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79 Cards in this Set
- Front
- Back
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What kind of epithelium is vascular (has blood supply?)
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Only inner ear
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Simple Squamous Epithelium functions:
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Ion and gas exchange
Diffusion Filtration |
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Locations of Simple Squamous Epithelium
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Air sacs of lungs (alveoli)
Lining of all blood and lymph vessels (endothelium) Bowman's Capsule of kidney Thin loop of henle Serosa of organs |
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Bowman's Capsule of kidney
Thin loop of henle Which kind of epithelium are these made of? |
Simple Squamous Epithelium
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Simple Cuboidal functions:
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Secretion
Absorption |
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Simple Cuboidal Epithelium locations:
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Germinal Epithelium of Ovary
Kidney tubules Lining of ducts or various glands Bile Ducts Bronchioles |
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Simple Columnar Epithelium Functions:
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Secretion
Absorption |
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Simple Columnar Locations:
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Uterus and uterine tube
Stomach Intestines Gall Bladder Part of Cervix |
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Pseudostratified Columnar functions:
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Secretion
Absorption |
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Pseudostratified Columnar Locations:
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Respiratory passages (trachea, bronchus)
Male reproductive system (epididymus, ductus deferens) Regions of male urethra |
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Stratified Squamous Keratinized Epithelium Function:
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Protection
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Stratified Squamous Keratinized Epithelium Location:
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Skin (epidermis)
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Stratified Squamous Non-Keratinized Function:
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Protection
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Stratified Squamous Non-Keratinized Location:
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Oral Cavity
Esophagus Vagina Portions of Cervix Cornea Nasal Cavity Urethra Rectum |
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Transitional Epithelium Functions:
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Protection
Distensibility |
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Transitional Epithelium Locations:
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Urinary System
(Urinary bladder, Ureter, part of Urethra) |
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Stratified Cuboidal or Stratified Columnar Functions:
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Protection
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Stratified Cuboidal or Stratified Columnar Locations:
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INFREQUENT
occasionally seen in areas going from one kind of epithelium to another, usually to/from stratified squamous (ducts, conjunctival fornix) |
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Three kinds of Epithelial surface specializations:
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Microvillus
Stereocilium Cilium |
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Of the 3 kinds of Epithelial surface specializations, which are Non-motile and which are motile cell projection?
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Microvillus - Non-motile
Stereocilium - Non-motile Cilium - Motile |
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Function of Microvillus?
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Increases cell surface area for a more efficient absorption.
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Function of Stereocilium?
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Increases cell surface area for a more efficient absorption.
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Where are MIcrovillus present?
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On free edges of most epithelial cells.
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Where are Stereocilium present?
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In epididymis (next to masses of sperm)
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Function of Cilium (as part of epithelial surface specializations)?
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Provides for rapid movement and increases cell surface area.
Clearance of particles and toxins from the lung. Moves fluid, egg, and sperm. |
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Where are Cilium present?
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Lung airways.
Move mucus blanket cephalad. Reproductive system. |
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What are both Microvillus and Stereocilium composed of?
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Microfilaments (actin).
Surface is coated with Glycocalyx. |
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What is Glycocalyx?
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Carbohydrate oligosaccharide of the cell membrane glycoproteins.
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Which is larger - Microvillus, Stereocilium, or Cilium?
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Microvillus (smallest) - 1-2um
Cilium - 5-10um Stereocilium - 7-12um |
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Structure of Cilium?
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Contains microtubules 9+2 doublets and Dynein arms.
Coolness: Beat synchronously 15-22/sec |
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What do the Brush border in kidney, Striated border in small intestine, and Stereocilia have in common?
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They all have microvilli
Stereocilia: Long microvilli |
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What maintains the structure of a Microvilli?
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Actin filaments that protrude out from the cell membrane and cytoplasm. Derived from the terminal web which is the cytoskeleton of the cell.
Without actin it would be resorbed and broken down. |
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Glycocalyx main functions:
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Forms Receptors on cell surface.
Identifies what is being absorbed. |
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What is the Cilium Basal Body?
What is its structure? |
The embryo and base of cilium.
1-2um cylinder contains microtubules in a 9+0 triplet similar to centrioles. |
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What is the Zonula Occludens? (ZO)
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Tight Junction.
Completely encircles cells, adjacent membranes fuse, ZO blocks diffusion between cells. It acts as a permeability seal. Responsible for the BBB (blood brain barrier). |
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What kind of cell-cell junction forms the Blood Brain Barrier?
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Zonular Occludens
(Tight Junctions) |
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What is the Zonula Adherens (ZA)?
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Intermediate Junction.
Completely encircles cells, Smaller intercellular space remains, associated with filaments, structural support usually within a cell, varient (fascia adherens) in cardiac muscle connects cells at the intercalated disk. |
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What kind of cell-cell junctions are seen in the cardiac muscles?
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Zonula Adherens
(Intermediate Junctions) |
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In absence of Tight Junctions..?
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There is diffusion from cell into lumen.
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What is the Macula Adherens (D)?
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Desmosomes.
Spot junction, small intercellular space with electron dense material between cells. Associated with internediate filaments, a strong spot attachment of cells, best seen in stratum spinosum of epidermis. |
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What is a Hemidesmosome?
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Hemidesmosomes are associated with basal surface of epithelium - half of a desmosome. Attaches Epithelial cells to the basal lamina. (basement membrane)
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What is the Macula COmmunicans/Nexus junction?
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Gap junction.
Spot junction, small intercellular space with bridges connecting cells to permit flow of small molecules from cell to cell. Links cell ionically and electronically (muscle). |
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What is the Basement membrane an interface between?
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Between epithelium and connective tissue.
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Two parts of Basal Lamina: classified by density.
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Lamina Lucida
Lamina Densa Structure is an acellular fibrillar sheet underlying the epithelium, secreted by epithelial cells. Other types also secrete their own Basal Lamina: Muscle cells, Adipose cells, Schwann cells, Astrocytes, and Glial cells. |
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Lamina Lucida made up of:
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Laminin, Entactin, Integrin, Fibronectin (GP), Heparan Sulfate (GAG)
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Lamina Densa made up of:
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Collagen type 4, Perlacan, Fibronectin (GP), Heparan sulfate (GAG)
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Heparan Sulfate
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Found in Basement Membane and Connective Tissue.
Very charged molecule. |
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Reticular Lamina consists of:
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Anchoring fibrils and plaques and C.T fibers, reticulin, GAGs, continuous with the surrounding C.T.
Structure: acellular fibrillar mesh underlying the basal lamina, secreted by C.T. cells. |
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Functions of Basement Membrane:
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Structural attachment and mechanical integrity for cells.
Permeability barrier, filtration. Determine cell polarity, differentiation, and metabolism. Scaffold or guide during regeneration after injury. |
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Basement Membrane role in cancer:
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Epithelia can proliferate abnormally and form tumors. Basement Membrane delineates epithelium from C.T. acting as a separator.
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Benign Tumors and Basement Membrane:
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Localized overgrowths in the area they arise, usually without breaching Basement Membrane. (papillomas)
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Malignant Tumors and Basement Membrane:
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Tumors containing cells that invade adjacent tissues and spread (metastasize) to distant sites.
T metastasize, the cell must lose their cell-cell adhesions and then penetrate the basal lamina to reach the underlying connective tissue. The cancer cells can then enter the blood vessels or lymphatics to spread. Malignant tumors of epithelial origin are called Carcinomas. |
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What is Carcinoma?
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Malignant tumors of epithelial origin are called Carcinomas.
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Without a basement membrane in muscle cells?
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The individual muscle cells can still contract but they won't contract the entire muscle since they wouldn't be connected to anything to latch on to.
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The epithelial cells specialized for secretion are called:
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Glands.
Two basic types: Exocrine and Endocrine glands |
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Exocrine Glands:
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Secrete onto epithelial surface. Cells release their product at the apical surface.
Usually associated with hollow epithelial tubes called ducts. Develop from and remain connected to the surface epithelia by their ducts. |
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Endocrine Glands:
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Secrete their product towards the basal lamina and connective tissue (basal surface) where the secretion of the hormone enters capillaries and travels throughout the vascular system to target cells (cells with receptors for the hormones).
NO DUCTS. |
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Exocrine glands have 3 modes of secretion:
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Merocrine (eccrine)
Apocrine Holocrine |
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Merocrine (eccrine)?
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Exocrine gland secretion.
Secretory vesicles are discharged by exocytosis with no appreciable loss of cytoplasm. Most glands are Merocrine. |
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Apocrine Secretion
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Exocrine secretion.
Secretory vesicles are discharged with loss of some apical cytoplasm. Mammary glands and some sweat glands are good examples. |
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Mammary glands and some sweat glands are good examples of what type of exocrine secretion?
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Apocrine
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Holocrine Secretion
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Exocrine secretion.
Secretory vesicles are discharged when the entire cell explodes. Sebaceous glands and tarsal glands are holocrine. |
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4 Shapes of Exocrine secretory units:
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Alveolar (acinar)
Tubular Coiled Tubular Branched Tubular |
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2 types of Exocrine arrangement of ducts:
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Simple - Single, unbranched
(simple alveolar gland) Compound - Duct branches (tubuloalveolar gland) |
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Glands have two major classifications of secretions:
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Serous or Mucous.
***Glands associated with the skin (sweat glands) are not classified in this manner. |
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Mucous glands secrete:
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Slimy, viscous, lubricating mucus (glycoprotein)
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Mucous Glands - EM appearance
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Cytoplasn is filled with lightly staining secretory granules filled with mucin. The basal portion of the cell has RER, a well developed golgi complex, and a flattened nucleus.
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Mucous Glands - LM appearance
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Empty, clear or vacuolated cytoplasm (mucus dissolved away), with a flat, heterochromatic nucleus at the base of the cell.
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Mucous secreting cells
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Exist as single isolated cells (goblet cells, as entire epithelial sheets, or as cells in large discrete glands.
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Mucous cells - Goblet cells
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Mucous cells with a characteristic, water goblet shape, found scattered in epithelial sheets throughout the body.
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Serous Cells
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secrete a watery protein rich secretion.
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Serous Cells - EM appearance
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RER fills the basal portion of the cell, the golgi apparatus is located above the nucleus, and dense secretory vesicles fill the apical portion of the cell.
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Serous Cells - LM appearance
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Round polyhedral or pyramidal shaped cell with round, euchromatic nucleus in the basal half of the cell. THe cytoplasm is basophilic with visible secretory granules.
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A glad can be classified as:
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Serous Gland (only serous cells)
Mucous Gland (only mucous cells) Mixed Gland (both serous and mucous cells, seromucous) |
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What is an Adenoma?
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Benign epithelial tumors derived from glands
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What is an Adenocarcinoma?
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Malignant epithelial tumors derived from glands
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Adenoma VS. Adenocarcinoma
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Adenoma: Benign
Adenocarcinoma: Malignant Epithelial tumors derived from glands. |
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A lot of Rough ER is found in a Serous or a Mucous cell?
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Serous
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Heterochromatic nucleus VS. Euchromatic nucleus found in which cells?
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Serous cell: Euchromatic round nucleus
Mucous cell: Heterochromatic flattened nucleus |
