Respiration - Structure and ventilation

Question 1

Inhalation process?

Answer 1

Inhalation
The diaphragm contracts and moves down.
The internal intercostal muscles relax.
The external ones contract.
The ribcage moves upward and outwards.
The air goes into the lungs and they inflate.
Thoracic volume increases which causes pressure to decrease.

Question 2

Exhalation process?

Answer 2

Exhalation
The diaphragm relaxes and moves up.
The internal intercostal muscles contract.
The external intercostal muscles relax.
The ribcage moves downward and inwards.
The air moves out of the lungs and they deflate.

Question 3

What is diffusion?

Answer 3

Diffusion is the net movement of molecules from a place of higher concentration to a place with lower concentration down a concentration gradient as a result of random movement.

Question 4

Differences in respiration in unicellular organisms and multicellular organisms?

Answer 4

Unicellular organisms rely on diffusion alone.
Multicellular organisms require a gas exchange system where gas exchange takes place in the alveoli.

Question 5

Adaptations of alveoli?

Answer 5

Thin Walls
Shorter diffusion path
Moist Lining
More efficient transporting because gases dissolve in moisture.
A rich blood supply
To absorb and carry dissolved food molecules.
Millions of Alveoli
There is as much gas exchange as possible can happen.
Large Surface Area
More surface area for absorption

Question 6

Diffusion in the alveoli process?

Answer 6

A - Deoxygenated blood flows to the alveoli after delivering oxygen to the body. The blood is low on oxygen and high in concentration of carbon dioxide.
B - Carbon dioxide moves by diffusion from high concentration in the blood to low concentration in the alveoli
C - Air is exhaled.
D - Air is inhaled.
E - The blood is oxygenated by diffusion, from high concentration in the alveoli to low concentration in the blood.
F - Oxygenated blood leaves the alveoli.

Question 7

How is air cleaned?

Answer 7

Air is warmed and moistened by evaporation of water from the lining of the nose.
The hair inside the nose filters air and removes particles and pathogens.
Trachea, bronchi and bronchioles are lined with ciliated epithelial cells and mucus secreting cells so dust particles and pathogens get trapped in the slimy mucus.
Cilia beat to carry mucus up the nose and throat to remove unwanted particles.
There’s a watery salin layer that allows cilia to push mucus towards the pharynx.

Question 8

Effects of smoking

Answer 8

Cilia lining burns up
Bacterial lining takes place and mucus gets deposited.
The bronchi & bronchioles start getting clogged.
Poor diffusion of gases occurs and less oxygen goes in/less carbon dioxide comes out.
Anaerobic respiration takes place.
This can lead to bronchitis, asthma, etc.
Arteries get clogged which can lead to