Chapter 5 - Section 5.5 - Study Guide - Assess Your Learning Outcomes - Page 173: 6

The general histology (microscopic structure) of a typical exocrine gland can be described as follows: **1. Epithelial Cells:** - Exocrine glands are composed of specialized epithelial cells that are adapted for secretion. - These secretory epithelial cells are organized into clusters or acini (singular: acinus) within the gland. **2. Duct System:** - Exocrine glands typically have a duct system that serves as a network of channels through which the gland's secretions are transported. - The ducts may be simple (unbranched) or compound (branched), depending on the complexity of the gland. **3. Secretory Units:** - The functional unit of an exocrine gland is the secretory unit or acinus. - Each acinus consists of secretory epithelial cells that produce the gland's specific secretions. **4. Basement Membrane:** - The secretory epithelial cells are anchored to a basement membrane, a thin sheet of extracellular matrix that separates the epithelium from the surrounding connective tissue. **5. Connective Tissue:** - Surrounding the secretory units and ducts is a supportive connective tissue framework. - Blood vessels and nerves also run through the connective tissue, providing nutrients and regulatory signals to the gland. **6. Types of Cells:** - Exocrine glands may contain different types of cells depending on their function. For example: - **Serous Cells:** These cells secrete watery and enzyme-rich fluids, such as in salivary glands. - **Mucous Cells:** These cells secrete thick, viscous mucus, as seen in goblet cells of the respiratory and digestive tracts. - **Myoepithelial Cells:** These contractile cells are often found surrounding secretory units and assist in expelling glandular secretions into the ducts. **7. Secretion and Ducts:** - The secretory cells within the acini produce the gland's specific secretion, which can include enzymes, mucus, sweat, or other substances. - The secretion is then released into the duct system, where it travels towards the gland's exit point (usually to a body surface or cavity). **8. Mode of Secretion:** - Exocrine glands can have various modes of secretion: - **Merocrine:** Secretory cells release their products via exocytosis, preserving the cell's integrity. This is the most common mode. - **Apocrine:** A portion of the cell membrane and cytoplasm is shed along with the secretion. Examples include some sweat glands. - **Holocrine:** Entire secretory cells are released as part of the secretion. Sebaceous (oil) glands in the skin are an example. The histology of exocrine glands can vary widely depending on the type and function of the gland. Exocrine glands are found throughout the body and serve diverse purposes, including digestion, temperature regulation, lubrication, and protection of various body surfaces and cavities.

The general histology (microscopic structure) of a typical exocrine gland can be described as follows: **1. Epithelial Cells:** - Exocrine glands are composed of specialized epithelial cells that are adapted for secretion. - These secretory epithelial cells are organized into clusters or acini (singular: acinus) within the gland. **2. Duct System:** - Exocrine glands typically have a duct system that serves as a network of channels through which the gland's secretions are transported. - The ducts may be simple (unbranched) or compound (branched), depending on the complexity of the gland. **3. Secretory Units:** - The functional unit of an exocrine gland is the secretory unit or acinus. - Each acinus consists of secretory epithelial cells that produce the gland's specific secretions. **4. Basement Membrane:** - The secretory epithelial cells are anchored to a basement membrane, a thin sheet of extracellular matrix that separates the epithelium from the surrounding connective tissue. **5. Connective Tissue:** - Surrounding the secretory units and ducts is a supportive connective tissue framework. - Blood vessels and nerves also run through the connective tissue, providing nutrients and regulatory signals to the gland. **6. Types of Cells:** - Exocrine glands may contain different types of cells depending on their function. For example: - **Serous Cells:** These cells secrete watery and enzyme-rich fluids, such as in salivary glands. - **Mucous Cells:** These cells secrete thick, viscous mucus, as seen in goblet cells of the respiratory and digestive tracts. - **Myoepithelial Cells:** These contractile cells are often found surrounding secretory units and assist in expelling glandular secretions into the ducts. **7. Secretion and Ducts:** - The secretory cells within the acini produce the gland's specific secretion, which can include enzymes, mucus, sweat, or other substances. - The secretion is then released into the duct system, where it travels towards the gland's exit point (usually to a body surface or cavity). **8. Mode of Secretion:** - Exocrine glands can have various modes of secretion: - **Merocrine:** Secretory cells release their products via exocytosis, preserving the cell's integrity. This is the most common mode. - **Apocrine:** A portion of the cell membrane and cytoplasm is shed along with the secretion. Examples include some sweat glands. - **Holocrine:** Entire secretory cells are released as part of the secretion. Sebaceous (oil) glands in the skin are an example. The histology of exocrine glands can vary widely depending on the type and function of the gland. Exocrine glands are found throughout the body and serve diverse purposes, including digestion, temperature regulation, lubrication, and protection of various body surfaces and cavities.