There are two groups of veins that move blood from the lower extremities back to the heart. The first system is superficial and consists of veins lying close to the surface; the other larger system is the deep venous system which, as its name implies, is deep within the leg. The superficial veins communicate with…
About 25 percent of people suffer from some sort of allergy. These allergies can manifest in a variety of ways, from mild skin eruptions to nasal congestion, and even severe respiratory distress. Regardless of the symptoms they cause, or the material (allergen) that initiates the allergic reaction, all allergies have something in common – namely,…
Consider two patients. Patient A develops abdominal pain and visits his doctor, who notes the patient has a low-grade fever and tenderness localized to the lower right side of the abdomen. Additionally, if the doctor presses slowly on the lower abdomen and then suddenly lets go of the pressure, the patient winces. A CT scan…
UV Radiation and the Risks Pilots Face Ultraviolet radiation is an electromagnetic wave that occupies a portion of the spectrum between X-rays and visible violet light. This corresponds to wavelengths of between approximately 400 nanometers on the visible light side to about 10 nanometers on the X-ray side. This spectrum is subdivided into several sub…
Runny nose, irritated and watery eyes, sneezing and general stuffiness are symptoms we all experience from time to time. These symptoms result from the release of a chemical called histamine from specific cells of our immune systems as a response to an external irritant or allergen. Histamine has many physiologic effects, including dilating blood vessels,…
Unlike many relatively incomprehensible FARs, the one dealing with alcohol use is reasonably clear. FAR 91.17 prohibits any person from acting or attempting to act as a crewmember of a civil aircraft: 1) Within eight hours after the consumption of any alcoholic beverage; 2) While under the influence of alcohol; 3) While using any drug…
In a recent article, I discussed myocardial infarction, a condition that occurs when the blood flow in one or more of the coronary arteries is blocked. A similar situation can occur with the arteries that supply the brain as well. When a portion of the brain is deprived of its blood supply, the person suffers…
You Gotta Have Heart – Pilot Medical Requirements The heart is a muscular organ located in the chest whose purpose is to pump blood throughout the body. It consists of four chambers – two atria and two ventricles. The right atrium receives blood from the body and pushes it into the right ventricle, which then…
Wa’did He Say? Pilot Reuirements – Hearing Of all our sense organs, it could be argued that the ear is the most complex. It consists of three distinct parts, the outer, middle and inner ear. The outer ear, also called the pinna, is the part of the ear we see sticking out from the sides…