| A | B |
|---|
| adolescence | stage of development that begins at age 13 and ends at age 20 |
| adrenal | endocrine gland on top of each kidney that produces the hormone adrenaline |
| adulthood | stage of development that begins at age 20 and lasts the rest of a person's life |
| alveolus | grape like clusters of round sacs in the lungs; site of gas exchange |
| amino acid | building block of protein |
| amniotic sac | fluid-filled sac that cushions and protects the developing baby |
| antigen | invading organism or substance that triggers the action of an antibody |
| anus | opening at the end of the rectum through which solid wastes are eliminated |
| artery | blood vessel that carries blood away from the heart |
| atherosclerosis | thickening of the inner wall of an artery |
| atrium | upper heart chamber |
| bone | structure that makes up the body's |
| skeleton brain | main control center of the central nervous system |
| bronchus | tube that branches of from the trachea and enters the lung |
| Calorie | amount of energy needed to raise the temperature of 1 kilogram of water by 1 degree Celsius |
| cancer | noninfectious disease in which the body'~ own cells multiply uncontrollably |
| capillary | tiny, thin-walled blood vessel that connects an artery to a vein |
| carbohydrate | energy-rich nutrient found in food1 such as vegetables and grain products |
| cardiac muscle | muscle tissue found only in tht heart |
| cardiovascular disease | disease that affects the heart and blood vessels |
| cartilage | dense, fibrous, flexible connective tissue |
| cerebellum | part of the brain that controls balance and coordinates musclt activity |
| cerebrum | largest part of tht brain; controls the senses, thought, and conscious activity |
| childhood | stage of development that begins al about 2 years of age and continues until tht age of 13 |
| cornea | transparent protective covering of the eye |
| dermis | bottom layer of the skin |
| diaphragm | dome-shaped musclf that aids in breathing |
| eardrum | membrane in the ear that vibrates when struck by sound waves |
| egg | female sex cell; ovum |
| embryo | developing baby from the second to the eighth week of development |
| epidermis | top layer of the skin |
| epiglottis | small flap of tissue that closes over the trachea (windpipe) |
| esophagus | tube that carries food to the stomach |
| excretion | process by which wastes are removed from the body |
| Fallopian tube | structure through which an egg travels from the ovary to the uterus; oviduct |
| fat | nutrient that supplies the body with energy and also helps support and cushion the vital organs in the body |
| fetus | developing baby from the eighth week to birth |
| fracture | break in a bone |
| hemoglobin | iron- containing protein found in red blood cells |
| homeostasis | process by which the delicate balance between the activities occurring inside the body and those occurring outside is maintained |
| hormone | chemical messenger produced by an endocrine gland |
| hypothalamus | endocrine gland at base of brain that provides a link between the nervous system and the endocrine system |
| nose | organ through which air enters the respiratory system |
| nutrient | usable portion of food |
| organ | group of different tissues that have a specific job |
| organ system | group of organs that work together to perform a specific job |
| ovary | endocrine gland that produces female hormones; female sex gland |
| ovulation | process by which the follicle in the ovary releases the egg |
| pancreas | organ that produces pancreatic juice and insulin |
| parathyroid | endocrine gland embedded in the thyroid that produces a hormone which controls the level of calcium in blood |
| peristalsis | waves of muscular contractions that move food through the |
| pituitary | endocrine gland located below the hypothalamus mat controls many body processes |
| placenta | structure through which a developing baby receives food and oxygen from its mother |
| plasma | fluid portion of the blood |
| platelet | cell fragment that aids in blood clotting |
| protein | nutrient that is used to build and repair body parts; made of amino acids |
| puberty | beginning of adolescences |
| pupil | small opening in the middle of me eye |
| receptor | special cell that receives information from its surroundings |
| rectum | end of the large intestine |
| red blood cell | cell that carries oxygen throughout the body |
| reflex | simple response to a stimulus |
| respiration | energy-releasing process that is fueled by oxygen |
| retina | inner layer of the eye on which an image is focused; contains the light- sensitive rods and cones |
| rheumatoid arthritis | disabling disease that affects the skin, lungs, and joints |
| semicircular canal | tiny canal in inner ear that is responsible for the sense of balance |
| sensory neuron | type of neuron that carries messages from the receptors to the brain or spinal cord |
| skeletal muscle | muscle tissue that is attached to bone and moves the skeleton |
| small intestine | digestive organ in which most digestion takes place |
| smooth muscle | muscle tissue responsible for involuntary movement |
| sperm | male sex cell |
| Spinal cord | provides the link between the brain and the rest of the body |
| sprain | injury in which ligaments are torn or stretched |
| stimulant | substance that speeds up the actions of the brain and spinal cord |
| stimulus | change in the environment |
| stomach | j-shaped digestive organ that connects the esophagus to the small intestine |
| synapse | tiny gap between two neurons |
| tendon | connective tissue that attaches bone to muscle v |
| testis | endocrine gland that produces male hormones; male sex gland |
| thymus | endocrine gland that is responsible for the development of the immune system |
| thyroid | endocrine gland located in the neck that produces a hormone which controls how quickly food is burned up |
| tissue | group of similar cells that perform the same function |
| trachea | windpipe; carries air from the nose to the lungs |
| ureter | tube that carries urine from a kidney to the urinary bladder |
| urethra | tube through which urine leaves the body |
| urinary bladder | muscular sac that stores urine |
| uterus | pear-shaped organ in which a fertilized egg develops into a child |
| vein | blood vessel that carries blood to the heart ventricle: lower heart chamber |
| villus | fingerlike structure that lines the small intestine through which food is absorbed into the bloodstream |
| vocal cord | fold of tissue stretched across the larynx that vibrates with the movement of air to form sounds |
| white blood cell | cell that defends the body against invading organisms |
