| A | B |
|---|
| The Outer Ear | The visible part of the ear also called the auricle. It channels sound waves into the external auditory canal. This canal leads to the remaining portion of the outer ear, called the eardrum. The ear drum acts as a barrier between the outer and middle ear. |
| Middle ear | Directly behind the eardrum, containing the auditory ossicles, which are three small bones linked together that connect the eardrum to the inner |
| The Inner Ear | Also called the labyrinth, consists of a network of curved and spiral passages that can be divided into three main parts. The cochlea, a spiral shaped canal, is the area of hearing in the inner ear. |
| Cornea | Also called the labyrinth, consists of a network of curved and spiral passages that can be divided into three main parts. The cochlea, a spiral shaped canal, is the area of hearing in the inner ear. |
| Sclera | a dense, white, fibrous membrane that, with the cornea, forms the external covering of the eyeball. |
| Retina | the innermost coat of the posterior part of the eyeball that receives the image produced by the lens, is continuous with the optic nerve, and consists of several layers, one of which contains the rods and cones that are sensitive to light. |
| Skeletal system | The framework of the body, consisting of bones and other connective tissues, which protects and supports the body tissues and internal organs. |
| Cartilage | a firm, elastic, flexible type of connective tissue of a translucent whitish or yellowish color; gristle. |
| Ligament | band of tissue, usually white and fibrous, serving to connect bones, hold organs in place, etc. |
| Tendon | a cord or band of dense, tough, inelastic, white, fibrous tissue, serving to connect a muscle with a bone or part; sinew. |
| Heart | a hollow, pumplike organ of blood circulation, composed mainly of rhythmically contractile smooth muscle, located in the chest between the lungs and slightly to the left and consisting of four chambers: a right atrium that receives blood returning from the body via the superior and inferior vena cavae, a right ventricle that pumps the blood through the pulmonary artery to the lungs for oxygenation, a left atrium that receives the oxygenated blood via the pulmonary veins and passes it through the mitral valve, and a left ventricle that pumps the oxygenated blood, via the aorta, throughout the body. |
| lungs | either of the two saclike respiratory organs in the thorax of humans and the higher vertebrates. |
| bronchi | either of the two main branches of the trachea. |
| alveoli | an air cell of the lungs, formed by the terminal dilation of tiny air passageways. |
| trachea | the tube in humans and other air-breathing vertebrates extending from the larynx to the bronchi, serving as the principal passage for conveying air to and from the lungs; the windpipe. |
| larynx | a muscular and cartilaginous structure lined with mucous membrane at the upper part of the trachea in humans, in which the vocal cords are located. |
| Esophagus | a muscular passage connecting the mouth or pharynx with the stomach in invertebrate and vertebrate animals; gullet. |
| stomach | a saclike enlargement of the alimentary canal, as in humans and certain animals, forming an organ for storing, diluting, and digesting food. |
| pancreas | a gland, situated near the stomach, that secretes a digestive fluid into the intestine through one or more ducts and also secretes the hormone insulin. |
| gallbladder | a pear-shaped, muscular sac attached to the undersurface of the right lobe of the liver, in which bile is stored and concentrated. |
| Small intestine | the narrow, longer part of the intestines, comprising the duodenum, jejunum, and ileum, that serves to digest and absorb nutrients. |
| Large Intestine | the broad, shorter part of the intestines, comprising the cecum, colon, and rectum, that absorbs water from and eliminates the residues of digestion. |
| Liver | a large, reddish-brown, glandular organ located in the upper right side of the abdominal cavity, divided by fissures into five lobes and functioning in the secretion of bile and various metabolic processes. |
| Kidney | either of a pair of bean-shaped organs in the back part of the abdominal cavity that form and excrete urine, regulate fluid and electrolyte balance, and act as endocrine glands. |
