Brainscape's Knowledge GenomeTM

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


See full index

Biology Module 3: Exchange and transport > 3.1 Exchange surfaces and breathing > Flashcards

3.1 Exchange surfaces and breathing Flashcards

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

What do cells need to survive?

A

Oxygen and nutrients, they need to remove waste products so they do not become toxic.

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

How do small organisms exchange substances?

A

Exchange through diffusion over the surface of the body.

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

How do large organisms exchange substances?

A

They need a specialised surface for the exchange of substances with their environment.

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

What are the three factors that affect the need for an exchange system?

A

Size,
Surface area: ratio
Level of activity

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

How does size affect the need for an exchange system?

A

-Small organisms have a very small diffusion pathway.
-This means diffusion will supply enough oxygen and nutrients to keep cells alive.
-Larger organisms have a longer diffusion pathway
-diffusion is too slow to enable sufficient supply to cells

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

How does SA:V ratio affect the need for an exchange system?

A

-Small organisms have a large SA:V ratio
-This means their SA is large enough to supply their cells with sufficient oxygen
-Larger organisms have a small SA:V ratio
-Their SA is small compared to their V
-Some organisms increase their surface area by adopting a different shape e.g flatworm
-Large organisms need a range of tissues to give body support.
-Their volume increases as their body gets thicker but the surface are does not increase as much

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

How does level of activity affect the need for an exchange system?

A

-Metabolic activity uses energy from food and requires oxygen to release energy from aerobic respiration
-Cells of active organism need good supplies of nutrients and oxygen to supply energy for movement.
-This need is increased in animals e.g mammals to keep themselves warm.

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

What are the features of a good exchange system?

A

-A large surface area to provide more space for molecules to pass through e.g root hairs in plants
- A thin barrier to reduce diffusion distance , barrier must be permeable to substances being exchanged e.g alveoli of lungs
-A good blood supply. This can bring fresh supplies of molecules to one side (supply side) keeping concentration high or it may remove molecules from demand side to keep concentration low. Important in maintaining a steep conc gradient so that diffusion can occur rapidly. E.g Gills in fish

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

What is the equation for surface area of spheres?

A

4 x π x r2

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

What is the equation for volume of spheres?

A

4/3 x π x r3

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

Calculate the surface area to volume ratio of a sphere with a radius of 10mm

A

SA= 4 x π x 10(2) = 1257
V= 4/3 x π x 10(3) = 1489
1257:1489 = 0.30:1

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

Calculate the surface are to volume ratio of a human, given that the typical skin surface area is 1.8m and the volume is 0.07m

A

25:1

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

Calculate the ratio of lung surface area to body volume of a human using lungs with a surface area of 70m

A

1000:1

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

Comment on the need of lungs in a human.

A

-To exchange gases in the body as oxygen and co2 cannot efficiently diffuse to all cells through the skin’s surface area
-This is because humans have a small SA:V ratio, and need an exchange system to keep oxygen supplies to cells for aerobic respiration.

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

What does the gaseous exchange system in mammals consist of?

A

Lungs and associated airways that carry air into and out of lungs.

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

State the pathway air takes when travelling to the lungs.

A

Through the nose, into the trachea, bronchi and bronchioles until it reaches the alveoli.

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

Where does the exchange of gases take place in the lungs

A

In the alveoli.

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

What protects the lungs?

A

The ribcage.

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

What holds the ribs together?

A

Intercostal muscles.

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

What do both the intercostal muscles and the ribcage help to do?

A

Help to produce movement of breathing (ventilation)

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

Explain the process of how gaseous exchange in the lungs occur. (4)

A

-Gases pass via diffusion through thin walls in alveoli.
-O2 passes from air in alveoli to the blood in the capillaries
-CO2 passes from blood to the air in the alveoli.
-Lungs must maintain steep co2 gradient to ensure diffusion can continue

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

How does large surface area of the lungs help gaseous exchange

A

-Individual alveoli are small
-Combined total surface area of lungs is larger than of our skin.
-Total surface area of exchange surface in humans is about 70m(2)
-Large surface area provides more space for molecules to pass through.

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

Why must the lungs produce a surfactant?

A

Alveoli coated in moisture that evaporates as we breathe in/out
-Lungs must produce a surfactant that coats the internal surface of the alveoli to reduce the cohesive forces between water molecules
-These forces tend to make alveoli collapse

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

How does the permeability of the exchange barrier help gaseous exchange?

A

-The barrier is compromised of the call of alveolus and wall of blood capillary
-It is permeable to co2 and o2 as the molecules are small and non-polar
-Allows molecules to pass through efficiently

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

What are some adaptations to reduce the distance the gases have to diffuse?

A

-Alveolus wall is one cell thick
-Capillary wall is one cell thick
-Both walls are made of squamous cells (thin/flattened)
-Capillaries in close contact with alveolus walls
-Capillaries are narrow, red blood cells are closer to air in alveoli causing rate of flow to decrease.

26
Q

How does ventilation help gaseous exchange?

A

Replaces the used air with fresh air, bringing in more o2 and removing co2, ensures that:
-Conc of o2 in air of alveolus remains higher than that in the blood
-Conc of co2 in alveoli remains lower than that in the blood
This. maintains concentration gradient for diffusion.

27
Q

Explain the process of inspiration and the relevant actions of muscles involved.

A

-Diaphragm contracts to move down and become flatter
-External intercostal muscles contract to raise the ribs
-The volume of the chest cavity is increased
-Pressure in chest cavity drops below the atmospheric pressure
-Air is moved into the lungs

28
Q

Explain the process of expiration and the relevant actions of muscles involved.

A

-Diaphragm relaxes and is pushed up by the displaced organs underneath
-External muscles relax and ribs fall, internal intercostal muscles can contract to push air out more forcefully
-Volume of chest cavity decreases
-Pressure increases
-Air moved out of lungs

29
Q

What is the function of elastic fibres in the alveoli?

A

To stretch during inspiration and recoil during expiration to push air out.

30
Q

What requirements must airways meet to be effective?

A

-Be large enough with no obstructions
-Need to be supported to prevent collapse when pressure is low
-Need to be flexible to provide movement

31
Q

What is the function of the airways being lined by ciliated epithelium?

A

To keep the lungs healthy,
contain goblet cells which secrete mucus.
-Mucus traps pathogens
-Cilia wafts pathogens up to the top of the airway where they are swallowed.

32
Q

What is the function of the airways being lined by ciliated epithelium?

A

To keep the lungs healthy,
contain goblet cells which secrete mucus.
-Mucus traps pathogens
-Cilia wafts pathogens up to the top of the airway where they are swallowed.

33
Q

What is the difference structurally between the trachea and bronchi?

A

Trachea split into bronchi’s, the bronchi is narrower than the trachea.

34
Q

Explain the structure of the Bronchioles

A

Bronchioles are narrower. Larger bronchioles may have some cartilage, smaller ones have none
-Wall is comprised mostly of smooth. muscle and elastic fibres.
-Smaller bronchioles have alveoli at the end.

35
Q

What is the function of the smooth muscle and elastic fibres?

A

-Smooth muscle involuntarily contracts, this constricts airway and flow of air to the alveoli.
-This can be important during an allergic reaction.
-Smooth muscle needs help from the elastic fibres to reverse this, as muscles relax elastic fibres recoil back to original shape and size.

36
Q

How can lung volumes be measured?

A

Measured using a spirometer.

37
Q

How does a spirometer work?

A

-Measures movement of air in and out of the lungs as a person breathes.
-During inspiration, air is drawn from the chamber so that the lid moves down
-During expiration, the air returns to the chamber, raising the lid.
-These movements may be recorded on a data logger
-The co2 rich air is passed through a chamber of soda lime, which absorbs the co2. This allows measure of oxygen consumption

38
Q

What precautions must be taken when using a spirometer?

A

-Subject should be healthy and free from asthma
-Soda lime should be fresh and functioning
-Should be no air leaks in the apparatus
-Mouthpiece should be sterilised
-Water chamber must not be overfilled

39
Q

Define the term vital capacity

A

The maximum volume of air that can be moved by the lungs in one breath.

40
Q

How can the vital capacity be measured?

A

By taking a deep breath and expiring all the air possible from the lungs.

41
Q

What factors affect vital capacity?

A

The size of a person (Height)
Age and gender
Their level of regular exercise.

42
Q

What is the average vital capacity?

A

2.5-5dm(3)

43
Q

Define the term residual volume

A

-The volume of air that remains in the lungs even after forced expiration.
-This air remains in the airways and alveoli.

44
Q

What is the average residual volume?

A

1.5dm(3)

45
Q

Define the term Tidal volume

A

The volume of air moved in and out with each breath. Measured at rest.

46
Q

What is the average tidal volume?

A

0.5dm(3)

47
Q

What is seen on a spirometer trace?

A

Volume of air

48
Q

How do we measure oxygen uptake?

A

By measuring the gradient of the decrease in volume.

49
Q

How do we measure the breathing rate from the spirometer trace?

A

-Count the number of peaks each minute

50
Q

What factors affect oxygen uptake?

A

Increased oxygen uptake results from:
-Increased breathing rate
-Deeper breaths

51
Q

How do bony fish exchange gas?

A

-Exchange gases with the water in which they live.
-They use their gills to absorb oxygen. dissolved in the water and release CO2 into the water.
-O2 concentration will be much lower than in the air.

52
Q

Explain the anatomy of the gaseous exchange system in bony fish.

A

Bony fish have five pairs of gills which are covered by a bony plate called the operculum.
-Each gill consists of two rows of filaments attached to a bony arch.
-Filaments are thin and surface is folded into many secondary lamellae.

53
Q

What do the lamellae in bony fish provide?

A

A large surface area, blood capillaries carry deoxygenated blood close to the surface of the secondary lamellae where exchange takes place

54
Q

What is the countercurrent flow?

A

-Blood flows along the gill arch and out along the filaments to the secondary lamellae.
-The blood then flows through capillaries in the opposite direction to the flow of water over the lamellae. This creates a countercurrent flow.

55
Q

What is an advantage of the countercurrent flow?

A

It absorbs the maximum amount of oxygen in the water.

56
Q

How can bony fish keep ventilated?

A

-They can keep water flowing over the gills by using a buccal-opercular pump.
-The buccal cavity can change volume.
-Floor of mouth moves downwards drawing water in.
-Mouth closes and the floor is raised again by pushing water through the gills
-movement of the operculum are coordinated with the buccal cavity
-As water is pushed from the buccal cavity the operculum moves outwards
-Movement reduces pressure in opercular cavity helping water to flow through the gills.

57
Q

What circulatory system do insects have?

A

An open circulatory system, they do not transport oxygen in blood. Circulation is slow and can be affected by body movements.

58
Q

Explain how the tracheal system works.

A

-Supplies air directly to all the respiring tissues.
-Air enters the system by a spiracle.
-Air is transported into the body through tubes called tracheae
-These divide into smaller tubes called tracheoles.
-Ends of trachoeles are open and filled with tracheal fluid.
-Gaseous exchange occurs between the air in the tracheole and the tracheal fluid.
-Some exchange can also occur across the thin walls of the tracheoles.

59
Q

What happens when insect’s tissues are active

A

-The tracheal fluid can be withdrawn into the body fluid in order to increase the surface area of the tracheole wall exposed to air.
-This means more oxygen can be. absorbed when the insect is active.

60
Q

How do larger insects ventilate their tracheal systems?

A

-By movements of the body. This can be achieved by:
-Flexible walls, acts as air sacs that can be squeezed by action of the flight muscles. Repetitive contraction ventilate the system
-Movement of wings: Change size of thorax, as volume decreases air in tracheal system is put under pressure and air is pushed out . vice versa when volume increases.
-Locusts can. change size of volume of abdomen by specialised breathing movements, these co-ordinate with valves in the spiracles

Biology Module 3: Exchange and transport (8 decks)

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