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hormone

(Encyclopedia)hormone, secretory substance carried from one gland or organ of the body via the bloodstream to more or less specific tissues, where it exerts some influence upon the metabolism of the target tissue. ...

platypus

(Encyclopedia)platypus plătˈəpəs [key], semiaquatic egg-laying mammal, Ornithorhynchus anatinus, of Tasmania and E Australia. Also called duckbill, or duckbilled platypus, it belongs to the order Monotremata (s...

feathers

(Encyclopedia)CE5 Structure of a bird feather feathers, outgrowths of the skin, constituting the plumage of birds. Feathers grow only along certain definite tracts (pterylae), which vary in different groups of ...

herbal medicine

(Encyclopedia)herbal medicine, use of natural plant substances (botanicals) to treat and prevent illness. The practice has existed since prehistoric times and flourishes today as the primary form of medicine for pe...

disease

(Encyclopedia)disease, impairment of the normal state or functioning of the body as a whole or of any of its parts. Some diseases are acute, producing severe symptoms that terminate after a short time, e.g., pneumo...

steroids

(Encyclopedia)CE5 Two examples of steroids steroids, class of lipids having a particular molecular ring structure called the cyclopentanoperhydro-phenanthrene ring system. Steroids differ from one another in th...

obesity

(Encyclopedia)obesity, condition resulting from excessive storage of fat in the body. Obesity is now usually defined using a formula known as the body mass index (BMI), in which weight (in kilograms) is divided by ...

cortisone

(Encyclopedia)cortisone kôrˈtĭsōnˌ [key], steroid hormone whose main physiological effect is on carbohydrate metabolism. It is synthesized from cholesterol in the outer layer, or cortex, of the adrenal gland u...

growth hormone

(Encyclopedia)growth hormone or somatotropin sōmătˌətrōˈpən [key], glycoprotein hormone released by the anterior pituitary gland that is necessary for normal skeletal growth in humans (see protein). Evidence...

arrhythmia

(Encyclopedia)arrhythmia ārĭᵺˈmēə [key], disturbance in the rate or rhythm of the heartbeat. Various arrhythmias can be symptoms of serious heart disorders; however, they are usually of no medical significan...