Health Sciences 2330A/B Lecture 2: The Integumentary System

• School: Western University
• Department: Health Sciences
• Course: Health Sciences 2330A/B
• Professor: Graham Fraser

Document Summary

Functions: regulate temp, stores blood, protects the body from external environment, detects cutaneous sensations, excretes and absorbs substances (ex. sweat), synthesizes vitamin d. Holds up to 7% of tbv (total blood volume) Thickness ranges throughout the entire body: finger and foot pads have the thickest layers of skin. Structure of the skin 4 major types of cells in the epidermis. Keratincytes: makes up 90% of the cells, produce keratin. Tough, fibrous, intracellular protein that helps protect skin and underlying tissues from abrasions, heat, microbes, and chemicals: produce lamellar granules. Release water-repellant sealant that decreases water entry and water loss. Inhibits passage of foreign materials: protected from uv damage due to melanin granules of melanocytes. Melanocytes: makes up 8, long projections transfer melanin granules to neighbouring keratinocytes. Once inside cluster to form protective veil over nucleus on side toward skin surface shields dna from uv damage: produce melanin. Yellow-black or brown-black pigment that contributes to skin colour.