Flashcards in Lecture 9: Epithelial Glands Part II Deck (13):
What is the difference between parenchyma, and stoma, and septa?
- The components of the gland derived from epithelium (secretory units and ducts) comprise the parenchyma.
- The connective tissue capsule surrounding the entire gland as well as the connective tissue partitions separating the lobules and lobes comprise the stroma.
- Septa (trabeculae) are extensions of the capsule into the epithelial components of the gland that divide the gland into subdivisions called lobes and lobules.
Give the difference between a lobule and a lobe
Lobes: A lobe is a subdivision of a compound gland separated from adjacent lobes by septae.
- Lobules: A lobule is a subdivision of a lobe. Lobules are separated from each other by delicate septae. Each lobule is equivalent to a simple, branched gland.
Define an Acinus
* Acini are the secretory components of a lobule.
* Acini may be serous, mucous, or sero-mucous (mixed)
* Basement membrane covers the outer surface of the acinus.
* Myoepithelial cells are found between the basement membrane and the secretory cells of the acinus.
- Myoepithelial cells are derived from epithelium but are characterized by extensive actin bundles resulting in contractility.
- Myoepithelial cells help to express the secretions of the acini into the intercalated ducts.
What are intralobular ducts?
What are the two types of intralobular ducts?
- Intralobular ducts are ducts that lie within a lobule.
- Intercalated Ducts
- Striated Ducts
Describe intercalated ducts
- Drain the secretory acini.
- Lined by simple squamous epithelium transitioning to low cuboidal epithelium.
- Involved in bicarbonate/chloride ion exchange.
Describe Striated Ducts
- Lined by cuboidal epithelium transitioning to columnar epithelium with basal striations (for active transport).
- Actively reabsorb sodium ions; passively reabsorb chloride ions; actively secrete potassium ions.
Describe Interlobular Ducts
- Interlobular ducts are formed by the confluence of two or more striated ducts and are found in the septae between adjacent lobules.
- These ducts are lined with pseudostratified columnar epithelium.
Describe Intralobar Ducts
(Yes, you are officially being fucked with now.)
- Intralobar ducts are joined by the confluence of two or more interlobular ducts.
- Intralobar ducts are lined with columnar epithelium transitioning into stratified columnar epithelium
Describe Lobar Ducts
- They are formed by the confluence of two or more intralobar ducts.
- Lobar ducts are lined with stratified columnar epithelium.
Review Slide 10 on Lecture 9 to make sure you understand the hierarchy of all those ducts and lobes and shit.
Describe the 4 minor salivary glands and their general function
- Located throughout the oral cavity and include:
- Von Ebner’s glands, labial glands, palatal glands, and buccal glands.
- These glands keep the surface of the oral cavity moist.
What are the 3 Major Salivary Glands and give their purpose
- Parotid glands: The parotid glands are composed only of serous acini.
-Submandibular glands: The submandibular glands are mixed glands with both mucous and serous acini, but the serous acini are predominant. Serous secretory cells form a crescent-shaped configuration around the mucous acini; these are called serous demilunes.
- Sublingual glands are also mixed glands, but the mucous acini are predominant.