Ventilation

Question 1

Breathing in

Answer 1

Inspiration

Question 2

Breathing out

Answer 2

Expiration

Question 3

Antagonistic pair

Answer 3

2 muscles working together one relaxes as the other contracts

Question 4

Inspiration process

Answer 4

External+diaphragm contract
Internal-relax
Diaphragm flattens ribs move out and up
Thorax volume increases
Pressure decreases
Moves down gradient
Into alveoli

Question 5

Expiration process

Answer 5

External and diaphragm relax
Internal contract
Diaphragm domes ribs move in and down
Thorax pressure decreases
Air pushed out through mouth and nose down conc gradient

Question 6

Boyles law

Answer 6

Volume of gas is inversely proportional to pressure (when temp is constant

Question 7

• When the volume of the thoracic cavity increases

Answer 7

the volume of the lungs increases and the pressure decreases (now lower than the atmosphere) – air rushes into the lungs, down the pressure gradient.

Question 8

Describe the gross structure of the human gas exchange system and how we breathe in and out.

Answer 8

• (nose/mouth), Trachea, bronchus/bronchi, bronchioles, alveoli
• Inspiration – External intercostal muscles contract, internal intercostal muscles relax – ribs move up and out diaphragm contracts
• Increases thorax volume, decreases pressure, air is drawn in down a pressure gradient
• Expiration – External intercostal muscles relax, internal intercostal muscles contract – ribs move down and in diaphragm relaxes
• Decreases thorax volume, increases pressure, air is forced out down a pressure gradient

Question 9

Alveoli and has exchange adaptations

Answer 9

Each lung contains millions of alveoli which have folded walls.
Large surface area for increased rate of diffusion
Alveolus wall is thin, made of one layer of flattened epithelium cells.
Short diffusion distance for increased rate of diffusion
Capillary wall is thin, made of one layer of flattened endothelium cells.
As above!
Ventilation brings in fresh supplies of atmospheric air
Maintains a high concentration gradient for fast diffusion
Circulation of blood continually replaces blood high in O2 with blood low in O2
As above!

Question 10

Tidal volume

Answer 10

Tidal volume (TV)
→the volume of air in each breath

Question 11

Breathing (ventilation rate)

Answer 11

BR)
→the number of breaths per minute

Question 12

Pulmonary Ventilation Rate (PVR)

Answer 12

→the volume of air exchanged by the lungs per minute, taking into account both the tidal volume and the
breathing rate: PVR = TV X BR

Question 13

Forced expiratory volume (FEV

Answer 13

→the maximum volume of air that can be breathed out in 1 second

Question 14

Forced vital capacity (FVC)

Answer 14

→the maximum volume of air that can be breathed out forcefully after a really deep breath in.