Physiology Flashcards
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
Vertigo can be causes by
a) ear squeeze
b) inner ear bartrauma
c) decompression sickness
d) all of the above
d
Sound vibrations are transferred from the outer to the inner ear via the
ossicles
The vestibular canals are located in the_____________ and are responsible for _____________.
inner ear
balance
Which portion of the ear is most affected by changes in pressure?
middle ear
A symptom of air embolism may be _____________, while two symptoms of decompression sickness may be _____________ and _____________.
Sudden unconsciousness/ pain in the joints and fatigue
Air embolism resembles a stroke (one side of the body affected) DCS involves both sides of the body - either upper or lower
In terms of the change in air embolism symptoms improve as a result of first aid. True or False?
True
In terms of the change in DCS improve as a result of first aid. True or False?
False (symptoms don’t change or worsen)
The most serious form of lung overexpansion injury is a(n) _____________ because air bubbles enter the _____________.
Air embolism/ arterial circulation
Surfactant is a substance that coats the inner surfaces of the _____________ and helps prevent them from _____________.
Bronchioles and alveoli/ collapsing
Position for DCS
Lay flat
Position for DCS
Lay flat
You manage shock ?
raise legs, keep calm and keep temp
Assessment first aid is the treatment of conditions that
not life threatening
chain of survival
early recognition and activation of the emergency response system, early CPR, rapid defibrillation, and advanced life support
While managing serious bleeding, if a pressure bandage or dressing becomes soaked with blood, you would generally remove it and replace it with a new one
false
Why are demand inhalator valves the first choice in treating injured, breathing divers?
on demand helps conserve 02 supply
deliver 100% o2 to diver
blood pressure and pulse
CAROTID
RADIAL
CAROTID: 60
RADIAL: 80
Heat ______ occurs when fluid intake does not compensate for perspiration loss, and heat _______ occurs when the body’s temperature control system fails and body temperature rises dangerously high.
EXHAUSATION
STROKE
Patient care for a chemical splash in the eye includes flushing the eye with water for _______, or until EMS arrives.
15 MINS
______ affects surface skin, while ______ affects entire tissue layers, including muscles, tendons, blood vessels and nerves.
FROSTNIP
FROSTBITE
TRUE OR FALSE
Strokes occur when the heart fibrillates, forcing too much blood into the brain.
FALSE
STROKE = LACK OF O2
