Biology

Pharynx Definition Pharynx is the passage that leads from the cavities of the nose and mouth to the larynx (voice box) and esophagus. Air passes…

Trachea Definition Trachea is the tube in vertebrate animals that leads from the larynx to the bronchial tubes and carries air to the lungs. In…

Aortic Arch Definition Aortic arch is the curved portion between the ascending and descending portions of the aorta, lying behind the manubrium and giving rise…

Thoracic Diaphragm Definition Thoracic diaphragm is the large muscle that separates the chest cavity from the abdominal cavity in mammals and is the principal muscle…

Aorta Definition Aorta is the main artery of the circulatory system, arising from the left ventricle of the heart in mammals and birds and carrying…

Mitral Valve Definition Mitral valve is a valve of the heart, composed of two triangular flaps, that is located between the left atrium and left…

Heart Ventricle Definition Ventricle is a chamber of the heart that receives blood from one or more atria and pumps it by muscular contraction into…

Tricuspid Valve Definition Tricuspid valve is a valve of the heart, usually having three cusps, that is located between the right atrium and right ventricle…

Cardiac Muscle Definition Cardiac muscle is responsible for pumping blood throughout the body. It is a type of muscle tissue that is found only in…

Heart Atrium Definition Atrium (Heart) is a chamber of the heart that receives blood from the veins and forces it by muscular contraction into a…

Scalene Muscles Definition Scalene muscles are a group of muscles consisting of the scalenus anterior, scalenus medius, and scalenus posterior. These muscles are located toward…

Pericardium Definition Pericardium is the membrane sac that encloses the heart in vertebrate animals. The pericardium’s outer coat (the parietal pericardium) is tough and thickened,…