Gas exchange - mammalian lungs adaptations

Question 1

How does air move into the lungs?

Answer 1

Air moves in through the nose and mouth before it is carried to the lungs through the trachea

This process is essential for respiration in mammals.

Question 2

What is the function of the trachea?

Answer 2

The trachea is a tube supported by rings of cartilage which help to support its shape and ensure it stays open while allowing it to move and flex with the body

The trachea is crucial for directing air to the lungs.

Question 3

What do the bronchi do?

Answer 3

The trachea divides to form the two bronchi, each leading to a lung

The bronchi are also supported by cartilage and smooth muscle.

Question 4

What is the role of ciliated epithelium in the trachea and bronchi?

Answer 4

Both trachea and bronchi are lined with ciliated epithelium to remove particles trapped in mucus that enter the airways

This helps keep the airways clear of debris.

Question 5

What are bronchioles?

Answer 5

Bronchioles branch off the two bronchi to form a network of narrow tubes

They play a key role in directing air to the alveoli.

Question 6

What regulates the flow of air into the lungs?

Answer 6

The walls of the bronchioles are lined with a layer of smooth muscle to alter the diameter of the bronchiole tubes

This allows for regulation based on airflow needs.

Question 7

What are alveoli and their function?

Answer 7

Groups of alveoli are found at the end of the bronchioles, providing a large surface area for gas exchange

They are essential for oxygen and carbon dioxide exchange.

Question 8

What surrounds each alveolus?

Answer 8

Each alveolus is surrounded by an extensive network of capillaries to provide a good blood supply for maximum gas exchange

This structure is vital for efficient respiratory function.

Question 9

How does blood flow relate to gas exchange in the lungs?

Answer 9

Deoxygenated blood enters the capillary beds from a branch of the pulmonary artery while oxygenated blood leaves the capillary beds via a branch of the pulmonary vein

This maintains the concentration gradient for gas exchange.

Question 10

What is the role of surfactant in the alveoli?

Answer 10

Cells of the alveolar wall secrete a substance called surfactant which lowers the surface tension in the alveoli

This prevents alveoli from collapsing during expiration.

Question 11

Fill in the blank: The trachea divides to form the two _______.

Answer 11

[bronchi]

Question 12

True or False: The alveoli are surrounded by a network of arteries.

Answer 12

False

Alveoli are surrounded by capillaries, not arteries.

Question 13

What is the structural adaptation of mammalian lungs for gas exchange?

Answer 13

Each mammalian lung is comprised of many, small alveoli which provide a large surface area for gas exchange

This structure is crucial for efficient respiration.