Lecture 7 Flashcards
(34 cards)
Define Endocrine Glands
epithelial downgrowth may degenerate, leaving the secretory tissue isolated from it’s parent epithelial layer
Lack ducts and secrete their own product (hormone) into surrounding blood vessels
give an example of an endocrine gland
Pituitary, thyroid, pineal, parathyroids, adrenals, gonads, liver, and pancreas
Define Exocrine Glands
the epithelial downgrowth may remain connected to the epithelial layer from which it originated
Retain their connection to the overlying epithelium in the form of one or more ducts
Give an example of an exocrine gland
Salivary glands, mammary glands, sweat glands, sebaceous glands, liver, and pancreas
what are the 4 types of glandular secretion? describe them
Exocrine: product transported via a ducts system (usually to the lumen or surface of an organ)
Endocrine: product is released directly into the blood in the absence of a duct
Paracrine: secretion product directly affects neighboring cells
Autocrine: secretion product affects the cell that released the product
what are the patterns of ductal branching? describe them
Simple and Compound
Simple: one duct
Compound: more than one duct
what are the types of secretory components that glands can have?
Tubular:
Alveolar (Acinar): flat shape, sort of like a erlenmeyer flask
Tubuloalveolar: mix of the 2
what are the 3 subdivisions of tubular types of secretory components in glands?
straight, coiled, and branched
What are the three types of Major salivary glands?
Parotid glands
Submandibular Glands
Sublingual Glands
Compare simple and compound styles of excretory ducts
Simple means “unbranched” so just one duct
Compound means branched
Describe Serous secretions and give an example
watery, enzyme filled secretion
Ex. Parotid salivary gland
Describe Mucous secretions
thick, mucin containing secretion
Describe serous-mucous secretions and give an example
combination of serous and mucus secretions
Ex. Submandibular and sublingual glands
Describe Merocrine secretion mechanism
secretory product is stored in membrane bound vesicles and the cytoplasm is retrieved in a cycle of exocytosis and endocytosis (cells isn’t really losing any cytoplasm)
Most glands use this mechanism
what is another name for merocrine?
eccrine
Describe Apocrine secretion mechanism
“a pop the top off” the apical cytoplasm is released along with the secretory product
Ex. Axillary sweat glands
Describe Holocrine secretion mechanism
“holocaust” the entire cells is released as part of the secretory product (cell dies and loses all cytoplasm)
Ex. Sebaceous glands in hair follicles.
Define Parenchyma
components of the gland that are derived from the epithelium (secretory units and ducts)
“Has high cellularity”
Define Stroma
connective tissue that surrounds the gland and creates the partitions between lobules and lobes
Describe the hierarchical structure of a compound gland in terms of lobes and lobules
Lobes: subdivision of a compound gland, separated by septae
Lobules: subdivision of a lobe, and are separated from one another by delicate septae
Describe the hierarchical structure of a compound gland in terms of Acinus, Lobular ducts, Intralobular ducts, and interlobular ducts
Acinus
Interlobular ducts
Intralobular ducts
Lobular duct
What are the 2 types of intralobular ducts?
○ Intercalated ducts: drain the secretory acini and are lined by simple squamous epithelium transitioning to low cuboidal epithelium
Striated ducts: actively reabsorb Na+ ions; passively reabsorb Cl- ions ; actively secrete K+ ions
Define Acinus
secretory component of a lobules whose outer surface is covered by the basement membrane
Myoepithelial cells are sometimes found between the basement membrane and the acinus
May be serous, mucous, or sero-mucus
Define Interlobular ducts. where are they found?
lined with pseudostratified columnar epithelium and are formed by the confluence of 2 or more striated ducts (smaller one)
Found in septae
