Diving/Space/Altitude Flashcards Preview

Biology 14 Exam 3 > Diving/Space/Altitude > Flashcards

Flashcards in Diving/Space/Altitude Deck (84):
1

What is the human free dive record?

230 ft

2

What is the human breath hold record?

6 minutes 30 seconds

3

How fast does water pressure increase?

1 atmosphere for every 10 meters of depth

4

What is one issue with the high pressure of water, and how have animals adapted?

It makes it difficult to draw air through a snorkel because it is difficult to expand the chest. Elephants have adapted with fibrous, cartilaginous tissue rather than air in the interpleural space- this helps them to generate higher negative pressures.

5

When was the first commercial diving/salvage business set up?

1830s

6

Name three problems associated with human diving

1) The Bends
2) Rapture of the Deep (narcotic effect of gases)
3) Oxygen toxicity

7

How are the Bends caused?

With increased pressure, more nitrogen dissolves in the blood. When we ascend rapidly, nitrogen comes out of the blood quickly and forms bubbles. Can cause pain, stroke, and death.

8

At what depth does the Bends become an issue?

20 meters

9

What is Rapture of the Deep and what causes it? How do we avoid it?

A narcotic effect of gasses. Nitrogen at high pressure has narcotic effects. Use a helium/ oxygen mix

10

What is oxygen toxicity?

Breathing pure oxygen irritates the lungs (can't do it for more than a few hours)

11

What is a nickname for the Bends?

Cassion disease

12

What are three ways of avoiding the Bends?

1) Ascend slowly (in 20-30 minute stages)
2) Use an inert gas other than nitrogen (could use helium)
3) Breathe liquid?

13

What are antarctic seals called? Where do they live?

Weddell Seals. the Ross Ice Shelf

14

Describe the dive characteristics of a Weddell Seal (time and depth)

Most dives last 20-25 min (max 1 hr)
70% of dives are 200m or less, can hit 600m.

15

What is a seal that can dive deeper than a Weddell Seal? What is its longest and deepest dive?

Elephant Seal. Dives to 1000m, can dive for up to 2 hrs.

16

Why do most Weddell Seal dives last about 25 mins?

This is their AEROBIC DIVING LIMIT (ADL)

17

What happens after the aerobic diving limit is passed?

Blood lactate levels rise

18

What are the two things that we see happen in seals while diving? Be specific about location

Oxygen depletion and lactate accumulation occur in skeletal muscle, but not in the blood!

19

Do Weddell Seals alter blood flow to the kidney during dives? How can we tell experimentally?

Yes, they reduce blood flow to the kidney, but only on longer dives. We can test by measuring INULIN concentration!

20

Do Weddell Seals alter blood flow to the liver during dives? How can we tell experimentally?

They reduce blood flow a bit. We can tell by measuring INDOCYANIN GREEN clearance

21

What is a second way to test blood flow to the kidneys during a dive?

Simulate dive by putting head underwater, image blood flow using a dye.

22

What happens to a seal's heart beat during a dive? What do we call this?

It slows down.

BRADYCARDIA

23

What happens to blood co2 content and blood o2 content during a dive?

The co2 content rises, while the o2 content falls

24

What can we say about where oxygen is stored in diving animals (lungs, blood, muscle)

Roughly similar amount stored in lungs. Much more oxygen stored in blood and muscle though!

25

What are three cardiovascular adaptations common to diving animals?

1) large blood volume (2-7x greater)
2) high hematocrit (55-60%)
3) lots of myoglobin

26

What happens to the lungs at great depths?

The lungs and alveoli actually collapse, forcing air into the dead spaces, and making gas exchange negligible!

27

What do seals have to prevent heat loss?

An insulating layer of BLUBBER

28

What are two adaptations to the seals head area?

They are located on the top of the head, so that the seal can easily see the ice above.
Also, have protruding teeth to open diving holes in the winter!

29

What two organs do the seals maintain blood flow to? What three organs do they reduce blood flow to?

Heart and brain
Kidney, liver and muscles

30

Why do the seals reduce blood flow to the muscles?

To prevent lactate buildup in blood until post-dive

31

Name three ways in which seals avoid the Bends

1) EXHALE before diving
2) Lung collapse at 25-30 meters
3) Very little blood to lungs during dive

32

Name a large diving penguin. How long/deep can it dive

Emperor Penguin: 23 minutes, 500 meters deep

33

Name four adaptations that allow birds to dive

1) high HEMATOCRIT
2) high MYOGLOBIN concentration
3) diving BRADYCARDIA
4) limited blood flow to skeletal muscle (to avoid lactate buildup in blood)

34

What organs do the birds increase blood flow to? What do they decrease blood flow to?

Heart
Kidney, Intestine, Muscles (PERIPHERAL)

35

What is one adaptation to diving birds' brains?

Small cerebral O2 requirement

36

What happens to body temperature during diving?

It decreases

37

Name three diving birds

Loons, Cormorants, Penguins, Puffins, Eiders, Murres

38

How tall is Mt. Everest (ft and meteres)

29,028 ft
8500 m

39

What bird migrates over Mt. Everest? How high does it reach?

Bar-headed goose (9500 m)

40

What is one high altitude mammal? How high up does it live?

the PIKA (6000 meters)

41

What are the highest elevations that humans live at?

4500-5500 meters

42

What was human's first experience with really high altitudes?

In hot air balloons (1860s)

43

What is another term for mm Hg?

Torr

44

What is atmospheric pressure at sea level? How about at the top of Mt. Everest?

760 mm Hg
250 mm Hg

45

What percent of air is oxygen?

21%

46

What is arterial saturation at sea level? How about at the top of Mt. Everest?

97%
24%

47

What height are most commericial flights at? How quickly would humans lose consciousness at that level?

10.500 m
Humans would go unconscious after 30 seconds

48

Describe the air flow though the avian lung. What does this allow for?

The air goes thorough the ANERTIOR AIR SACS, LUNG, and POSTERIOR AIR SACS. This allows for efficient gas exchange during both inhalation and exhalation.

49

What is another adaptation that helps birds be more efficient at gas exchange?

THINNER MEMBRANES, made possible by more SUPPORT for alveoli and pulmonary capillaries

50

What kind of exchanger are bird lungs?

CROSS CURRENT EXCHANGER

51

Name two cardiovascular adaptations that allow high altitude birds to tolerate low oxygen conditions

1) Proportionally larger hearts
2) Hemoglobin has a higher affinity for O2

52

What two things separate high altitude birds from humans at low co2 levels

1) Tolerant of respiratory alkalosis
2) Maintain normal blood flow to brain

53

What are the two main effects of low oxygen pressure in the human body? What is interesting about these two effects?

Chemoreceptors fire to increase ventilation, wihch decreases the arterial co2 pressure (Alkalosis) and should increase hemoglobin affinity. However, more 2,3-DPG is produced, which decreases hemoglobin affinity for O2. These are COMPETING EFFECTS.

54

What is alkalosis?

It is blood that is too basic

55

What signals for a higher hematocrit? Where is this produced?

ERYTHROPOIETIN, synthesized in kidney

56

What do we call it when people adapt to high altitude conditions over a period of weeks?

ACCLIMATIZATION

57

What are 8 changes that occur during acclimatization?

1) increase in ventilation (2-7x)
2) alkalosis from low pCO2
3) increased hematocrit (45% to 60%)
4) increased blood volume
5) increased lung volume
6) increased cardiac output (initially)
7) increased vascularity of peripheral tissues
8) increased efficiency of o2 use by tissues

58

How long does it take for the human hematocrit to increase from 45% to 60%?

3-5 days!

59

What breathing pattern do we see at high elevations (name and description)? What causes this?

CHEYNE-STOKES RESPIRATION
Rapid bursts of breathing activity because O2 levels are low, then inhibition of breathing because the increased ventilation leads to lower CO2 levels. Eventually fades after a couple of days.

60

What is a sickness that occurs if you ascend too rapidly. Describe the symptoms

ACUTE MOUNTAIN SICKNESS
- Feel euphoria, tiredness, dizziness nausea. Worst case can get PULMONARY EDEMA, where pulmonary arterioles vasoconstrict, which leads to hypertension and leaks in lung capillaries, and you can actually drown in fluid

61

What is a sickness associated with long periods at high altitude, describe

CHRONIC MOUNTAIN SICKNESS
Hypoventilation, hypertension, heart hypertrophy, headaches, diziness

62

What is a disorder involving high hematocrit?

POLYCYTHEMIA

63

What is a disorder involving blue tinted skin?

CYANOSIS

64

What are three pulmonary/cardiovascular adaptations in people living at high altitudes?

1) Pulmonary hypertension (elevated pressure due to vasoconstriction b/c low o2)
2) Increased muscle in pulmonary arteries
3) Cardiac hypertrophy
4) Elevated hematocrit
5) Higher hemoglobin affinity for o2

65

What two physical adaptations can we see in high elevation populations?

Smaller body size, increased chest size

66

What is one interesting difference between Tibetan and Andeans?

Tibetans don't have higher hemoglobin levels, but Andeans do!

67

What transcription factor do Tibetans have? What is its purpose?

HIF (hypoxia inducible factor). It regulates genes involved in red blood cell production. Interestingly HIF reduces red blood cell produciton, so that it avoids extra work on the Tibetan's hearts!

68

What is the term for red blood cell production?

ERYTHROPOIESIS

69

What is the highest a human has ever free fallen?

23 miles

70

What is the elevation at which blood will boil?

12 miles

71

What are five physiological stresses humans would experience in space?

1) No atmosphere
2) Fluid/mineral homeostasis
3) No gravity (if in free fall)
4) Temperature
5) Radiation

72

How cold is space?

-270 degrees C

73

What happens to fluids when in low gravity? How does the boy react?

Move from legs to chest and head. Reacts with increased urination and decreased water intake

74

What happens to red blood cell production and cardiac output?

both diminish

75

What do astronauts have trouble doing when they first get back to earth?

Standing (orthostatic intolerance)

76

What happens to muscle and bone density in space?

Muscles atrophy, bones become less dense.

77

What happens to height in space?

People get taller

78

Why do we lose bone mass?

DIMINISHED OSTEOBLAST ACTIVITY

79

What happens to the risk of kidney stones, why?

Increased risk of kidney stones due to Ca concentration in urine from bone breakdown

80

What happens to sacromere length and myofibril diameter?

Sacromere length is normal, but myofibril diameter is smaller

81

What is responsible four our balance?

the VESTIBULAR SYSTEM

82

What are the three bumps called in the vestibular system? What does each respond to? What is inside these swellings?

Ampullae (x3) (rotational acceleration)
Utricle (verticle movement)
Saccule (horizontal movement)

83

What two changes do we see having to do with orientaion?

1) changes in vestibular system function
2) altered activity in hippocampus

84

What does space throw off in humans?

Sleep and circadian rhythms!