Secretory units

An acinus resembles a grapefruit cut in half, with each grapefruit segment representing an individual cell.  The RER and nucleus are basally located in the cells, while their secretory granules are present in the apical regions.  At the center of the acinus is a narrow lumen.  Acinar secretions are watery or serous which enter the small central lumen.

An acinus resembles a grapefruit cut in half, with each grapefruit segment representing an individual cell.  The RER and nucleus are basally located in the cells, while their secretory granules are present in the apical regions.  At the center of the acinus is a narrow lumen.  Acinar secretions are watery or serous which enter the small central lumen.

An acinus resembles a grapefruit cut in half, with each grapefruit segment representing an individual cell.  The RER and nucleus are basally located in the cells, while their secretory granules are present in the apical regions.  At the center of the acinus is a narrow lumen.  Acinar secretions are watery or serous which enter the small central lumen.

An acinus resembles a grapefruit cut in half, with each grapefruit segment representing an individual cell.  The RER and nucleus are basally located in the cells, while their secretory granules are present in the apical regions.  At the center of the acinus is a narrow lumen.  Acinar secretions are watery or serous which enter the small central lumen.

An acinus resembles a grapefruit cut in half, with each grapefruit segment representing an individual cell.  The RER and nucleus are basally located in the cells, while their secretory granules are present in the apical regions.  At the center of the acinus is a narrow lumen.  Acinar secretions are watery or serous which enter the small central lumen.

Tubules, as the name indicates, are linear secretory units lined by cuboidal to columnar cells.  A number of tubules in longitudinal and cross section are visible in the image.  Most tubules secrete mucus and the apical region appears frothy or clear because the mucus is easily extracted during tissue processing.  The nuclei are basally located and compressed by the mass of mucus above them.  Tubules have a wide lumen to accommodate the thick, mucus secretion.

Tubules, as the name indicates, are linear secretory units lined by cuboidal to columnar cells.  A number of tubules in longitudinal and cross section are visible in the image.  Most tubules secrete mucus and the apical region appears frothy or clear because the mucus is easily extracted during tissue processing.  The nuclei are basally located and compressed by the mass of mucus above them.  Tubules have a wide lumen to accommodate the thick, mucus secretion.

Tubules, as the name indicates, are linear secretory units lined by cuboidal to columnar cells.  A number of tubules in longitudinal and cross section are visible in the image.  Most tubules secrete mucus and the apical region appears frothy or clear because the mucus is easily extracted during tissue processing.  The nuclei are basally located and compressed by the mass of mucus above them.  Tubules have a wide lumen to accommodate the thick, mucus secretion.

Tubules, as the name indicates, are linear secretory units lined by cuboidal to columnar cells.  A number of tubules in longitudinal and cross section are visible in the image.  Most tubules secrete mucus and the apical region appears frothy or clear because the mucus is easily extracted during tissue processing.  The nuclei are basally located and compressed by the mass of mucus above them.  Tubules have a wide lumen to accommodate the thick, mucus secretion.

Tubules, as the name indicates, are linear secretory units lined by cuboidal to columnar cells.  A number of tubules in longitudinal and cross section are visible in the image.  Most tubules secrete mucus and the apical region appears frothy or clear because the mucus is easily extracted during tissue processing.  The nuclei are basally located and compressed by the mass of mucus above them.  Tubules have a wide lumen to accommodate the thick, mucus secretion.

Polarity is a feature of cells in which their organelles are distributed asymmetrically in the cytoplasm.  This stable distribution of organelles reflects the differing functions performed in these areas.  The secretory products, e.g., enzymes or mucus, are synthesized basally in the RER, packaged into secretory granules that are stored in the apical region of the cells for later release.  Polarity is a characteristic feature of exocrine gland cells.