Biology exhange

Question 1

Function of smooth muscle in gaseous exchange

Answer 1

Involuntary muscle,
Contracts and causes the airways to constrict
narrows the lumen
Controles air flow to the alveoli

Question 2

Function of cartilage in gaseous exchange

Answer 2

Supports airways
Keeps airways open
incomplete c shaped rings provide flexibility
Prevents collapsing when air pressures are low (inhaling)
Allows oesophagus to expand when swallowing

Question 3

Likely effect of smoking on cilia and Goblet cells

Answer 3

Smoking damages the ciliated cells, and are paralyzed.

Stimulates goblet cells to secrete more mucus, and can lead to the diameter of bronchioles decreasing

Question 4

Function of elastic fibres in the alveoli

Answer 4

Works with smooth muscle
When smooth muscle contract, they deform
when smooth muscle relax elastic fibres recoil and return back to normal shape, aiding airways to dilate

Question 5

Describe how the Goblet and ciliate epithelial cells protect the alveoli from damage

Answer 5

Goblet cells secrete MUCUS, which is STICKY, TRAPS dust, viruses and pathogens
	Cilia beat in a  SYNCHRONISED PATTERN 
	Particles are WAFTED  by cilia 
	Mucus is SWALLOWED
	Pathogens KILLED BY ACIDITY OF  STOMACH

Question 6

Adaptations of a good gas exchange

Answer 6

LArge SA
Thin barrier 
Diffusion gradient
prevention from dryng out
Maintains a steep concentration gradient

Question 7

Path of CO2 from blood capillary to lumen of alveoli

Answer 7

Diffuses out of the capillary wall past the epithelial layer of the alveoli into the lumen of the alveoli

Question 8

Why do people with emphysema have trouble forcing air out their lungs when they breathe out

Answer 8

Alveolus destroyed–> lack elastic fibres to stretch and recoil, widening the diameter of the airway when you breathe out

Question 9

why do singled cell organisms not need a specialised area for gas exchange

Answer 9

1. Gas exchange occurs through diffusion, single celled organisms are so small that their high SA:V allows diffusion to occur quickly due to the shorter diffusion distance

Question 10

What happens to the air chamber during inspiration

Answer 10

Volume of air inside chamber decrease and the hinge drops down

Question 11

What chemical absorbs CO2

Answer 11

Soda lime/ sodium hydroxide

Question 12

11. Why should someone measuring their vital capacity use a nose clip

Answer 12

Prevent air from escaping and leading to invalid results

Question 13

Precautions taken when using a spirometer

Answer 13

1. sterolize mouthpiece
2. don’t use if you have asthma
3. don’t use for more than 5 minutes, can lead to unconsciousness

Question 14

How can a spirometer be used to measure tidal volume

Answer 14

Breather in- volume of air decreases, float/ pen falls down
Breather out- Volume of air increases, float/ pen rises
measure TV from peak to trough

Question 15

How spirometer is used to measure oxygen uptake

Answer 15

12. Measure the differece in volume of air at the beginning and end, measure the time taken for that total volume (end-beginning) 60 x vol

Question 16

Explain using SA and V, why large active oragnisms require a specialised exchange surface

Answer 16

As an organism gets larger, their SA:V decreases

In order for effeicient exchange they need to find other ways to provide enough surface

Question 17

How dot the lungs prevent drying out

Answer 17

17. Alveoli are tucked away deep in the body, away from direct exposure

Cells secrete mucus and fluid that covers the lining and keeps them moist

Question 18

How do the leaves increase surface area

Answer 18

Highly branched

Open air spaces mean more cell surfaces are exposed

Question 19

How to plants ensure they have a steep CG

Answer 19

Photosynthesis means that CO2 is being used, low concentration inside palnts
O2 used for respiration at night, CG in opposite direction

Question 20

Function of macrophages

Answer 20

Digest and engulf particulates from smoke. Bacteria that are harmful to alveoli, they are phagocytes

Question 21

How does the mechanism of relaxed breathing out work

Answer 21

Intercostal muscles relax, diaphragm relaxes decreasing the volume of the thorax, the alveoli recoil and pressure inside is higher than outside
air is forced out

Question 22

How does inspiration work

Answer 22

The external intercostal muscles contract, diaphragm contracts
ribcage moves up and out
volume of thorax increases
pressure inside

Question 23

Forced Expiration

Answer 23

Internal intercostal muscles CONTRACT, 
volume of thorax decreases
ribcage moves downwards and inwards
Diaphragm RELAXES
ABDOMINAL WALL CONTRACT, RAiSES PRESSURE IN ABDOMEN, raises diaphragm

Question 24

The requirements of an effective airwya

Answer 24

Large enough for sufficient air to flow without obstruction
divide into smaller airways that can deliver air tp aveoli
strong enough to prevent collapsing during low pressures
flexible
stretch and recoil

Question 25

Composition of tissue in bronchus bronchiole and trache

Answer 25

trachea and Bronchus - cartilage, SM, EF, GC, CE, RBS

Bronchioles- same but no cartilage

Question 26

Definition of tidal volume

Answer 26

The volume of air moved in and out of lungs with each breath when you are at rest

Question 27

Definition of residual volume

Answer 27

The volume of air left in lungs, even after the maximum air has been exhaled

Question 28

Definition of inspiratory reserve

Answer 28

The volume of extra air inspired on top of the tidal volume, what’s used in excercise

Question 29

Vital capacity

Answer 29

The maximum volume of air moved in and out in one breath

Question 30

How do the lungs maintain a steep concentration gradient

Answer 30

Ventilation replaces used air with fresh air ensures that the air in the air in the alveoli is oxygen rich, and CO2 poor

Blood brings CO2 rich and O2 poor bloodso the concentration of O2 is lower than alveoli