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The small terminal sac of an acinous gland, lined with secreting cells.
An individual drupelet of a multiple fruit.



(1) A structural and functional unit or the terminal secretory portion of the salivary, pancreatic, lacteal, sebaceous, or other saccular (alveolar) glands. The acinus is a bubble-like formation of one or more types of gland cells situated on a basement membrane and surrounded by connective tissue, capillaries, and nerve fibers. The apexes of the cells with their microvilli are directed toward the chamber of the acinus into which the secretion is discharged.

(2) A part of the respiratory apparatus in mammals that includes a section of the lung corresponding to the branches of the terminal bronchus—that is, the bronchioles, alveolar passages, and alveoli. One pulmonary lobule consists of 12–18 acini.

References in periodicals archive ?
3D and 4D): The acini of uniform size are completely filled by mature oocytes with a relatively homogenous size, and a visible nucleus occupies the lumen.
Morphologically, the acini in these p63-positive carcinomas frequently appear atrophic, with a high nuclear-cytoplasmic ratio and a basaloid appearance (Figure 1, E).
Changes in nerve terminals and acini of the lacrimal gland and changes in secretion induced by autonomic denervation.
Not only do cancer cells continue to grow irregularly when they shouldn't, recent studies have shown that they do not rotate coherently when forming acini.
In both Ariopelta species, the ovotestis consists of tightly packed acini of which the basal parts are often divided into a few short lobes.
The Heinrich classification system is frequently used to classify heterotopic pancreas: type 1 (containing acini, islets and ducts), type 2 (acini and ducts, no islets) and type 3 (ducts alone) (9).
It is thought that pancreatic acini in infants with CF are capable of producing trypsinogen, but ductules are blocked, preventing trypsinogen from reaching the small intestine to be converted to trypsin, hence leading to 'spillage' into the circulation.
Recent studies show hypofunction of salivary glands in patients with pSS, but higher concentrations of nitrite and iNOS in the salivary gland acini in these patients (20).
According to the pathology report, the specimens consisted of fibromuscular tissue containing hyperplastic prostate acini and solid accumulations of malignant cells of various sizes.
Prostate-specific antigen is a glycoprotein produced primarily by the prostate epithelial cells that line the ducts and acini of the prostate.
In previous studies, Furuta and collaborators have shown that conditioned-medium, taken from normal mammary epithelial cells while in the process of forming acini in a 3D lamin-rich extracellular matrix culture, can revert the malignant phenotype of breast cancer cells so that they behave as if they were normal breast cells.
The neoplastic acini of adenoid hepatocellular carcinomas may contain proteinaceous material, while cholangiocarcinomas are more likely to have PAS positive mucin within neoplastic acini [15].