Lecture Outline - General Human Anatomy

LECTURE OUTLINE & REVIEW QUESTIONS LECTURE OUTLINE: GLANDS Two major classes of glands: Endocrine Exocrine Endocrine Glands AKA: Glands of internal secretion, ductless glands Development Epitheliummitosisglandular primordium Apoptosis breaks epithelial connection Capsule formation & infiltration by blood vessels General Functions Gland cells  hormones  tissue fluids  capillaries  bloodstream  capillaries  tissue fluids  target cell activity regulation Examples Adenohypophysis - “clumps” of cells Adrenal cortex – “cords” of cells Thyroid – “follicular” Hormone stored in follicles until release Cytocrine Cells Cytokines = “local hormones” Paracrine cell  hormone  tissue fluid target cell activity regulation Autocrine cell  hormone  tissue fluid  self (autocrine cell) ANATOMY 25 - GUTHRIE Exocrine Glands AKA: Glands of external secretion, ducted glands “Unicellular” Goblet cells. Always in epithelia. Secrete mucus. Multicellular Development: Epitheliummitosisglandular primordium Apoptosis “hollows” out primordium  duct + secretory unit. Myoepithelial cells. Surround secretory unit cells. Help express secretion. Structural Classification Simple Glands One unbranched duct + one or more secretory units Simple Alveolar or Acinar Duct: single, unbranched Secretory unit shape: round or ovoid alveolus (pl.= alveoli; adj. alveolar) acinus (pl. = acini; adj. acinar) Simple Branched Alveolar or Acinar Duct: single, unbranched Two or more alveoli or acini empty into duct Example: Sebaceous gland, skin Simple Tubular Duct: single, unbranched Secretory unit shape: tubular Simple Branched Tubular Duct: single, unbranched Two or more tubular secretory units empty into duct LECTURE OUTLINE & REVIEW QUESTIONS Examples: simple tubular: colon simple branched tubular: stomach simple coiled tubular: sweat gland Compound Glands Branched duct system + many secretory units Compound Alveolar or Acinar Duct branched Secretory unit shape: round, ovoid, or flask-like Compound Tubular Duct branched Secretory unit shape: tubular Compound Tubuloalveolar or Tubuloacinar Duct branched Secretory units: tubular with expanded ends More About Compound Glands: Basic Organization & Terminology Parenchyma = gland secretory units & ducts Stroma = supporting connective tissues Capsule & septa Lobes & Lobules Duct terminology: Secretory cells  intercalated ducts  intralobular ducts  interlobular ducts  lobar ducts  main (excretory) duct Example: sublingual salivary gland, light microscope ANATOMY 25 - GUTHRIE Secretory Unit Terminology: Mucous units: light staining; secrete mucus solution Serous units: dark staining; secrete watery solution Serous demilunes Crescent-like array of serous cells around a mucous secretory unit. On the basis of their secretory units, compound glands are often described as mucous, serous, or mixed (seromucous). Example: submandibular salivary gland, light microscope. Modes of Secretion Describes how gland cells (exocrine or endocrine) release their secretion from the cell. Merocrine No loss of cytoplasm Most gland cells Apocrine Some loss of cytoplasm & plasmalemma Mammary glands Holocrine Accumulation of secretion Cytolysis  release of secretion + cellular debris Sebaceous glands Regulated pathway: gland cell stores its secretion until it receives a “signal” to release it. Constitutive pathway: gland cell continuously releases its secretion. LECTURE OUTLINE & REVIEW QUESTIONS REVIEW QUESTIONS 1. Select the incorrect statement about all glands. (a) They may be unicellular or multicellular. (b) They synthesize and secrete useful substances (c) They are derived from epithelia (d) They release their secretions into the bloodstream. (e) They are either endocrine or exocrine. 2. Select the incorrect statement about exocrine and endocrine glands. (a) Both are produced by mitosis of epithelial cells. (b) Both begin as a glandular primordium. (c) In endocrine glands, apoptosis and cytolysis destroys the primordium’s connection to the epithelium. (d) In exocrine glands, apoptosis and cytolysis convert the primordium into duct(s) and secretory unit(s). (e) In exocrine glands, the secretory unit cells are called myoepithelial cells. 3. Hormones _?_. (a) are produced and released by endocrine gland cells (b) are transported by the bloodstream (c) affect only cells with the appropriate cell membrane receptors (d) affect the rates at which target cells perform specific functions (e) all of these 4. _?_ cells release cytokines that diffuse through the tissue fluids and regulate the activities of nearby cells; _?_ cells release substances that regulate their own activities. (a) autocrine, paracrine (b) paracrine, autocrine (c) endocrine, exocrine (d) cytocrine, exocrine (e) none of these 5. During _?_ secretion, the unit membrane surrounding a secretory droplet is incorporated into the cell membrane; during _?_ secretion, the secretory product is released along with a small amount of cell membrane and cytoplasm; and during _?_ secretion, the secretory product is released by cytolysis of the cell that produced and stored it. (a) apocrine, merocrine, holocrine (b) merocrine, apocrine, holocrine (c) holocrine, apocrine, merocrine (d) apocrine, holocrine, merocrine (e) none of these ANATOMY 25 - GUTHRIE 6. Goblet cells _?_. (a) are cytocrine cells (b) are located in epithelia and secrete mucus (c) are located in endocrine glands and secrete hormones (d) all of these (e) none of these 7. If a gland has a branched duct, then it must be a _?_ gland. (a) simple endocrine (b) simple exocrine (c) compound exocrine (d) compound endocrine (e) paracrine 8. If an exocrine gland has an unbranched duct and a long, narrow secretory unit, then it would be described best as _?_. (a) simple alveolar (b) simple tubular (c) simple acinar (d) compound tubular (d) compound alveolar 9. If a gland has an unbranched duct and two or more rounded secretory units attached directly to the duct, then it would be described best as _?_. (a) compound tubular (b) simple branched tubular (c) simple branched acinar (d) simple tubular (e) compound branched acinar 10. If a gland has a branched duct and tube-like secretory units that are expanded at their ends, then it would be described best as _?_. (a) compound tubular (b) simple branched tubuloacinar (c) compound tubuloalveolar (d) simple tubular (e) simple branched tubuloalveolar 11. Through which of the listed parts of the duct system would a secretion pass fourthly after it is released from the secretory unit cells ? (a) main (b) intralobular (c) lobar (d) interlobular (e) intercalated 12. The stroma of a compound gland _?_. (a) is connective tissue (b) provides pathways for blood vessels, nerves, and ducts (c) forms a supportive "skeleton" for the gland (d) all of these (e) none of these. LECTURE OUTLINE & REVIEW QUESTIONS 13. The epithelial components of a compound gland - its secretory units and ducts - are referred to as the gland _?_. (a) primordium (b) stroma (c) parenchyma (d) none of these 14. Serous secretory unit cells (a) release a watery secretion (b) usually have oval to round nuclei (c) usually have a granular looking cytoplasm (d) stain more darkly than mucous cells (e) all of these 15. Mucous secretory unit cells (a) release a viscous fluid (b) have nuclei that are compressed toward the base of the cell (c) have a "fluffy" appearing cytoplasm (d) stain more lightly than serous cells (e) all of these 16. A group of serous cells arranged in a crescent around a mucous secretory unit is called a serous _?_. (a) demilune (b) desmosome (c) desmin (d) demimonde (e) demifacet 17. Compound glands are described as mucous, serous, or seromucous on the basis of the characteristics of their _?_. (a) ducts (b) lobes (c) secretory units (d) stroma (e) lobules 18. Which of the following is not necessarily characteristic of a gland cell synthesizing and secreting large amounts of protein ? (a) a prominent nucleolus (b) a well-developed smooth endoplasmic reticulum (c) a well-developed Golgi apparatus (d) a welldeveloped rough endoplasmic reticulum (e) prominent areas of euchromatin. 19. Myoepithelial cells _?_. (a) are contractile (b) are associated with the secretory units of some exocrine glands (c) may help move secretions into the duct system (d) all of these (e) none of these. ANATOMY 25 - GUTHRIE