TCDHA Histology & Embryology Test 2 Questions With Correct Answers

Exocrine Glands - Answer gland that secretes its products through excretory ducts to the surface of an organ or tissue or into a vessel Endocrine glands: - Answer glands that secrete chemicals called hormones directly into the bloodstream Exocrine glands have 4 characteristics; - Answer 1. Duct system 2. Shape of secretory unit 3. Mode of Secretions 4. Nature of secretion Serous Secretions are - Answer Clear, watery, with protein. Contains digestive enzyme Amylase Mucous Secretions are - Answer cloudy, mucin (glycoproteins) with water Unicellular Secretory Unit - Answer Goblet Cells Multicellular secretory unit - Answer Tubular, alveolar/acinus Merocrine Glands - Answer secrete product through free surface, no loss of cytoplasm/cell (salivary glands, pancreas) Apocrine Glands - Answer Secrete small amounts of cytoplasm/cell with secretory product. Apical portion pinches off + detaches. Ex. Mammary glands Holocrine Glands - Answer entire cells are discharged as secretion (sebaceous glands) Acinus/Acini - Answer Consists of single layer cuboidal epithelial cells surrounding a lumen(central opening) where the saliva is deposited after being produced by secretory cells Located at terminal part of gland Intercalated duct - Answer Duct associated with acinus or terminal part of salivary gland. Parotid Gland - Answer Largest (Stensons Duct) Duct system consists of LONG intercalated ducts and SHORT striated ducts with basal striations. Serous secretion 25% salivary volume Mumps - Answer viral infection of the parotid gland Submandibular Salivary Gland - Answer Medium, capsulated gland Wharton's duct, opens under tongue near frenum at sublingual caruncle Duct system consists of SHORT intercalated ducts and LONG striated ducts with basal striations 60-65% salivary volume Mixed gland, but serous dominates Sublingual Salivary Gland - Answer Under tongue Smallest, NO capsule Bartholins Duct Mixed, but mainly mucous 10% salivary volume Mucocele - Answer accumulation of saliva in mucosa due to trauma to minor salivary duct Xerostomia - Answer dry mouth Enamel - Answer Avascular, NON vital 96% inorganic - mainly calcium hydroxyapatite 1% organic - enamelin (protein component) Amelogenesis - Answer Process of enamel matrix formation and mineralization Occurs during APPOSITIONAL STAGE (formation of enamel/dentin matrix) of tooth development. Does NOT contain collagen proteins; dentin, cementum, alveolar bone. Dentin MUST be present Enamel matrix is produced by - Answer Ameloblasts (and secreted by Tomes Process) Enamel Pearl - Answer Small spherical enamel projections on tooth surface Enamel Dysplasia - Answer faulty development of enamel Structure of Enamel - Answer Rods aligned PERPENDICULAR to DEJ except in cervical regions of PERMANENT teeth. Line of Retzius - Answer Concentric series of bands on the enamel rods, represent incremental growth lines that extend from DEJ Neonatal Line - Answer Pronounced line of retzius, marked by stress/trauma experienced by ameloblasts during birth Nasmiths Membrane - Answer (primary enamel cuticle) - A delicate membrane covers the entire crown of the newly erupted tooth. Green or yellow and is easily worn away.