In order to understand contemporary psychology, it is important to look back at the origins and influences on this science. Courses on the history of psychology generally begin with the subject's ancient philosophical origins and explore the contributions of major thinkers up through the modern-day.
Spinous cells, or prickle cells, are keratin producing epidermal cells owing their prickly appearance to their numerous intracellular connections. They make up the stratum spinosum (prickly layer) of the epidermis and provide a continuous net-like layer of protection for underlying tissue.hey are pushed upward into the stratum spinosum by the continuous formation of new cells in the basal layer. They reach the outmost layer of the skin as flattened dead flaking skin cells we shed daily. The journey from origin to shed takes 25 to 45 days.
The epidermis is the outer layer of skin, which is composed of several layers of cells. It provides a barrier of protection from foreign substances. The epidermis is thickest in large animals like horses.It includes multiple types of cells, including keratinocytes, melanocytes, Langerhans cells, and Merkel cells.Each of these cells has special functions. Keratinocytes provide a protective layer that is constantly being renewed in a process called keratinization.In this process, new skin cells are created near the base of the epidermis and migrate upwards.ach of these cells has special functions. Keratinocytes provide a protective layer that is constantly being renewed in a process called keratinization. In this process, new skin cells are created near the base of the epidermis and migrate upwards.