HLSC 1200U Lecture Notes - Lecture 10: Subcutaneous Tissue, Melanoma, Apocrine
Document Summary
Defines boundary between environment from external environment. Support and protection, acts as a physical barrier for chemicals and microorganisms. Skin prevents dehydration; in the case that someone"s skin is burnt, water evaporates and is lost to the environment. Cells in the skin prevent uv exposure, therefore decreases the chance for cancer to occur. Sensory receptors enable detection of pressure, pain, and temperature. Skin excretes water and other waste products. The epidermis is relatively thin without blood vessels. The dermis is underneath the epidermis, it consists of connective tissue and blood vessels. The boundary between the epidermis and dermis is deemed as the dermo-epidermal junction (substances must diffuse out of the blood vessels in the dermis into the epidermis) Hypodermis is under the dermis, a second layer of connective tissue, and contains lipids as well as a pressure sensor. Thin skin is found everywhere except where thick skin is located. Friction ridges are present on thick skin, they help in gripping.
