HOW EXOCRINE GLANDS ARE STRUCTURED
Using the example of a parotid gland section we can study how most exocrine glands are structured and organized.
These glands are usually covered by a layer of dense connective tissue that separates and protects the inner tissue of the gland. Observe that the parotid is placed inside a connective tissue (that can be seen at the lower left and upper right corners of the image) and this gland does not need an extra layer of connective tissue to cover it.
Looking at the image of the parotid, it is possible to see that the gland is divided into several pink stained parts, separated by spaces.
These spaces are however artificial, they are artifacts that result from the histological fixation and other procedures used to finally obtain a section.
Each large pink stained part of the gland, that in vivo is separated from their neighbours by a thin layer of connective tissue is called a lobe. Most glands are formed by several lobes. Each lobe is often formed by smaller portions called lobules.
The pink regions of the gland constitute its functional portion. Now you know that the functional portion of the parotid is formed by acini and excretory ducts. The functional part of a gland is called its parenchyma.
The connective tissue usually associated to a gland, important for joining together the parenchyma and also because it contains the blood vessels, lymphatics and nerves that sustain and control the cells of the gland is called stroma of the gland.
After putting the mouse cursor or clicking on the image you will see parts of two lobes of the gland, that is parts of its parenchyma, in clear blue and also three small lobules in dark blue.
The stroma of the gland is not depicted. It is formed by the thin layers of connective tissue that join together the lobules as well as the lobes. A larger amount of connective tissue suports each excretory duct. A thin layer of connective tissue is present around small ducts and progressively more connective tissue as the small ducts join together to form larger excretory ducts. A large excretory duct of the parotid can be seen surrounded by connective tissue at the upper right corner of the image.
These glands are usually covered by a layer of dense connective tissue that separates and protects the inner tissue of the gland. Observe that the parotid is placed inside a connective tissue (that can be seen at the lower left and upper right corners of the image) and this gland does not need an extra layer of connective tissue to cover it.
Looking at the image of the parotid, it is possible to see that the gland is divided into several pink stained parts, separated by spaces.
These spaces are however artificial, they are artifacts that result from the histological fixation and other procedures used to finally obtain a section.
Each large pink stained part of the gland, that in vivo is separated from their neighbours by a thin layer of connective tissue is called a lobe. Most glands are formed by several lobes. Each lobe is often formed by smaller portions called lobules.
The pink regions of the gland constitute its functional portion. Now you know that the functional portion of the parotid is formed by acini and excretory ducts. The functional part of a gland is called its parenchyma.
The connective tissue usually associated to a gland, important for joining together the parenchyma and also because it contains the blood vessels, lymphatics and nerves that sustain and control the cells of the gland is called stroma of the gland.
After putting the mouse cursor or clicking on the image you will see parts of two lobes of the gland, that is parts of its parenchyma, in clear blue and also three small lobules in dark blue.
The stroma of the gland is not depicted. It is formed by the thin layers of connective tissue that join together the lobules as well as the lobes. A larger amount of connective tissue suports each excretory duct. A thin layer of connective tissue is present around small ducts and progressively more connective tissue as the small ducts join together to form larger excretory ducts. A large excretory duct of the parotid can be seen surrounded by connective tissue at the upper right corner of the image.
