Physiology Flashcards
oxygen is transported efficiently throughout the body because of a substance called ______ contained in the _____
Hemoglobin. Red blood cells
_______is the fluid in which all the components in blood are suspended.
_____ comprise ____% of the blood mass
Plasma
Red blood cells
45%
Without hemoglobin blood would have to circulate 15-20 times faster to transport oxygen to keep up with body? T/F
True
Large amounts of CO2 can be carried by the circulatory system back to the lungs for expiration primarily because ______
Can be converted into bicarbonate
You breathe deeply in scuba diving in order to compensate for the
A) increased dead air spaces resulting from snorkel and regulator
B) reduced lung volume from compression of chest
C) increased amount of alveolar CO2 due to increased resistance of breathing while submerged
A, B , C
You breathe slowly when scuba diving because
A) minimize resistance caused by turbulence in the airways
B) compensate for the decrease in energy from cold water
C) avoid potential for thoracic squeeze
A
Slower breathing reduces turbulence. Turbulence results in increased resistance and therefore increased effort
When a breathe hold diver immerses his _____ in cold water his heart rate _____
Referred to as the _______ diving reflex, which is common to all diving mammals.
Head
Decrease
Mammalian
To reduce the demand for O2 while breath holding diving the diver should
A) take a few rapid deep breathes before diving
B) take lots of rapid breathes before diving
C) move slowly and deliberately underwater
D) breathe pure O2
C
Breathing slowly from the diaphragm before a dive can
A) promote relaxation
B) promote better gas exchange
C) reduce dead air volume
All
Breathing is regulated based on the amount of _____ in the blood
CO2
The urge to breathe is suppressed because of the low level of oxygen in breath holding diving? T/F
False CO2
In breath holding diving if the tissues continue to be air starved they begin to cease functioning and the diver loses consciousness due to lack of CO2? T/F
False loose consciousness due to lack of Oxygen even though lack of CO2 caused the issue initially
Hypoxia results when the diver’s CO2 can’t accumulate to a level high enough to stimulate breathing before the tissues consume available oxygen? T/F
True
Blackout on ascent occurs because the _____ ______ of the alveolar ______ rapidly decreases
Partial pressure O2
Hyperventilating at the surface prior to a breath hold dive reduces the level of ____
CO2
The carotid- sinus receptors, which are located in the carotid arteries stimulate the ____ ____ _____ which is located in the _____
Cardio inhibitory center. brain
If the neck seal of your dry suit is too tight it could cause the carotid sinus reflex causing heart rate to decrease/increase because the brain thinks the blood pressure is to low/high
Decrease high
Carbon monoxide is ____ and _____ which makes it hard to detect
Odorless. Tasteless
Carbon monoxide bonds with hemoglobin ____ times more readily than _____ and can take _____ hours for the circulatory system to eliminate
200
Oxygen
8-12 hours
Symptoms of carbon monoxide not as noticeable at _____ because high levels of _____ are dissolved in the ______ allowing tissues to meet their _____ requirement
Depth. Oxygen. Plasma. Oxygen
How can the plasma carry more oxygen at depth?
Because higher partial pressure of oxygen
Smoking cigarettes prior to diving can raise the ____ _____ level _____ times above normal which impairs _____ transport and _____ elimination
Carbon monoxide. 3-12. Oxygen. Carbon Dioxide
Carbon monoxide locks up the ____ in the blood impairing the transport of _____ and elimination of _______
Hemoglobin. Oxygen. Carbon Dioxide
Factors that cause body tissues to absorb and eliminate nitrogen at different rates
A) high or low blood supply
B) distance from skin surface
C) tissue density
D) distance from lungs
A C
ie bone denser than skin; density effects how gas is focused when reaches the skin
Blood supply differs among tissues; more blood supply will have more gas delivered and eliminated
Bubble formation cannot occur until the tissues become _______
Supersaturation
Supersaturation cannot occur until the ambient pressure is _______ upon ______
Reduced. Ascent
You can get DCS if you stay at a depth indefinitely? T/F
False, you can remain at depth indefinitely
Decompression sickness occurs upon surfacing rather than at depth because ______ does not occur in body tissues until the ambient pressure is reduced
Supersaturation
Any amount of supersaturation results in significant bubble formation?T/F
False
Otherwise gets DCS going to top of skyscraper
Factors increasing susceptibility to DCS
A) tissue half times
B) physical conditioning
C) changes to respiration
D) changes to circulation
B D
We can only control which factor that effects gas absorption?
Amount of blood flow (circulation)
Can’t control tissue density
Circulation changes in the following ways effecting gas absorption
______ circulation efficiency with age
______ circulation from exercise
changes in circulation during ______ consumption
Recent _____ or _______
Decreased
Increased
Alcohol
Illness injury
Silent bubbles cause signs and symptoms of DCS? T/F
False- Are so small they do not cause signs and symptoms of DCS
What device used to detect presence of silent bubbles is it a stethoscope? Y/N
No Doppler Ultrasound Flowmeter
A criterion used to test decompression models and some dive tables/computers are the presence of silent bubbles as they travel in venous circulation to the lungs detected with the Doppler Ultrasound Flowmeter? T/F
True
Silent bubbles are thought to form because of the presence of ____ _____
Gas seeds (micro nuclei)
Why don’t oxygen bubbles cause DCS
Metabolized by body
Inert gases are ones such as nitrogen not metabolized by the body? T/F
True
In DCS bubbles form because the nitrogen can’t escape quickly enough to remain in solution? T/F
True
Whatever nitrogen is absorbed as the ambient pressure ______ must be eliminated as the ambient pressure is _____
Increases. Reduced
Why does breathing pure Oxygen help with DCS
It increases the pressure gradient between the tissue nitrogen level and the alveolar nitrogen levels resulting in a significant increase in the driving force of the tissue nitrogen aiding in its elimination
If the nitrogen in the tissues is high but low in the alveolar air what happens to the nitrogen
It comes out
Narcosis results from disruptions in ______ impulses transmissions. _____ gases particularly when breathed under pressure have the capacity to cause this disruption.
Can Oxygen or CO2 cause gas narcosis?
Nerve. inert
Yes
Nitrogen has no effect at surface pressure but when breathed under sufficient pressure can cause disruption of nerve impulses? T/F
True
The degree of disruption from narcosis depends on how well the gas dissolved into the lipid? T/F
True
Gas narcosis signs and symptoms typically begin at _____. Yet many divers have succumbed much shallower particularly where _____ or ____ have been consumed.
30m/100’
Drugs. Alcohol
What are signs and symptoms of gas narcosis?
Poor judgement
Decreased coordination
A feeling of false security
Others include foolish behavior, anxious or uncomfortable feelings and a general disregard for safety
Barotrauma means
Pressure injury
An excessively forceful Valsalva maneuver could cause a _____ _____ rupture or rupture of your ___ ___
Round window
Ear drum
Severe lung squeeze could result if a skin diver descends with his lungs nearly ____
Empty
Could result in severe tissue damage and bleeding
Squeezes take place on _____ whereas reverse squeezes take place on _____
Descent. Ascent
Vertigo can be caused by
A) ear squeeze
B) inner ear barotrauma
C) decompression sickness
All
Sound vibrations transferred from the outer ear to inner ear via
Ossicles
Series of bones attached at one end of tympanic membrane (ear drum)
Ossicles
Ossicles are connected to the ____ _____ of the inner ear
Oval window
Vestibular canals (semi circular canals) are located in the ____ ____ and are responsible for _____
Inner ear. Balance
Movement of air in the vestibular canals can be interpreted by the brain to determine balance and orientation? T/F
False - movement of fluid in canals
Portion of ear most effected by pressure changes
Why not the others
Middle ear
Inner ear not because fluid filled
Outer ear not because open to the water
Symptom of air embolism may be sudden ____ while two symptoms of decompression sickness may be ____ ____ _____ ______ and _____
Sudden Unconsciousness
Pain in the joints and fatigue
In an air embolism air bubbles are transported into the pulmonary vein then to the heart and then most likely to the brain? T/F
True
Air embolism- air bubbles block arterial circulation when too numerous to pass through the blood vessels? T/F
False - too large
Decompression sickness from nitrogen elimination occurring so quickly that it comes out of solution and forms bubbles? T/F
True
Decompression sickness occurs immediately/over time
Over time (usually 30 minutes or more)
In terms of symptom location, air embolism is characterized by one/both sides of body whereas decompression sickness is characterized by one/both sides of the upper or lower body
Air embolism- one side of body like a stroke; entire right or left side effected
DCS- both sides upper or lower, like paralysis when involves CNS, depends on where bubble damage is in spinal cord
In terms of change of symptoms, air embolism is characterized by improvement/worsening/neither from first aid while DCS is characterized by improvement/worsening/neither from first aid
Improvement of symptoms for AGE
No change for DCS with first aid as condition requires time to develop and therefore requires time and aggressive treatment to improve
The most serious form of lung overexpansion injury is an _____
Why
AGE
Air Bubbles enter arterial circulation (similar to stroke) block blood flow; bubbles usually migrate to brain and expand as diver ascends
When breathing normally could a diver suffer from a lung over expansion injury? Y/N
Yes - any obstruction can cause over pressurization, including one deep in the lungs caused be asthma and other pulmonary disorders.
A more prevalent cause of lung obstructions in divers are those resulting from ______ or diving after having a severe ____ _____.
Smoking
Chest cold
Surfactant is a substance that coats the inner surfaces of ____ and ______ help prevents them from ______
Bronchioles and alveoli
Collapasing
_____ ______ destroys the _____ in bronchioles and alveoli, which inhibits their reopening
Smoking cigarettes
Surfactant
During exhalation the bronchioles and alveoli _____ because of their size and flexibility
Collapse
There are higher than normal CO2 levels in the alveoli when diving brought about by the increased resistance of breathing while submerged? T/F
True
Turbulence causes breathing to become more/less difficult which is why you should breathe slowly/quickly
More
Slowly
An AGE usually occurs within the ____ ____ ______whereas DCS tends to be _____ usually more than _____ minutes after the dive.
First five minutes
Delayed
30
Most common symptom of AGE vs DCS
Sudden unconsciousness
Pain in joints, fatigue
When administering O2 to someone with DCS you have them
Lay on left side with head low??? (Rainbow reef)
Or
Lay flat (PADI)
Too much CO2 in the blood is known as
Hypercapnia
Skin divers use ____ to increase breath hold times by reducing the level of CO2 in lungs
Diaphragmatic breathing
When diving in a current a poorly adjusted regulator may cause a diver to
A) become over exerted
B) have excessive CO2 build up
C) have labored shallow breathing
All
