Q Is it true that signing a donor card doesn't guarantee that my organs will be used for transplantation? S.J., Tucson

A Yes, it is true that signing a donor card is not enough. This is one of several misconceptions and myths about organ donation.

Signing a donor card doesn't guarantee that a person's wishes will be followed; the family must consent to donation at the time of their loved one's death, otherwise donation doesn't happen, regardless of documentation.

Therefore, it's important to talk with your family about your wishes when you make the decision to share your life through donation. More than 90 percent of families support their loved one's wishes if they've had a conversation about donation.

Another myth about organ donation that continues to flourish on the Internet and in other media is that people can buy and sell organs. It is a federal crime to buy or sell organs or tissues. Income, gender or celebrity status are not given consideration when determining who receives an organ transplant.

The allocation and distribution of organs is based on blood type, the length of time a patient has been on the waiting list, geographical location, the severity of the illness and other medical criteria.

Patients can't buy a place on the waiting list. And there is no cost to the donor family for the donation process.

Another myth about organ donation is that doctors let patients die so their organs can be transplanted to others. The fact is that doctors who treat patients at the time of death have nothing to do with the donation or transplantation of organs or tissues. Every effort is made to save a patient's life before donation can be considered.

Donation doesn't delay funeral arrangements, either. Most organ and tissue donations take place within 24-hours after death. Donations don't disfigure the body or change the way a person looks in a casket.

All major religions — Roman Catholicism, Protestantism, Judaism, Hinduism, Islam, Buddhism — support donation.

Another myth is that transplants are still experimental. More than 19,000 solid-organ transplants and 450,000 tissue transplants take place annually in the U.S. Transplantation is a standard medical procedure and survival and success rates are extremely high.

For more information about donation, contact Donor Network of Arizona at 1-800-94DONOR or check out their website at www.dnaz.org.

—Nancy Edling, R.N., lead cardiothoracic heart transplant coordinator, Transplantation Service,University Medical Center, Tucson.

(EDITORS NOTE: May 31 is World No Tobacco Day)

Q Is it true that smoking cigarettes causes wrinkles? C.S., Tucson

A Smokers, especially women, show visible signs of aging — such as wrinkles around the corners of the eyes and mouth and pronounced wrinkling and creping on the backs of the hands — at earlier ages than do non-smokers.

Smoking affects the elastin in all body tissue. Elastin is a protein that is the principal substance of the elastic fibers that make up elastic tissue.

Elasticity gives skin, especially skin on the face and hands, the qualities of softness and suppleness. Chemicals in tobacco smoke dry the elastin in tissue, causing the skin to wrinkle more readily.

The appearance of the skin also can be affected by the tars in cigarette smoke. (Tars are the residues left in tobacco smoke after even a substantial gain in weight.

Some less-obvious physical effects from smoking include extra, unnecessary work for the liver and kidneys, which process nicotine.

One of the most toxic drugs known, nicotine acts with almost as much speed as cyanide. A lethal dose of nicotine in humans is 60 milligrams. A pack of "full-flavor" cigarettes contains 20 to 36 milligrams of nicotine; the most popular brands average about 22 to 24 milligrams. Some cigars may contain more than 100 milligrams in one cigar. Not all of the nicotine is delivered to the smoker or absorbed by the tobacco user because it is primarily deactivated in the liver and excreted through the kidneys.

Nicotine slows the loss of body fluids and also decreases the effects of some prescription medicines, such as benzodiazepines (tranquilizers, sleeping tablets and other sedatives), some antidepressants and analgesics.

—Cliff Franks, research technician, Arizona Prevention Center, TheUniversity of Arizona Health Sciences Center, Tucson.