Term | Definition |
Pseudocoelom | The type of body cavity that forms between the mesoderm and the endoderm in rotifers and roundworms |
Spectrometer | A tool that measures wavelengths of visible light or other electromagnetic radiation |
Diaphragm | A dome-shaped muscle that is attached to the lower ribs and that functions as the main muscle in respiration |
Proglottid | One of the many sections of a tapeworm; contains reproductive organs |
Planula | The free-swimming, ciliated larva of a cnidarian |
Urethra | The tube that carries urine from the urinary bladder to the outside of the body |
Esophagus | A long, straight tube that connects the pharynx to the stomach |
Digestion | The breaking down of food into chemical substances that can be used for energy |
Bronchus | One of the two tubes that connect the lungs with the trachea |
Trachea | The tube that connects the larynx to the lungs |
Minerals | A class of nutrients that are chemical elements that are needed for certain body processes |
Ovary | An organ that produces eggs in the female reproductive system |
Vitamin | An organic compound that participates in biochemical reactions and that builds various molecules in the body |
Calorie | The amount of energy needed to raise the temperature of one gram of water 1 degree Celsius |
Spongin | A fibrous protein that contains sulfur and makes up the skeleton of some sponges |
Rigor Mortis | Temporary stiffness of muscles after death |
Spinneret | An organ that spiders and certain insect larvae use to produce silky threads for webs and cocoons |
Nutrient | A substance or compound that provides nourishment (or food) or raw materials needed for life processes |
Heart Attack | The death of heart tissue due to a blockage of their blood supply |
Keratin | A hard protein that makes up hair and nails |
Epithelial Tissue | Tissue that covers a body surface or lines a body cavity |
Sebum | Oily secretions of the sebaceous glands |
Mandible | A type of mouthpart found in some arthropods that is used for eating |
Myosin | A protein that forms the thick filaments in muscle fibers |
Water-Vascular System | In echinoderms, a system of canals filled with a watery fluid |
Plasma | The liquid component of blood |
Testis | The primary male reproductive organ, which produces sperm cells and testosterone |
Fetus | A developing human from the end of the eighth week after fertilization until birth |
Uterus | In female mammals, the hollow, muscular organ in which an embryo embeds itself and develops into a fetus |
Vein | A vessel that carries blood to the heart |
Tendon | A tough connective tissue that attaches a muscle to a bone |
Bone Marrow | Soft tissues inside bones that either produces blood cells or stores fat |
Urine | The liquid excreted by the kidneys, stored in the bladder, and passed through the urethra to the outside of the body |
Pepsin | Am enzyme that is found in gastric juices and that helps break down proteins into smaller molecules |
Ossicle | One of the small, calcium carbonate plates that make up the endoskeleton of an echinoderm |
Semen | The fluid that contains sperm and various secretions produced by the male reproductive organs |
Polyp | A form of a cnidarian that has a cylindrical, hollow body and that is usually attached to a rock or another object |
Ovulation | The release of an ovum from a follicle of the ovary |
Penis | The male organ that transfers sperm to a female and that carries urine out of the body |
Medusa | A free-swimming, jellyfish-like, and often umbrella-shaped sexual stage in the life cycle of a cnidarian |
Radula | A rasping, tonguelike organ that is covered with teeth and that is used for feeding |
Vagina | The female reproductive organ that connects the outside of the body to the uterus and that receives sperm during reproduction |
Compound Eye | An eye composed of many light detectors separated by pigment cells |
Algor Mortis | Cooling of the body after death |
Artery | A blood vessel that carries blood away from the heart to the body's organs |
Malphighian Tube | An excretory tube that opens into the back part of the intestine of most insects and certain arthropods |
Septum | A dividing wall, such as the internal wall between an annelid's adjacent segments |
Seta | One of the external bristles or spines that project from the body of an animal |
Stroke | A sudden loss of consciousness or paralysis that occurs when the blood flow to the brain is interrupted |
Atrium | A chamber that receives blood that is returning to the heart |
Cardiovascular System | A collection of organs that transport blood throughout the body |
Siphon | A hollow tube of mollusks used for sucking in and expelling sea water |
Pedipalp | In certain arthropods, one of the second pair of appendages |
Nephron | The functional unit of the kidney |
Livor Mortis | Settling of blood to the lowest points in the body after death |
Nervous Tissue | Tissue of the nervous system, including neurons and their supporting cells |
Muscle Tissue | The tissue made of cells that can contract and relax to produce movement |
Chelicera | In arachnids, either of a pair pf appendages used to attack prey |
Pulse | The rhythmic pressure of the blood against the walls of a vessel, particularly an artery |
Peristalsis | The series of rhythmic muscular contractions that move food through the digestive tract |
Alveolus | Any of the tiny air sacs of the lungs where oxygen and carbon dioxide are exchanged |
Spiracle | An external opening in an insect or arthropod, used in respiration |
Ureter | One of the two narrow tubes that carry urine from the kidneys to the urinary bladder |
Genital Herpes | A sexually transmitted infection that is caused by a herpes simplex virus |
Urinary Bladder | A hollow, muscular organ that stores urine |
Excretion | The process of eliminating metabolic wastes |
Chrysalis | The hard-shelled pupa of certain insects, such as butterflies |
Menstrual Cycle | The female reproductive cycle, characterized by a monthly change of the lining of the uterus and the discharge of blood |
Caste | A group of insects in a colony that have a specific function |
Seminiferous Tube | One of the many tubules in the testis where sperm are produced |
Embryo | An organism in an early stage of development; in humans, a developing individual from first cleavage through the next eight weeks |
Blood Pressure | The force that blood exerts on the walls of the arteries |
Lymphatic System | A collection of organs whose primary function is to collect extracellular fluid and return it to the blood |
Platelet | A fragment of a cell that is needed to form blood clots |
Ventricle | One of the two large, muscular chambers that pump blood out of the heart |
Larynx | The area of the throat that contains the vocal chords and produces vocal sounds |
Pharynx | The passage from the mouth to the larynx and the esophagus |
Melanin | A pigment that helps determine skin and hair color |
Fallopian Tube | A tube through which eggs move from the ovary to the uterus |
Vas Deferens | A duct through which sperm move through the epididymis to the ejaculatory duct at the base of the penis |
Skin Gill | A transparent structure that projects from the surface of a sea star and that enables respiration |
Tube Foot | One of the many small, flexible, fluid filled tubes that project from the bidy of an echidnoderm and that are used in locomotion, feeding, gas exchange, and excretion |
Pupa | The immobile, nonfeeding stage between the larva and the adult of insects that undergo complete metamorphosis |
Implantation | The process by which a blastocyte embeds itself in the lining of the uterus |
Trocophore | A free-swimming, ciliated larva of many worms and some mollusks |
Ovum | A mature egg cell |
White Blood Cell | A type of cell in the blood that that destroys pathogens and helps the body develop immunities |
Red Blood Cell | A disc-shaped cell that has no nucleus, that contains hemoglobin, and that transports oxygen in the circulatory system |
Flexor | A muscle that bends a joint |
Nematocyst | A stinging organelle that is used to inject a toxin into prey |
Cnidocyte | A stinging cell of a cnidarian |
Metamorphosis | A phase in the life cycle of many animals during which a rapid change from the immature organism to the adult takes place |
Myofibril | A structure found in skeletal muscle cells that is made up of actin and myosin |
Subcutaneous Tissue | The layer of cells beneath the dermis |
Leukemia | Cancer of the blood-forming organs |
Ligament | A type of connective tissue that holds together the bones in a joint |
Extensor | A muscle that extends a joint |
Osteocyte | A mature bone cell that maintains the mineral content of bones |
Actin | A protein that forms the thin filaments in muscle fibers |
Dermis | The layer of skin below the epidermis |
Stem Cell | A cell that can develop into many different types of cells |
Villus | One of the many tiny projections from the cells in the lining of the small intestine |
Thorax | In arthropods, the mid-body region |
Spicule | A needle of silica or calcium carbonate in the skeleton of some sponges |
Joint | A place where two or more bones meet |
Capillary | A tiny blood vessel that allows an exchange between blood and cells in tissue |
Urea | The principal nitrogenous product of the metabolism of proteins that forms in the liver from amino acids and from compounds of ammonia and that is found in urine and other body fluids |
Pelvic Inflammatory Disease | A sexually transmitted infection of the upper female reproductive system, including the uterus, ovaries, fallopian tubes, and other structures |
Prostate Gland | A gland in males that contributes to the seminal fluid |
Forensic Science | The use of science to investigate legal matters |
Epididymis | The long, coiled tube that is on the surface of a testis and in which sperm mature |
Amoebocyte | In sponges and other invertebrates, an amoeba-like cell that moves through the body fluids, removes wastes, and participates on other processes |
Trachea | In insects, myriapods, and spiders, one of a network of air tubes |
Appendage | A structure that extends from the main body, such as a limb, tentacle, fin, or wing |
Pathology | The scientific study of disease |
Toxicology | The study of toxins and their effects on the body |
Ballistics | The science that deals with the motion and impact of projectiles |
Visceral Mass | The central section of a mollusk's body that contains the mollusk's organs |
Cerebral Ganglion | One of a pair of nerve cell clusters that serve as a primitive brain |
Sarcomere | The basic unit of contraction in skeletal and cardiac muscle |
Menstruation | The discharge of blood and discarded tissue from the uterus during the menstrual cycle |
Foot | An appendage that some invertebrates use to move |
Epidermis | The outer surface layer of cells |
Chromatograph | A tool that separates chemicals based on various physical propterties |
Choanocyte | Any of the flagellate cells that line the cavities of a sponge |
Connective Tissue | A tissue that connects and supports other tissues |
Mantle | In biology, a layer of tissue that covers the body of many invertabrates |
Cephalothorax | In arachnids and some crustaceans, the body part made of the head and the thorax |
Muscle Fiber | A muscle cell |
Autopsy | An examination of a body after death, usually to determine the cause of death |