Special Topics

Question 1

Regulation of body temperature is mediated by:

Answer 1

Hypothalamus

Question 2

Initiate heat generating mechanisms

Answer 2

Set-point Temperature

Question 3

Initiate heat loss mechanisms

Answer 3

Detected Temperature

Question 4

Shivering, Thyroid hormone production, decreased sweating, piloerection, skin vasoconstriction (alpha 1), brown fat in babies (beta 3)

Answer 4

Heat-generating Mechanisms

Question 5

Sweating, skin vasodilation, decreased heat production

Answer 5

Heat-loss Mechanisms

Question 6

What is the role of fat in terms of regulation of body temperature?

Answer 6

Insulator

Question 7

What is the role of skin in terms of regulation of body temperature?

Answer 7

Radiator System (when cold: blood vessels constrict; when hot: blood vessels dilate)

Question 8

Most of the body heat is lost through which way?

Answer 8

Radiation>Evaporation>Conduction of air>Conduction of objects

Question 9

What is the pathophysiology of fever?

Answer 9

Pyrogens➡️Increases IL-1➡️Increases Prostaglandins➡️ Increases set-point temperature in Hypothalamus

Question 10

Excessive sweating causing fainting

Answer 10

Heat Exhaustion

Question 11

High temperature causing tissue damage & impaired responses

Answer 11

Heat stroke

Question 12

High temperature secondary to the use of succinylcholine & halothane?

Answer 12

Malignant Hyperthermia

Question 13

What is the basis for muscle endurance?

Answer 13

Glycogen levels in the body

Question 14

What is the best diet for muscle glycogen recovery?

Answer 14

High carbohydrate diet

Question 15

How long does it take to recover muscle glycogen?

Answer 15

2 days (high carbohydrate diet)

Question 16

An increase in muscle strength is always due to what?

Answer 16

Increase in muscle size

Question 17

Maximal breathing capacity

Answer 17

150-170L/min

Question 18

Pulmonary ventilation during maximal exercise

Answer 18

100-110L/min

Question 19

Difference (50L/min) is used to compensate for:

Answer 19

Exercise at high altitudeExercise under hot conditionsAbnormalities of the respiratory system

Question 20

During most strenuous exercise, muscle blood flow increase up to?

Answer 20

20x

Question 21

At maximal exercise, CO is at ? Of its maximum

Answer 21

90%

Question 22

At maximal exercise, pulmonary ventilation is at ? Of its maximum

Answer 22

65%

Question 23

At high altitude, oxygen molecules are farther apart so?

Answer 23

Decreases oxygenation

Question 24

At high altitude, its most important effect is?

Answer 24

Decreased mental proficiency

Question 25

High altitude: Coma and death at ? Feet

Answer 25

23,000 feet

Question 26

High altitude: Twitching and seizures at ? Feet

Answer 26

18,000 feet

Question 27

High altitude: Drowsiness, Lassitude, Mental & Muscle fatigue, Headache, Nausea, & Euphoria at ? Feet

Answer 27

12,000 feet

Question 28

Mechanisms of Acclimatization to Low PO2: Respiratory rate increases by 5x

Answer 28

Increased Pulmonary Ventilation

Question 29

Mechanisms of Acclimatization to Low PO2: Shift to the right of the O2-HgB dissociation curve

Answer 29

Polycythemia

Question 30

Mechanisms of Acclimatization to Low PO2: Increased pulmonary capillary blood volume, Increased lung volume, Increased pulmonary arterial BP

Answer 30

Increased Diffusing Capacity of Oxygen

Question 31

Mechanisms of Acclimatization to Low PO2: Cardiac Output increases by 30%

Answer 31

Increased vascularity of the Peripheral tissues

Question 32

Mechanisms of Acclimatization to Low PO2: Increased cell mitochondria and cellular oxidative enzymes

Answer 32

Increased ability of cells to use Oxygen despite low PO2

Question 33

Changes seen in natural acclimatization

Answer 33

Decreased body massIncreased chest sizeLarger hearts and lungsBetter O2 delivery (increased HgB, better O2 utilization)

Question 34

Manifestations of Acute Mountain Sickness

Answer 34

Acute Pulmonary EdemaAcute Cerebral Edema

Question 35

Manifestations of Chronic Mountain Sickness

Answer 35

Pulmonary VasoconstrictionRight-sided Heart Failure

Question 36

Adaptations to Flight: Pilot pushed against seat, more dangerous, blood shunted to the lower extremities

Answer 36

Positive G

Question 37

Adaptations to Flight: Pilot pushed against his seatbelt, less dangerous, blood shunted to the head

Answer 37

Negative G

Question 38

Motion sickness, Translocation of fluids, Diminished physical activity

Answer 38

Acute effects in Space

Question 39

Decreased blood volume, Decreased RBC, Decreased muscle strength, Decreased maximum cardiac output, Loss of calcium and phosphate from bones

Answer 39

Chronic effects in Space

Question 40

May lead to toxicities from high nitrogen, oxygen and carbon dioxide pressures

Answer 40

Diving

Question 41

High Nitrogen Pressures: "Raptures of the depths"

Answer 41

Beyond 250 feet

Question 42

High Nitrogen Pressures: Drowsiness

Answer 42

At 200-250 feet

Question 43

High Nitrogen Pressures: Joviality

Answer 43

At 120 feet

Question 44

Breathing oxygen at 4atm (PO2=3040mmHg) will cause sudden brain seizures followed by coma; Due to Oxygen Free Radicals (O2 and H2O2)

Answer 44

High Oxygen Pressure

Question 45

Happens only if diving apparatus has a malfunction; Severe respiratory acidosis, lethargy, narcosis

Answer 45

High Carbon Dioxide Pressure

Question 46

Sudden ascent a can lead to formation of nitrogen bubbles a blocks blood vessels

Answer 46

Decompression Sickness

Question 47

Pain in the joints and muscles

Answer 47

"Bends"

Question 48

Dyspnea

Answer 48

"Chokes"

Question 49

Chronic Decompression Sickness

Answer 49

Caisson's Disease