SEROUS ACINUS – 1
This and the following pages will analyze the serous acinus (plural: acini), a type of exocrine secretory unit that, together with the mucous tubule, is widely found in the body.
It is found in several places in the body. In the digestive system, for example, it forms small glands in the tongue and cheek wall as well as large glands such as the parotid gland and pancreas.
The secretion of the serous acini is fluid and is rich in proteins. Many of these proteins are important digestive enzymes for breaking down nutrients into smaller molecules, facilitating their absorption in the intestines.
Unlike the mucous tubules, the serous acini are spherical, rounded or oval and they are not usually branched like the mucous tubules.
Their cells are usually pyramidal and the free surface of the cells faces the lumen of the acinus. The schematic drawing shows a relatively wide lumen, but in sections the lumen appears narrow and often difficult to observe under the microscope, unlike the lumen of the mucous tubules which is more dilated.
The cytoplasm of the serous cells is well stained, mostrly acidophilic, stained with eosin, due to the presence of numerous secretory vesicles located in the apical region of the cell. In some organs, as in the pancreas, their basal regions stain well with hematoxylin because there lies a great amount of rough endoplasmic reticulum (ergastoplasm).
Their nuclei are spherical and are placed close to the basal region of the cell.
Each acinus has a small and narrow excretory duct.
It is found in several places in the body. In the digestive system, for example, it forms small glands in the tongue and cheek wall as well as large glands such as the parotid gland and pancreas.
The secretion of the serous acini is fluid and is rich in proteins. Many of these proteins are important digestive enzymes for breaking down nutrients into smaller molecules, facilitating their absorption in the intestines.
Unlike the mucous tubules, the serous acini are spherical, rounded or oval and they are not usually branched like the mucous tubules.
Their cells are usually pyramidal and the free surface of the cells faces the lumen of the acinus. The schematic drawing shows a relatively wide lumen, but in sections the lumen appears narrow and often difficult to observe under the microscope, unlike the lumen of the mucous tubules which is more dilated.
The cytoplasm of the serous cells is well stained, mostrly acidophilic, stained with eosin, due to the presence of numerous secretory vesicles located in the apical region of the cell. In some organs, as in the pancreas, their basal regions stain well with hematoxylin because there lies a great amount of rough endoplasmic reticulum (ergastoplasm).
Their nuclei are spherical and are placed close to the basal region of the cell.
Each acinus has a small and narrow excretory duct.
