Physiology Flashcards Preview

Aerospace Medicine > Physiology > Flashcards

Flashcards in Physiology Deck (96)
Loading flashcards...
0

Barosinusitis occurs during ________ according to Boyle's Law.
a) Decent only
b) descent or ascent
c) ascent only
d) at a level of alititude

b) Descent or ascent. Barosinusitis occurs during descent due to inability to equalize sinus pressure. Lower pressure in the sinuses disrupts the mucosal lining, resulting in pain. Although rare during ascent, barosinusitis can occur if there is no route for gas to escape due to respiratory infection with swollen mucosa.

1

The gas law that predicts drops in partial pressure of oxygen (PO2) with increasing altitude is _________ law. According to this law, decrease in PO2 result from__________.
a) Boyle's law; percentage of oxygen stays the same but barometic pressure falls.
b) Dalton's law; percentage of oxygen falls but barometric pressure remains the same.
c) Henry's law; percentage of oxygen stays the same, but barometric pressure falls.
d) Dalton's law; percentage of oxygen stays the same, but barometric pressure falls.

d) Dalton's law; percentage of oxygen stays the same, but barometric pressure falls. Dalton's law states that the total barometric pressure is made up of the sum of the individual partial pressures of the component gases. With increasing altitude, the relative pressure of oxygen remains the same, but the barometric pressure drops, resulting in a lower partial pressure of oxygen.

2

If the FEV1 or FVC is than _______ of predicted or the FEV1/FVC ratio is less than _______, the airman's PFT will require review by the FAA. In general, if any of these values are less than _______, an applicant will usually be unqualified for pilot duties.

If the FEV1 or FVC is less than 70% or predicted, or the FEV1/FVC ratio is less than 70% it will require review by the FAA. If the values are less than 50%, the applicant is unqualified for pilot duties.

3

At _____ + Gz's, the apical perfusion of the lung is nearly zero and air trapping at the base is increased. The Gz induced ventilation and perfusion mismatch results in decreased arterial oxygen and progressive hypoxic effects as G loads are sustained.

+ 3 Gz

4

The _________ contain the sensors responsible for the hypoxic override that stimulates respiration at low oxygen tension. Oxygen does not play a major role in controlling respiratory rate until the PO2 falls below 60 mmHg (aproximately 8,500 feet), where there is an increase in ventilatory rate.

Aortic and carotid bodies.

5

Hyperventilation may cause symptoms of generalized weakness, paresthesias, and a "feeling of impending doom". What is the treatment of a pilot who is having hyperventilation?

At altitude, hyperventilation may be secondary to hypoxia, the primary treatment of hyperventilation in a pilot is to administer supplemental oxygen.

6

An obstructive defect of the lower airway will have a decreased FEV1/FVC ratio. In addition, the Pulmonary Function Test (PFT) flow-volume loop will show:
a) Flattening of the inspiratory phase with no effect on FEV1.
b) Flattening of the inspiratory phase with a reduced FEV1.
c) Minimal or no flattening of the respiratory phase. The area of the loop will look similar to a normal PFT study except the area will be smaller.
d) Flattening of both the inspiratory and expiratory loops with a reduced FEV1.

B) Flattening of the inspiratory phase with a reduced FEV1. The FEV1/FVC ratio will typically be below 75%.

A restrictive defect would cause the area of the loop to look similar to a normal PFT but smaller. The obstructive defects flatten the inspiratory phase.

7

Which of the following statements correctly identifies how respired gases drive the rate and depth of ventilation?
a) Sustained G forces result in increased ventilatory drive due to small airway collapse and air trapping in basilar lung segments with decreased perfusion of apical areas.
b) blood oxygen concentration (PaO2) does not play a major role in controlling rate and depth of breathing at altitudes above 8,500 feet.
c) Carbon monoxide poisoning and anemia lower the oxygen content of the blood with a compensatory increase in rate and depth of breathing.
d) Carbon dioxide tension is the primary drive for respiratory rate below altitudes of 8,500 feet.

d) Carbon dioxide tension is the primary drive for respiratory rate below altitudes of 8,500 feet.

Above 8,500 feet, decreases in oxygen tension may also cause an increase in respiration.

8

This type of hypoxia results from reduced oxygen partial pressure in the atmosphere at altitude, oxygen or pressurization systems malfunction or failure, gradual or slow decompression, rapid or explosive decompression, and poor oxygen system discipline. Poor symptom recognition and delayed corrective action can lead to serious consequences, including death.

Hypoxic hypoxia

9

This type of hypoxia involves impaired cellular respiration through the disruption of oxidative phosphorylation enzymes. Alcohol, narcotic drugs, and cyanide are common causes

Histotoxic hypoxia

10

This type of hypoxia is caused by a reduction in circulating hemoglobin or reduced oxygen carrying capacity due to gases such as carbon monoxide that bind tightly to hemoglobin. Other causes include cold, alkalosis, or drugs that can shift the oxygen hemoglobin dissociation curve to the left (reduced oxygen delivery for a given PaO2). Other direct causal factors include hemorrhage, anemia, and/or sulpha drugs.

Hypemic Hypoxia

11

This type of hypoxia represents a diminished ability of the heart to circulate blood due to local arterial constriction, obstruction of arterial flow, or general circulatory failure. Prolonged positive pressure breathing, shock, G-forces, extreme temperatures, and constriction from straps can be contributing factors.

Stagnant hypoxia

12

The stages of hypoxia can be categorized into four stages corresponding to altitude and level of saturation. At 10,000 feet to 15,000 feet the O2 saturation is approximately 90-98%. At this stage efficiency is impaired and night vision is decreased by 50%. What is this stage called?

Compensatory stage.

13

CAMI recommends that on any unpressurized flight to or above _______ feet in the day, or above _________ feet at night, supplemental oxygen should be used.

10,000 feet in the day, 5,000 feet at night.

14

The ______, like the rest of the retina, depends on a continuous supply of oxygen to function and is exquisitely sensitive to the effect of hypoxia, even at relatively low altitudes.

Fovia

15

An obstructive defect of the lower airway will have a decreased FEV1/FVC ratio. In addition, the Pulmonary Function Test (PFT) flow-volume loop will show:
a) Flattening of the inspiratory phase with no effect on FEV1.
b) Flattening of the inspiratory phase with a reduced FEV1.
c) Minimal or no flattening of the respiratory phase. The area of the loop will look similar to a normal PFT study except the area will be smaller.
d) Flattening of both the inspiratory and expiratory loops with a reduced FEV1.

B) Flattening of the inspiratory phase with a reduced FEV1. The FEV1/FVC ratio will typically be below 75%.

A restrictive defect would cause the area of the loop to look similar to a normal PFT but smaller. The obstructive defects flatten the inspiratory phase.

16

Which of the following statements correctly identifies how respired gases drive the rate and depth of ventilation?
a) Sustained G forces result in increased ventilatory drive due to small airway collapse and air trapping in basilar lung segments with decreased perfusion of apical areas.
b) blood oxygen concentration (PaO2) does not play a major role in controlling rate and depth of breathing at altitudes above 8,500 feet.
c) Carbon monoxide poisoning and anemia lower the oxygen content of the blood with a compensatory increase in rate and depth of breathing.
d) Carbon dioxide tension is the primary drive for respiratory rate below altitudes of 8,500 feet.

d) Carbon dioxide tension is the primary drive for respiratory rate below altitudes of 8,500 feet.

Above 8,500 feet, decreases in oxygen tension may also cause an increase in respiration.

17

This type of hypoxia results from reduced oxygen partial pressure in the atmosphere at altitude, oxygen or pressurization systems malfunction or failure, gradual or slow decompression, rapid or explosive decompression, and poor oxygen system discipline. Poor symptom recognition and delayed corrective action can lead to serious consequences, including death.

Hypoxic hypoxia

18

This type of hypoxia involves impaired cellular respiration through the disruption of oxidative phosphorylation enzymes. Alcohol, narcotic drugs, and cyanide are common causes

Histotoxic hypoxia

19

This type of hypoxia is caused by a reduction in circulating hemoglobin or reduced oxygen carrying capacity due to gases such as carbon monoxide that bind tightly to hemoglobin. Other causes include cold, alkalosis, or drugs that can shift the oxygen hemoglobin dissociation curve to the left (reduced oxygen delivery for a given PaO2). Other direct causal factors include hemorrhage, anemia, and/or sulpha drugs.

Hypemic Hypoxia

20

This type of hypoxia represents a diminished ability of the heart to circulate blood due to local arterial constriction, obstruction of arterial flow, or general circulatory failure. Prolonged positive pressure breathing, shock, G-forces, extreme temperatures, and constriction from straps can be contributing factors.

Stagnant hypoxia

21

The stages of hypoxia can be categorized into four stages corresponding to altitude and level of saturation. At 10,000 feet to 15,000 feet the O2 saturation is approximately 90-98%. At this stage efficiency is impaired and night vision is decreased by 50%. What is this stage called?

Compensatory stage.

22

CAMI recommends that on any unpressurized flight to or above _______ feet in the day, or above _________ feet at night, supplemental oxygen should be used.

10,000 feet in the day, 5,000 feet at night.

23

The ______, like the rest of the retina, depends on a continuous supply of oxygen to function and is exquisitely sensitive to the effect of hypoxia, even at relatively low altitudes.

Fovia

24

_____________ describes useful flying performance and is affected by physical factors such as rate of decompression, exercise/physical activity, and partial pressure of oxygen related to altitude.

Effective Performance Time (EPT)

25

An individual with mild COPD can have inadequate cardiopulmonary response at altitude. An important but under recognized cause of COPD is:
a) tobacco use
b) alpha-1-antitrypsin deficiency
c) carbon monoxide poisoning
d) pulmonary fibrosis due to occupational exposure

b) Alpha-1-antitrypsin deficiency.

26

Hyperventilation causes an alteration of consciousness. This is due to:
a) Displacement of carbon dioxide by oxygen when the flier goes on 100% oxygen under pressure
b) cerebral vasoconstriction, and alkalotic diminution of oxygen release from blood into tissues
c) thoracic hemodynamic changes due to increased minute ventilation
d) distraction of the flier due to anxiety about the symptoms

B) cerebral vasoconstriction, and alkalotic diminution of oxygen release from blood into tissues.

27

Symptoms of _______ typically start a few hours after arrival at altitudes as low as 6,500 feet but are frequently first noticed the next morning. The major symptom is headache. Other symptoms include fever, nausea, vomiting, dizziness, apathy , general malaise, pallor, and periorbital edema.

Acute Mountain Sicness

28

Optimal treatment for AMS includes immediate descent to lower altitude and 100% oxygen. If descent is not possible, symptoms may be improved with a portable hyperbaric chamber such as a Gamow bag. As a standard drug treatment, ________ can help relieve symptoms and dexamethasone must be reserved for severe AMS.

Acetazolamide

29

__________ symptoms start one to two days after arrival to the new altitude above 8,000 feet. It is recognized by shortness of breath and rales accompanied by coughing. Signs include tachycardia, tachypnea, and central cyanosis. Treatment includes immediate descent, and when not feasible or delayed, oral nifedipine can be used.

High Altitude Pulmonary Edema