The integumentary system, or skin, represents the interface between the internal body and the external environment. This chapter will cover the integument.
Chapter Learning Objectives
By the end of this chapter, you should be able to do the following:
- Describe the histologic appearance, organization and function of each of the four layers of the epidermis: stratum basale, stratum spinosum, stratum granulosum, and stratum corneum.
- Describe the histologic appearance and physiologic roles of the dermal adnexa, including sebaceous glands, apocrine (epitrichial) glands, and hair.
- Describe the physyiologic roles of melanin and melanocytes.
- Describe and illustrate the normal histologic anatomy of the carnivore digit/claw.
- Describe and illustrate the normal histologic anatomy of the hoof and apply this anatomy to the concept of “laminitis.”
- Describe the source of the three layers of hoof wall stratum corneum.
- Compare and contrast the name, topography, and functional roles of specialized/modified sebaceous and apocrine glands.
By the end of this chapter, you should be able to answer the following:
- Which layer of the epidermis is primarily responsible for proliferation?
- What molecular structures are responsible for cell-cell adhesion in the epidermis?
- Name two protective roles of melanin in the epidermis.
- Name two protective roles of hair/feathers.
- Sebaceous adenitis in dogs is associated with immune-mediated destruction of sebaceous glands. What clinical symptoms do dogs with sebaceous adenitis present with (Hint: think of the normal function of sebum, and how the absence of sebaceous glands would impact this)?
- Damage to the coronary band would be expected to impact which layers of the hoof wall?
- Identification of rotation of P3 (by radiographs) is a classic feature of severe laminitis in horses. Why does P3 rotation occur secondary to laminitis (Hint: recall the anatomic structures of this region and their functions)?