The Integumentary System
The Skin Waterproof Self repairing Chemical Barrier Physical Barrier Biological Barrier Thermoregulatory
Cells of the Epidermis Keratinocytes- contain kerotin Melanocytes- melanin production Langerhans’ cells- epidermal macrophage Merkel cells- touch receptors
Dermis Connective tissue Vascularized and innervated Fibroblasts, macrophages, mast cells and white blood cells Two layers – papillary and reticular
Sweat Glands Thermoregulatory role Two main types Eccrine sweat glands – found in palms, soles of the feet, and forehead Apocrine sweat glands – found in axillary and anogenital areas
Sebaceous Glands
Hair Structure Made up of the shaft projecting from the skin, and the root embedded in the skin Consists of a core called the medulla, a cortex, and an outermost cuticle Pigmented by melanocytes at the base of the hair
Hair Follicle Figure 5.5a
Nail matrix Root of nail Proximal nail fold Eponychium (cuticle) Body of nail Free edge of nail Nail bed Body of nail Free edge of nail Lateral nail fold Hyponychium Phalanx (bone of fingertip) Lunula Eponychium (cuticle) (a) (b)
Epithelial Membranes