Which type of cells in the dermis are known as 'guard cells'?

Langerhans cells are referred to as 'guard cells' in the dermis due to their crucial role in the immune response. These specialized dendritic cells are part of the skin's immune system and help protect against pathogens and foreign substances that penetrate the skin barrier. They act as sentinels, identifying and capturing potential threats. Once they capture antigens, Langerhans cells migrate to lymph nodes, where they activate T-cells, thereby initiating an immune response. This function is vital for maintaining skin health and defending against infections. Their presence in the epidermis and dermis underscores the skin's role not just as a physical barrier but also as an active participant in the immune system.