y11 human bio- SLO5

What are the main structures of the pulmonary system?

Trachea, bronchi, bronchioles, alveoli, diaphragm, ribs, intercostal muscles, and pleural membranes

What is the function of the trachea?

It carries air to and from the lungs

What is the function of the cartilage rings in the trachea?

They keep the airway open

What are bronchioles?

Small branching airways inside the lungs

What are alveoli?

Tiny air sacs where gas exchange occurs

what is ventilation?

The mechanical process of breathing air into and out of the lungs

What happens during inhalation?

• External intercostal muscles contract

• Rib cage moves up and out

• Diaphragm contracts and flattens

• Lung volume increases

• Pressure decreases

• Air moves into the lungs

What happens during exhalation?

• External intercostal muscles relax

• Rib cage moves down and in

• Diaphragm relaxes and domes upward

• Lung volume decreases

• Pressure increases

• Air moves out of the lungs

Why does air enter the lungs during inhalation?

Pressure inside the lungs becomes higher than atmospheric pressure.

Why does air leave the lungs during exhalation?

Pressure inside the lungs becomes higher than atmospheric pressure

How does increased ventilation affect oxygen delivery?

More oxygen enters the alveoli and diffuses into the blood, increasing oxygen delivery to tissues

How does reduced ventilation affect the body?

Less oxygen enters the blood and carbon dioxide removal decreases