Respiratory Structures
Mechanisms of Gas Exchange
Respiratory Processes
Evolutionary Adaptations
Respiratory Disorders and Gases
100

This tiny air sac in the lungs is where gas exchange primarily occurs.

What is the alveolus?

100

This law explains the rate of diffusion of gases across a respiratory surface.

What is Fick’s Law?

100

This type of respiration includes all oxidative reactions that produce ATP in cells.

What is cellular respiration?

100

Unlike mammals, birds have these sacs that help them maintain one-way airflow through their lungs.

What are air sacs?

100

A buildup of this gas in the blood leads to acidosis, as it combines with water to form carbonic acid.

What is carbon dioxide?

200

The respiratory tubes found in insects that bring air directly to body cells are known as this.

What are tracheae?

200

In fish gills, this mechanism maximizes gas exchange efficiency by moving water and blood in opposite directions.

What is countercurrent exchange?

200

This term describes the flow of blood or body fluids on the internal side of the respiratory surface.

What is perfusion?

200

In aquatic animals with delicate respiratory structures, these types of gills are located outside the body and exposed to water.

What are external gills?

200

This colorless, odorless gas can cause hypoxia by binding tightly to hemoglobin, blocking oxygen transport.

What is carbon monoxide?

300

In fish, these structures extend outward into water, allowing them to extract oxygen.

What are gills?

300

The rate of gas exchange increases with a larger concentration gradient and this variable, which refers to the total surface for exchange.

What is surface area?

300

The diaphragm is a muscle that contracts to help air enter the lungs, a process known as this type of breathing.

What is negative pressure breathing?

300

These respiratory structures are the primary adaptation that allowed vertebrates to live on land.

What are lungs?

300

The main muscle involved in inhalation, this structure contracts to draw air into the lungs.

What is the diaphragm?

400

These flaps covering the gills in fish help with ventilation by creating a one-way flow of water.

What are opercula?

400

The diffusion of ______ from alveoli to blood occurs because this gas’s partial pressure is higher in the alveoli than in the blood.

What is oxygen?

400

During intense exercise, this happens to the breathing rate to meet increased oxygen demand.

What is it increases?

400

Some insects have this respiratory system, composed of tubes that allow air to flow directly to tissues without lungs.

What is the tracheal system?

400

When this pH effect occurs, hemoglobin releases more oxygen in tissues with a lower pH, aiding oxygen delivery.

What is the Bohr effect?

500

The flap that prevents food from entering the trachea when swallowing is called this.

What is the epiglottis?

500

In the lungs, this form of respiration involves the intake of oxygen and release of carbon dioxide between alveoli and capillaries.

What is physiological respiration?

500

This volume of air, exchanged in a normal breath, is about 500 mL at rest.

What is tidal volume?

500

This group of marine animals, including clams, circulate water over their internal gills using beating cilia.

What are mollusks?

500

The partial pressure of this gas is around 160 mmHg at sea level and drives diffusion into the blood.

What is oxygen?