Lecture 8: Epithelial Glands Part I Flashcards
Give the primary difference between endocrine glands and exocrine glands
- Exocrine glands are epithelial outgrowths into underlying connective tissue that retain their connection to the overlying epithelium in the form of one or more ducts.
- Endocrine glands are epithelial outgrowths into underlying connective tissue that lose their connection to the overlying epithelium. These glands lack ducts and must secrete their product (hormone) directly into surrounding blood vessels.
How are exocrine glands formed? What are some examples?
Secretory cells may remain incorporated within the epithelial layer (unicellular glands) or may grow down into the underlying connective tissue (multicellular glands).
- If the epithelial down growth remains connected to the epithelial layer from which it originated, this gives rise to an exocrine gland.
- Exocrine glands include salivary glands, mammary glands, sweat glands, sebaceous glands, liver, and pancreas. This type of gland secretes its product via a duct derived from the original connection to the epithelial layer.
How are endocrine glands formed and what are some examples of them?
- The epithelial down growth may degenerate, leaving the secretory tissue isolated from its parent epithelial layer: This gives rise to an endocrine gland.
- Endocrine glands include pituitary, thyroid, pineal, parathyroids, adrenals, gonads, liver, and pancreas. This type of gland secretes its product (a hormone) into surrounding blood vessels.
What are the 3 types of secretion a gland can have?
- Serous: Watery, enzyme-filled secretion.
- Example: parotid salivary gland
- Mucous: Thick, mucin-containing secretion.
- Mixed (serous-mucous): Secretion is a combination of serous and mucous.
- Mixed Example: Acinus is typically mostly mucous capped by a half moon shaped group of serous cells forming a serous demilune.
- Another Example: Submandibular and sublingual glands.
What kind of cells can have ductal branching?
- Simple multicellular glands do not exhibit ductal branching.
- Compound multicellular glands have ductal branching.
- Don’t really know the difference at the time of making this flashcard.
What are some the types of ductal branching/non-branching glands can have?
(Review Slide 12, and Slide 14 - Lecture 8)
- Simple excretory duct - Secretory portion could be: (Tubular, Coiled, Tubular-branched, or Acinar/alveolar)
- Compound (branched) excretory duct - Secretory portion could be (Branched tubular, Branched alveolar(acinar), or Branched tubuloalveolar (-acinar))
Give examples of glands with each of the types of gland shapes
- Tubular:
- Straight: crypts of Lieberkuhn in large intestine
- Coiled: sweat glands of skin
- Branched: fundic, pyloric, and cardiac glands of stomach
- Alveolar(Acinar):
- Meibomianglands of eyelid
- Sebaceous glands of skin
- Tubuloalveolar(-acinar):
- Salivary glands
- Brunner’s glands of duodenum
- Mucous glands of esophagus
What are the 3 mechanisms of secretion and give an example of each.
(Review Slide 17)
- Merocrine (eccrine): Secretory product is typically stored in membrane-bound vesicles, and cytoplasm/cell membrane is retrieved in an exocytosis endocytosis cycle. This includes most glands.
- Apocrine: Apical cytoplasm is released along with secretory product. Examples include axillary sweat glands.
- Holocrine: The entire cell is released as part of the secretory product. An example is Sebaceous glands.
Review gland photomicrographs from this chapter. And all the other ones.
(Slides 18, 20-26)
DO IT!
Give a comparison of the 3 different Salivary Glands
- Submandibular Gland:
- Both serous and mucous cells
- Serous cells form serous demilune capping mucous acini.
- Myoepithelial cells surround acini.
- Sublingual Gland:
- Mucous acini (pale in appearance)(PAS+)
- Flattened nuclei at basal poles of cells
- Myoepithelial cells surround acini.
- Parotid Gland:
- Serous acini
- Apical regions contain zymogen granules.
- RER predominates in basal regions of secretory cells.
