BIO 240 Lecture Notes - Lecture 4: Apocrine, Homeostasis, Dense Irregular Connective Tissue
Document Summary
A group of two or more tissues that performs a specific function is called an organ. A group of two or more organs that work together towards a common goal is a system. The skin and organs that are embryonic epidermal derivatives comprise the integumentary system. These include hair, nails, glands, and enamel of teeth. Epidermis the epidermis is the outer, thinner, waterproof portion of the skin. It is composed of keratinized stratified epithe- lium divided into four (thin skin) or five (thick) distinct layers or strata. Dermis -- the epidermis is attached to the dermis, the inner, thicker portion of skin. It is composed of elastic and collagenous connective tissues and bears a vascular supply. The dermis is very thick on the palms and soles, and tends to be thicker on the dorsal body surfaces than on the ventral surfaces. Hypodermis - deep to the dermis is the hypodermis (subcutaneous layer or superficial fascia).
