![Page 1: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/1.jpg)
Glandular Tissue
Curriculum : Phase 1/Semester2/TOB /Session 4
2017/2018
Lecturer : Dr. Rajaa Ali Al- Taee
Msc. PhD. Histology G.mail: [email protected]
Hammurabi Medical Collage / Babylon University
![Page 2: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/2.jpg)
References:
• Histology Textbooks ‘Basic Histology’, Junqueira,13 th
Edition chapter 1,2,3.pp:1-72
• ‘Colour Atlas of Histology’ Gartner and Hiatt 5 th
Edition.
• http://www.histologyguide.com/
Glandular Tissue
![Page 3: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/3.jpg)
Glandular Tissue
Objectives of the lecture:
1. Define a gland as an epithelial cell or aggregate of cells specialised for
secretion.
2. Classify glandular tissue, describing the meaning of the following
terms:
Exocrine or endocrine
Merocrine, apocrine or holocrine.
3. Describe the above mechanisms of secretion.
![Page 4: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/4.jpg)
Glandular Tissue
4 . describe the mechanisms of endocytosis.
5. describe how endocytosis and secretion combine to give transepithelial transport.
6. explain the mechanism and importance of the glycosylation of newly synthesised
proteins in the Golgi apparatus.
7. describe the role of secretions in cell functions (e.g. in communication).
8. describe simple mechanisms of control of secretion (e.g. nervous, endocrine).
![Page 5: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/5.jpg)
Glandular Tissue
Glandular Epithelium:
Glandular epithelium is more complex and varied than the epithelial
cells which cover surfaces or line tubules or vessels.
A gland is a single cell or a mass of epithelial cells adapted for
secretion.
![Page 6: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/6.jpg)
Classification of Glands
• By destination
• By structure
• By nature of the secretion
• By the method of discharge
![Page 7: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/7.jpg)
1. Exocrine glands
2. Endocrine glands:
• ductless glands
• Secretion
• Cells
By destination
Thyroid glandAdrenal gland
https://youtu.be/GUi84E6lUiY
![Page 8: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/8.jpg)
Exocrine glands secrete into ducts or directly onto a free surface.
Their secretions include mucus, sweat, oil, ear wax and digestive
enzymes.
EXO = out side and crine = secret
Examples include :-
pancreas , stomach , sweat glands , salivary glands , mammary
glands , sebaceous glands , etc .
![Page 9: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/9.jpg)
Endocrine glands - called “ductless glands” discharge their
secretions into the intracellular fluid, where it diffuses into the blood
stream. These secretions are hormones, or chemical messengers,
which regulate many body functions.
ee Examples include :-
Pituitary gland ,thyroid gland,adrenal gland,parathyroideees
exe
![Page 10: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/10.jpg)
3. Mixed gland
(an exocrine and
endocrine gland)
The Pancreas.
![Page 11: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/11.jpg)
![Page 12: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/12.jpg)
Formation of glands from covering epithelia.
During fetal development epithelial cells proliferate and penetrate the
underlying connective tissue.
They may-or may not-maintain a connection with the surface
epithelium. When the connection is maintained, exocrine glands are
formed; with the connection lost, endocrine glands are formed.
Exocrine glands secrete to the body surface or gut via duct systems
formed from the epithelial connection.
![Page 13: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/13.jpg)
Formation of glands from covering
epithelia.
![Page 14: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/14.jpg)
The cells of endocrine glands, which secrete hormone) can be
arranged in cords or in follicles with lumens for storing the secretory
product.
From either the cords or follicles of endocrine cells, the secretory
product is released outside the cells and picked up by the blood
vessels for distribution throughout the body.
![Page 15: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/15.jpg)
General structure of exocrine glands.
• Exocrine glands by definition have ducts that lead to an
organ or body surface.
• Inside the gland the duct runs through connecting septa and
branches repeatedly, until its smallest branches end in the
secretory portions of the gland.
![Page 16: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/16.jpg)
![Page 17: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/17.jpg)
Classification by
Structure
Secretory part: unicellular /
multicellular
acinar (alveolar) / tubular
coiled / branched *
![Page 18: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/18.jpg)
Parotid gland: branched
![Page 19: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/19.jpg)
Duct system:
1. Simple gland (single duct)
2. Complex gland (branched ducts)
![Page 20: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/20.jpg)
![Page 21: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/21.jpg)
Branching
ducts:
Main
↓
interlobular
↓
Intralobular
↓
Intercalary
![Page 22: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/22.jpg)
Salivary gland
![Page 23: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/23.jpg)
1-Exocrine glands:
Structural classification of exocrine glands:
1) unicellular glands
2) multicellular glands ↓
Goblet cell
Salivary gland
https://youtu.be/cdqLLa81-eE
![Page 24: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/24.jpg)
Multicelular gland:
composed of :
1) An epithelial lined duct
2) A secretory unit called the acinus
3) Interstitial connective tissue
![Page 25: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/25.jpg)
![Page 26: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/26.jpg)
![Page 27: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/27.jpg)
Classification by method of secretion:
Merocrine (exocytosis )
• secretion is released by exocytosis
of secretory granules (pancreas,
parotid gland, protein component
of milk from mammary gland).
![Page 28: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/28.jpg)
Apocrine (pinch of )
• apical portion of cell along
with secretory product is
pinched off (lipid
component of milk from the
mammary gland).
![Page 29: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/29.jpg)
Holocrine (rupture)
• entire cell is shed along with
secretory product (sebaceous
glands).
https://youtu.be/E5aJTpiwakI
![Page 30: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/30.jpg)
![Page 31: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/31.jpg)
• Classification by nature of secretion:
Ex: Salivary glands
![Page 32: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/32.jpg)
• Classification by nature of
secretion:
mucous glands
Secretion: contains
mucopolysaccharides which collects in
the apical part of cell.
Cytoplasm: stain very lightly with H/E
stain
Nuclei: basally placed & flattened
(mucoid pushes the nuclei).
![Page 33: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/33.jpg)
Secretion: thin, watery, rich in enzymes, protein in nature.
Cytoplasm: granular stain darkly & rich in rER.
Nuclei: rounded & basally placed.
serous glands
![Page 34: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/34.jpg)
Sero-mucous gland
Mixed gland
muco-serous or mixed gland
Contain both serous & mucous secretory units.
Sometimes serous cells form crescentic caps on mucous acinicalled as serous demilunes.
![Page 35: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/35.jpg)
According to above 4 criteria of classifications ,classify parotid
gland?
![Page 36: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/36.jpg)
Endocytosis
• Engulfing
• Opposite of exocytosis
(merocrine secretion)
• Endo- & Exo-cytosis
(Transepithelial Transport)
https://www.youtube.com/watch?v=sBCDxPvu4F0&feature=youtu.be
![Page 37: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/37.jpg)
Transepithelial Transport
• material endocytosed at one surface
• transport vesicle shuttles across cytoplasm
• material exocytosed at opposite surface
![Page 38: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/38.jpg)
Golgi Apparatus:
Structure
Stack of disc-shaped cisternae
• One side of discs are flattened;
other concave
• Discs have swellings at their edges
• Distal swellings pinch off as
migratory Golgi Vacuoles
Golgy apparatushttps://youtu.be/3H5dSPQNlX8
![Page 39: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/39.jpg)
Golgi Apparatus:
Function
• Packaging through condensation of contents
• Transport
• Adding sugars to proteins and lipids (Glycosylation)
Golgi Product Destinations
• Majority extruded in secretory vesicles
• Some retained for use in the cells (e.g. lysosomes)
• Some enters the plasma membrane (Glycocalyx)
![Page 40: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/40.jpg)
Glycosylation & Specificity
• Branching sugars offer complex shapes for specific
interactions in the glycocalyx
• Destruction of this layer by enzymes alters many
specificity based properties of cells:
adhesion to substrates & neighboring cells
mobility of cells
communication with neighboring cells
contact inhibition of movement and division
![Page 41: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/41.jpg)
Control of Secretion
• Nervous
• Endocrine control
• Neuro-endocrine control
• Negative feedback chemical mechanism
Q:Give one or more examples of glands for each type of above
controls?
![Page 42: Glandular Tissue - University of Babylon · Glandular Tissue 4 . describe the mechanisms of endocytosis. 5. describe how endocytosis and secretion combine to give transepithelial](https://reader036.vdocuments.net/reader036/viewer/2022070806/5f04a3897e708231d40ef772/html5/thumbnails/42.jpg)
Thank you for listen