Glandular epithelium Flashcards
Epithelia of ________ a
re organized as a continuous system composed of many small secretory portions and ducts that transport the secretion out of the gland.
exocrine glands
Glands can be
simple (ducts not branched) or
compound (ducts with two or more branches)
Secretory portions can be
tubular
acinar
(either short or long and coiled)
Tubular
(rounded and saclike)
either type of secretory unit may be branched, even if the duct is not branched.
Acinar
can have branching ducts and can have multiple tubular, acinar, or tubuloacinar secretory portions
Compound glands
Compound glands can be:
Tubular
Acinar (Alveolar)
Tubuloacinar
Elongated secretory portion; duct usually short or absent
Mucous glands of colon;
intestinal glands or crypts (of Lieberkühn)
Simple - Tubular
Several long secretory parts joining to drain into duct
Glands in the uterus and stomach
Simple - Branched Tubular
Secretory
portion is very long and coiled
Sweat glands
Simple - Coiled Tubular
Rounded, saclike secretory portion
Small mucous glands along the urethra
Simple - Acinar (or Alveolar)
Multiple saclike secretory parts entering the same duct
Sebaceous glands of the skin
Simple - Branched Acinar
Several elongated coiled secretory units and their ducts converge to form larger ducts
Submucosal mucous glands (of Brunner) in the duodenum
Compound - Tubular
Several saclike secretory units with small ducts converge at a larger duct
Exocrine pancreas
Compound - Acinar (Alveolar)
Ducts of both tubular and acinar secretory units converge at larger ducts
Salivary glands
Compound - Tubuloacinar
Consist of a single cell distributed among non secretory cells
UNICELLULAR
Example of unicellular
Goblet cell
Formed when epithelial layer invaginates in deeper tissue to form a diverticulum
MULTICELLULAR
Example of multicellular
Proximal part of diverticula forms duct
Distal part forms secretory units
Branching Pattern of Ducts:
no branching
branched
SIMPLE
COMPOUND
Shape of Secretory End Piece
TUBULAR
ALVEOLAR/ ACINAR
TUBULO-ALVEOLAR
Classification based on secretion
Merocrine
Apocrine
Holocrine
Eccrine, Epicrine
Merocrine
Secretion by exocytosis - simple release without any loss of cellular compartment
No loss of cytoplasm
MOST EXOCRINE GLANDS ARE_____
MEROCRINE
Example:
Protein content of mammary gland,parotid, pancreas, typical sweat gland, salivary glands
Merocrine
Apical portion (luminal) of cell disintegrate
Nucleus & basal portion remain intact from which cell can regenerate
Partial loss of cytoplasm
Apocrine
Example:
Lipid content of mammary gland, atypical sweat gland (axilla & groin), ceruminous gland ear, moll’s gland in eyelid
Apocrine
Entire cell disintegrate
Result in death cell/ programmed cell death (apoptosis)
Complete loss of cytoplasm
Holocrine
Example:
Sebaceous gland
Tarsal glands in eyelid
Holocrine
