Gas exchange - Humans

Question 1

Describe what is meant by anatomy

Answer 1

Anatomy refers to the structure of the human body

Question 2

Describe what is meant by gross anatomy

Answer 2

Gross anatomy refers to anything we can see with the naked eye

Question 3

Describe how to structure of the trachea links to its function

Answer 3

The trachea is supported by rings of C-shaped cartilage that add strength preventing collapse, but also flexibility

Question 4

What’s the role of cartilage in the bronchus

Answer 4

Cartilage provides strength in order to prevent the airway from collapsing

Question 5

What would happen if the airway collapsed in the bronchus

Answer 5

No air would get through, stopping gas exchange, and eventually stopping respiration

Question 6

Why is cartilage in the bronchus C shaped and not a solid ring

Answer 6

Provides flexibility

Question 7

Why is smooth muscle in the bronchus significant

Answer 7

The brain causes smooth muscle to automatically contract or relax (bc it’s involuntary) when needed to control the size of the bronchi and therefore the volume of air passing through.

Question 8

What is significant about the ciliated epithelial cells in the bronchus

Answer 8

These cells have tiny hairs to move things like mucus and debris out of the bronchi

Question 9

Describe how the structure of the bronchus is linked to its function

Answer 9

• C shaped cartilage
• Smooth muscle wall

Question 10

Describe how the structure of the bronchus is linked to its function

Answer 10

• Smooth muscle wall
• Some have cartilage

Question 11

Describe how the number of tubes changes as you move from the conducting zone to the respiratory zone. Suggest an explanation for this change

Answer 11

• The number of tubes greatly increases from the conducting zone to the respiratory zone.
• As there are more tubes in the respiratory zone, the total surface area is higher there. This means that diffusion can take place at a higher rate, increasing the rate of exchange.

Question 12

Describe the movement of oxygen from the alveolus to the blood

Answer 12

Oxygen diffuses across the alveolar epithelium, across the capillary endothelium before associating with haemoglobin in red blood cells

Question 13

Alveoli have folded walls
therefore..

Answer 13

The total surface area is higher, increasing the rate of diffusion

Question 14

Alveoli are small so..

Answer 14

They have a large surface area to volume ratio, increasing the rate of diffusion

Question 15

The squamous epithelial cells which make up the wall are thin
therefore..

Answer 15

The diffusion distance between the alveoli and the blood is shorter, increasing the rate of diffusion

Question 16

The capillaries surrounding the alveoli are highly branched so..

Answer 16

The capillaries have a large surface area and there is always a short distance between any capillary and an alveolus. This increases the rate of diffusion

Question 17

Blood is continually flowing through the capillaries therefore..

Answer 17

A concentration gradient is maintained between the alveoli and the blood, preventing equilibrium from being reached

Question 18

Blood flows slowly through the capillaries surrounding the alveoli so..

Answer 18

There is more time for diffusion to occur

Question 19

Ventilation ensures a fresh supply of air therefore is continually brought into the lungs therefore..

Answer 19

A concentration gradient is maintained between the alveoli and the blood, preventing equilibrium from being reached