Brainscape's Knowledge GenomeTM

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


See full index

biology > gas exchange > Flashcards

gas exchange Flashcards

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

explain how SA:volume ratio changes as the organism gets larger.

A

in small animals the SA:volume ratio is relatively large. whereas in large animals it is low.

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

why is diffusion enough to supply single celled organisms with oxygen?

A
  • large SA:volume ratio

- metabolic activity in single celled organisms is also low so they can get enough oxygen as they require less.

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

what is the formula for the surface area of a sphere?

A

4piRsquared

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

what is the formula for the volume of a sphere?

A

4/3piRsquared

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

how is level of activity related to demand for oxygen and glucose?

A

the higher the level of activity the higher the demand for oxygen and glucose. mammals usually contain lots of muscle tissue as their activity levels are higher.

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

explain how volume is related to demand and SA related to supply.

A

the larger the volume of the organism the higher the demand. the larger the surface area of the gas exchange system the more oxygen can be supplied to the muscles/cells.

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

suggest why some organisms need specialised exchange surfaces.

A

larger organisms cannot supply their cells with oxygen through diffusion alone as the distance to the internal cells is too large and the SA:volume ratio is too small.

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

state 4 features of a specialised exchange surface.

A
  • increased/large surface area
  • thin layers of cells (squamous)
  • good blood supply
  • ventilation to maintain diffusion gradient.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why is an increased surface area good for exchange?

A

overcomes the limitations of SA:volume ratio in larger organisms. increased area means a greater distance molecules are able to diffuse in across.

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

why are thin exchange surfaces useful?

A

the distance that a substance has to diffuse is short and this makes the process faster and more efficient.

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

why is a good blood supply useful in an exchange surface?

A

the steeper the concentration gradient the faster diffusion takes place. good blood supply means that substances are constantly removed and delivered to the exchange surface, this maintains the concentration gradient.

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

how is ventilation useful in an exchange surface?

A

this is specifically for gases. ventilation increases the concentration gradient and makes the exchange process more efficient.

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

state Fick’s law.

A

Rate of Diffusion = Suface area x difference in concentration / thickness of exchange surface.

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

describe and explain the importance of the nasal cavity.

A
  • large surface area and good blood supply so air is warmed to body temperature
  • hairy lining that secretes mucous to trap dust and bacteria to stop it from entering the lungs
  • moist surfaces which reduce evaporation from the exchange surfaces.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe and explain the importance of the trachea.

A

wide tube supported by incomplete (so food can pass down the oesophagus) string, flexible cartilage - which stop the trachea from collapsing. lines with ciliated epithelium and goblet cells. carries the air into the bronchi (lungs)

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

describe and explain the importance of the bronchus.

A

the trachea divides into the left bronchus and right bronchus. one going into each lung. similar structure to the trachea but smaller.

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

describe and explain the importance of the bronchioles.

A

the bronchi divide into smaller bronchioles. these start of larger and gradually get much smaller. terminal brochioles have no cartilage. bronchioles contain smooth muscle which can contract and relax to change the amount of air reaching the lungs. they have a layer of epithelium cells which makes gas exchange possible here.

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

describe and explain the importance of the alveoli.

A

tiny air sacs, which are the main gas exchange surface in the body. each has a diameter of around 200-300um. and consists of a layer of squamous epithelial cells - along with some collagen and elastic fibres. elastic tissues allow the alveoli to stretch as you breathe in and return to resting size which helps push air out. (known as elastic recoil.

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

explain how the lungs are protected from bacteria.

A

cilliated epthelial cells move in wave like motions to sweep microscopic things back up the bronchi and trachea to the throat. this is helps by the goblet cells that produce mucous to collect bacteria and dust from the bronchi and trachea.

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

describe the importance of elastic fibres and lung surfactant in the alveoli.

A

elastic fibres help elastic recoil - meaning the alveoli can stretch when you breathe in and recoil to help push the air out. lung surfactant stops the alveoli from collapsing in on themselves by breaking the water tension in the moist lining of the lungs.

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

what are the adaptations of the alveoli?

A
  • large surface area, there are many (300-500 million) alveoli per lung and each have a large surface area individually.
  • both the wall of the alveoli and the capillary walls are one epithelial cell thick.
  • good blood supply as the alveoli are surrounded by many (280 million) capillaries
  • breathing serves as tidal ventilation and maintains a steep concentration gradient.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

define the term ‘breathing’

A

the action of drawing air into the lungs and expelling it again

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

define the term ventilation

A

the system of replacing used/spent air with fresh air.

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

define the term gas exchange

A

Gas exchange is a biological process through which different gases are transferred in opposite directions across a specialized respiratory surface.

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

define the term inspiration.

A

inspiration is the active process of drawing air into the lungs.

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

define the term expiration.

A

expiration is the passive process of expelling air from the lungs.

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

define the term active process.

A

a process that requires energy

28
Q

define the term passive process

A

a process that does not require energy - relaxation.

29
Q

describe the process of inspiration.

A
  • the diaphragm contracts and flattens
  • the external intercostal muscles contract
  • the ribs move upwards and outwards
  • the volume of the thorax increases so the relative pressure decreases.
  • air is drawn into the lungs to equalise the pressure.
30
Q

describe the process of normal expiration.

A
  • the diaphragm relaxes so it moves u into it’s normal dome shape.
  • the external intercostal muscles relax so the ribs move down and in.
  • the elastic fibres in the alveoli return to their normal length.
  • volume of the thorax decreases so the pressure is higher than atmospheric pressure.
  • air moves out of the lungs to equalise the pressure
31
Q

describe the process of forced expiration.

A
  • the internal intercostal muscles contract
  • the ribs are puled down hard and fast.
  • abdominal muscles contract forcing the diaphragm up.
  • pressure in the lungs increases rapidly so air is forced out faster.
32
Q

state three ways lung function can be measured.

A
  • a peak flow meter (measures the rate at which air can be expelled from the lungs)
  • vitalographs (patient breathes out as quickly as they can through a mouthpiece. the instrument produces a graph of the amount of air they breathe out and how quickly. the volume of air is called the forced expiratory volume in one second.)
  • spirometer (measures aspects of the lung volume or investigates breathing patterns.)
33
Q

describe how a spirometer works.

A
  • the patient breathes into a mouthpiece, in and out until oxygen is used up.
  • there is a canister of soda lime to remove the carbon dioxide produced and stop the patient from breathing it in again.
  • there is an airtight chamber filled with water, a lid resting on top creates an oxygen chamber.
  • as the patient breathes in the lid goes down, as they breathe in it goes up.
  • a trace attached to the lid measures the breathing patterns of the patient.
34
Q

define the term tidal volume

A

the volume of air that moves into or out of the lungs with each resting breath. it is around 15% (500cm^3) of the vital capacity of the average adult lung.

35
Q

define the term vital capacity.

A

the volume of air that can breathed in when the strongest possible exhalation is followed by the deepest possible intake of breath.

36
Q

define the term inspiratory reserve volume.

A

the maximum volume of air you can breathe in over and above the normal inhalation.

37
Q

define the term expiratory reserve volume.

A

the extra amount of air you can force out of your lungs over and above the normal tidal volume that you breathe out.

38
Q

define the term residual volume.

A

the volume of air that is left behind in your lungs when you have exhaled as hard as possible. this cannot be directly measured.

39
Q

define the term total lung capacity

A

the sum of the vital capacity and the residual volume

40
Q

what is meant by breathing rate?

A

the number of breaths per minute

41
Q

what is meant by ventilation rate?

A

the total volume of air inhaled in one minute.

42
Q

how do you calculate ventilation rate?

A

ventilation rate = tidal volume x breathing rate (per minute)

43
Q

what happens to the tidal volume during exercise?

A

it increases from 15% to up to 50% of the vital capacity.

44
Q

define the term exoskeleton.

A

a rigid external covering for the body - through which gas exchange cannot take place.

45
Q

define the term spiracle.

A

small openings on an insects exoskeleton through which air enters and leaves the body of an insect.

46
Q

define the term thracheae.

A

tubes leading away from the spiracles into the insect. they are up to 1mm in diameter and run both into and along the body of the insect, they are lined with spirals of chitin which keeps them open.

47
Q

define the term tracheoles

A

the tracheae branch into tiny tracheoles. each one is a single, elongated cell. it has no chitin lining so gas exchange happens here. they spread through the tissues of the cell.

48
Q

define the term tracheal fluid.

A

tracheal fluid is found towards the end of the tracheoles. limits the penetration of air for diffusion. however when oxygen demand builds, a lactic acid build up in the tissues results in water moving out of the tracheoles by osmosis. exposing more surface area for diffusion.

49
Q

describe how the insect gas exchange system works.

A
  • air enters the insect through the spiracles, which are open when energy demands are high
  • air travels down the tracheae to the tracheoles. no gas exchange happens in the tracheae.
  • gas exchange takes place in the tracheoles , which are small enough to fit between cells in the body tissue of the insect.
50
Q

why are the spiracles closed when oxygen demands are low?

A

to minimise water loss via the spiracles. this maximises the efficiency of gas exchange

51
Q

describe the adaptations of the insect gas exchange system.

A
  • spiracles which can open and close depending on oxygen requirements
  • large surface area (many tracheoles)
  • moist lining to the tracheoles for gas exchange
  • tracheal fluid at the end of tracheoles
52
Q

describe two adaptations of larger insects that require more energy.

A
  • mechanical ventilation (air is actively pumped into the system by the movement of the abdmen. these movements change the volume and pressure inside the insect to draw air in or force it out. inspiration is a passive process, expiration is active)
  • collapsible air sacs that act as reservoirs (used to increase the amount of air moved through the gas exchange system. inflated or deflated by the ventilating movements of the abdomen)
53
Q

what advantages do animals living in water have?

A

do not have to worry about water loss from their gas exchange system.

54
Q

what disadvantages do animals living in water have?

A
  • water is 1000 times denser than air and 100 times more viscous. it also has a much lower water content
55
Q

define the term operculum.

A

a protective bony flap over the gills which plays an active role in maintaining water flow over the gills.

56
Q

define the term buccal cavity

A

the space in the fish’s mouth that is open or constricted to control water movement into the mouth and over the gills.

57
Q

define the term opercular valve

A

the valve underneath the operculum that opens or closes to let water out over the gills

58
Q

define the term gill arch

A

a bony structure that supports the structure of the gills (fillaments and lamellae)

59
Q

define the term gill filament

A

occur in large stacks. need a flow of water to keep them apart, exposing the large surface area needed for gas exchange.

60
Q

define the term gill plate

A

the stacks of gill filaments are known as gill plates

61
Q

define the term lamellae

A

have a rich blood supply and large surface area. make up the main site of gas exchange in fish.many small protrusions from each filament.

62
Q

describe the mechanism of ventilation in bony fish.

A
  • the mouth opens and the floor of the buccal cavity lowers - this increases the volume and draws water in.
  • the opercular cavity expands, lowering the pressure.
  • the floor of the buccal cavity moves up, increasing the pressure and forcing water over the gills
  • the mouth closes, the operculum opens and the sides of the opercular cavity move inwards
  • the opercular valves open and water is forced over the gills and out. the floor of the buccal cavity moves up steadily, maintaining the flow of water over the gills.
63
Q

describe the adaptations that make the fish’s gas exchange system effective.

A
  • the tips of the gill filaments overlap which creates resistance to the water - increasing the amount of time for gas exchange
  • water and blood in the gills flow in opposite directions which increases the distance for gas exchange.
64
Q

define the term countercurrent exchange system.

A

blood in the gills and water flow in opposite directions. it creates a steeper concentration gradient over a longer distance so there is more capacity for gas exchange. this way the fish extract about 80% of the oxygen in the water flowing over their gills.

65
Q

define the term parallel exchange system.

A

when blood and water flow in the same direction. fish that use this system only extract 50% of the oxygen from the water.

biology (22 decks)

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