PLN 103 Lecture Notes - Lecture 6: Stratum Granulosum, Stratum Corneum, Stratum Spinosum

• School: Ryerson University
• Department: Physiology
• Course: PLN 103
• Professor: Nick Bellissimo

Document Summary

The integument: is the largest system of the body, 16% of body weight. The integument is made up of two parts: cutaneous membrane (skin), accessory structures. Accessory structures: originate in the dermis, extend through the epidermis to skin surface. Connections: cardiovascular system, blood vessels in the dermis. Nervous system: sensory receptors for pain, touch, and temperature. Loose connective tissue (separates muscle and bones), below the dermis, location of hypodermic injections (slow release of drug) Functions of skin: protection of underlying tissues and organs, excretion of salts, water, and organic wastes (glands), maintenance of body temperature (insulation and evaporation), production of melanin. Functions of skin: production of keratin, synthesis of vitamin d3, storage of lipids, detection of touch, pressure, pain, and temperature. The epidermis: is avascular stratified squamous epithelium, nutrients and oxygen diffuse from capillaries in the dermis. Keratinocytes (the body"s most abundant epithelial cells): contain large amounts of keratin, most abundant cells in the epidermis.