscle or muscle to bone
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KINDS of connective tissues and their functions - Dense Irregular connective tissue collagen fibers are
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interwoven without regular orientation where tensions are applied in various directions
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KINDS of connective tissues and their functions - Dense Elastic connective tissue has
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dentrite or branching appearance of elastic fibers which are often accordion in shape and capable of stretching and recoiling.
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KINDS of connective tissues and their functions – Dense elastic tissue is
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present in the arteries and lung tissue.
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KINDS of connective tissues and their functions - Cartiliage (gristle) is
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a white avascular tissue composed of dense network of collagen and elastic fibers embedded in matrix of chondrortin sulfate It has great strength and resilience.
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KINDS of connective tissues and their functions - There are 3 types of cartiliage:
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hyaline, fibrocartilage, elastic
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KINDS of connective tissues and their functions - Hyaline cartilage is made up of
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a bluish-white, shiny ground substance with fine collagen fibers and many chondrocytes (chondro = cartlidge) (cytes = cells)
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KINDS of connective tissues and their functions - Hyaline cartilage Microscopically resembles
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eyeballs floating in jello.
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KINDS of connective tissues and their functions - Hyaline cartilage is found in
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the ends of long bones and the costal cartilage (connects ribs to sternum)
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KINDS of connective tissues and their functions - Fibrocartilage consists of
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chondrocytes scattered among bundles of collagen fibers.
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KINDS of connective tissues and their functions – Fibrocartilage is found in
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pubic symphysis (cartilage between pubic bones), intervertebral discs and various mienisci (of the knee).
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KINDS of connective tissues and their functions - Elastic cartilage consists of
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chondrocytes located in a threadlike network of elastic fibers.
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KINDS of connective tissues and their functions – Elastic cartilage is Found in
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the auricle of the ear, auditory tubes and eastachian tube.
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KINDS of connective tissues and their functions - Osseous (bone) consists of
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concentric ring formations called osteons or haversian systems which contain thousands of osteocytes (bone cells).
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KINDS of connective tissues and their functions – osseus bone osteons have
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a Haversian canal that contains nerves and blood vessels.
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KINDS of connective tissues and their functions – osseus bone Form a
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rigid structure for support and protection
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KINDS of connective tissues and their functions – Vascular (blood) tissue consists of
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blood plasma and formed elements including erythrocytes (pink-RBC), Leukocytes (WBC) and Thrombocytes (platelettes)(white centers).
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KINDS of connective tissues and their functions – Vascular(blood) tissue functions in
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transport of oxygen and carbon dioxide, and other substances; protecting body from infections; contains clotting factors.
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Muscular Tissue - Muscle tissue consists of
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fibers (cells) that are specialized for contraction
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Muscular Tissue - Main functions of muscle tissues are
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i. motion, ii. heat production, iii. posture
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Muscular Tissue - Three types of muscle tissue:
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skeletal, cardiac, smooth
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Muscular Tissue - skeletal muscle tissue is
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voluntary
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Muscular Tissue - skeletal muscle tissue has
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alternating light and dark bands, striated which run transversely to the axis of the fiber.
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Muscular Tissue - skeletal muscle tissue - A single fiber is
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cylindrical and contains multiple slender nuclei.
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Muscular Tissue - Cardiac muscle tissue is found
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in the Heart
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Muscular Tissue - Cardiac muscle tissue appears
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striated
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Muscular Tissue - Cardiac muscle tissue is
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involuntary
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Muscular Tissue - Cardiac muscle tissue branching fibers are
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short and joined to each other at their ends by intercalated discs.
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Muscular Tissue - Cardiac muscle tissue Contains
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only one nucleus
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Muscular Tissue - Smooth muscle tissue is Located
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in the walls of hollow internal structures. (Gut uterus)
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Muscular Tissue - Smooth muscle tissue appears
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Non-striated
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Muscular Tissue - Smooth muscle tissue is
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involuntary
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Muscular Tissue - Smooth muscle tissue Fibers are
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long and tapered at the ends.
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Muscular Tissue - Smooth muscle tissue Contain
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only one nucleus
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Nervous Tissue – is
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Specialized for picking up stimuli, converting them into nerve impulses and conducting nerve impulses.
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Nervous Tissue – Consists of two types of cells
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neurons & neurolglia
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Nervous Tissue – Neurons function at
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detecting and conducting nerve impulses.
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Nervous Tissue – a nerve cell (neuron) resembles
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an octopus.
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Nervous Tissue – Neurons have
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i. A central nucleus within the soma (body) of the cell, ii. Branching projections called dendrites that conduct nerve impulses towards the neuron, iii. A single long “arm” called an axon for conducting nerve impulses away from the neuron,
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Nervous Tissue – Neuroglia (glial cells) are
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Smaller than neurons and 5 -25 times more numerous.
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Nervous Tissue – Neuroglia (glial cells) are Involved in
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tissue repair of damaged nervous tissue.
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Nervous Tissue – Neuroglia (glial cells) Function in
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supportive role in both CentralNervousSystem and PeriphialNervousSystem. Do not conduct nerve impulses.
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