| A | B |
|---|
| epidermis | the thin outer layer of skin |
| dermis | the thick layer of cells below the epidermis |
| perspiration | liquid waste made of heat, water and salt released through the skin |
| excretory system | a series of organs that get rid of cell wastes in the form of urine |
| urine | liquid waste formed in the kidneys |
| ureter | a tube that carries urine from the kidney to the urinary bladder |
| urethra | the tube that carries urine out of the body |
| kidneys | organ that filters nitrogen wastes out of the blood and remove some extra water and salt from the blood |
| urinary bladder | muscular bag that collects urine and stretches as it fills. When you urinate, the urinary bladder squeezes urine out of the urethra |
| renal artery | brings dirty blood to the kidneys |
| renal veins | carry clean blood away from the kidneys |
| nephron | functional unit of the kidney responsible for the purification and filtration of the blood |
| sebaceous gland | glands in the dermis of the skin that open into a hair follicle and produce and secrete sebum (oil) |
| hair | many fine, usually cylindrical, filaments growing from the skin of humans and animals |
| sweat gland | one of the tiny, coiled, tubular glands of the skin that secrete sweat |
| pore | a tiny opening in the skin serving as an outlet for perspiration |
| subcutaneous layer | layer below the dermis |
