Lecture 12 glands Flashcards
two type of glands
exocrine
enodcrine
exocrine gland
release of secretory product via a system of ducts that open into the outside world
endocrine gland
release their secretory products( typically hormones) into the space between the glands and the surface, extracellular space, then enters the blood stream
development of glands
epithelium cells proliferate and grow down or deep
- *exocrine -**cells remain contact with outside epithelial cells
- *endocrine-** connection is lost
exocrine glands can be classified by
overal structure
type of secretion
mode of secretion
overall structure
multicellular
most cells
unicellular
goblet cells
what is the only example of unicellular glands
goblet glands
goblet glands
found in epithelium of mucous membranes
- gut, stomach and trachea
- secrete the glycoprotein mucin, which by the uptake of water is converted to a slimy substance, mucous
mucin is produced by ___ and when added with water forms ___
mucin
mucous
what is this
goblet cell
multicellular glands
intraepithelial glands
extraepithelial glands
intraepithelial glands
cluster of a few secretory cells within the surface epithelium
stomach secretory epithelial sheath
extraepithelial glands
multicellular glands that extends into underlying connective tissue
- secretory portion embedded in the connective tissue underlying the epithelium
- product is secreted onto the surface or through ducts
extraepithelial glands can be ___ or ___ structures
simple
compound
refers to the branching of the excretory ducts
secretory portion of glands have three morphology:
tubular
acinar (alveolar)
tubuloacinar
example of tubular extraepithelial glands
colon- intestinal glands
a gland can have a combo of shapes of their secretory cells. ___ is an example
pancreas
has tubular glands that produce Na+HCO3- (alkaline bicarbonate-neutralizes the acidic stomach content released into the duodenum)
has acinar glands (acini) that produce precursors of digestive enzymes
when a gland is branched __ part of the cell has multiple parts
the secretory
if a gland is simple then ___
there is one duct leading out can have branched or not branched secretory cells
if a gland is compound then ___
there are multiple ducts
simple tubular
intestinal glands
simple branched tubular
stomach gastric glands
compound tubular
duodenal glands of small intestine
simple alveolar
simple branched alveolar
sebaceous (oil) gland)
compound alveolar
mammary glands
compound tubuloalveolar
salivary glands
Type of secretion
serous gland
mucous gland
mixed/seromucous glands
serous glands
parotid gland
low viscosity, watery
- nucleus round pushed to outside of cells
- secretory vesicles are visible in the apical cytoplasm
- glands containing serous acini
glands that contain serous acini are called ___
serous glands
parotid gland
serous gland
watery
Mucous glands
make mucin, high viscosity, slimy
- secretory vesicles make foamy/ frothy/ empty appearance of cells
- nucleus appear darker and are pressed against the basal membrane
- mucous acini
example: sublingual gland
mucous gland
sublingual gland
glands that contain mucous acini are
mucous glands
example of a mixed gland
sublingual gland
mixed glands
have mucous and serous portions
-sublingual, submaxillary
-serous deminlunes
mucous tubules
crescent shaped serous cells
serous deminlunes
found in sublingual gland, submaxillary
what is this
submaxillary gland
mixed serous (serous deminlunes) and mucous gland
pink is duct work
parasympathetic nerves help with ___ of salivary glands
branching of secretory glands
modes of secretion
Merocrine (eccrine)
apocrine
Holocrine
lipid soluble (diffuse directly-hormones)
transporters (membrane proteins) actively move secretory products across the plasma membrane (parietal cells of gastric glands)
Merocrine (eccrine)
exocytosis
gland makes vesicles filled with product
moves to border of cell and releases product outside of cell
apocrine secretion
part of cell containing product is pinched off
mammary glands
holocrine secretion
mature cell dies and whole dead cell is secreted
type of secretion that is essentially exocytosis through vesicles
eccrine (merocrine) secretion
eccrine sweat glands (serous product)
type of secretion where part of cell is lost
apocrine secretion
type of secretion when whole cell is broken down and secreted
holocrine secretion
eccrine sweat gland
serous glands- makes watery product
footpads of dogs and cats, nasolabial region of ruminants, everywhere is humans
- empty directly onto the surface of the skin
- layer of myoepithelial cells is found between the secretory cells of the epithelium and the basement membrane (work like small muscle, squeeze and help move product)
- secretory tubules and initial part of the excretory duct are coiled into a ball deep into the dermis
myoepithelial cells
eccrine sweat glands
layer of myoepithelial cells is found between the secretory cells of the epithelium and the basement membrane (work like small muscle, squeeze and help move product)
examples of merocrine/eccrine gland
eccrine sweat gland
exocrine pancreas
apocrine secretion
part of the apical cytoplasm of the cell is lost together with the secretory product
- continuity of the plasma membrane is restored by the fusion of the broken edges of the membrane
- sole example of apocrine secretion is mammary gland
what is this and what type of secretion
mammary gland
apocrine secretion
Holocrine secretion
breakdown and discharge of the entire secretory cell
- cells become filled with lipids and move toward duct, cell degrades and contents are extruded
example: sebaceous gland and meibomian gland of eyelids
examples of holocrine secretion
sebaceous gland
meibomian gland of eyelids
what is this
sebaceous gland
preforms holocrine secretion
-simple branched alveoli structure
Sebaceous glands:
basal cells in the outermost layer of the alveolus are ___ active stem cells that ___ the pool of cells as they are displaced toward the center of the alveolus, toward the hair follicle
mitotically
replenish
what is this
sebaceous gland
preforms holocrine secretion onto hair follicle
-simple branched alveoli structure
compound glands
secretory units and ducts are collectively called
parenchyma
usually epithelial in nature
compound glands:
supportive or connective tissue make up the ___
stroma
usually mesenchyme in nature
compound gland
entire gland is surrounded by a layer of dense connective tissue
collagen, elastic and reticular fibers
capsule
connective tissue (___) extend from the capsule into the secretory portion of the gland and subdivide it into ___ and then ___
septae
lobes
lobules
branching of ducts
Main
interlobar
intralobar
interlobular
intralobular
striated
intercalated
secretory acini
___ conveys the products to the surface of the body
main excretory duct
the duct before it reaches the lobes but after it splits
interlobar ducts
duct inside the individual lobules of the gland
interlobular duct
branches of the interlobular duct that enters the individual lobules ___
intralobular ducts
terminal branches of the duct system, connect to intralobular ducts
intercalated ducts
why intralobular ducts
within the lobule of the submandibular gland
if duct is surrounded by connective tissue then it is
interlobular or interlobar
what is this
end of duct leading to musous acinus
acini
intercalated duct
striated duct
what is this
myoepthelial cell
- very flat nucleus on border of mucous acini
- help with movement of product
what is this
intercalated duct
acini-intercalated-striated- intralobular-interlobular-intralobar-interlobar-main
what is this
striated duct
type of intralobular duct
acini-intercalated-striated- intralobular-interlobular-intralobar-interlobar-main
submucosal glands have myoepithelial cells that can act as ___
reserve stem cells if surface epithelium gets injured
protected because deep in skin, will travel out and make new epithelium, transient process, will eventually go back to their home
