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30 Cards in this Set
- Front
- Back
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Salivary glands |
exocrine glands that produce saliva (700 – 1100mg per day); The ducts open into oral cavity
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Exocrine
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hormones that go outside blood VIA DUCTS
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Endocrine
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DUCTLESS glands secrete hormones into blood or lymph
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Pancreas
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both an exocrine and an endocrine gland.
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4 Roles of Saliva
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1) INITIATES DIGESTION: salivary amylase, 2) TASTING AND DEGLUTITION: moistens and lubricates via water and glycoproteins synthesized by mucus and some serous glands, 3) ANTIBACTERIAL (3): Latoferrin binds iron, which is a nutrient necessary for bacterial growth; Lysozyme hydrolyzes bacterial cell wall; Immunoglobulins are secreted by acinar and duct cells, 4) PARTICIPATE IN CLOTTING AND WOUND HEALING: Clotting factors and epidermal growth factor
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Amylase
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powerful and fast-working enzyme that starts the breakdown of carbohydrates immediately.
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3 Major Salivary Glands (in pairs)
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1) PAROTID: serous and makes 30% of saliva (LARGEST at 20-30g), 2) SUBLINGUAL: mixed (but mostly mucus saliva)and makes 5% of saliva (SMALLEST at 2-3g), 3) SUBMANDIBULAR: mixed and makes 60% of saliva (medium size at 12-15g); *There are also many minor salivary glands, most of which are mucus glands; Know numbers?
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Parotid gland
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Contains secretory granules of salivary amylase AND high levels of secretory IgA; Highly developed connective tissue
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Sublingual
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Contains many mucus cells with serous demilunes; Contains Several ducts open into the floor of the mouth and into the duct of the submandibular gland
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Serous gland
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Makes MORE FLUID AND PROTEIN THAN CARBS but secretes both proteins and polysaccharides
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Histology of serous cells
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1) APPEARANCE: pyramidal cells with round nucleus at the base; broad base and narrow apical surface; 2) ARRANGEMENT: Acinar/alveolar arrangement; 3) FEATURES: short irregular MICROVILLI; Well developed RER, GOLGI and BASAL MITOCHONDRIA for making proteins/enzymes; SECRETORY GRANULES rich in salivary amylase (or ptyalin);
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Histology of mucus cells
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1) APPEARANCE: Cuboidal to columnar; Oval (flattened) nuclei pressed towards the base; 2) ARRANGEMENT: Tubular arrangement; 3) FEATURES: Fewer mitochondria and less extensive RER, GREATER GOLGI complex for carb secretion; Abundant secretory granules at apical portion; *Look of the nucleus is major difference when looking at pic of mucus vs serous cell
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Mucus gland
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Makes more carbohydrates
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2 Parts of Glands
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1) EPITHELIAL TISSUE: penetrates into underlying tissue to become the gland itself, 2) BASAL LAMINA: Consists of PARENCHYMA (secretory units and ducts) and STROMA (connective tissue)
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2 Types of Secretary Pathways
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1) CONSTITUTIVE: secreted on a continuous basis, 2) REGULATED: Secreted only when prompted by a signaling molecule/ligand
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Simple Duct
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No branching
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Compound Duct
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Branching
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3 Types of Compound ducts
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1) Tubular, 2) Acinar or Alveolar, 3) Tubuloalveolar
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Tubuloalveolar gland
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Secretary units surrounded by connective tissue capsule that sends septae that divide the gland into small compartments (lobes and lobules); Amalgamation of diff types of cells
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Salivon
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Functional unit of a salivary gland
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3 Parts of a salivon
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1) Acinus: secretory portion, 2) Intercalated duct: connects acinus to striated duct, 3) Striated duct
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3 types of cells in the acinus (secretory portion; also called Terminal secretory units)
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1) Serous cells, 2) Mucus cells, 3) Myoepithelial cells (basket cells)
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2 Types of ducts
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1) Intercalated (smallest), 2) Terminal/Principal ducts (largest; also called Excretory ducts); *Ducts are generally highly branched
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Myoeptihelial cells (Function, Features, Histo)
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1) FUNCTION: Surrounding acini and intercalated ducts; Contract their cytoplasmic processes to press the acinus and facilitate release of secretory process (resembles smooth muscle cells); 2) FEATURES: Rich in actin and myosin with cytoplasmic processes; 3) HISTO: Spindle shaped cells running parallel to mucus acini and intercalated ducts; *Also called basket cells
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Order of Duct System (6)
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1) Intercalated duct (single layer of cuboidal cells), 2) IntraLOBULAR Duct/Striated duct (cuboidal; transports ions), 3) InterLOBULAR, 4) IntraLOBAR, 5) InterLOBAR (stratified cuboidal changing to stratified columnar; *Stratified columnar processes saliva before secretion), 6) Main Duct (stratified squamous epithelium emptying into oral cavity)
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Striated Duct (IntraLOBULAR) (Function, histo, features)
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FUNCTION: Ion-transporting cell that pumps sodium out of the cell into the connective tissue to conserve sodium, HISTO: Radial striations from base to nucleus, FEATURES: Infoldings of basal plasma membrane with elongated mitochondria, Basolateral membranes have Na+-ATPase that pumps out sodium
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PNS Stimulation of salivary glands
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smell and taste of food provokes a copious watery secretion with relatively little organic content
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SNS Stimulation of salivary glands |
produces small amount of viscous saliva rich in organic material
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Blood supply to salivary glands
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Very rich; 20 times more than the flow of blood to skeletal muscles
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How much saliva is secreted per day?
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700-1100ml per day |
