Deck 9: The Respiratory System

Question 1

During a vaginal delivery, what facilitates the removal of fetal lung fluid from the pulmonary system?

A) High PaO₂
B) Low intrapulmonary pressures
C) Thoracic compression
D) Triaging of core functions

Answer 1

C
Explanation: During normal vaginal delivery, approximately one-third of the lung fluid is cleared by compression of the thorax in the birth canal.

Question 2

What is the length of the trachea in a small preterm infant?

A) 2 cm
B) 4 cm
C) 6 cm
D) 8 cm

Answer 2

A
Explanation: In small preterm infants, the trachea may be only 2 cm long and 2 to 3 mm wide.

Question 3

The fetus is potentially viable if born at the end of which stage of development?

A) Alveolar
B) Canalicular
C) Pseudoglandular
D) Saccular

Answer 3

B
Explanation: At the end of the canalicular period (24 to 26 weeks of gestation), the fetus, if born, is capable of sufficient gas exchange and is viable if supported completely with an artificial airway, O₂, ventilatory support, and surfactant administration.

Question 4

Which factors contribute to maintaining a patent ductus arteriosus during fetal life?
1) Large amounts of fetal hemoglobin
2) Low PaO₂
3) Presence of LDH
4) Presence of prostaglandins

A)1, 2, and 3
B)2 and 4
C)3 only
D)1, 2, 3, and 4

Question 5

What maintains lung inflation during fetal development?

A) Fetal lung fluid
B) Radial tethering
C) Rigidity of the chest wall
D) Surfactant

Question 6

Developmental morphogenesis of the human respiratory system can be categorized into:

A) three periods.
B) five stages.
C) 6 weeks.
D) 40 weeks.

Question 7

What strong stimulus to the infant provides the impetus for the first breath?

A) Acidosis
B) Exposure to warmth
C) Fright from passing through the birth canal
D) High PaO₂

Question 8

By what mechanism does gas exchange across the lung occur?

A) Active transport
B) Facilitated diffusion
C) Facilitated transport
D) Simple diffusion

Question 9

In the fetal heart, the foramen ovale allows blood to flow between which two structures?

A) Bypass the liver and enter the inferior vena cava.
B) Pulmonary artery to aortic arch.
C) Right atrium to left atrium.
D) Right atrium to left ventricle.

Question 10

What would be a normal P₅₀ for a fetus?

A) 10
B) 15
C) 20
D) 25

Question 11

What is meant by "internal respiration"?

A) Any gas exchange that occurs inside the body
B) Consumption of O₂ in the mitochondria
C) Continuous absorption of O₂ and excretion of carbon dioxide
D) Exchange of gases between the blood and the tissue

Question 12

Which of the following would NOT promote transition from fetal circulation to a normal extrauterine circulatory pattern?

A) Closure of the foramen ovale
B) Constriction of the ductus arteriosus
C) Decreased pulmonary vascular resistance
D) Decreased systemic vascular resistance

Question 13

The fetus is potentially viable if born prematurely after how many weeks of gestation?

A) 12 to 16 weeks
B) 18 to 20 weeks
C) 24 to 26 weeks
D) 28 to 32 weeks

Question 14

Which factor contributes to increased likelihood of an upper airway obstruction in an infant compared to an adult?

A) Higher percentage of body fat
B) Higher volumes of sinus discharge
C) Relatively smaller head size
D) Tongue that is proportionally larger

Question 15

During which phase of fetal development do mature alveoli appear?

A) Alveolar
B) Canalicular
C) Pseudoglandular
D) Saccular

Question 16

What percentage of right ventricular output is circulated through the fetal lungs?

A) 10%
B) 35%
C) 75%
D) 100%

Question 17

Which of the following is an index commonly used to determine relative lung maturity?

A) FRC/TLC ratio
B) L:S ratio
C) RQ ratio
D) SP-A

Question 18

By which of the following routes does blood flow through the umbilical cord between the placenta and the fetus?

A) One umbilical vein and one umbilical artery
B) One umbilical vein and two umbilical arteries
C) Two umbilical veins and one umbilical artery
D) Two umbilical veins and two umbilical arteries

Question 19

What is the primary purpose of the respiratory system?

A) Continuous absorption of oxygen (O₂) and excretion of carbon dioxide
B) Filtering to prevent allergens and microbes from reaching the lungs
C) Transport oxygenated blood to the tissues
D) Warm and humidify inspired gas

Question 20

Abnormalities of the placenta that can cause intrauterine growth retardation or fetal asphyxia include which of the following?
1) Abnormal implantation of the placenta
2) Separation of the placenta from the uterine wall
3) Decreased placental blood flow

A)2 and 3 only
B)1 and 2 only
C)1 and 3 only
D)1, 2, and 3

Question 21

Running vertically down each hemithorax anteriorly is an imaginary line that is used as an anatomical landmark. What is that line called?

A) Anterior axillary line
B) Midaxillary line
C) Midclavicular line
D) Midsternal line

Question 22

Which of rib pairs connect directly to the sternum?

A) 1 through 4
B) 1 through 7
C) 1 through 12
D) 11 through 12

Question 23

What external landmark can be used to show the highest point the dome of the right hemidiaphragm reaches in a healthy individual?

A) Fifth rib posteriorly
B) Sixth rib posteriorly
C) Seventh rib posteriorly
D) Eighth rib posteriorly

Question 24

What pulmonary disorder could lead to acute flattening of the diaphragm?

A) Adult respiratory distress syndrome
B) Asthma
C) Atelectasis
D) Pneumonia

Question 25

What is the physiologic result of the infants' more compliant thorax compared with that of an adult?

A) It is easier for infants to breathe.
B) Their functional residual capacity is reduced based on predicted body weight (PBW).
C) They breathe larger tidal volumes based on IBW.
D) They have less of a tendency to develop atelectasis.

Question 26

What is unique regarding the blood supply to the lung?

A) It receives blood from right and left ventricles.
B) It requires no dedicated blood supply as it exists in a gas environment.
C) Pulmonary venous drainage contributes to the normal anatomic shunt.
D) The pulmonary arteries are the primary source of O₂ for lung structures.

Question 27

The intercostal arteries, veins, and nerves run through which of the following?

A) Costal groove on the top of each rib
B) Costal groove on the bottom of each rib
C) Fibers of the intercostal musculature
D) Surface of the parietal pleura

Question 28

Compared to a normal diaphragm, contraction of a diaphragm that is low and flat may result in which of the following?

A) Compression of the thoracic cavity
B) Enhanced venous return and thus cardiac output
C) Greater diaphragmatic efficiency
D) Larger than normal change in thoracic volume

Question 29

What is the name of the external landmark that identifies the point at which the trachea branches into the right and left main stem bronchi?

A) Sternal angle
B) Cricoid cartilage
C) Suprasternal notch
D) Xiphoid process

Question 30

Infants can generate auto-PEEP by which of the following methods?

A) Active expiration
B) Increased diaphragmatic excursion
C) Laryngeal braking
D) Retractions

Question 31

Approximately how many alveoli are there in a 10-year-old's lung?

A) 50 million
B) 200 million
C) 350 million
D) 480 million

Question 32

Which of the following muscles are considered primary muscles of ventilation?
1) Diaphragm
2) Intercostals
3) Scalenes
4) Sternomastoid

A)1, 3, and 4
B)1 and 2
C)3 only
D)1, 2, 3, and 4

Question 33

What is the name of the thin serous membrane that covers the inner layer of the thoracic wall?

A) Cupula
B) Mesothelioma
C) Parietal pleura
D) Visceral pleura

Question 34

Where does the sternal angle lie?

A) At the depression in the body of the sternum to which the clavicles attach
B) At the join between the manubrium and sternal body
C) At the superior edge of the sternum
D) Where the xiphoid process connects to the sternum

Question 35

What is the function of the thorax?

A) Facilitate digestion.
B) Heat, humidify, and filter gases.
C) Protect the vital organs.
D) Vocalization.

Question 36

What is the name of the upper portion of the sternum?

A) Angle of Louis
B) Manubrium
C) Vertebral process
D) Xiphoid process

Question 37

What does the "pump handle" movement of rib pairs 2 through 7 achieve?

A) Anchor of the upper chest for diaphragmatic contraction
B) Diminish of the energy wasted by inefficient muscular contraction
C) Increase in the anteroposterior diameter of the chest
D) Increase in the lateral dimensions of the chest

Question 38

What are rib pairs 11 and 12 known as?

A) False ribs
B) Faux ribs
C) Floating ribs
D) True ribs

Question 39

Approximately what percent of the normal changes in thoracic volume during quiet inspiration is due to the action of the diaphragm?

A) 15
B) 25
C) 50
D) 75

Question 40

How far is the diaphragm pulled down during tidal breathing?

A) 1 to 2 cm
B) 3 to 5 cm
C) 6 to 8 cm
D) 8 to 10 cm

Question 41

Why is the left lung narrower than the right lung?

A) Liver compresses the left lung.
B) Mediastinal organs push laterally into the left hemithorax.
C) There is poorer blood flow during fetal development.
D) There is upward pressure of the abdominal contents.

Question 42

When a COPD patient leans forward braced in a tripod position, this lends particular advantage to which accessory muscles of inspiration?

A) External intercostals
B) Pectoralis
C) Scalenes
D) Sternocleidomastoids

Question 43

What will most commonly blunt the costophrenic angle as seen on chest radiograph in an upright individual?

A) Air
B) Bile
C) Excess fluids
D) Liver on the right, intestines on the left

Question 44

What is the name given to the acute angle formed by the costal pleura joining the diaphragmatic pleura?

A) Angle of Louis
B) Costophrenic angle
C) Diaphragmatic groove
D) Oblique fissure

Question 45

The abdominal muscles can actually contribute to inspiration by:

A) contracting at end-exhalation.
B) contracting at end-inhalation.
C) causing a cough.
D) increasing end-inspiratory lung volume.

Question 46

Limited, short-term spontaneous ventilation is possible in a patient with a paralyzed diaphragm because of_____________________.

A) reflex diaphragm activity
B) accessory muscle use
C) active exhalation
D) high intraabdominal pressures

Question 47

To what structures do the parietal pleural membranes adhere?

A) Fissures
B) Intrapulmonary bronchi
C) Lung
D) Mediastinum

Question 48

Which accessory muscles are active during resting and active inspiration and pull up on all the ribs expanding the thorax?

A) External intercostals
B) Internal intercostals
C) Scalenes
D) Sternocleidomastoids

Question 49

Which of the following statements describes a normal adult lung?

A) The left lung is bisected by two fissures.
B) The left lung has an upper, a middle, and a lower lobe.
C) The right lung has only an upper and a lower lobe.
D) The right lung has three lobes and two fissures.

Question 50

Which of the following nerves innervates the diaphragm?

A) Glossopharyngeal
B) Phrenic
C) Seventh cranial
D) Vagus

Question 51

Approximately how far do the normal adult lungs extend above the clavicles?

A) 2 cm
B) 3 cm
C) 4 cm
D) 5 cm

Question 52

The nerves that innervate the diaphragm arise from which area?

A) Lumbar region of the spine
B) Sacral vertebrae 4 and 5
C) Spinal plexuses at T2 to T11
D) Spinal nerves C3 to C5

Question 53

What is the lowest level on the spinal cord that an injury could cause diaphragmatic impairment or paralysis?

A) C3
B) L2
C) S5
D) T4

Question 54

Which accessory muscles of ventilation work to pull the ribs closer together?

A) External intercostals
B) Internal intercostals
C) Scalenes
D) Sternocleidomastoids

Question 55

As ventilatory muscles, the sternocleidomastoids do which of the following?

A) They elevate the upper chest, increasing chest anteroposterior diameter.
B) They elevate the ribs and decrease chest anteroposterior diameter.
C) They increase lateral chest movement during inspiration.
D) They lower the sternum, thus increasing chest anteroposterior diameter.

Question 56

What is the mediastinum?

A) Membranous sac surrounding the heart and great vessels
B) Middle layer of muscle fibers constituting the heart
C) Point of division of the trachea into the bronchi
D) Structure separating the right and left thoracic cavities

Question 57

What is the function of the very small amount of pleural fluid that is found in the pleural space?

A) Composes part of anatomic shunt.
B) Liquid barrier for pathogens.
C) Part of pulmonary blood flow.
D) Reduces friction.

Question 58

Which of the following is the most important ventilatory function of the scalene muscles?

A) Activate if intrathoracic pressure falls to -40 cm H₂O.
B) Elevate and fix the first seven ribs.
C) Lift upper chest particularly during times of high ventilatory demand.
D) Support the trachea within the thorax during heavy exercise.

Question 59

Which of the muscles below when stimulated will contract and push up on the diaphragm?
1) External intercostals
2) External obliques
3) Internal obliques
4) Rectus abdominous

A)1, 2, and 3 only
B)1 and 4 only
C)2, 3, and 4 only
D)1, 2, 3, and 4

Question 60

What will happen when the lung is surgically removed from the thorax?

A) The lung will appear to undergo no change.
B) The lung will collapse.
C) The lung will expand.
D) The response of the lung will depend on its age and pathology.

Question 61

How does the lung parenchyma receive most of its O₂?

A) From the alveolar gases
B) From the bronchial arteries/capillaries
C) From the pulmonary arteries/capillaries
D) From the pulmonary lymphatic system

Question 62

Via what pathway does much of the bronchial venous drainage occur?

A) Bronchial veins emptying into the inferior vena cava
B) Bronchopulmonary veins emptying into pulmonary veins
C) Direct connections between bronchial and pulmonary arteries
D) Thebesian venous drainage into the heart chambers

Question 63

Which of the following statements is/are true of the pulmonary lymphatic system?
1) It consists of both superficial and deep vessels.
2) It drains into the right lymphatic or thoracic duct.
3) Vessels begin as dead-end lymphatic channels in the lung.
4) With phagocytes, it defends against foreign material.

A)1, 3, and 4 only
B)2, 3, and 4 only
C)2 only
D)1, 2, 3, and 4

Question 64

Compared with the systemic circulation under normal conditions, pressure in the pulmonary circulation is:

A) higher.
B) lower.
C) the same.
D) not connected.

Question 65

The pulmonary venous circulation does which of the following?
1) Delivers oxygenated blood back to the heart.
2) Delivers deoxygenated blood to the lungs.
3) Empties into the left atrium.
4) Empties into the right atrium.

A)2 and 3 only
B)1 and 4 only
C)2 and 4 only
D)1 and 3 only

Question 66

What is the name of the reflex associated with the sensory stimulation of the pulmonary stretch receptors that stimulates a deeper breath upon inspiration?

A) Carotid sinus
B) Head's paradoxical
C) Hering-Breuer
D) Vagovagal

Question 67

What does the detection of lymphatic channels on standard chest radiographs indicate?

A) Abnormally low pressures in the lymphatic channels
B) Anastomoses with the pulmonary circulation
C) Normal fibrotic changes that occur with aging
D) System that is overwhelmed by excessive fluid

Question 68

How would lung perfusion in a "zone 1" area best be described?

A) Increased
B) Normal or average
C) Reduced
D) Unaffected

Question 69

Which of the following statements is false regarding the pulmonary circulation?

A) Pulmonary blood flow is highly dependent on gravity.
B) The pulmonary circulation is a low-pressure system.
C) Toward the top of the upright lung, blood flow is high.
D) Toward the top of the upright lung, blood flow is low.

Question 70

What is the primary mechanism that stops the lungs from collapsing at the end of exhalation?

A) Radial tethers, stretched to their maximum length, then halt lung collapse.
B) Surfactant neutralizes the tendency of the lung to collapse.
C) There is a tendency of the chest wall to lock at the level of FRC.
D) There is an equal opposing tendency of the chest wall to expand.

Question 71

Which of the following describes a function of pulmonary circulation?

A) Breakdown of angiotensin II
B) Filtering of blood clots
C) Production of erythropoietin
D) Regulation of breathing

Question 72

What determines the airway diameter in the normal lung?

A) Balance between sympathetic and parasympathetic tone
B) In large part, the amount of patient effort
C) Activity level of the submucosal glands
D) Amount of dopamine present in the airway walls

Question 73

What is the effect of damage to the recurrent laryngeal nerves?

A) Diaphragmatic paralysis
B) Pulmonary circulatory failure
C) Inactivation of pulmonary surfactant production
D) Vocal cord impairment or paralysis

Question 74

How does the lung respond to regional lung hypoxia?

A) Bronchial artery vasoconstriction
B) Bronchial artery vasodilation
C) Pulmonary artery vasoconstriction
D) Pulmonary artery vasodilation

Question 75

How does the body compensate for a pulmonary embolus that occludes a branch of the pulmonary artery?

A) Increased bronchial arterial flow to the area
B) Increased cardiac output
C) Pulmonary arteriole and metarteriole vasodilation
D) Release of prostaglandins to fight inflammation

Question 76

Fluid transport to and from the lungs is provided by which of the following?
1) Bronchial circulation
2) Lymphatic system
3) Pulmonary circulation

A)2 and 3 only
B)1 and 3 only
C)2 only
D)1, 2, and 3

Question 77

What forces establish the sub-atmospheric pressure found in the pleural space?

A) Contraction of accessory muscles of inspiration
B) Contraction of expiratory muscles
C) Equal opposing tendency of the chest wall to expand and lung to collapse
D) Effect of gravity, particularly at the base of the lungs

Question 78

What is the name of the negative feedback reflex associated with the termination of inspiration?

A) Carotid sinus
B) Head's paradoxical
C) Hering-Breuer
D) Vagovagal

Question 79

The pulmonary arterial circulation does which of the following?
1) Delivers oxygenated blood back to the heart.
2) Delivers deoxygenated blood to the lungs.
3) Originates on the left side of the heart.
4) Originates on the right side of the heart.

A)1 and 4 only
B)2 and 4 only
C)1 and 3 only
D)2 and 3 only

Question 80

Pressures in the pulmonary circulation are lower than those in the systemic circulation because of what characteristic of the pulmonary circulation?

A) Higher resistance than the systemic circulation
B) Less blood flow than the systemic circulation
C) Lower resistance than the systemic circulation
D) More blood flow than the systemic circulation