Science Menu crossword puzzle

the internal organ in which the major part of the digestion of food occurs, being (in humans and many mammals) a pear-shaped enlargement of the alimentary canal linking the esophagus to the small intestine
a large membranous tube reinforced by rings of cartilage, extending from the larynx to the bronchial tubes and conveying air to and from the lungs; the windpipe.
a large lobed glandular organ in the abdomen of vertebrates, involved in many metabolic processes.
an organ of soft nervous tissue contained in the skull of vertebrates, functioning as the coordinating center of sensation and intellectual and nervous activity.
a hollow muscular organ that pumps the blood through the circulatory system by rhythmic contraction and dilation. In vertebrates there may be up to four chambers (as in humans), with two atria and two ventricles.
the surface epithelium of the skin, overlying the dermis.
a specialized cell transmitting nerve impulses; a nerve cell.
a large cartilage of the larynx, a projection of which forms the Adam's apple in humans.
each of a pair of organs in the abdominal cavity of mammals, birds, and reptiles, excreting urine.
the kneecap.
a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.
each of the pair of organs situated within the rib cage, consisting of elastic sacs with branching passages into which air is drawn, so that oxygen can pass into the blood and carbon dioxide be removed.
relating to the breast or chest.
any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body.
a membranous sac in humans and other animals, in which urine is collected for excretion.