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113 Cards in this Set
- Front
- Back
What is histology? |
Microscopic study of tissues. |
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Define "biopsy." |
Removal of tissues for diagnostic purposes. |
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Define "autopsy." |
Examination of organs of a dead body to determine cause of death. |
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How is tissue classified? (3) |
1. Structure of cells 2. Composition of non-cellular extracellular matrix 3. Cell function |
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What are the four classifications of tissues? |
1. Epithelial 2. Connective 3. Muscle 4. Nervous |
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What are the three germ layers of embryonic tissue? |
1. Endoderm 2. Mesoderm 3. Ectoderm |
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What layer does the endoderm form? What structures does it form? |
1. Inner layer 2. Forms lining of digestive tract and derivatives |
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What layer does the mesoderm form? What structures does it form? |
1. Middle layer 2. Forms tissues such as muscle, bone, and blood vessels. |
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What layer does the ectoderm form? What structures does it form? |
1. Outer layer 2. Forms skin and neuroectoderm. |
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What is the basement membrane formed by? Is it cellular or acellular? |
Secretions of both epithelium and connective tissue. It is an acellular layer. |
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What are some functions of the basement membrane? (3) |
1. Attachment to C.T. 2. Guides cell migration during tissue repair 3. Acts as a filter in the nephron of the kidney. |
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Does every epithelium have a basement membrane associated with it? |
No. |
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What is the primary composition of epithelial tissue? |
Cells. |
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What are the basic functions of epithelial tissue? |
Covers the body surface (lining) and forms glands. |
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Where can epithelial tissue be found? (4) |
1. Outside the surface of the body 2. Lining of digestive, respiratory, and urogenital systems 3. Heart and blood vessels 4. Linings of many body cavities |
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What are the three surfaces of epithelial tissue? |
1. Free surface 2. Basal surface (basement membrane) 3. Lateral surface |
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What are the three classifications of epithelium? |
1. Simple 2. Stratified 3. Specialized |
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Define "simple epithelium." |
One layer of cells. Each extends from basement membrane to the free surface. |
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Define "stratified epithelium." |
More than one layer. Shape of cells of the apical layer used to name the tissue. |
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Define "squamous." |
Flat, scale-like. |
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Define "cuboidal." |
About equal in height and width. |
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Define "columnar." |
Taller than wide. |
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Define "pseudostratified." |
Tissue appears to be stratified, but all cells contact basement membrane so it is in fact simple. Associated with cilia and goblet cells. |
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Define "transitional epithelium." |
Cells transition between cuboidal and squamous (urinary system.) |
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What are the functional characteristics of simple epithelium? |
1. Diffusion of gases 2. Filtration of blood 3. Secretion 4. Absorption |
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What is the function characteristic of stratified epithelium? |
Protection, particularly against abrasion. |
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What is the functional characteristic of squamous epithelium? |
Allows diffusion, or acts as a filter. |
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What are the functional characteristics of cuboidal and columnar epithelium? |
1. Secretion 2. Absorption 3. May include goblet cells that produce and secrete mucus. |
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What are the five structures of the free surfaces of epithelium? |
1. Smooth 2. Microvilli 3. Cilia 4. Sterocilia 5. Folds |
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What is the purpose of a smooth surface? |
It reduces friction. |
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What is the function of microvilli? |
Increase surface area for absorption or secretion. |
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What is the function of cilia? |
Move materials across the surface. |
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What are stereocilia? What is their function? |
They are elongated microvilli. They are used for sensation and absorption. |
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Where are folds found? |
In transitional epithelium where an organ must be able to change shape. |
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Simple squamous epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Single layer of flat cells 2. Location:
3. Functions:
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Simple cuboidal epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Single layer of cube-shaped cells; some types have microvilli (kidney tubules) or cilia (terminal bronchioles of the lungs) 2. Location:
3. Functions:
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Simple columnar epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Single layer of tall narrow cells. Some have cilia (bronchioles of lungs, auditory tubes, uterine tubes, and uterus) or microvilli (intestine) 2. Location:
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Stratified squamous epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Multiple layers of cells that are cuboidal in the basal layer and progressively flatten toward the surface. In moist surfaces, surface cells retain a nucleus and cytoplasm. In keratinized, surface cells are dead. 2. Location:
3. Functions: Protection against abrasion, caustic chemicals, water loss, and infection. |
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Stratified cuboidal epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Multiple layers of somewhat cube-shaped cells 2. Location:
3. Functions:
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Stratified columnar epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Multiple layers of cells with tall thin cells resting on layers of more cuboidal cells. Cells ciliated in the larynx. 2. Locations:
3. Function:
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Pseudostratified Columnar Epithelium:
1. Structure 2. Location 3. Function |
1. Structure: All cells reach basement membrane. Appears stratified because nuclei are at various levels. Almost always ciliated and associated with goblet (mucus-producing) cells 2. Location:
3. Functions:
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Transitional Epithelium:
1. Structure 2. Location 3. Function |
1. Structure: Stratified; cells change shape depending upon amount of distention in the organ 2. Location: Lining of urinary bladder, ureters and superior urethra 3. Functions: Accomodates fluctuations in the volume of fluid in an organ or tube; protection against the caustic effects of urine. |
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Where are cell connections found? |
On lateral and basal surfaces of cells. |
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What are some functions of cell connections? |
1. Form permeability layer 2. Bind cells together 3. Provide mechanism for intercellular (between) communication. |
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What are some types of cell connections? |
1. Desmosomes 2. Tight junctions 3. Gap junctions |
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Define "desmosomes." What substances make up the desmosome? |
Disk-shaped regions of cell membrane; often found in areas that are subjected to stress.
Desmosomes contain especially adhesive glycoproteins. They also contain intermediate protein filaments that extend into the cytoplasm of cells. |
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Define "hemidesmosomes." What do they do? |
Half of a desmosome; attach epithelial cells to basement membrane. |
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What are the two types of tight junctions? And what is their function. |
Zonula adherens are found between adjacent cells. They function as a weak glue that holds cells together. Found in simple epithelium.
Zonula occludens function as a permeability barrier (carrier proteins), e.g. stomach and urinary bladder, chemicals cannot pass between cells. |
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What are gap junctions? Their functions? |
They are protein channels that aid intercellular communication.
1. Allows ions and small molecules to pass through. 2. Coordinate function of cardiac and smooth muscle. 3. May help coordinate movement of cilia in ciliated types of epithelium. |
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How are exocrine and endocrine glands formed? |
By infolding of the epithelium. |
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Define "exocrine." |
Open contact maintained with exterior; ducts. |
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Define "endocrine." |
No open contact with exterior; no ducts; produce hormones (secrete into bloodstream). |
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What are the three methods of secretion? |
1. Merocrine 2. Apocrine 3. Holocrine |
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Merocrine gland |
Cells of the gland produce secretion by active transport or produce vesicles that contain secretory products, and the vesicles empty their contents into the duct through exocytosis. |
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Apocrine gland |
Secretory products are stored in the cell near the lumen of the duct. A portion of the cell near the lumen containing secretory products is pinched off the cell and joins secretions produced by a merocrine process. |
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Holocrine gland |
Secretory prducts are stored in the cells of the gland. Entire cells are shed by the gland and become part of the secretion. The lost cells are replaced by other cells deeper in the gland. |
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How are multicellular exocrine glands classified? |
On the basis of types of ducts or mode of secretion. |
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What are the two types of multicellular exocrine gland ducts? |
1. Simple 2. Compound |
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Define a simple duct in a multicellular exocrine gland. |
Ducts with few branches. |
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Define a compound duct in a multicellular exocrine gland. What are the two types? |
Ducts with many branches.
Acini: ducts ending in tubules or sac-like structures. Alveoli: ducts ending in simple sacs |
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What are four characteristics of connective tissue? |
1. Abundant; found in every oran 2. Consists of cells separated by extracellular matrix 3. Many diverse types (solid, semi-solid, fluid) 4. Performs variety of important functions |
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What are seven functions of connective tissue? |
1. Enclose organs as a capsule and separate organs into layers 2. Connect tissues to one another (tendons and ligaments) 3. Support and movement (bones) 4. Storage (fat) 5. Cushion and insulate (fat) 6. Transport (blood) 7. Protect (cells of the immune system) |
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Blasts |
Create the matrix, example osteoblast (bone-forming cells) |
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Cytes |
Maintain the matrix, example chondrocyte (mature cartilage cells) |
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Clasts |
Break the matrix down for remodeling, example osteoclasts |
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What are the three protein fibers of the matrix? |
1. Collagen 2. Reticular 3. Elastic |
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Collagen |
Most common protein in body; strong, flexible, inelastic (made by fibroblasts) |
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Reticular |
Fill spaces between tissues and organs. Fine collagenous, form branching networks. |
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Elastic |
Returns to its original shape after distension or compression. Contains molecules of protein elastin that resemble coiled springs; molecules are cross-linked. |
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Name three ground substance molecules. |
1. Hyaluronic acid 2. Proteoglycans 3. Adhesive molecules |
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Hyaluronic acid |
Polysaccharide. Good lubricant. Vitreous humor of eye. |
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Proteoglycans |
Protein and polysaccharide. Protein part attaches to hyaluronic acid. Trap large amounts of water. |
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Adhesive molecules |
Hold proteoglycan aggregates together.
1. Chondronectin 2. Osteonectin 3. Fibronectin |
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Define loose (areolar) connective tissue. |
Loose packing material of most organs and tissues, also known as stroma. |
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Name the locations of loose (areolar) connective tissue. |
1. Packing between glands, muscles, and nerves. 2. Attaches the skin to underlying tissues. 3. Often seen in association with other types of C.T., like reticular tissue and fat. |
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What does loose (areolar) connective tissue contain? |
1. Collagen 2. Reticular 3. Elastic 4. All five types of cells |
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Yellow (white) adipose |
Most abundant type, has a wide distribution. White at birth and yellows
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Brown adipose |
Found only in specific areas of body: axillae, neck and near kidneys
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Reticular tissue |
1. Forms superstructure of lymphatic and hemopoietic tissues 4. Found within the lymph nodes, spleen, and bone marrow |
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Dense regular connective tissue |
• Has abundant collagen fibers that resist stretching |
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Dense Irregular Connective Tissue |
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Dense Regular Elastic Connective Tissue |
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Dense Irregular Elastic Connective Tissue |
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Cartilage |
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Perichondrium |
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Types of cartilage |
1. Hyaline (articulating cartilage) |
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Hyaline cartilage
1. Structure 2. Locations |
• Structure:
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Fibrocartilage
1. Structure 2. Locations |
• Structure:
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Elastic Cartilage
1. Structure 2. Location |
• Structure:
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Bone |
Hard connective tissue composed of living cells (osteocytes) and mineralized matrix.
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Bone matrix |
Gives strength and rigidity; allows bone to support and protect other tissues
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Blood plasma |
– Liquid and lacks fibers. |
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Formed elements of blood. |
– Red cells (erythrocyte) |
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Hemopoietic tissues:
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– Forms blood cells |
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Types of bone marrow |
– Red: |
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Characteristics of muscle tissue. |
– Contracts or shortens with force |
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Skeletal muscle |
Most attached to skeleton, but some attached to other types of connective tissue. Striated and voluntary.
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Cardiac muscle. |
Muscle of the heart. Striated and involuntary.
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Smooth muscle |
Muscle associated with tubular structures and with the skin. Nonstriated and involuntary. |
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Parts of a neuron. |
• Cell body: contains nucleus
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Three types of neurons. |
1. Multipolar 2. Bipolar 3. Unipolar |
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Mucous membranes |
– Line cavities that open to the outside of
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Serous membranes |
– Simple squamous epithelium called
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Synovial membranes |
– Line freely movable joints |
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Manifestations (cardinal signs) of tissue damage. |
– Redness “Rubor” |
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Chemical mediators of tissue damage. |
– Stimulate pain receptor and
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Tissue repair |
Substitution of dead/damaged cells by viable/functional cells |
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Labile |
• Capable of mitosis through life. |
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Stable |
• No mitosis after growth ends, but can divide after injury.
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Permanent |
• If killed, replaced by a different type of cell. |
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Primary union |
– Edges of wound are close together
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Secondary union |
Edges of wound are not closed; greater chance of infection |
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Effects of Aging on Tissues |
• Cells divide more slowly |