Myoepithelial Cells

Definition

Myoepithelial cells are a specialized type of contractile cells found in certain exocrine glands, such as the mammary and sweat glands. They play a crucial role in the process of lactation by contracting and facilitating the expulsion of milk from the glandular tissue.

5 Must Know Facts For Your Next Test

1. Myoepithelial cells are located between the basal lamina and the secretory epithelial cells in exocrine glands.
2. These cells contain contractile proteins, such as actin and myosin, which allow them to contract and expel the secreted products from the gland.
3. In the mammary gland, myoepithelial cells contract in response to the hormone oxytocin, which is released during breastfeeding, to facilitate the ejection of milk.
4. Myoepithelial cells also play a role in maintaining the structural integrity of the glandular tissue and the ductal system.
5. Dysfunction or abnormalities in myoepithelial cells have been associated with certain breast diseases, such as breast cancer.

Review Questions

• Describe the role of myoepithelial cells in the process of lactation.
  • Myoepithelial cells in the mammary gland play a crucial role in the process of lactation. These contractile cells are located between the basal lamina and the secretory epithelial cells, and they contain actin and myosin proteins that allow them to contract. When the hormone oxytocin is released during breastfeeding, the myoepithelial cells contract, facilitating the expulsion of milk from the glandular tissue and through the ductal system. This milk ejection reflex is essential for the efficient delivery of milk to the nursing infant.
• Explain how the structural and functional properties of myoepithelial cells contribute to the maintenance of the mammary gland.
  • Myoepithelial cells in the mammary gland have both structural and functional roles that contribute to the maintenance of the glandular tissue. Structurally, the myoepithelial cells help to maintain the integrity of the ductal system and the overall architecture of the mammary gland. Functionally, the contractile properties of these cells allow them to expel the secreted milk from the glandular tissue during lactation, facilitating the milk ejection reflex. Additionally, myoepithelial cells produce and secrete various extracellular matrix components, growth factors, and other signaling molecules that support the growth, differentiation, and function of the mammary epithelial cells. This multifaceted role of myoepithelial cells is crucial for the proper development and maintenance of the mammary gland.
• Analyze the potential implications of myoepithelial cell dysfunction or abnormalities in the context of breast diseases, such as breast cancer.
  • Disruptions or abnormalities in the structure and function of myoepithelial cells have been associated with certain breast diseases, including breast cancer. Myoepithelial cells normally act as a barrier between the basement membrane and the luminal epithelial cells, helping to maintain the structural integrity of the mammary gland and preventing the invasion of malignant cells. However, in some breast cancers, the myoepithelial cell layer may be disrupted or lost, allowing the tumor cells to invade the surrounding tissue. Additionally, changes in the gene expression or signaling pathways within myoepithelial cells have been linked to the development and progression of certain breast cancers. Understanding the role of myoepithelial cells in maintaining normal breast tissue architecture and function, as well as their potential involvement in breast disease pathogenesis, is crucial for developing better diagnostic and therapeutic strategies for breast cancer and other mammary gland disorders.

Related terms

Exocrine Glands:

Exocrine glands are glands that secrete their products, such as sweat, saliva, or milk, through ducts to the exterior of the body or into body cavities.

Mammary Glands:

Mammary glands are the milk-producing organs in female mammals, responsible for the production and secretion of milk for the nourishment of offspring.

Lactation: Lactation is the process of milk production and secretion by the mammary glands, which occurs in female mammals after childbirth to provide nourishment for their young.