Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biology: exchange of substances > gas exchange > Flashcards

gas exchange Flashcards

(50 cards)

Start Studying
1
Q

what is fick’s law?

A

surface area x difference in conc / diffusion distance

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

name three features of an efficient gas exchange system

A

● large surface area

● short diffusion distance

● steep conc gradient (maintained by blood supply or ventilation)

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

what is ventilation?

A

breathing

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

what is the trachea?

A

wind pipe

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

what is the thoracic cavity?

A

space where the lungs are

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

explain the human gas exchange system

A

● as you breathe in, air enters trachea

● trachea splits into 2 bronchi

● each bronchus branches off into smaller tubes called bronchioles

● bronchioles end in small air sacs called alveoli

● ribcage, intercostal muscles and diaphragm work together to move air in and out

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

explain inspiration

A

● external intercostal muscles contract

● ribcage - moves upwards and outwards

● diaphragm contracts to flatten

● increasing volume of thoracic cavity

● as volume increases, lung pressure decreases (to below atmospheric pressure)

● air flows down the trachea and into lungs down pressure gradient

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

what does inspiration require?

A

energy (active)

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

explain expiration

A

● external intercostal and diaphragm muscles relax

● ribcage moves downward and inwards

● diaphragm becomes curved

● volume of thoracic cavity decreases, causing pressure to increase (to above atmospheric pressure)

● air forced down pressure gradient and out of lungs

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

what does expiration not require?

A

energy (passive)

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

explain forced expiration

A

● external intercostal muscles relax

● internal intercostal muscles contract

● pulling ribcage further down and in

● movement of 2 sets of intercostal muscles are antagonising

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

what are alveoli made from?

A

alveolar epithelium

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

what is the alveolar epithelium made of?

A

a single layer of thin, flat squamous cells

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

how does human gaseous exchange happens in the alveoli?

A

● oxygen diffuses out alveoli, across the alveolar epithelium and capillary endothelium

● into haemoglobin in red blood cells

● carbon dioxide diffuses from blood across capillary endothelium and alveolar epithelium and into alveoli and is breathed out

● movement happens down a diffusion gradient

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

what is the capillary endothelium?

A

type of epithelium that forms the capillary wall

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

how does human gaseous exchange happens in the alveoli? (simplified)

A

● oxygen - trachea - bronchi - bronchioles - alveoli

● happens down a pressure gradient

● alveoli - diffuse across alveolar epithelium and capillary endothelium - capillary - haemoglobin in blood

● happens down a diffusion gradient

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

how are alveoli adapted for gas exchange?

A

● short diffusion distance - alveolar epithelium is made of squamous cells (thin exchange surface)

● large surface area - large number of alveoli means there’s a large surface for gas exchange and folds in alveolar epithelium

● steep concentration gradient of O2 and CO2 between alveoli and capillaries

● capillaries give good blood supply

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

what is the composition of gases inhaled?

A

● higher conc of O2

● N2 stays the same

● lower conc of CO2

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

what is the composition of gases exhaled?

A

● lower conc of O2

● N2 stays the same

● higher conc of CO2

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

what is tidal volume?

A

● tidal volume is the volume of air in each breath

● average 0.4 - 0.5dm^3

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

what is forced expiratory volume (FEV1)?

Study These Flashcards
A

maximum volume of air that can be breathed out in 1 second

22
Q

what is forced vital capacity (FVC)?

Study These Flashcards
A

maximum volume of air that can be breathed forcefully out after a deep breath

23
Q

what is pulmonary ventilation?

Study These Flashcards
A

● volume of air ventilated by the lungs in 1 minute

● PV (dm^3) = tidal volume x ventilation rate

24
Q

what is ventilation rate?

Study These Flashcards
A

● number of breaths per minute

● average 15

25
how does pulmonary fibrosis slow gas exchange
● scar tissue makes alveoli thicker ● reduces elasticity of alveoli ● increases diffusion distance
26
how does TB slow gas exchange
● scar tissue makes alveoli thicker ● reduces elasticity of alveoli ● increases diffusion distance
27
how does asthma slow gas exchange
● tidal volume reduced ● decreases conc gradient
28
how does lung cancer slow gas exchange
● tidal volume reduced ● decreases conc gradient
29
how does emphysema slow gas exchange
● reduced elasticity ● prevents exhalation ● decreases conc gradient
30
correlation doesn't equal
causation
31
why can't in
32
what is a spiracle
● opening in the exoskeleton of insects body ● most of the time closed to avoid water loss
33
what is an insects exoskeleton?
● made of chitin ● impermeable to gases
34
explain insect gas exchange system
spiracle - tracheal tubes - tracheoles - respiring cells
35
how are insects adapted for gas exchange?
● highly branched tracheoles - increases surface area ● tracheoles have thin walls - short diffusion distance ● cells constantly respiring & abdominal pumping (a form of ventilation) - maintains conc gradient
36
how do insects control water loss?
● if losing too much water, closes spiracles ● waterproof waxy cuticle and tiny hairs around spiracles - reduce evaporation
37
where does water flow in fish
water - mouth - water passes across gills
38
what is the structure of a fish's gills
● gill arch ● gill filaments attached to gill arch ● gill lamellae on the surface of each gill filament ● gill lamellae contain capillaries
39
how are fish adapted for gas exchange?
● many gill filaments that are highly branched with lamellae - increases surface area ● ventilation + blood flow + counter current flow - maintains concentration gradient ● lamellae have thin walls(epithelium) - decreases diffusion distance
40
what is counter-current flow?
● blood and water flow in opposite directions - through and over the lamellae ● there is a conc gradient maintained along entire lamellae ● O2 conc between water and blood does not reach equilibrium
41
what is the structure of a leaf?
● waxy cuticle ● upper epidermis - layer of tightly packed cells ● palisade mesophyll layer - layer of elongated cells containing chloroplasts ● spongy mesophyll layer - layer of cells that contains network of air spaces ● stomata - pores (usually) on underside of the leaf which allows air to enter ● guard cells - pairs of cells that control the opening and closing of stomata ● lower epidermis - layer of tightly packed cells
42
how are leaves dicotyledonous plants adapted to gas exchange
● large surface area - main gas exchange surface are mesophyll cells inside leaf ● when guard cells are turgid (full of water), stoma open allowing air to enter leaf (opposite of turgid is flaccid) ● air spaces within spongy mesophyll layer allows CO2 to rapidly diffuse into cells ● conc gradient maintained - CO2 is quickly used up in photosynthesis by cells containing chloroplasts ● short diffusion distance - thinness of plant tissues and stomata so no active ventilation is required
43
what is the formula for photosynthesis
6CO2 + 6H2O --(light)--> C6H12O6 + 6O2
44
what is the formula for aerobic respiration
C6H12O6 + 6O2 ---> 6CO2 + 6H2O
45
how does H2O enter plant
osmoses into roots
46
how do minerals enter plant
actively transported into roots
47
how do plants control water loss
● day: CO2 and O2 diffuse through stomata. H2O lost through transpiration ● night: closed stomata to stop water loss by transpiration. water can not be used in photosynthesis ● waxy cuticle
48
how are xerophytic plants adapted to reduce transpiration?
● waxy cuticle - increases diffusion distance ● spines of cactus - decreases surface area ● rolled leaf - decreases surface area and conc gradient ● stomata sunken In pits - decreases conc gradient
49
what is the singular for stomata?
stoma
50
how do you draw scientific drawings?
● no shading ● label lines need to be parallel ● label lines need to be on one side ● no hanging lines ● no sketched lines ● draw with sharp pencil ● labels with ruler and with pen ● use key for magnification ● add title ● no arrow heads

biology: exchange of substances (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions