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Exam 4 Human Phys Questions and
Answers (100% Correct Answers)
Already Graded A+
type I alveolar cells Ans: flat squamous cells where gas
exchange occurs
© 2026 Assignment
type II alveolar cells Ans: secretes surfactant
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Expert
what is the pathway of air? Ans: nose, pharynx, larynx,
trachea, bronchi, bronchioles, alveoli
What is the main function of the respiratory system? Ans:
supply body tissues with O2 and dispose of CO2 generated by
cellular metabolism
external respiration Ans: O2 and CO2 exchange between lungs
and blood
internal respiration Ans: Exchange of gases between cells of
the body and the blood
what is the first step of gas exchange? Ans: O2 leaves alveolar
ducts and pushed into pulmonary capillaries/bloodstream
creating oxyhemoglobin (high to low concentration movement)
how do tissues receive gas exchange of O2? Ans: 1. dissolved
in plasma and erythrocyte cytosol
2. combines with hemoglobin in erythrocyte,
, 2
how to tissues receive gas exchange of CO2? Ans: 1. 10%
dissolves in plasma
2. react and binds with hemoglobin
3. 60-65% converted to bicarbonate and obtains hydrogen that
alters pH levels
How does CO2 gas exchange occur in the lungs? Ans:
deoxygenated blood travels through bloodstream as
© 2026 Assignment
bicarbonate into alveoli to be expelled (high to low
concentration)
Guru01 - Stuvia
what type of pressure does the lungs have during gas
Expert
exchange? Ans: high O2 low CO2
what type of pressure does the tissues have during gas
exchange? Ans: low O2 high CO2
expiration Ans: alveoli -> lungs -> external environment
what happens to the diaphragm during expiration? Ans: dome
relaxes and moves up, thoracic cavity reduces
what neurons are stimulated during expiration? Ans: nervous
motor neurons decrease AP to diaphragm and intercostals
what pressure is greater during expiration? Ans: alveolar
pressure is greater than atmospheric (Palv>Patm)
inspiration Ans: external environment -> lungs -> alveoli;
lungs and alveoli enlarge
what happens to the diaphragm during inspiration? Ans:
contracts, flattens, and moves down, thoracic cavity expands
Exam 4 Human Phys Questions and
Answers (100% Correct Answers)
Already Graded A+
type I alveolar cells Ans: flat squamous cells where gas
exchange occurs
© 2026 Assignment
type II alveolar cells Ans: secretes surfactant
Guru01 - Stuvia
Expert
what is the pathway of air? Ans: nose, pharynx, larynx,
trachea, bronchi, bronchioles, alveoli
What is the main function of the respiratory system? Ans:
supply body tissues with O2 and dispose of CO2 generated by
cellular metabolism
external respiration Ans: O2 and CO2 exchange between lungs
and blood
internal respiration Ans: Exchange of gases between cells of
the body and the blood
what is the first step of gas exchange? Ans: O2 leaves alveolar
ducts and pushed into pulmonary capillaries/bloodstream
creating oxyhemoglobin (high to low concentration movement)
how do tissues receive gas exchange of O2? Ans: 1. dissolved
in plasma and erythrocyte cytosol
2. combines with hemoglobin in erythrocyte,
, 2
how to tissues receive gas exchange of CO2? Ans: 1. 10%
dissolves in plasma
2. react and binds with hemoglobin
3. 60-65% converted to bicarbonate and obtains hydrogen that
alters pH levels
How does CO2 gas exchange occur in the lungs? Ans:
deoxygenated blood travels through bloodstream as
© 2026 Assignment
bicarbonate into alveoli to be expelled (high to low
concentration)
Guru01 - Stuvia
what type of pressure does the lungs have during gas
Expert
exchange? Ans: high O2 low CO2
what type of pressure does the tissues have during gas
exchange? Ans: low O2 high CO2
expiration Ans: alveoli -> lungs -> external environment
what happens to the diaphragm during expiration? Ans: dome
relaxes and moves up, thoracic cavity reduces
what neurons are stimulated during expiration? Ans: nervous
motor neurons decrease AP to diaphragm and intercostals
what pressure is greater during expiration? Ans: alveolar
pressure is greater than atmospheric (Palv>Patm)
inspiration Ans: external environment -> lungs -> alveoli;
lungs and alveoli enlarge
what happens to the diaphragm during inspiration? Ans:
contracts, flattens, and moves down, thoracic cavity expands
