Biology

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,…

Fibroblast Definition Fibroblast is a cell that manufactures and maintains connective tissue, the structural framework that supports the organs of all animals. It is responsible…

Gland Definition Gland is an organ or group of specialized cells in the body that produces and secretes a specific substance, such as a hormone.…

Epithelium Definition Epithelium is the thin, membranous tissue that lines most of the internal and external surfaces of an animal’s body. It is composed of…

Adipose Tissue Definition Adipose tissue is a connective tissue consisting chiefly of fat cells surrounded by reticular fibers and arranged in lobular groups or along…

Reticular Connective Tissue Definition Reticular connective tissue is a type of tissue found in the body that is supported with a branching framework of collagen…

Loose Connective Tissue Definition Loose connective tissue is a loose, irregularly arranged connective tissue that consists of collagenous and elastic fibers, a protein polysaccharide ground…

Tendon Definition Tendon is a band of tough, fibrous, inelastic tissue that connects a muscle to a bone. Tendons are made chiefly of collagen. Ligaments…

Effects and Uses of Nitric Oxide Definition of Nitric Oxide Nitric Oxide is a chemical compound that has a chemical formula of NO. It consists…

Nitric Oxide Definition Nitric oxide is a colorless, poisonous gas produced as an intermediate compound during the manufacture of nitric acid from ammonia or from…