mod 6 Respiratory System: Anatomy and Function

Question 1

• 1) Air and food are routed into the proper channels by
the
• a. trachea
• b. pharynx
• c. larynx
• d. carina
• e. uvula

Answer 1

• 1) Air and food are routed into the proper channels by
the

• c. larynx

Question 2

• 2) The walls of the alveoli are composed of two types
of cells, type I and type II.
The function of type II is
• a. to secrete pulmonary surfactant
• b. to trap dust and other debris
• c. to replace mucus in the alveoli
• d. to facilitate movement of macrophages into the
alveoli
• e. to secrete defensins and lysosymes

Answer 2

2) The walls of the alveoli are composed of two types
of cells, type I and type II.
The function of type II is
• a. to secrete pulmonary surfactant

Question 3

3) The smallest airways in the conducting zone is (are) the
•
• a. primary bronchioles
• b. terminal bronchioles
• c. respiratory bronchioles
• d. alveolar ducts
• e. alveolar sacs

Answer 3

• 3) The smallest airways in the conducting zone is (are) the
• b. terminal bronchioles

Question 4

• 4) The pleurae are vital to the integrity of the lungs
because
• a. they contain cilia that protect the lungs
• b. they control the volume of the lungs
• c. they maintain the proper temperature of the lungs
• d. they produce a lubricating serous secretion,
allowing the lungs to glide
• over the thorax wall during breathing
• e. they secrete lung surfactant

Answer 4

• 4) The pleurae are vital to the integrity of the lungs
because

• d. they produce a lubricating serous secretion,
allowing the lungs to glide over the thorax wall during
breathing

Question 5

5) The relationship between the pressure and volume of gases is
given by
• a. Dalton's law
• b. Henry's law
• c. Charles' law
• d. Boyle's law
• e. Poiseuille’s law

Answer 5

• 5) The relationship between the pressure and volume of gases is
given by

• d. Boyle’s law P1V1 = P2V2

Question 6

6) The statement, "in a mixture of gases, the total
pressure is the sum of the individual partial pressures
of gases in the mixture" paraphrases
• a. Henry's law
• b. Boyle's law
• c. Dalton's law
• d. Charles' law
• e. Poiseuille’s law

Answer 6

6) The statement, “in a mixture of gases, the total
pressure is the sum of the individual partial pressures
of gases in the mixture” paraphrases

• c. Dalton’s law

Question 7

• 7) Surfactant helps to prevent the alveoli from
collapsing by
• a. humidifying the air before it enters
• b. warming the air before it enters
• c. Increasing the stabilising force of surface tension at
the air liquid interface
• d. interfering with the cohesiveness of water
molecules, thereby reducing the surface tension of
alveolar fluid
• e. protecting the surface of alveoli from dehydration
and other environmental variations

Answer 7

• 7) Surfactant helps to prevent the alveoli from
collapsing by

• d. interfering with the cohesiveness of water
molecules, thereby reducing the surface tension of
alveolar fluid

Question 8

• 8) For gas exchange to be efficient, the respiratory
membrane must be
• a. less than 0.1 micrometer thick
• b. 0.5 to 1 micrometer thick
• c. at least 3 micrometers thick
• d. between 5 and 6 micrometers thick
• e. the thickness of the respiratory membrane is not
important in the efficiency of gas exchange

Answer 8

8) For gas exchange to be efficient, the respiratory
membrane must be

• b. 0.5 to 1 micrometer thick

Question 9

• 9) Oxygen and carbon dioxide are exchanged in the lungs and through
all cell membranes by
• a. osmosis
• b. diffusion
• c. filtration
• d. active transport
• e. reabsorption

Answer 9

• 9) Oxygen and carbon dioxide are exchanged in the lungs and through
all cell membranes by

• b. diffusion

Question 10

23) Select the correct statement about the pharynx
• a. the adenoids are located in the laryngopharynx
• b. the auditory tube drains into the nasopharynx
• c. the laryngopharynx blends posteriorly into the
nasopharynx
• d. the palatine tonsils are embedded in the lateral
walls of the nasopharynx
• e. the oropharynx is lined with pseudostratified
columnar ciliated cells

Answer 10

10) Select the correct statement about the pharynx

• b. the auditory tube drains into the nasopharynx

Question 11

11) The larynx contains
• a. the thyroid cartilage
• b. C-shaped rings of cartilage
• c. a cricoid cartilage also called the Adam’s apple
• d. an upper pair of avascular mucosal folds called true vocal folds
• e. lateral cartilage ridges called false vocal folds

Answer 11

• 11) The larynx contains

* a. the thyroid cartilage

Question 12

12) Which respiratory-associated muscles would contract if you were
to blow up a balloon?
• a. diaphragm and external intercostals
• b. diaphragm and internal intercostals
• c. diaphragm and abdominal muscles
• d. internal intercostals and abdominal muscles
• e. external intercostals and abdominal muscles

Answer 12

12) Which respiratory-associated muscles would contract if you were
to blow up a balloon?

• d. internal intercostals and abdominal muscles

Question 13

• 13) Which of the following is not found on the right lobe of the lung?
• a. middle lobe
• b. cardiac notch
• c. horizontal fissure
• d. oblique fissure
• e. segmental bronchi

Answer 13

• 13) Which of the following is not found on the right lobe of the lung?
• b. cardiac notch

Question 14

• 14) Which of the following provide the greatest surface area for gas
exchange?
• a. respiratory bronchioles
• b. alveolar ducts
• c. alveolar sacs
• d. alveoli
• e. alveolar pores

Answer 14

14) Which of the following provide the greatest surface area for gas
exchange?

• d. alveoli

Question 15

15) The respiratory membrane is a combination of
• a. alveoli and alveolar sacs
• b. alveoli, alveolar sacs and alveolar ducts
• c. alveoli, alveolar sacs, alveolar ducts and respiratory
bronchioles
• d. the area of the alveoli covered by type I cells
• e. alveolar and capillary walls and their fused
basement membranes

Answer 15

• 15) The respiratory membrane is a combination of

• e. alveolar and capillary walls and their fused
basement membranes

Question 16

• 16) The nose serves all the following functions except
• a. as a passageway for air movement
• b. speech production
• c. as the initiator of the cough reflex
• d. warming and humidifying the air
• e. cleansing the air

Answer 16

16) The nose serves all the following functions except

• c. as the initiator of the cough reflex

Question 17

• 17) The factors responsible for holding the lungs to
the thorax wall are
• a. the smooth muscles of the lung
• b. the diaphragm and the intercostal muscles alone
• c. the visceral pleurae and the changing volume of the
lungs
• d. adhesion forces acting between visceral and
parietal pleurae
• e. the opposing lung and chest wall recoil forces

Answer 17

17) The factors responsible for holding the lungs to
the thorax wall are

• d. adhesion forces acting between visceral and
parietal pleurae

Question 18

18) Most inspired particles such as dust fail to reach the lungs
because of the
• a. ciliated mucous lining in the nose
• b. abundant blood supply to nasal mucosa
• c. porous structure of turbinate bones
• d. action of the epiglottis
• e. powerful cough reflex

Answer 18

• 18) Most inspired particles such as dust fail to reach the lungs
because of the
• a. ciliated mucous lining in the nose

Question 19

19) Which of the following is not the case?
• a. gas flow equals pressure gradient divided by
resistance
• b. pressure gradient equals gas flow divided by
resistance
• c. resistance equals pressure gradient divided by gas
flow
• d. intrapleural pressure is always negative during quiet
breathing
• e. the amount of gas flowing in and out of the alveoli is
directly proportional to the pressure gradient between
the external atmosphere and the alveoli

Answer 19

• 19) Which of the following is not the case?

• b. pressure gradient equals gas flow divided by
resistance

• The flow of gases through tubes can be described in the same way as
blood flow though blood vessels
• F = Δ P/R or R = Δ P/F
• F= flow, ΔP = pressure gradient, R = resistance

Question 20

• 20) Additional muscle action is required for breathing when
• a. lung compliance increases
• b. chest wall compliance increases
• c. airway resistance decreases
• d. alveolar surface tension increases
• e. amount of surfactant in the lungs increases

Answer 20

• d. alveola• The ability of the lungs to expand is expressed using a
measure known as the lung compliance
• Lung compliance is the volume change that can be
achieved in the lungs per unit pressure change
• C = Δ V / Δ P
• The increase in lung volume during inspiration results from
an “inflating pressure” (the transpulmonary pressure)
Note: error in lecture slides (replace “intrapulmonary :
with “transpulmonary”
• For a given change in transpulmonary pressure (ΔP) the
resultant change in volume (ΔV) depends on the
“stretchiness” of the lungs and chest wall
• Compliance depends on the distensibility of the lung tissue
and alveolar surface tensionr surface tension increases

Question 21

21) Low lung compliance tends to make inflation ___, and low airway
resistance tends to make rapid breathing ___
• a. easy and easy
• b. easy and difficult
• c. difficult and easy
• d. difficult and difficult
• e. none of the above

Answer 21

c. difficult and easy

Question 22

22) The flow of air into the alveoli is
• a. trachea - bronchioles - bronchi - alveoli
• b. trachea - bronchi - bronchioles - alveoli
• c. bronchi - trachea - bronchioles - alveoli
• d. bronchioles - trachea - bronchi - alveoli
• e. bronchi - bronchioles - trachea - alveoli

Answer 22

• b. trachea - bronchi - bronchioles - alveoli

Question 23

23) The trachea, bronchi, and bronchioles do all of the following
EXCEPT
• a. warm the air.
• b. filter the air to remove impurities.
• c. distribute air to exchange surfaces.
• d. remove O2
from the air.
• e. humidify the air.

Answer 23

d. remove O2

from the air.

Question 24

24) To overcome the problem of surface tension in
the alveoli, specialised alveolar cells secrete fluid
containing
• a. carbohydrate
• b. lipid
• c. acid
• d. base
• e. salt

Answer 24

b. lipid

Question 25

• 25) Pulmonary surfactants do all of the following
EXCEPT
• a. prevent IRDS
• b. reduce surface tension
• c .increase lung compliance
• d. prevent alveolar collapse
• e. decrease airway resistance

Answer 25

• e. decrease airway resistance

Question 26

• 26) An arteriole is like a bronchiole in that both
• a. allow gas exchange
• b. allow flow in both directions
• c. are lined with cilia
• d. contain a layer of smooth muscle
• e. increase flow rate when constricted

Answer 26

• d. contain a layer of smooth muscle

Question 27

• 27) According to gas laws, if the pressure in a closed
container doubles, and the temperature stays the
same, then the volume must
• a. double
• b. be cut in half
• c. be cut by three-fourths
• d. quadruple
• e. be cut by one fourth

Answer 27

• b. be cut in half

Question 28

• 28) Suppose a sealed, rigid container held normal air
(21% O2
, 78% N2
, 1% argon) at 760 mmHg pressure.
If then more N2 were pumped into the container to
raise the total pressure to 800 mmHg, the PO2 would
then
• a. increase to 160 mmHg
• b. increase to 168 mmHg
• c. decrease to 160 mmHg
• d. decrease to 168 mmHg
• e. remain the same

Answer 28

e. remain the same
Dalton’s Law of partial pressures
• In a mixture of gases, each gas contributes to the total pressure: the
pressure it would exert if the gas were present in the container by
itself.
• If all the other gases were removed from atmospheric air, oxygen
would still exert the same pressure (160 mm Hg)
• To obtain a total pressure, add all of the partial pressures:
• P total = P1 +P2 +P3 +…PN

Question 29

• 29) Closing the upper airway passage at the end of a
lung inflation and contracting abdominal and internal
intercostal muscles rapidly produces a marked increase
in alveolar pressure. Sudden opening of the airway
causes a rapid return of alveolar pressure to normal as
air is expelled very quickly. This describes a
• a. sniffle
• b. cough
• c. gasp
• d. yawn
• e. whistle

Answer 29

• b. cough

Question 30

• 30) Which of the following gases exerts the greatest partial pressure
in venous blood
• a. oxygen
• b. carbon dioxide
• c. water vapour
• d. nitrogen
• e. argon

Answer 30

• d. nitrogen

Question 31

31) The greatest partial pressure gradient across
the alveolar-capillary membrane is found for
• a. H2O
• b. CO2
• c. N2
• d. O2
• e. NO

Answer 31

• d. O2

Question 32

32) Which one of the following conditions
does NOT occur on a large inspiration?
• a. inspiratory muscles contract
• b. size of the thoracic cavity increases
• c. intrapleural pressure becomes more positive
• d. transpulmonary pressure increases
• e. lung becomes more inflated

Answer 32

• c. intrapleural pressure becomes more positive

Question 33

33) During expiration, which of the following
does NOT occur?
• a. respiratory muscles relax
• b. intrapleural pressure becomes less negative
• c. transpulmonary pressure decreases
• d. lung deflates
• e. alveolar pressure decreases below
atmospheric pressure

Answer 33

• e. alveolar pressure decreases below

atmospheric pressure

Question 34

34) The pressure that keeps the lungs inflated is
• a. atmospheric
• b. alveolar
• c. transpulmonary
• d. intratracheal
• e. partial

Answer 34

• c. transpulmonary
Transpulmonary pressure
• Keeps the lungs inflated
• Prevents lungs from collapsing
• Also called the “distension pressure”
• Transpulmonary pressure describes the
difference between the alveolar pressure and
the pleural pressure in the lungs and is
measured by subtracting pleural pressure
from alveolar pressure

Question 35

35) Intrapulmonary pressure is the
• a. pressure within the alveoli of the lungs
• b. pressure within the pleural cavity
• c. negative pressure in the intrapleural space
• d. difference between atmospheric pressure
and respiratory pressure
• e. pressure within the thoracic cavity

Answer 35

• a. pressure within the alveoli of the lungs

Question 36

36) What kind of cell innervates the diaphragm?
• a. parasympathetic neurone
• b. interneurone
• c. preganglionic sympathetic neurone
• d. postganglionic sympathetic neurone
• e. alpha motor neurone

Answer 36

• e. alpha motor neurone

Question 37

37) Tidal volume is air
• a. remaining in the lungs after forced
expiration
• b. exchanged during normal breathing
• c. forcibly inhaled after normal inspiration
• d. forcibly expelled after normal expiration
• e. the volume of the conducting airways that
has to be cleared during an inspiration before
air reaches the alveoli

Answer 37

• b. exchanged during normal breathing

Question 38

38) The vital capacity of an average young male is
around
• a. 1200 ml
• b. 2400 ml
• c. 3600 ml
• d. 4800 ml
• e. 6000 ml

Answer 38

d. 4800 ml

Question 39

39) The lung volume that represents the
maximum volume that can be inspired or
expired is
• a. tidal volume
• b. total lung capacity
• c. vital capacity
• d. inspiratory capacity
• e. functional residual capacity

Answer 39

c. vital capacity

Question 40

40) The maximal amount of air that can be
inspired after a normal (not forced)
inspiration is called
• a. inspiratory reserve volume
• b. inspiratory capacity
• c. functional residual capacity
• d. vital capacity
• e. total lung capacity

Answer 40

• a. inspiratory reserve volume

Question 41

41) Inspiratory capacity is
• a. the total amount of air that can be inspired
after a tidal expiration
• b. the total amount of air that can be inspired
after a tidal inspiration
• c. the total amount of air that can be inspired
after a maximal expiration inspiration
• d. vital capacity minus functional residual
capacity
• e. total lung capacity minus residual volume

Answer 41

a. the total amount of air that can be inspired

after a tidal expiration

Question 42

42) All of the following can be determined
from a spirogram EXCEPT
• a. expiratory reserve volume
• b. inspiratory reserve volume
• c. vital capacity
• d. functional residual capacity
• e. inspiratory capacity

Answer 42

d. functional residual capacity

Question 43

43) Respiratory groups of neurones that
control breathing are located in the
• a. midbrain and pons
• b. midbrain and medulla
• c. midbrain and upper spinal cord
• d. medulla and pons
• e. medulla and upper spinal cord

Answer 43

• d. medulla and pons

Question 44

44) The most powerful respiratory stimulus for
breathing in a healthy person is
• a. increase in temperature of arterial blood
• b. decrease in oxygen partial pressure in arterial
blood
• c. decrease in pH (acidosis) in arterial blood
• d. increase in pH (alkalosis) in arterial blood
• e. increase of carbon dioxide partial pressure in
arterial blood

Answer 44

e. increase of carbon dioxide partial pressure in

arterial blood

Question 45

• 45) Another name for the inflation reflex is
• a. Bohr-Haldane
• b. Poiseuille-Laplace
• c. Fick-Dalton
• d. Hering-Breuer
• e. Charles-Henry

Answer 45

d. Hering-Breuer

Question 46

46) Which of the following is not a stimulus
for breathing?
• a. rising carbon dioxide levels
• b. rising blood pressure
• c. arterial PO2 below 60 mm Hg
• d. decreased arterial pH
• e. increased body temperature

Answer 46

b. rising blood pressure

Question 47

47) Which of the following cells concerned with
respiration are not located in the brainstem?
• a. dorsal respiratory group
• b. ventral respiratory group
• c. pontine respiratory group
• d. carotid bodies
• e. central chemoreceptors

Answer 47

• d. carotid bodies

Question 48

• 48) Which of the following statements is correct?
• a. H+ acts directly on central chemoreceptors to
increase ventilation
• b. low arterial pH is the most powerful stimulator
of respiration.
• c. arterial blood pH affects central
chemoreceptors directly
• d. arterial blood pH does not affect peripheral
chemoreceptors directly
• e. H+ has little effect on the blood pH

Answer 48

a. H+ acts directly on central chemoreceptors to

increase ventilation

Question 49

49) Which of the conditions is the most
powerful stimulant to alveolar ventilation?
• a. increased PO2
• b. decreased PO2
• c. increased H+ concentration
• d. decreased arterial pH
• e. increased PCO2

Answer 49

• e. increased PCO2

Question 50

50) Under which condition is alveolar
ventilation stimulated via peripheral
chemoreceptors?
• a. PO2 below 60 mmHg
• b. PO2
above 60 mmHg
• c. PCO2 below 20 mmHg
• d. PCO2 between 20 and 40 mmHg
• e. pH Above 7.5

Answer 50

• a. PO2 below 60 mmHg

Question 51

51) In the plasma of arterial blood of a healthy
person, the quantity of oxygen dissolved in
solution
• a. less than 2 % of the oxygen combined with
haemoglobin
• b. about 7% of the oxygen combined with
haemoglobin
• c. approximately equal to the amount combined
with haemoglobin
• d. much greater than the amount combined with
haemoglobin
• e. zero because oxygen is insoluble in aqueous
solution like plasma

Answer 51

a. less than 2 % of the oxygen combined with

haemoglobin

Question 52

• 52) Which statement about CO2
is incorrect?
• a. its concentration in the blood is decreased by
hyperventilation
• b. its accumulation in the blood is associated with
a decrease in pH
• c. CO2
concentrations are greater in venous blood
than arterial blood
• d. raised CO2
levels in arterial blood stimulates
central chemoreceptors
• e. more CO2 dissolves in the blood plasma than is
carried in the red blood cells

Answer 52

e. more CO2 dissolves in the blood plasma than is

carried in the red blood cells

Question 53

53) Which of the following correctly describes
mechanisms of CO2
transport?
• a. 20% of CO2
is dissolved directly into the plasma.
• b. 7-8% of CO2
is carried in the form of
carbaminohaemoglobin.
• c. the majority of CO2
transported in the blood is in
the form of carbonic acid
• d. carbonic anhydrase is responsible for bonding
CO2
to haemoglobin.
• e. the chloride shift mechanism enhances CO2
transport

Answer 53

e. the chloride shift mechanism enhances CO2

transport

Question 54

54) Select the correct statement about oxygen transport in
blood:
• a. at rest, a molecule of haemoglobin returning to the
lungs typically contains one molecule of O2
• b. during conditions of acidosis, haemoglobin will release
less of its O2
to the tissues
• c. oxyhaemoglobin saturation levels of greater than 95%
are only achieved during exercise when ventilation is
increased
• d. a 50% oxyhaemoglobin saturation level of blood
returning to the lungs might indicate a physical activity
level higher than normal
• e. binding of an O2 molecule to a haemoglobin molecule
makes subsequent binding of O2 molecules more difficult

Answer 54

d. a 50% oxyhaemoglobin saturation level of blood
returning to the lungs might indicate a physical activity
level higher than normal

Question 55

• 55) Carbonic anhydrase is a(n)
• a. carrier of carbon dioxide in the blood
• b. storage site for carbon dioxide
• c. enzyme that accelerates the combination of
carbon dioxide and water
• d. enzyme that splits the bicarbonate ion
• e. enzyme that splits carbonic acid into hydrogen
and bicarbonate ions

Answer 55

c. enzyme that accelerates the combination of

carbon dioxide and water

Question 56

56) During the chloride shift in tissue capillary
blood, \_\_\_the red blood cell
• a. HCO3
- exits
• b. H2CO3 enters
• c. CO2 exits
• d. Cl- exits
• e. carbonic anhydrase enters

Answer 56

• a. HCO3

- exits

Question 57

57) With the Bohr effect, more oxygen is released
from haemoglobin at the tissues because
• a. a decrease in pH (acidosis) weakens the
haemoglobin-oxygen bond
• b. a decrease in pH (acidosis) strengthens the
haemoglobin-oxygen bond
• c. an increase in pH (alkalosis) strengthens the
haemoglobin-oxygen bond
• d. an increase in pH (alkalosis) weakens the
haemoglobin-oxygen bond
• e. none of the above since the Bohr effect concerns
the effect of oxygen
• unloading on carbon dioxide loading in the blood

Answer 57

a. a decrease in pH (acidosis) weakens the

haemoglobin-oxygen bond