Explain the reasons for the observed changes in blood flow velocity in the different regions of the circulation.

Your friend Jillian, who knows little about science, is reading a magazine article about a patient who had an 'aneurysm at the base of his brain that suddenly grew much larger.' The surgeons' first goal was to 'keep it from rupturing,' and the second goal was to 'relieve the pressure on the brain stem and cranial nerves.' The surgeons were able to 'replace the aneurysm with a section of plastic tubing,' so the patient recovered. Jillian asks you what all this means. Explain.

People with allergies commonly take antihistamines with decongestants to relieve their symptoms. The container warns that individuals who are being treated for high blood pressure should not take the medication. Why not?

How are nutrients, wastes, and respiratory gases transported to and from the blood and tissue spaces?

Edema is a common clinical problem. On your first day of a clinical rotation, you encounter four patients who have edema for different reasons. Your challenge is to explain the edema in terms of either an increase or a decrease in one of the four pressures that causes bulk flow (see Focus Figure 18.1).(1) First you encounter Mrs. Taylor in the medical unit awaiting a liver transplant. What is the connection between liver failure and her edema?(2) Next in the obstetric ward, Mrs. So is experiencing premature labor and has edema in her legs. Which bulk flow pressures might be altered here?(3) In emergency, Mr. Herrera is in anaphylactic shock. His capillaries have become leaky, allowing plasma proteins that are normally kept inside the blood vessels to escape into the interstitial fluid. Which of the bulk flow pressures is altered in this case and in what direction is the change?(4) Finally, in oncology Mrs. O'Leary is recovering from breast cancer surgery. Her right breast and all of her axillary lymph nodes were removed. Unfortunately, this severed most of the lymphatic vessels draining her right arm. You notice that this arm is quite edematous. Why? Mrs. O'Leary is given a compression sleeve to wear on this arm to help relieve the edema. Which of the bulk flow pressures will be altered by the compression sleeve?