Special Topics Flashcards

1
Q

Regulation of body temperature is mediated by:

A

Hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Most potent mechanism for heat generation

A

Shivering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the role of fat and skin in terms of regulation of body temperature

A

Fat: Insulator
Skin: Radiator system ( cold: blood vessels constrict; hot: blood vessels dilate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Most of the body heat is lost through which way?

A

Radiation > Evaporation > Conduction to air > Conduction to objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the pathophysiology of fever?

A

Pyrogens increase IL-1 (alpha and beta) and IL-6 –> increase prostaglandins –> increase set point temperature in hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the difference between heat exhaustion and heat stroke?

A

Heat exhaustion: excessive sweating causing fainting

Heat stroke: high temperature causing tissue damage and impaired responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

High temperature secondary to the use of succinylcholine and halothane

A

Malignant hyperthermia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the pathophysiology of Malignant hyperthermia?

A

Defective ryanodine receptors causes Ca2+ to move out of SR very fast –> overexcitation of skeletal muscles –> consume ATP and produce heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Treatment of malignant hyperthermia

A

Dantrolene - Ca2+ channel blocker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Strength per square centimeter of crosssectional area of a muscle in both men and women

A

3-4 kg/cm2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Energy system that uses cell ATP and cell phosphocreatinine; utilized during the first 8 - 10 seconds

A

Phosphagen energy system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Energy system that uses anaerobic glycolysis; utilized for the 1.3 to 1.6 minutes after phosphagen system is used up

A

Glycogen-Lactic acid system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Energy system that uses aerobic glycolysis; utilized for unlimited time as long as with energy supply

A

Aerobic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the basis for muscle endurance?

A

Glycogen levels in the body
100g stored in liver, 400g stored in muscles
For every gram of glycogen, 3mL H20 is needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the best diet for muscle glycogen recovery

A

High carbohydrate diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How long does it take to recover muscle glycogen

A

2 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

An increase in muscle strength is always due to what?

A

Increase in muscle size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Maximal breathing capacity

A

150 - 170 L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pulmonary ventilation during maximal exercise

A

100 - 110 L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Formula to get the maximal heart rate

A

220 - age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Muscle blood flow increases by how much during the most strenous exercise?

A

20 times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In athletes, resting cardiac output is 5L/min. In exercise this increases to ___ and accounts for ___ percent increase.

A

30L/min, 600% increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In non-athletes, resting cardiac output is 5L/min. In exercise this increases to ___ and accounts for ___ percent increase.

A

20L/min, 400% increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Change from resting cardiac output to exercise cardiac output is called:

A

Cardiac reserve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

At maximal exercise, CO is at __% maximum which pulmonary ventilation is at __% maximum

A

CO: 90%

Pulmonary ventilation: 65%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What percentage of nutrient energy is converted to muscle work?

A

25% (the rest is released as heat)

27
Q

How many pounds of body weight may be lost in 1 hour of athletic event?

A

10 lbs (mainly water)

28
Q

Sweat glands may acclimatize to hot and humid conditions because of:

A

Aldosterone

29
Q

Most important effect of high altitude

A

Decreased mental proficiency (judgment, memory, motor movements are affected)

30
Q

What happens at 18,000 feet?

A

twitchings/seizures

31
Q

What happens at 23,000 feet?

A

coma and death after

32
Q

Symptoms start at what feet above sea level?

A

12,000 feet (drowsiness, lassitude, mental and muscle fatigue, headache, nausea, euphoria)

33
Q

5 mechanisms for passive acclimatization to low PO2

A
  1. Increased pulmonary ventilation
  2. polycythemia
  3. increased diffusing capacity of O2
  4. increased vascularity of the peripheral tissues
  5. increased ability of cells to use oxygen despite low PO2
34
Q

Passive acclimatization: after a few minutes, RR increases by: _____; after a few day RR increases by: _____

A

Few minutes: 1.65x

Few days: 5x

35
Q

Passive acclimatization: in polycythemia, increase in this enzyme will increase 2,3 BPG which causes a shift to the right of the O2-Hgb dissociation curve

A

BPG mutase

36
Q

Passive acclimatization: diffusing capacity of oxygen from alveoli to pulmonary capillaries increases up to ___ times of normal

A

3 times

37
Q

Passive acclimatization: cardiac output increases by ___ immediately but tapers off after Hct increases

A

30%

38
Q

Passive acclimatization: what are the mechanisms by which cells are able to use oxygen despite low PO2?

A

Increased cell mitochondria and cellular oxidative enzymes

39
Q

What are the changes seen in NATURAL acclimatization?

A

Decreased body mass, increased chest size, larger hearts and lungs, better O2 delivery (increased Hgb, better O2 utilization)

40
Q

What are the manifestations of acute mountain sickness?

A

Acute pulmonary edema, acute cerebral edema

41
Q

What are the manifestations of chronic mountain sickness?

A

Pulmonary vasoconstriction, R-sided heart failure

42
Q

A unit of force equal to the force exerted by gravity; used to indicate the force to which a body is subjected when it is accelerated

A

G force

43
Q

G force: Positive or negative?

Pilot is pushed against his seat

A

Positive

44
Q

G force: Positive or negative?

Less dangerous

A

Negative

45
Q

G force: Positive or negative?

Blood is shunted to the head

A

Negative

46
Q

Amount of positive G force that can cause blackouts, LOC, death

A

+6 to +10G

47
Q

Amount of Positive G force that can cause vertebral fracture

A

+20G

48
Q

G force: Positive or negative?

Blood is shunted to the lower extremities

A

Positive

49
Q

G force: Positive or negative?

More dangerous

A

Positive

50
Q

G force: Positive or negative?

Pilot is pushed against his seatbelt

A

Negative

51
Q

G force: Positive or negative?

May results in “red out” of the eyes and transient psychotic disturbances

A

Negative

52
Q

Amount of Negative G force that can cause death

A

-20G

53
Q

The constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration

A
Terminal velocity (12 seconds with speed of 175 feet/sec)
Parachute: reduces speed to 1/9th of terminal velocity (equivalent to speed of jumping from a height of 6 feet)
54
Q

Artificial climate in a spacecraft:

A

20% oxygen at 760mmHg

55
Q

Chronic stay in space may have deleterious effects to the body and is called:

A

Deconditioning (Decreased: blood volume, RBC, muscle strength, max CO, Ca and P04 from bones)

56
Q

High nitrogen pressures: What happens are 120 feet?

A

Joviality

57
Q

High nitrogen pressures: What happens are 200-250 feet?

A

Drowsiness

58
Q

High nitrogen pressures: What happens beyond 250 feet?

A

“Raptures of the depths” - alters ionic conductance in brain cells

59
Q

Breathing oxygen at ___ will cause sudden brain seizures followed by coma (due to oxygen free radicals)

A

4 atm (3040 mmHg)

60
Q

Decompression sickness: pain in the joints and muscles?

A

Bends

61
Q

Decompression sickness: dyspnea

A

Chokes

62
Q

What do you call chronic decompression sickness?

A

Caisson’s disease

63
Q

What is the pathophysiology of decompression sickness?

A

Sudden ascent –> formation of nitrogen bubbles –> blocks blood vessels –> s/sx