| A | B |
|---|
| alveolus | a tiny air sac where gas exchange occurs |
| fetus | an embryo after eight weeks of development in the uterus |
| trachea | the tube that carries air to the bronchi |
| diaphragm | the muscle below the lungs that controls breathing |
| perspiration | liquid waste released through the skin |
| kidney | the organ in the excretory system where urine forms |
| ureter | a tube that carries urine from a kidney to the urinary bladder |
| urethra | the tube that carries urine out of the body |
| penis | the male organ that delivers sperm to the female's body |
| scrotum | the exterior sac that holds the testes |
| testis | the male reproductive organ that produces sperm cells |
| vagina | the tube like canal in the female body through which sperm enter the body |
| fallopian tube | a tube through which eggs pass from an ovary to the uterus |
| ovulation | the release of an egg from an ovary |
| semen | a mixture of fluid and sperm cells |
| uterus | the female reproductive organ that holds and protects a developing baby |
| menstruation | the process which an unfertilized egg, blood, and pieces of the lining the uterus exit the female's body |
| placenta | a blood-rich tissue that grows into the lining of the uterus during pregnancy |
| pregnancy | the period during which a fertilized egg develops into a baby inside a female's body |
| bronchus | a tube that connects the trachea and lungs |
| umbilical cord | the cord that connects an embryo with the placenta |
