An Independent Practice Association, or IPA, is an organization comprised of physicians who maintain their independent practices and also join together as an association. The IPA negotiates with organizations, like HMOs, which will supply both patients and income to physicians.
There are 11 major organ systems in the human body, which include the circulatory, respiratory, digestive, excretory, nervous and endocrine systems. The immune, integumentary, skeletal, muscle and reproductive systems are also part of the human body.
Quick Answer. According to Neurogenetics at the University of Tennessee Health Science Center, the human body has 95 to 100 billion neurons or nerve cells. The brain alone has at least 85 billion of these cells, although estimates go as high as 1 trillion.