| A | B |
|---|
| Integumentary System | includes Skin & hair & nails & glands |
| Functions of Integumentary System | Maintenance of normal body temperature & Storage & Excretion & Synthesis & Sensory reception |
| Skin layers | Epidermis & Dermis & Hypodermis |
| Epidermis | is made of Stratified squamous epithelium sitting on a thin connective tissue layer called the basement membrane |
| Stratum corneum | is the top layer of the epidermis containing dead keratinized cells |
| Intermediate layer | is the middle layer of the epidermis |
| Stratum germinativum | is the bottom layer of the epidermis and contains stem cells for regenerating the epidermis |
| Melanocytes | Specialized cells found in the stratum germinativum that produces the pigment melanin |
| Melanin | Pigment injected into epithelial cells & absorbs UV radiation |
| Skin Color | is due to amount of pigment produced not the number of melanocytes |
| Freckles | are due to uneven distribution of pigment |
| Ultraviolet radiation | damages the DNA in cells |
| Dermis | is the layer of connective tissue below the epidermis that contains glands & hair follicles & nerves & Blood vessels |
| Hypodermis | is also called subcutaneous layer and contains mostly loose connective tissue especially adipose |
| Hair | slnder outgrowth of mammalian skin |
| Hair structure | the cuticle & medulla & cortex. |
| Hair parts | shaft and root |
| Hair growth | hair grows from the papilla |
| Hair components | basic components are keratin (a protein)& melanin (a pigment) & and trace quantities of metallic elements. |
| Hair Texture | derived from differences in shape of hair shaft |
| Function of Hair | Protection from UV radiation & Cushioning & Heat retention &Prevent entry of foreign substances |
| Skin Exocrine Glands | sebaceous glands and sweat glands |
| Sebaceous glands | sebum secretion that is sensitive to hormones |
| sebum | oily secretion which lubricates hair shaft and inhibits bacterial growth |
| Sweat Glands | apocrine and merocrine |
| Apocrine Sweat Glands | Produce thick cloudy secretion that produces odor when broken down by bacteria |
| Merocrine Sweat Glands | Produce clear secretion containing water, salts and urea and functions in evaporative cooling of the body |
| Nails | made of nail body that grows from the nail root |
| Nail cuticle | is continuous with the stratum corneum |
