1. CH. 6- SKIN & THE INTEGUMENTARY SYSTEM
Organ- Two or more kinds of tissues grouped together and performing a specialized function.
Membranes- Organs composed of epithelial and connective tissue.

2. TYPES OF MEMBRANES
Serous- line body cavities with NO opening to the outside
Mucous- line body cavities WITH opening to the outside
Synovial- line inner areas of the joint between the ends of bones
Cutaneous- skin, epithelial, outside

3. SKIN & ITS TISSUES Skin Functions Tissues of the skin
Largest organ of the body
Helps regulate homeostasis
Temp, H2O, sensory receptors
Tissues of the skin
Epidermis- outside
Stratified squamous epithelium
Dermis- middle, thicker
Fibrous connective, epithelial, muscular, nervous and vascular tissue
Subcutaneous layer- inner
Loose connective & adipose tissue
Binds skin to underlying organs

4. EPIDERMIS Lacks blood vessels Stratum basale- deepest layer
Nourished by dermal blood vessels
Cells divide and grow from this layer pushing older ones outward
Stratum corneum- outer layer
Cells die as they move away from nutrient supply
Keratinization- dying cells harden and become waterproof
Melanocyte- specialized cells in deep epidermis
Melanin- dark pigment that absorbs light
Amount of melainin determines skin color

5. DERMIS & SUBCUTANEOUS Dermis- Subcutaneous Layer (Hypodermis)
Mostly fibrous connective tissue that bind epidermis to subcutaneous layer
Contains the following:
Dermal blood vessels- for nutrients
Nerve fibers- motor and sensory
Hair follicles
Sebaceous glands
Sweat glands
Subcutaneous Layer (Hypodermis)
Continuation of the dermis
Provides insulation
Contain major vessels for blood supply

6. Stratum Corneum
Stratum basale

7. ACCESSORY ORGANS OF THE SKIN
Hair Follicles- tubelike depression of the epidermis
Hair Shaft- made up of keratonized epidermal cells
Arrector Pili Muscle- moves follicle
Sebaceous Gland- specialized epithelial cells attached to hair follicles
Sebum- oily mixture of fatty material and cellular debris
Nails- keratonized sratified squamous epithelial cells
Sweat glands- exocrine glands
Eccrine glands- most common, all over
Apocrine glands- armpits & groin