Gas Exchange In Humans

Question 1

Thorax

Answer 1

Trachea, bronchus, bronchioles, alveoli

Ribs, intercostal muscle, pleural membranes, diaphragm

Question 2

Inhaling

Answer 2

• Diaphragm contracts, flattening downwards.

* external intercostal muscles contract, pulling ribs up and out.

Question 3

Exhaling

Answer 3

• diaphragm moves back.

* internal intercostal muscles contract pulling the in and downwards.

Question 4

Alveoli

Answer 4

- gas exchange occurs
• thin permeable walls
• moist lining where gases dissolve
• large surface area
• high concentration gradient for gases

Question 5

Smoking in the circulatory system

Answer 5

• tar is carcinogenic
• nicotine, increases heart rate and blood pressure
• carbon monoxide, binds with haemoglobin reducing oxygen supply
• encourages cholesterol and fat to be deposited in the walls of the coronary arteries, reducing blood flow which leads to a heart attack

Question 6

Smoking in the lungs

Answer 6

• substances paralyse the cilia and makes mucus sticky (cough more). Risk of PNEUMONIA
• coughing and the increased production of protease (breaks down alveoli lining, less S.A causing less gas exchange leaving them short of breath) causes EMPHYSEMA
• bronchi lining becomes irritated and inflamed (leaving them short on breath) risk of BRONCHITIS

Question 7

Effect of exercise on breathing

Answer 7

C- intensity.
O- people of the same sex, age, mass, health etc…
R- repeat each intensity for each person over 2 days.
M- the breathing rate in breaths per minute by counting how many breath are taken in 15 seconds and then times it by 4.
S- temperature, diet, humidity, hydration etc…

Question 8

Ribs:

Answer 8

Protects lungs and heart

Question 9

Diaphragm:

Answer 9

Controls breathing and changes the pressure in the lungs

Question 10

Trachea:

Answer 10

Moves air into the lungs and catches dirt