T7 Lungs and breathing

Question 1

What is tidal volume

Answer 1

Volume of air inhaled at rest

Question 2

What is vital capacity

Answer 2

Maximum volume of air that can be breathed in and out

Question 3

What is minute ventilation

Answer 3

Volume of air inhaled in one minute

Question 4

What is the ventilation centre

Answer 4

Located in the medulla oblongata, responsible for controlling breathing rate

Question 5

Explain what happens to the lungs in inhalation

Answer 5

External intercostal muscles and diaphragm contract
This increases the volume in the lungs
So pressure decreases
This forces air into the lungs

Question 6

Explain what happens during exhalation

Answer 6

The lungs inflate so bronchiole strech receptors are stimulated
This sends an impulse to the ventilation centre so the muscles relax

Elastic recoil of the lungs causes exhalation

Question 7

When do the internal intercostal muscles contract

Answer 7

During deep exhalation

Question 8

Label the parts of a spirometer trace

Question 9

What is residual volume

Answer 9

Amount of air left in lungs after fully exhaling

Question 10

Explain the process to notify the ventilation centre of information to determine breathignrate

Answer 10

Co2 is breathed in and converts to carbonic acid in blood plasma
CO2 + H2O > H2CO3 #
acid dissociates releasing H+
H2CO3> H+ + HCO3-
pH decrease is detected by chemoreceptors
sends an impulse to ventilation centre in the medulla

Question 11

Explain what happens once the ventilation has received information about blood pH

Answer 11

Sends an excitatory impulse to muscles and diaphragm causing them to contract

Lung capacity increases drawing air into the lungs

Question 12

Explain what happens when the inhale is finished

Answer 12

Stretch receptors in the lungs send an inhibitory impulse to the ventilation centre and elastic recoil of the lungs pushes air out