Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Exam 3 Biology > Gas Exchange in Animals > Flashcards

Gas Exchange in Animals Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Barometric pressure

A

Atmospheric pressure at sea level is 760 mm Hg.

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

Partial pressure

A

Partial pressure is the concentration of a particular gas in a mixture.

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

What is the partial pressure of O2

A

Partial pressure of O2 (PO2) is 160 mm Hg (21% of barometric pressure).

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

How does gas exchange relate to animal size?

A

The need to exchange respiratory gases limits the size and shape of many animals

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

What are some evolutionary adaptations for distributing gases?

A

Adaptations in species without internal system for distributing gases: small size, thin flat body; thin body wall around central body cavity

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

Fick’s law of diffusion

A

Fick’s law of diffusion applies to all gas exchange systems

Q = DA [(P1-P2)/L]

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

Q in Fick’s law

A

Q—the rate of diffusion.

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

D in Fick’s law

A

D—the diffusion coefficient: a characteristic of the diffusing substance, the medium, and the temperature. Expressed as mole/m2.s

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

A in Fick’s law

A

A—the area where diffusion occurs.

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

P1 and P2 in Fick’s law

A

P1 and P2—partial pressures of the gas at two locations.

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

L in Fick’s law

A

L—the diffusion path length between the locations.

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

(P1 – P2)/L in Fick’s law

A

(P1 – P2)/L is a partial pressure gradient (diffusion gradient).

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

What determines the concentration of gas in a liquid?

A

The concentration of gas in a liquid depends on the partial pressure of the gas in the air above the liquid and also on the solubility of gas in that liquid.

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

How does turbulence affect rate of diffusion?

A

Turbulence increases rate of diffusion until saturation is reached

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

why do we need oxygen?

A

to accept electrons that are created due to break down of food, which eventually forms water from H+ diffusing into mitochondrial matrix

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

Solubility of gases and temperature

A

The solubility of gases declines with temperature.

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

Metabolic cost of ventilation

A

it takes more energy to move water over gas exchange surface, compared to moving air over it.

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

Challenges of Water-Breathing for an Ectotherm

A
  1. In water, partial pressure of O2 is ~20 times lower than it is in air.
  2. Diffusion is slower in water than in air.
  3. The solubility of gases declines with temperature.
  4. Oxygen needs increase with temperature for an ecotherm.
  5. It takes more energy to ventilate
    gas exchange surface with water than with air.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why do animals require a specialized body surface for respiratory gas exchange and a system to transport O2 and CO2?

A

because the two processes require differently characterized cells; gas exchange requires a large surface area, whereas O2 and CO2 transport require large volume

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

Ventilation

A

the act of moving the gas exchange medium through gas exchange surfaces.

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

Is there more or less oxygen in cold water?

A

In cold water, there is more oxygen.

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

A denser fluid has a ___ metabolic cost to move.

A

A denser fluid has a greater metabolic cost to move.

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

Percentage of O2 in lakes

A

Lakes 1-2.5% O2

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

Percentage of O2 in sea water

A

Water .5-1% O2

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

What happens to oxygen availability as elevation increases?

A

Increase in altitude reduces available oxygen for air breathers due to lower partial pressure of oxygen at high altitudes

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

Does the overall percentage of oxygen in air change as altitude changes?

A

Partial pressure of oxygen declines with altitude, but the overall percentage of oxygen does not change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Overall atmospheric pressure ____ with altitude

A

The overall atmospheric pressure declines with altitude, as well as the pressure of all gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Air at sea level: ___% O2

A

Air at sea level: 21% O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Freshwater has ____ dissolved oxygen than saltwater does

A

Freshwater has more dissolved oxygen than saltwater does

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

CO2 is relatively ____ exchanged

A

CO2 is relatively easily exchanged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does altitude affect the cocentration of CO2?

A

The concentration gradient of CO2 from air-breathers to the environment is always large; change with altitude is negligible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Is CO2 soluble in water?

A

CO2 is very soluble in water and is easy for aquatic animals to exchange

33
Q

Content of CO2 in air

A

400ppm (0.04%)

34
Q

Content of CO2 at water surface

A

~10ppm at water surface

~0.0001%

35
Q

Adaptations that increase surface area for gas exchange

A

external gills, internal gills, lungs, tracheae

36
Q

Why are external gills adaptive?

A

Increase surface area - also minimize the diffusion path length (L) of O2 and CO2 in water

37
Q

Why are internal gills adaptive?

A

Protected from predators and damage

38
Q

why are lungs adaptive?

A

internal cavities for respiratory gas exchange with air

39
Q

What are tracheae

A

air-filled tubes in insects

40
Q

Tracheal system in insects

A

Spiracles open into tracheae that branch to tracheoles, which end in air capillaries (actual gas exchange surfaces)

Spiracles in the abdomen open to allow gas exchange and close to limit water loss; air sacs serves as air reservoir

41
Q

What force does gas exchange in the tracheal system rely on?

A

Relies mainly on diffusion; contraction of abdominal muscles helps in ventilation in some insects; note: no reliance on circulatory system

42
Q

Air capillaries in the tracheal system

A

Terminal ends of the tracheoles are called air capillaries – this is where Q is maximized an the diffusion happens. The air capillaries are the true gas exchange surface.

43
Q

How are alveoli adaptive for gas exchange?

A
  • Increased surface area
  • Thin film of liquid inside our alveoli and thin walls minimizes diffusion path length
  • Minimize the diffusion that takes place in an aqueous medium
  • Maximized partial pressure gradients
44
Q

What is perfusion?

A

circulating blood over the gas exchange surfaces

45
Q

What is ventilation?

A

active moving of the respiratory medium over the gas exchange surfaces

46
Q

Partial pressure gradients increased by:

A
  • Minimizing the diffusion path length (L) of O2 and CO2
  • Perfusion
  • Ventilation
47
Q

Fish gills use _______ to maximize gas exchange

A

Fish gills use countercurrent flow to maximize gas exchange

48
Q

In fish, how does taking water through the mouth and gills work, why is it adaptive?

A

Take in water through their mouth and then open their gills – Maximizes P1 to P2

49
Q

In fish, what is the operculum?

A

operculum of a bony fish is the hard bony flap covering and protecting the gills. In most fish, the rear edge of the operculum roughly marks the division between the head and the body.

50
Q

What is special about gas exchange in sharks?

A

Sharks – don’t have an operculum, so they move swiftly with their mouths open which create water currents that help water move unidirectionally through the gills.

51
Q

Gill filament

A

Sheet of epithelium with capillaries inside

52
Q

What are glls made up of?

A

Gills are made up of gill filaments that are covered by folds, or lamellae.

53
Q

What are lamellae?

A

Lamellae are the site of gas exchange and minimize the diffusion path length (L) between blood and water.

54
Q

In what direction does blood flow in the lamellae?

A

Blood flows through the lamellae in the direction opposite to the flow of water

55
Q

What is the purpose of countercurrent flow?

A

The countercurrent flow optimizes the PO2 gradient

Because of countercurrent flow, a broad PO2 gradient is maintained over the full length of each gill lamella

56
Q

Why are bird lungs so efficient?

A

Bird lungs use unidirectional air flow to maintain

a high PO2 gradient

57
Q

After exhalation bird lungs have very little dead space (residual volume), why is this adaptive?

A

helps to maintain a high PO2 gradient.

58
Q

What are air sacs in birds?

A

Birds have air sacs that receive inhaled air but are not sites of gas exchange.

59
Q

Air pathway in birds

A

Air enters through the trachea, which divides into bronchi, then into parabronchi, and then into air capillaries

Air flows unidirectionally through the parabronchi

60
Q

tidal ventilation

A

A type of breathing in which the lungs are inflated with air and then the chest muscles and diaphragm relax and recoil back to their original positions as an animal exhales.

61
Q

What is the adaptive value of tidal ventilation?

A 
Tidal ventilation in humans
produces a residual volume
(dead space) of poorly-mixed air
that has lower oxygen levels than
bulk air outside
62
Q

Is inhalation passive or active?

A

active - requires contraction of the diapaphragm and external intercostal muscles.

63
Q

Why does inhalation enable gas exchange?

A

Intrapleural pressure becomes more negative than atmospheric pressure

64
Q

What happens during exhalation?

A
  • Internal intercostal muscles not stretched
  • Intrapleural pressure
    less negative
  • Elastic recoil of lung tissue and diaphragm pulls thoracic cavity in; pushes air out
65
Q 
Why does
pneumothorax
(air in pleural cavity)
cause shortness 
of breath?
A

pneumothorax is an abnormal collection of air or gas in the pleural space that causes an uncoupling of the lung from the chest wall.

66
Q

How do respiratory tract secretions help ventilation in the lungs?

A
  • The fluid covering inside of the alveoli has surface tension that makes the lungs elastic.
  • A surfactant reduces the surface tension of a liquid.
  • Lung surfactant is released by cells in the alveoli when they are stretched.
  • It is critical for reducing the work needed to inflate the lungs.
67
Q

How do lung surfactants relate to premature babies?

A
  • Premature babies may not have developed the ability to make lung surfactant.
  • Without it, they have great difficulty breathing and may die from exhaustion and lack of O2.
68
Q

What are the advantages of using water as a respiratory media?

A

aquatic breathers can keep respiratory surfaces moist; aquatic breathers gain or lose ions and water via their respiratory surfaces

69
Q

what are the disadvantages of using water as a respiratory media?

A

water contains much less oxygen than air, meaning they have to process much more water than the air processes by air breathers; water is denser and much more viscous than air, so aquatic breathers have to expend more energy to ventilate their respiratory surfaces than air breathers

70
Q

what are the advantages of using air as a respiratory media?

A

contains much more oxygen than water; have to expend less energy to ventilate respiratory surfaces because air is relatively low in density and viscosity

71
Q

what are the disadvantages of using air as a respiratory media?

A

air breathers have to prevent dessication of respiratory surfaces by keeping them moist

72
Q

what happens to oxygen consumption of fish as water temperature increases?

A

fish consume more oxygen

73
Q

why does high water temperature present a double challenge to water breathers?

A

because oxygen content of water decreases with increased temperature and water breathers consume more oxygen when water temp increases

74
Q

what is the average % oxygen in air?

A

~21% at ALL altitudes

75
Q

why does reduced partial pressure make it difficult for humans to breath?

A

because as the partial pressure of oxygen decreases, the pressure difference between the atm and inside the lungs diminishes, making it more difficult to inspire

76
Q

what are the characteristics of gills that make them efficient for gas exchange?

A

have thin cells, a large surface area and partial pressure gradients via efficient circulation and countercurrent flow

77
Q

what organisms are more efficient in extracting oxygen from air than mammals?

A

birds; because air flow in birds is unidirectional continuous and occurs in two cycles through parabronchi; however, this type of flow does not minimize evaporation

78
Q

what is the low-altitude person typical response to high altitudes? why?

A

Increased respiration and increased heart rate because body needs to work harder to get oxygen from air

79
Q

what is the most important feedback stimulus for air-breathing animals?

A

the level of CO2 in blood

Exam 3 Biology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions