Physiology

Question 1

Definition of Tidal volume

Answer 1

volume inspired or expired with each normal breath.

Question 2

Difference between physiologic dead space and anatomic dead space?

Answer 2

Physiologic dead space- volume of the lungs that does not participate in gas exchange. Usually equal to anatomic dead space, can be greater in some lung diseases
Anatomic dead space- volume of air within the conducting zone

Question 3

What is the equation for physiologic dead space?

Answer 3

VD = VT x (PACO2 - PECO2)/ PACO2

Question 4

What is minute ventilation rate and its formula?

Answer 4

Volume of gas inhaled/exhaled per minute
VT x breaths/min

Question 5

What is alveolar ventilation rate and its formula?

Answer 5

exchange of gas between alveoli and external environment
VA = (VT-VD) x breaths/min

Question 6

What is functional residual capacity? (FRC)

Answer 6

The volume remaining in the lungs after tidal volume is expired
ERV + RV

Question 7

What is vital capacity? (FVC)

Answer 7

Maximum volume of air expelled after maximum inhalation
VT + IRV + ERV

Question 8

What is FEV1?

Answer 8

volume of air that can be expired in the first second of a forced maximal expiration.
normally 80% of FVC