F211 Exchange Surfaces And Breathing

Question 0

Exchange Surfaces

Multicellular Organisms

Answer 0

Small surface area to volume ratio
Cannot obtain substances fast enough by diffusion
Cells in the centre of the organism would not receive any nutrients without specialised exchange surfaces

Question 1

Exchange Surfaces

Single-Celled Organisms

Answer 1

Large surface area to volume ratio

Able to exchange enough gases nutrients and waste across their outer surface to function

Question 2

Ficks Law

Answer 2

Rate of Diffusion =

SurfaceArea x ConcentrationDifference/DistanceForDiffusion

Question 3

Lung Adaptations - Surface Area

Answer 3

Large numbers of alveoli

Alveoli have large surface area and a folded outer surface

Question 4

Lung Adaptations - Concentration Difference

Answer 4

Inhaling and exhaling regularly keeps oxygen concentration in the lungs as high as possible and removes as much CO2 as possible to keep the concentration low
Moving the blood around the body moves blood with high oxygen concentration away from the lungs and brings deoxygenated blood towards the lungs

Question 5

Lung Adaptations - Distance for Diffusion

Answer 5

Alveoli and capillary walls are only one cell thick
Capillaries are positioned as close to the lungs as possible
Alveoli and capillary wall cells are made of squamous cells

Question 6

Lung Adaptations - Moisture

Answer 6

The lungs are lined with a thin layer of moisture which increases the rate of diffusion because the molecules are dissolved

Question 7

Inhaled Air

Answer 7

20% oxygen

0.04% carbon dioxide

Question 8

Exhaled Air

Answer 8

16% oxygen

4% carbon dioxide

Question 9

Larynx

Answer 9

Voice box
If you have a bigger voice box you will have a deeper voice
Vocal chords vibrate as air exits

Question 10

Trachea

Answer 10

Surrounded by horse shoe shaped cartilage
-can move neck without constricting airways
-allows oesophagus to expand during swallowing
Smooth muscle and elastic fibres
Epithelium layer

Question 11

Bronchi

Answer 11

Reinforced with cartilage
One for each lung
Smooth muscle and elastic fibres
Epithelium layer

Question 12

Internal Intercostal Muscles

Answer 12

For exhalation during high intensity exercises

Question 13

External Intercostal Muscles

Answer 13

Contract and lift ribs up and out for inhalation

Relax and ribs fall for exhalation

Question 14

Cartilage

Answer 14

For structure and support
Prevents airways from collapsing when air pressure is low during inhalation
Trachea and bronchi

Question 15

Smooth Muscles

Answer 15

When they contract the airway constricts
Contraction isn’t voluntary
Trachea bronchi bronchioles

Question 16

Bronchioles

Answer 16

Smooth muscles contracts to constrict airway if air contains harmful substances
Involuntary

Question 17

Elastic Fibres

Answer 17

They recoil to return the airway to original diameter after smooth muscles contract and constrict the airway
Trachea, bronchi, bronchioles, alveoli

Question 18

Goblet Cells

Answer 18

Part of the epithelium layer
Secrete mucus to trap bacteria in the lungs
Trachea and bronchi

Question 19

Ciliates Epithelium

Answer 19

Part of the epithelium layer
Cells have numerous tiny hair like structures projecting from membrane called cilia
Cilia move in synchronised pattern to move mucus to the back of the throat
Mucus is swallowed and stomach acidity kills bacteria

Question 20

Surfactant

Answer 20

Breaks down cohesive forces between water molecules lining the alveoli to prevent the alveoli from collapsing

Question 21

Inhalation

Answer 21

Diaphragm contracts and flattens
Intercostal muscles contract so ribs move up and out
Volume of thorax increases, increases volume of lungs and alveoli
Pressure decreases (same amount of air in a larger space) below pressure of air in the atmosphere
SO air flows in to equalise this

Question 22

Exhalation

Answer 22

Diaphragm relaxes and curves upwards
Intercostal muscles relax and ribs fall
Decreases volume of thorax, decreases lung and alveoli volume
Pressure in lungs increases (same amount of air in a smaller space) above pressure of air in the atmosphere
SO air flows out to equalise this

Question 23

Resting Tidal Volume

Answer 23

Volume of air taken in one breath at rest

Question 24

Vital Capacity

Answer 24

Maximum volume of air taken in or out during high intensity exercise

Question 25

Bell Jar - Resting Tidal Volume

Answer 25

Slow regular movements of the membrane in time with your own breathing

Question 26

Bell Jar - Vital Capacity

Answer 26

Quickly pull membrane in and out as far as possible

Question 27

Pulmonary Ventilation

Answer 27

Pulmonary Ventilation = Tidal Volume x Ventilation Rate

Question 28

Residual Volume

Answer 28

The volume of air that always remains in the lungs

Question 29

Dead Space

Answer 29

The air in the bronchioles, bronchi and trachea. There is no gas exchange between this air and the blood

Question 30

Expiratory Reserve Volume

Answer 30

How much more air can be breathed out over and above the amount that is breathed in a tidal volume breath

Question 31

Spirometer

Consists of…

Answer 31

A chamber filled with oxygen that floats on a tank of water
A person breathes in and out of a disposable mouth piece attached to a tube connected to the chamber of medical grade oxygen

Question 32

Spirometer

Breathing In

Answer 32

Takes oxygen out of the chamber causing the lid to fall

Question 33

Spirometer

Breathing Out

Answer 33

Pushes air into the chamber pushing the lid up

Question 34

Spirometer

Recording Data

Answer 34

The movements of the lid are recorded using a data logger to produce a spirometer trace

Question 35

Spirometer

Carbon Dioxide Absorber

Answer 35

If someone breathes out into the spirometer for a long period of time carbon dioxide levels will build up to dangerously high levels

Soda Lime