Which part of the ear is most affected by pressure change?
Middle ear
Excessive hyperventilation with apnea diving may cause
Shallow water blackout
Unconsciousness
Hypoxia
If the blood did not contain hemoglobin, it would have to circulate 15 to 20 times faster to keep up with the body’s demand for oxygen.
True
Large amounts of carbon dioxide can be carried by the circulatory system back to the lungs for expiration primarily because carbon dioxide:
can be converted into bicarbonate
The practice of breathing deeply when scuba diving is important in order to compensate for the:
- Increased dead air space
- reduced lung vol due to chest compression
- increased alveolar co2
The practice of breathing slowly when scuba diving is important in order to:
Minimize resistance caused by turbulence in the airways
When a breath-holding diver submerges in cold water, his heart rate will:
decrease - dive mammalian reflex
To reduce the demand for oxygen while breath-hold diving, the diver should:
Move slowly and deliberately while underwater
Breathing slowly from the diaphragm before a breath hold dive is essential because
a) promote better gas exchange
b) reduce the proportional dead air volume
c) promote relaxation
d) all of the above
d) all of the above
Blackout normally occurs on ascent because:
The partial pressure of the alveolar oxygen rapidly decreases
The carotid-sinus receptors, which are located in the carotid arteries, stimulate the _____________, which is located in the _____________.
Cardioinhibitory center in the brain
The carotid-sinus reflex is caused by an excessively tight
hood or wetsuit
When the carotid-sinus receptors detect high pressure, they cause the heart to
Slow down
Carbon monoxide bonds with hemoglobin over _____________ times more readily than oxygen can, and takes _____________ for the circulatory system to eliminate.
200 times more
8 -12 hours
The symptoms of carbon monoxide poisoning are not as noticeable at depth because
high levels of 02 are dissolved in the plasma allowing tissues to meet their oxygen requirements
Smoking cigarettes prior to diving can raise the carbon monoxide level _____________ times above normal, which in turn _____________.
3 -12
impairs oxygen transport and co2 elimination
What factors cause body tissues to absorb and eliminate nitrogen at different rates?
high or low blood supply
tissue density
Supersaturation
amount of inert gas in the body is greater than the amount found in the surrounding atmosphere
What is the device used to detect the presence of silent bubbles?
Doppler Ultrasound Flowmeter
Silent bubbles are thought to form because of the presence of..
gas ‘seeds’ (micronuclei)
Breathing pure oxygen aids the individual with decompression sickness because it ..
increases the pressure gradient between the nitrogen pressure in the tissues and the alveolar nitrogen pressure
It is believed that nitrogen (gas) narcosis results from
disruptions in the transmissions between nerve cells
Other than potential damage to the eardrum, an excessively forceful Valsalva maneuver can result in an ..
Round window rupture
Forceful Valsalva manoeuvre, increased pressure in the chest inhibits the flow of blood returning to the heart. This raises the pressure of the cerebrospinal fluid, which includes the perilymph within the inner ear, raising the pressure within the inner ear
Severe lung squeeze can occur in shallow depths in which of the following conditions?
A scuba diver descends with their lungs nearly empty
