GAS EXCHANGE in HUMANS

FLASHCARDS

Which process takes place at the alveoli?

The process that takes place in the alveoli is gas exchange.

True or False?

Alveoli are surrounded by several layers of cells.

False.

Alveoli are surrounded by a single layer of cells to minimise diffusion distance.

What are the features of alveoli that make them an efficient exchange surface?

Alveoli are an efficient gas exchange surface because they have a:

large total surface area

short diffusion distance

steep concentration gradient, maintained by a good blood supply and good ventilation

How is a steep concentration gradient for both oxygen and carbon dioxide maintained in the alveoli?

A steep concentration gradient for both oxygen and carbon dioxide is maintained in the alveoli as follows:

good ventilation supplies oxygen to, and removes carbon dioxide from, the alveoli

A good blood supply means that the blood immediately next to each alveolus is always low in oxygen and high in carbon dioxide

Why is a large surface area important for gas exchange within the lungs?

A large surface area is important for gas exchange within the lungs because it allows for faster diffusion of oxygen and carbon dioxide across the alveoli walls.

What are the structures labelled A-D?

Diagram of the human respiratory system showing A: trachea, B: diaphragm, C: bronchiole, D: intercostal muscle, with labels pointing to each part.

The structures are:

A = trachea

B = diaphragm

C = bronchiole

D = intercostal muscle

Diagram of the human respiratory system showing A: trachea, B: diaphragm, C: bronchiole, D: intercostal muscle, with labels pointing to each part.

What is the function of the trachea?

The trachea, or windpipe, connects the nose and mouth to the lungs.

Describe the alveoli.

Alveoli are tiny air sacs surrounded by a network of capillaries, serving as the site of gas exchange between the air and the blood.

What is the role of the bronchi?

The bronchi (singular bronchus) branch off the trachea and carry air into the right and left lungs. They contain mucus to trap dust and pathogens.

True or False?

The diaphragm is located next to the larynx.

False.

The diaphragm is a sheet of connective tissue located beneath the lungs, while the larynx is the voice box, located at the top of the trachea.

What structures are shown in the image?

A diagram of alveoli showing associated red and blue blood vessels indicating sections of oxygenated and deoxygenated blood flow.

The structures shown in the image are:

alveoli

capillaries

the end of a bronchiole

A diagram of alveoli showing associated red and blue blood vessels indicating sections of oxygenated and deoxygenated blood flow.

What is inspired air?

Inspired air is air drawn into the body from the environment.

True or False?

Expired air is air breathed out from the body.

True.

Expired air is air breathed out from the body. Also known as exhaled air.

What is the role of limewater in an investigation into the composition of inspired and expired air?

Limewater will turn from colourless to milky/cloudy white in the presence of carbon dioxide, indicating whether CO2 is present in inspired or expired air.

What results would be expected in tube A and tube B in an investigation into inspired and expired air?

Diagram showing two test tubes labeled 'A' and 'B' with lime water, connected to a central tube where air labeled 'Breathe Out' flows in, indicating a breathing experiment.

The following results would be expected in tubes A and B: