Every 3.7 seconds someone in the United States is receiving a blood transfusion and a total of thirty million units of blood is transfused throughout the world annually (Cannell 1999)1. In the 1600's Louis XIV physician, Jean-Baptiste, performed the first blood transfusion when he took nine o...

Hypoxia Hypoxia is a condition in humans that is caused by the reduction in partial pressure of oxygen, inadequate oxygen transport, or when tissues are simply unable to make use of the oxygen provided. This disease occurs in the tissues and brain. It results in a shortness of breath, and an...

A businessman in his late forties is sitting in coach on an airplane. The seating is quite tight and he can't seem to get comfortable. Suddenly, his leg starts to tingle. Thinking that his leg just fell asleep, he starts to massage it. As he rubs, he notices a slight pain growing. He decides to...

Most cells are freely permeable to water that diffuses through aquaporins (water channels) in the selectively permeable plasma membrane. This movement of water is termed osmosis and occurs in response to an osmotic pressure gradient across the cell membrane. The osmolality of a solution is the total...