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February 10, 2012


Scuba Diving and Snorkeling Tips Glossary of Terms

The following are health and medical definitions of terms that appear in the Scuba Diving and Snorkeling Tips article.

Adrenaline: A substance produced by the medulla (inside) of the adrenal gland, adrenaline (the official name in the British Pharmacopoeia) is synonymous with epinephrine. Technically speaking, adrenaline is a sympathomimetic catecholamine. It causes quickening of the heart beat, strengthens the force of the heart's contraction, opens up the bronchioles in the lungs and has numerous other effects. The secretion of adrenaline by the adrenal is part of the "fight-or-flight" reaction that we have in response to being frightened.

Allergy: A misguided reaction to foreign substances by the immune system, the body system of defense against foreign invaders, particularly pathogens (the agents of infection). The allergic reaction is misguided in that these foreign substances are usually harmless. The substances that trigger allergy are called allergen. Examples include pollens, dust mite, molds, danders, and certain foods. People prone to allergies are said to be allergic or atopic.
See the entire definition of Allergy

Centers for Disease Control and Prevention: The US agency charged with tracking and investigating public health trends. The stated mission of the Centers for Disease Control and Prevention, commonly called the CDC, is "To promote health and quality of life by preventing and controlling disease, injury, and disability."
See the entire definition of Centers for Disease Control and Prevention

CPR: Cardiopulmonary resuscitation. Also cardiac and pulmonary rehabilitation and computer-based patient records.

Decompression: 1. In general, the removal of pressure.
2. In surgery, a procedure to remove pressure on a structure, as in decompression of the spinal cord.
3. The lessening of atmospheric pressure on deep-sea divers returning to the surface, or on persons ascending to great heights.

Ear: The hearing organ. There are three sections of the ear, according to the anatomy textbooks. They are the outer ear (the part we see along the sides of our head behind the temples), the middle ear, and the inner ear. But in terms of function, the ear has four parts: those three and the brain. Hearing thus involves all parts of the ear as well as the auditory cortex of the brain. The external ear helps concentrate the vibrations of air on the ear drum and make it vibrate. These vibrations are transmitted by a chain of little bones in the middle ear to the inner ear. There they stimulate the fibers of the auditory nerve to transmit impulses to the brain.
See the entire definition of Ear

Epinephrine: A substance produced by the medulla (inside) of the adrenal gland. The name epinephrine was coined in 1898 by the American pharmacologist and physiologic chemist (biochemist) John Jacob Abel who isolated it from the adrenal gland which is located above (epi-) the kidney ("nephros" in Greek). (Abel also crystallized insulin). Technically speaking, epinephrine is a sympathomimetic catecholamine. It causes quickening of the heart beat, strengthens the force of the heart's contraction, opens up the airways (bronchioles) in the lungs and has numerous other effects. The secretion of epinephrine by the adrenal is part of the fight-or-flight reaction. Adrenaline is a synonym of epinephrine and is the official name in the British Pharmacopoeia.

Gastric: Having to do with the stomach.

Hyperbaric: Pertaining to gas pressures greater than 1 atmosphere* of pressure. Also pertaining to solutions that are more dense than the medium to which they are added. The term "hyperbaric" is derived from Greek roots: "hyper-" meaning high, beyond, excessive, above normal + "baros" meaning weight.
See the entire definition of Hyperbaric

Immunization: Vaccination. Immunizations work by stimulating the immune system, the natural disease-fighting system of the body. The healthy immune system is able to recognize invading bacteria and viruses and produce substances (antibodies) to destroy or disable them. Immunizations prepare the immune system to ward off a disease. To immunize against viral diseases, the virus used in the vaccine has been weakened or killed. To immunize against bacterial diseases, it is generally possible to use only a small portion of the dead bacteria to stimulate the formation of antibodies against the whole bacteria. In addition to the initial immunization process, it has been found that the effectiveness of immunizations can be improved by periodic repeat injections or "boosters." Also see Immunizations (in the plural) and Immunization of a specific type (such Immunization, Polio).

Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.
See the entire definition of Infection

Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.

Insect sting: Stings from large stinging insects such as bees, hornets, yellow jackets and wasps can trigger allergic reactions varying greatly in severity. Avoidance and prompt treatment are essential. In selected cases, allergy injection therapy is highly effective.

Marker: A piece of DNA that lies on a chromosome so close to a gene that the marker and the gene are inherited together. A marker is thus an identifiable heritable spot on a chromosome. A marker can be an expressed region of DNA (a gene) or a segment of DNA with no known coding function. All that matters is that the marker can be detected and trailed.
See the entire definition of Marker

Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
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Sinus: 1. An air-filled cavity in a dense portion of a skull bone. The sinuses decrease the weight of the skull. The sinuses are formed in four right-left pairs. The frontal sinuses are positioned behind the forehead, while the maxillary sinuses are behind the cheeks. The sphenoid and ethmoid sinuses are deeper in the skull behind the eyes and maxillary sinuses. The sinuses are lined by mucous-secreting cells. Air enters the sinuses through small opening in bone called ostia. If an ostium is blocked, air cannot pass into the sinus and likewise mucous cannot drain out. See also: Sinusitis.
See the entire definition of Sinus

Tetanus: An often fatal infectious disease caused by the bacteria Clostridium tetani (C. tetani) which usually enters the body through a puncture, cut, or open wound. Tetanus is characterized by profoundly painful spasms of muscles, including "locking" of the jaw so that the mouth cannot open (lockjaw). C. tetani releases a toxin that affects the motor nerves, (the nerves which stimulate the muscles).
See the entire definition of Tetanus

Tooth: The structures within the mouth that allow for biting and chewing. Teeth have different shapes, depending on their purpose. The sharp canine and frontal teeth allow for biting, while the flattened, thick molars in the back of the mouth provide grinding surfaces for masticating food. All teeth have essentially the same structure: a hard crown above the gum line, which is attached to two or four roots by a portion called the neck. The roots are covered with a very thin layer of bone, and keep the tooth embedded in the bones of the jaw. The exposed exterior of the tooth is covered with tough enamel. Under the enamel is a thick layer of dentin, and in the center is the pulp. Blood vessels and nerves are found within the pulp.

Travel medicine: A branch of medicine that specializes in diseases and conditions that are acquired during travel. Travelers to different countries should be aware of the potential for acquiring diseases and injury which are not common in their own country. Immunizations, preventative medications, and general precautions should be considered prior to trips to different parts of the world.
See the entire definition of Travel medicine

Venomous: 1. Full of venom. 2. Having venom, like some snakes and insects. 3. By extension, noxious, as a venomous tongue.

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Scuba Diving and Snorkeling Tips

Ear Squeeze Overview

Scuba diving can affect the external ear, middle ear, and inner ear. Ear problems are commonly caused by inadequate equalization, forceful equalization, diving with a cold or allergies, wax buildup, a tight hood, or a mask over the ear. If symptoms of ear squeeze begin at depth, they can be very dangerous for the diver.

Ear Squeeze Symptoms

Symptoms of ear squeeze include the following:

  • Ear pain
  • Fullness in the ear
  • Hearing loss
  • Ringing in the ear
  • Nausea
  • Vomiting
  • Vertigo
  • Discharge from the ear, nose, or mouth 

Ear Squeeze Treatment

  • Rest; avoid further dives, coughing, sneezing, bending, and attempts to equalize pressure in the ears.
  • Pain may be relieved with 1-2 acetaminophen (Tylenol) every 4 hours and/or 1-2 ibuprofen (Advil, Motrin) eve...

Read the Scuba Diving: Ear Squeeze article »


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