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Biology Stonehouse Y12 > Exchange & Transport > Flashcards

Flashcards in Exchange & Transport Deck (55):
1

Why is diffusion alone enough to supply the needs for single celled organisms

Metabolic activity is usually low so oxygen demands and CO2 production is low
Surface area to volume ratio is large

2

Problems bigger organisms face

Smaller SA:V ratio
Distance between the cells and where oxygen is needed and the supply of oxygen is too far for effective diffusion to take place.
Have high oxygen demand

3

What does an increased surface area do?

Gases can be exchanged quickly And in large amounts

4

What do thin layers do?

The distances that substances have to diffuse are short, making the process fast and efficient

5

What does a good blood supply do?

The steeper the concentration gradient, the faster diffusion takes place. Ensures substances are constantly delivered to and removed from the exchange surface. This maintains a steep concentration gradient for diffusion.

6

What does good ventilation do?

A ventilation system helps maintain a concentration gradient and makes the process more efficient.

7

What components do mammals have?

Small SA:V ratio
Large volume of cells
High metabolic rate as they are active and maintain body temp
Need lots of oxygen for cellular respiration.

8

What does the nasal cavity do

Large surface area with good blood supply, which warms the air
Hairy lining which secretes mucus to trap dust and bacteria
Moist surfaces which increases the humidity of the incoming air reducing evaporation

9

What is the trachea

The main airway carrying clean warm moist air from the nose to chest.
Wide tube made of incomplete rings of cartilage which stop it from collapsing

10

What do goblet cells do

Secrete mucus onto the lining of the trachea to trap dust that have escaped the nasal cavity

11

What do ciliated epithelial cell’s do?

The cilia beat and move the mucus away from the lungs.

12

Structure of bronchus

Trachea divides to form bronchus. Similar structure to trachea with same rings of cartilage but are smaller

13

What do bronchioles do

Bronchi divide into small bronchioles. Small ones have no cartilage rings. Walls of them contain smooth muscle.
Lined with thin layer of flattened epithelium

14

What happens when smooth muscle of bronchioles contract

Bronchioles constrict- changes amount of air reaching lungs

15

What happens when smooth muscle of bronchioles relax

The bronchioles dilate- which changes amount of air reaching lungs

16

What do the alveoli do

Tiny air sacs which are the main exchange surfaces of the body
Consist of a layer of thin flattened epithelial cells along with some collagen and elastic fibres. The elastic tissues allow the alveoli to stretch as air is drawn in- elastic recoil

17

What allows alveoli to remain inflated?

Lung surfactant

18

Define ventilation

Movement of air
(In and out of the lungs)

19

What happens during inspiration

Diaphragm contracts and flattens
External intercostal muscles contract, moving the ribs upwards and outwards
Volume of thorax increased so pressure reduces, and is now lower than atmospheric pressure so air is drawn in

20

What happens during expiration

Diaphragm relaxes and turns dome shaped
External intercostal muscles relax so ribs move down and inwards.
Pressure is greater than atmospheric pressure so air moves out of lungs

21

What happens when you exhale forcibly?

You use energy
Internal intercostal muscles contract pulling the ribs down hard and fast and the abdominal muscles contract forcing the diaphragm up to increase pressure rapidly

22

What is a peak flow meter

Measures the rate at which air can be expelled from the lungs

23

What are vitalographs

Produces a growth of the amount of air breathed out and how quickly it is done so

24

What is a spirometer

Measures lung volume/ ventilation

25

What is tidal volume

Volume of air yet moves into and out of the lungs with each resting breath

26

What is vital capacity

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

27

Wha is inspiratory reserve volume

Maximum volume of air you can breathe in over and above a normal inhalation

28

What is exploratory reserve volume

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

29

What is residual volume

Volume of air that is left in your lungs when you have exhaled as hard as possible

30

What is total lung capacity

The sum of the vital capacity and the residual volume

31

What is the breathing rate

Number of breaths taken per minute

32

How to work out ventilation rate

Tidal volume x breathing rate (per minute)

33

What does an insect have the prevents gas exchange

A tough exoskeleton and no blood pigments that can carry oxygen

34

What are spiracles

Small openings along the thorax and abdomen

35

How are spiracles opened and closed

By sphincters

36

What are the tracheae (insects)

Carry air into the body and run into and along the body

37

What are the tracheae tunes lined with

Chitin- keeps them open if they are bent or pressed and is impermeable

38

What is a tracheole?

A single, elongated cell with no chitin lining- freely permeable and spread throughout the tissues of the Insect

39

How does air move around in an insect

Moves along the tracheae and tracheoles by diffusion. Oxygen dissolves in moisture on the walls of the teacheoles and diffuses into surrounding cells.

40

Where is tracheal fluid and what does it do

It is found at the end of the tracheoles and limits the penetration of air for diffusion

41

What happens when an insect is flying

Lactic acid builds up in the tissue and water is moved out of the tracheoles via osmosis- more surface area

42

Alternative methods of increasing levels of gas exchange

Mechanical ventilation of the tracheal system
Collapsible enlarged tracheae or air sacs

43

What does a mechanical ventilation of the tracheal system do?

Air pumped into the system by muscular pumping movements of the thorax, which changes the volume of the body and the pressure in the tracheoles and tracheae- air drawn in or forced out as pressure changes

44

What do collapsible enlarged tracheae or air sacs do?

Increase amount of air moved through gas exchange system. Inflated and deflated by ventilating movements of the thorax

45

Differences between water and air

Water 1000 denser than air and 100 times thicker

46

How do bony fish supply inner cels with oxygen

Maintain a flow of water in one direction Over the gills

47

What are the features of gills

Large SA:V ratio-Gill lamellae
Good blood supply to maintain a steep concentration gradient
Thin layers

48

Where are gills on a bony fish

Contained in a full cavity and covered by a protective operculum which maintains a flow of water

49

How do fish keep a flow of water over the gills

Opening their mouth and operculum

50

What is ram ventilation

Ram water past the gills

51

What does the overlapping of the tips of adjacent gills do?

Increase the resistance to the flow of water Over the gill surfaces and slows down the movement of water- more time for gas exchange

52

Why is a steep concentration gradient needed?

Fast and effficient diffusion.

53

What does the countercurrent system between blood and water do?

Ensures the concentration gradients are maintained, allowing more gas exchange to take place

54

What is the countercurrent system?

Blood and water flow in opposite directions do and oxygen concentration between them is maintained along the gill. Oxygen continues to diffuse down the favourable concentration gradient

55

What is a parallel system?

Blood in the gills and water flowing over goes in the same direction, giving a steep oxygen concentration gradient. Diffusion takes place until the concentrations are equal then no net movement of oxygen in blood occurs