| A | B |
|---|
| integumentary system | the outer protective layer of the body composed of nails, hair, sweat/oil glands and skin. |
| epidermis | skins outer most layer composed of living and non living cells |
| dermis | second layer of skin below the epidermis with nerves, muscles, vessels, and hair follicles; composed of all living skin cells |
| hypodermis | third layer of skin, that is not skin at all, but provides an area of attachment for the dermis layer. |
| adipose tissue | composed of fat tissues, connectie tissue which provide insullation for the body |
| epithelial cells | cells of the epidermis and dermis which constantly divide forming new skin cells. |
| keratin | tough protein found in hair, nails, fish scales, feathers and animal horns which help waterproof the outer skin layer. |
| melanin | brown (and redish orange) skin pigment which protects from UV rays |
| carotene | yellow pigment of the sking |
| melanocytes | cells which produce melanine; |
| vitamin D | Vitamin produced by the body when exposed to the sun. |
| ultraviolet light | high energy light rays which can cause damage to skin if there is too much sun exposure. |
| elastin | proteins which make up elastic connective tissue preventing wrinkles in the skin. |
| sebaceous glands | produce the oily substance, sebum, which keeps your skin smooth and supple, and kills off a number of germs. |
| sweat glands | produce sweat which helps to keep your body cool. |
| heat exhaustion | when the body looses water and salt faster than it is replaced; heavy sweating, pale skin, muscle cramps, dizziness, nausea are just a few symptoms of this. |
| matrix | base of hair follicle where hair cells are produced; filled with hard keratin and pushed upward, they die producing hair as we know it. |
| cuticle | outer most layer of hair composed of clear, overlapping cells which make the hair water resistant; thicker hair has more cuticle in it. |
| cortex | middle layer of hair containing a mixture of pigments which give you your hair color. |
| medulla | noncontinuous core of hair layer which may or maynot be present; fine hair and blonde hair rarely have a medulla. |
| cleavage lines | dermal indentions due to deep patterns in the dermis layer. |
| subcutaneous tissue | another name for the hypodermis layer; keeps your sking form sliding around on your body. |
| free nerve endings | epidermal nerve endings stimulated by heat, cold, pain, itch or skin movement. |
| Meissner's corpuscles | tiny sensors in the skin which detect distance between things touching the skin; bristles of tooth brush vs. wide comb teeth. |
| hair follicle receptors | receptors that are wrapped around each hair follicle. |
| Pacinian corpuscles | sensors in skin for vibration and pressure. |
| lunula | the lunar shaped pigment (white half moon shape) at the base of the fingernails. |
