Module 8: Resp. A&P

Question 1

Airway

Answer 1

Question 2

Larynx 9 cartilages

Answer 2

Question 3

Larynx and Vocal Cords

Answer 3

Question 4

Nerve supply to the larynx

1. Superior and inferior laryngeal nerves (branches of the cranial nerve ______)
2. The superior laryngeal nerve arises from the ganglion of the vagus and divides into:
3. ___________ segment gives a branch to the inferior constrictor muscle of the pharynx & the cricothyroid muscle. It _____ or _____ tension of vocal cords. Damage results in ________.
4. _______ segment enters the larynx, provides sensation from the laryngeal side of the epiglottis down to the true vocal cords. Damage = ____________.

Answer 4

1. X
2. 2 branches, the external and the internal.
3. External, lengthens or increases; hoarseness
4. Internal; difficulty phonating

Question 5

Nerve supply

1. The inferior or recurrent laryngeal nerves – arise from the _________ nerve at 2 different levels.
2. _______ nerve descends with the vagus and loops around the arch of the aorta to the neck.
3. ______ nerve travels with the vagus to the subclavian artery, loops around the subclavian up to the neck.
4. Damage to the recurrent laryngeal nerve during surgery can lead to unilateral or bilateral vocal cord paralysis with _______ or _______.
5. Blood supply to the larynx is from the _____________(branch of the ____________) and also the _________ (branch of the ___________).

Answer 5

1. vagus
2. Left
3. Right
4. hoarseness or dyspnea
5. superior thyroid artery (external carotid artery); inferior thyroid artery (thyrocervical trunk).

Question 6

Trachea

1. Lined with __________________ and extends from the inferior larynx to the carina.
2. Distance from your incisors to the carina is _______ cm (or roughly _____ inches)
3. Diameter is ______ cm
4. Not a fixed structure
5. Bifurcates into 2 main bronchi
6. Blood supply is from the _____________.

Answer 6

1. pseudo stratified ciliated columnar epithelium
2. 26 ; 10.4
3. 2.5
4. inferior thyroid artery

Question 7

Bronchi

1. Cellular structure begins to change at this level
2. From ________ to ___________.
3. From the carina, the bronchi branch off slightly at different angles.

Answer 7

2. columnar to cuboidal epithelium

Question 8

Right Bronchus

1. Takes off at _________ degrees from trachea
2. Mainstem is ______ and _______ than the left.
3. Nearly _________ as compared to the left
4. Divides into _______ lobar bronchi
5. Mainstem bronchus ends ___________ cm from the carina and gives rise to the RUL bronchus
6. After the RUL takeoff, main bronchus continues into _________ cm as the bronchus intermedius then divides into the middle and lower lobes

Answer 8

1. 25
2. wider; shorter (2cm)
3. vertical
4. 3
5. 2 - 2.5
6. 3

Question 9

Left Bronchus

1. Takes off at _______ degrees
2. Left mainstem is _______ cm
3. Divides into _______ lobar bronchi
4. The left main bronchus is _______ cm long and terminates by bifurcation into the left _______ lobe bronchus and the left _______ lobe bronchus.
5. The left ____ lobe bronchus divides into halves, and upper half and a lower half (lingular branch)

Answer 9

1. 45
2. 4
3. 2
4. 4; upper; lower
5. upper

Question 10

Lung lobes and segments

Question 11

Lung lobes and segments

1. Each division is referred to as a generation. ___________ is the first generation.
2. Third generation is called the ____________. Delivery of ventilation to the various bronchopulmonary segments of the lung.
3. __________ segments create distinct units.
4. _____-_____ generations before the alveoli
5. __________ are the last structure perfused by the bronchial circulation and are at the end of the conducting airways.
6. Terminal lead to _____________ that are perfused by pulmonary circulation .

Answer 11

1. Mainstem bronchi
2. segmental bronchi
3. Bronchopulmonary
4. 20-25
5. Terminal bronchioles
6. respiratory bronchioles

Question 12

Transitional airways

1. The _________ follows the terminal bronchiole and is the first site where gas exchange occurs.
2. In adults, ___-___ generations of respiratory bronchioles lead to alveolar ducts, of which ___-___ generations, each with multiple openings into alveolar sacs.
3. The final divisions of alveolar ducts terminate in _________ that open into alveolar clusters.

Answer 12

1. respiratory bronchiole
2. 2 - 3 ; 4 - 5
3. alveolar sacs

Question 13

Section of lung showing many alveoli and a small bronchiole. The pulmonary capillaries run in the walls of the alveoli.
The holes in the alveolar walls are the ________. They function as a means of collateral ventilation; that is, if the lung is partially deflated, ventilation can occur to some extent through these pores. They also allow air to pass through, this provides collateral ventilation and even distribution of air to the alveoli. They equalize the pressure in adjacent alveoli and thus play an important role in prevention of collapse of lung.

Answer 13

pores of Kohn

Question 15

Respiratory airways and alveolar-capillary membrane

Two primary functions:

Answer 15

1. Transport of respiratory gases (oxygen & carbon dioxide).
2. Production of a wide variety of local and humoral substances.

Question 16

Respiratory Zone

1. The respiratory zone is comprised of the:
2. The respiratory zone is where:

Answer 16

1. Respiratory bronchioles
   Alveolar ducts
   Sacs
   Alveoli
   2. Gas exchange occurs.

Question 17

Respiratory airways

1. Gas transport is facilitated by the __________.
2. These are the ________ capillary networks in the body.
3. There are 3 types of alveolar cells – Type I, II and III.

Type I –

Type II –

Type III –

Answer 17

1. pulmonary capillary beds
2. densest

I - flattened, squamous cells, which covers ~80% of the
alveolar surface

II - polygonal cells have vast metabolic and
enzymatic activity and manufacture
surfactant.

III - alveolar macrophages, which are important to
immunologic lung defense. Permit ingestion
of foreign materials within alveolar spaces.

Question 18

Two major circulatory systems supply blood
to the lungs:

Answer 18

1. Pulmonary vascular networks
2. Bronchial vascular networks

Question 19

Pulmonary Vascular system

1. Delivers ____________ from the right ventricle to the pulmonary capillary bed via two pulmonary arteries.
2. After gas exchange occurs, oxygenated blood returns to the left atrium via four pulmonary veins.
3. Pulmonary veins run independently along the ________ planes.
4. The pulmonary capillary system adequately provides the metabolic and oxygen needs of the ____________.

Answer 19

1. mixed venous blood
3. intra-lobar connective tissue
4. alveolar parenchyma

Question 20

Bronchial Vascular System

1. Provides oxygen to the:
2. Anatomic connections between the bronchial and pulmonary venous circulations create an absolute shunt of ~____-____ % of the total cardiac output, and represents a “normal” shunt.

Answer 20

1. conductive airways and pulmonary vessels.
2. 2 – 5

Question 21

Location and Contents

Answer 21

Question 22

Pleura

1. _________ lines the thoracic wall and lungs.
2. The parietal pleura attaches to the ________,_______, and ___________.
3. Reflected back to cover the lungs and thereafter referred to as the ___________.
4. Closely opposed with a thin layer of pleural fluid in between them, a potential space, known as the ___________.

Answer 22

1. Serous membrane
2. chest wall, diaphragm and mediastinum.
3. visceral pleura
4. pleural space

Question 23

Pleura

1. An accumulation of air in the _________ is referred to as a pneumothorax.
2. ____________ – inspired air accumulates in the pleural space and is not expelled.
3. The elastic recoil of the lung tends to favor lung collapse once the negative pressure of the pleural space is disrupted by the breach.

Answer 23

1. Pleural space
2. Tension pneumothorax

Question 24

Lung Mechanics

1. The ______ and _________ are the muscles that contract during normal breathing (eupnea).
2. Contraction of the muscles of inspiration ______ intrathoracic pressure → the volume of thoracic cavity to ________.
3. Boyle’s law: ↑ volume creates ↓ pressure.
4. This causes air to enter the atmosphere.
5. Spontaneous respiration is ________ movement of gas.

Answer 24

1. diaphragm and external intercostals
2. ↓; ↑
3. -
5. passive

Question 25

Mechanics of Breathing

1. Each half of the diaphragm is innervated by a branch of the phrenic nerve arising from _____,_____,____(“keeps me alive!”)
2. Eupneic expiration results from passive recoil of the chest wall. _______________ may be used to augment exhalation. (Signs of respiratory distress)
3. During forced exhalation (coughing), the ________ may be used.
4. Sternocleidomastoid and scalene muscles contract in conjunction with the diagram and intercostal muscles for _____________. (Alternatively, they can be used for __________ per your textbook!)

Answer 25

1. C 3, 4 and 5
2. Internal intercostal muscles
3. abdominal muscles
4. forceful exhalation; forceful inhalation,

Question 26

Lung mechanics

1. Lung movement occurs secondary to __________.
2. During spontaneous ventilation, external forces are produced by the _________..
3. The response to the lungs to these forces is
   governed by:

Answer 26

1. external forces.
2. ventilatory muscles
3. • ease of elastic recoil of the chest wall
   • resistance to gas flow within the airways

Question 27

Mechanics of Ventilation:Elastic Resistance

1. ________ has a tendency to expand outward.
2. _________ have a tendency to collapse.
3. As a result, __________ pressure is ________.
4. Because the outward force of the thoracic cage _______ the inward force of the lung, the overall tendency is for the lungs to remain inflated.

Answer 27

1. Chest
2. Lungs
3. Intrapleural; negative
4. Exceeds

Question 28

Elastic work

1. FRC (functional residual capacity) represents the gas volume in the lungs when the outward and inward forces on the lung are _______.
2. FRC is defined as the volume of air remaining in the lung at the end of a ____________.
3. Gravitational forces create a more sub-atmospheric pressure in the ________ areas of the lung than the _______ areas of the lung.
4. A ___________ allows lung to collapse and thorax to spring out.

Answer 28

1. equal
2. normal expiration
3. nondependent; dependent
4. pneumothorax

Question 29

Mechanics of Ventilation

1. ________ forces occur at an air-fluid interface
2. Produces forces that reduce the area of the ________.
3. Favor alveolar ___________.
4. Gas-fluid interface lining the alveoli  behave like bubbles. For a bubble to remain inflated, the gas pressure within a bubble, which is contained by surface tension must be ↑ than surrounding gas pressure.

Answer 29

1. Surface tension
2. interface
3. collapse

Question 30

Mechanics of Ventilation

1. Unlike a bubble, alveolar gas communicates with the atmosphere via airways
2. As alveolar radius decreases during exhalation, Law of Laplace’s (P = 2T/r) is satisfied and the alveoli do not _______.
3. Pressure = EQUATION?
4. Pressure = inside the bubble (alveolus)

Alveolar collapse
1. directly proportional to
1. inversely proportional to

Answer 30

1. -
2. collapse
3. P = 2 x Surface Tension of the liquid/ Radius of the bubble
   4.

1. surface tension
2. alveolar size

Question 31

Mechanics of Ventilation:Elastic Resistance

1. Surface tension of the liquid in the lung :
   * Increases during ________
   * Decreases during ________

1. Unlike a bubble, pressure within the alveolus ___________ as the radius decreases
2. Creates gas flow from larger to smaller alveoli
3. Maintains structural stability and prevents lung collapse

Answer 31

1.
* Increases during inspiration
* Decreases during expiration

1. decreases
   2.

Question 32

Mechanics of Ventilation: Elastic Resistance

1. Pulmonary Surfactant ___________ alveolar surface tension; directly proportional to its concentration within the alveolus
2. The smaller the alveolus, the more __________ the surfactant, and the more effectively surface tension is _______.
3. Over distended alveoli surfactant is less concentrated and surface tension ________.
4. Net effect is to stabilize alveoli. Small ones prevented from collapsing and large ones prevented from getting larger.

Answer 32

1. decreases
2. concentrated; reduced; increases

Question 33

Physiologic Work of Breathing

1. ________ is defined as the work required to overcome the elastic recoil of the pulmonary system. This occurs during ________ as expiration is passive during normal breathing.
2. _______ is defined as work to overcome resistance to gas flow in the airway and includes equipment-imposed resistance such as the endotracheal tube (ETT).

Answer 33

1. Elastic work; inspiration
2. Resistive work;

Question 34

Mechanics of Ventilation: Compliance (CL)

1. Defined as:
2. ____________ – is the pressure-volume relationship for a lung when the air is not moving. (e.g., fibrosis, obesity, vascular engorgement, edema, ARDS, external compression, etc.)
3. Static compliance can be increased by _______ which destroys the elasticity of lung tissue (e.g., problem with ______, not _______).
4. Compliance changes as lung volume changes. It is _________ dependent. ___________ compliant at both very high or very low volumes.

Answer 34

1. The change in volume divided by the change in pressure V/P
2. Static compliance
3. emphysema (deflation; inflation
4. volume; Less

Question 35

Mechanics of Ventilation: Compliance (CL)

1. **Sum of the pressure-volume relationships of the _____ and _______  (∆V/∆P) **
2. Results in a sigmoidal pressure-volume curve (compliance curve)
   * Vertical line at end expiration —> ________
   * Normally breathe on the ________ part of sigmoidal curve
   * Where compliance (∆V/∆P) or slope is ________
3. Restrictive pulmonary disease (↓ compliance)
   * curve shifts to the ________
   * _______ slope,
   * or both
   * Results in smaller FRC
4. **↓ Compliance **
   * Larger changes in ____________ needed to create the same TV
   * Expend more _______ to get the same volume into the lungs
   * Tend to breathe more ____ and _____
   * ___________ will increase TV and slow RR

Answer 35

1. thorax and lung
2. • FRC.
   • steepest
   • highest
3. • right
   • decreased
4. • intrapleural pressure
   • elastic work
   • rapid and shallow
   • CPAP

Question 36

Mechanics of Ventilation: Elastic Resistance

1. Reduced compliance: (4)
2. Increased compliance (2)

Answer 36

1. • Increase in fibrous tissue in the lung (pulmonary fibrosis)
   • Alveolar edema (prevents inflation of some alveoli)
   • Unventilated lung for a long period
   • Increased pulmonary venous pressure
2. • Pulmonary emphysema
   • Normal aging lung

Question 37

Mechanics of Ventilation: Elastic Resistance

1. Chest Wall Compliance (~ ________ ml/cm H2O)
   CW =
2. Total compliance of lung and chest wall together ~_______ ml/cm H2O
3. When the patient lies supine, then chest wall compliance _______ and the weight of abdominal contents against the diaphragm.

Answer 37

1. 200
2. 100
3. reduced

Question 38

Resistance to Gas Flow

Patterns of gas flow in the respiratory tract
* Laminar (distal to small bronchioles)
* Turbulent (large airways)
* Mixed

Resistance
1. ________ in proportion to gas flow
1. ________ proportional to gas density
1. _________ proportional to the radius
1. If radius is halved, resistance ↑ ________
1. Doubling the length only _______ the resistance

Answer 38

1. Increases
2. Directly
3. Inversely
4. 16-fold
5. doubles

Question 39

Turbulent Gas Flow

1. Laminar flow occurs when low flow rates move through a straight tube result in a series of concentric cylinders of gas flowing at different velocities. They are ______ to sides of tube and have a velocity of _________ at the cylinder wall . The maximum velocity at the ________ of the advancing “cone.” _________ is relevant under laminar flow.
2. Turbulent flow occurs when ______ to gas flow is significant. Random movement of gas molecules down air passages . It is very loud and audible.

Four conditions that will change laminar flow to turbulent flow:

Answer 39

1. parallel; zero; center; Viscosity
2. resistance

high gas flows
sharp angles within the tube
branching in the tube
decrease in the tube’s diameter

Question 41

At low flow rates, stream lines are parallel to the sides of the tube. As the flow rate increases, unsteadiness develops, especially at branches and separation of stream lines occurs with formation of local eddies. At Higher flow rates, there is complete disorganization of the stream lines.

Question 42

Volume-Related Airway Collapse

• ________ lung volumes and loss of _______ increases contribution of small airways to total resistance.
• Airway resistance becomes ________ proportional to lung volume.
• Increasing lung volume up to normal with ______ can ________ airway resistance.

Answer 42

1. Low; radial traction
2. inversely
3. PEEP; reduce

Question 43

Flow-Related Airway Collapse

1. Forced exhalation causes a reversal of normal transmural pressure and can cause dynamic airway compression, which limits air flow during a forced expiration. This results in a large pressure ________ across intrathoracic airways.
2. ____________ is defined as the point along the airways where dynamic compression occurs.
3. ____________: destroys elastic tissues that support smaller airways
4. _________: bronchoconstriction and edema intensify airway collapse
5. __________ or premature termination of exhalation helps to prevent reversal of transmural pressure gradients and trapping of air.

Answer 43

1. drop
2. Equal Pressure Point
3. Emphysema
4. Asthma
5. Pursed-lip breathing

Question 44

Ventilation

1. ________ Dead Space are the gases in non-respiratory airways.
2. ________ dead space involves alveoli that are not _______.
3. Physiologic dead space = the sum of the two .
4. Physiologic dead space refers to areas of the lung that are ventilated but poorly perfused.

1. Dead space
   * normally about _______ ml/Kg
   * nearly all _______

Answer 44

1. Anatomic
2. Alveolar; perfused

• 2
• anatomic

Question 45

Distribution of Ventilation

1. Alveolar ventilation is unevenly distributed
   * ______ receives more than _______.
2. ________ areas tend to be better ventilated
   * Alveoli in upper lung areas are nearly maximally inflated and relatively ___________.
   * Smaller alveoli in dependent areas are more _______ and undergo greater ________.

Answer 45

1. Right; left
2. Dependent
   - noncompliant
   - compliant; expansion

Question 46

Pulmonary Perfusion

1. Blood flow ______ L/min (Cardiac Output)
2. ~ ____ -______ ml at any one time in pulmonary capillaries undergoing gas exchange
3. Supine to erect position decreases pulmonary blood volume up to ________%.
4. Trendelenburg has the opposite effect.

Pulmonary vascular tone —-> vasoconstriction

• _______ is the most powerful stimulus.
• Pulmonary arterial and alveolar hypoxia reduces pulmonary blood flow from _________ areas to ________ areas and prevents hypoxemia.

Answer 46

1. 5
2. 70 to 100
3. 27

• Hypoxia
• non-dependent; dependent

Question 47

Hypoxic Pulmonary Vasoconstriction (HPV)

HPV and Bronchoconstriction allow the lungs:
* To maintain optimal _________
* Stimulated by __________
* Severely decreases _____________
* Decreased regional pulmonary blood flow results ___________ and diminishes the degree of __________ ventilation.

Answer 47

• V/Q matching
• alveolar hypoxia
• blood flow
• bronchoconstriction; dead space

Question 48

Hypoxic Pulmonary Vasoconstriction

HPV and ____________ protect the lungs, particularly during one-lung ventilation.

When either a shunt or dead space occurs, the unit of the lung effectively becomes a “silent” unit in which little _____ or _______occurs.

Answer 48

• Bronchoconstriction
• ventilation or perfusion

Question 49

Factors that reduce effectiveness of HPV (10)

Answer 49

1. Hypervolemia
2. Hypovolemia
3. Excessive tidal volume or PEEP
4. Hypocapnia
5. Acidosis
6. Hypothermia
7. Volatile agents > 1.5 MAC
8. Vasoactive medications
9. Calcium channel blockers (may)
10. Vasodilators (may)

Question 50

Distribution of Pulmonary Perfusion

Pulmonary blood flow is not uniform. The ___________ portions receive greater flow than the ___________ portions. Gravity exerts a significant influence on blood flow.
3 lung zones based on
* Alveolar pressures
* Arterial pressures
* Venous pressures

Answer 50

dependent; upper

Question 51

Thezones of the lungdivide thelunginto four vertical regions, based upon the relationship between the pressure in thealveoli(PA), in thearteries(Pa), in theveins(Pv) and the pulmonaryinterstitialpressure (Pi):
Zone 1:
Zone 2:
Zone 3:
Zone 4:

Answer 51

Zone 1: PA > Pa > Pv
Zone 2: Pa > PA > Pv
Zone 3: Pa > Pv > PA
Zone 4: Pa > Pi > Pv > PA

Question 52

Distribution of Pulmonary Perfusion

Zone 1 (upper zone)
* Alveolar ___________
* Alveolar pressure continually occludes the

Zone 2 (middle zone)
* Pulmonary capillary flow is __________ and
* Varies during __________
* According to _________-________ gradient

Zone 3 (lower zone)
* Pulmonary capillary flow is _______
* Proportional to the ________-_______pressure gradient

Answer 52

Zone 1:
* dead space
* pulmonary capillaries

Zone 2 (middle zone)
* intermittent
* respiration
* arterial-alveolar pressure gradient

Zone 3 (lower zone)
* continuous
* arterial-venous

Question 53

Ventilation/Perfusion Ratios

1. (V) Alveolar ventilation ~ ______L/min
2. (Q) Pulmonary capillary perfusion ~ L/min
3. Overall V/Q ratio ~ _______
4. No ventilation  intrapulmonary shunt
5. No perfusion  alveolar dead space

Throughout the lungs, V/Q
normally ranges from ___ -______
Majority are close to ________

Answer 53

1. 4
2. 5
3. 0.8

• 0.3 to 3
• 1

Question 54

Ventilation/Perfusion Ratios

Pulmonary venous blood from areas with low V/Q ratios
* has low ________ and high_______ tension.
* tends to depress arterial O2 tension more profoundly than CO2 tension.

Compensatory increase in O2 uptake cannot take place where V/Q is __________
* ________________ blood usually already maximally saturated with O2.

Answer 54

• O2 tension; CO2

*normal, pulmonary end-capillary

Question 55

Shunts

• Desaturated, mixed venous blood from the right heart returns to the left heart without being re-saturated with O2 in the lungs.
• Overall effect dilutes arterial O2 content.
• Absolute shunt are:
  __________ shunts
  lung units where V/Q is “________”
  _________ partially correct with increased FIO2

Relative shunt
__________ but finite V/Q ratio
__________ correct with increased FIO2

Answer 55

• anatomic
• 0
• cannot

• low
• can partially

Question 56

Effects of Anesthesia on Gas Exchange

1. _______ dead space
2. _______ventilation
3. ________ intrapulmonary shunting
4. _______ scatter of V/Q ratios
5. Atelectasis and airway collapse increases ___________ 5 to 10 %.
6. Inhalation agents can inhibit hypoxic __________ in high doses (2 MAC)
7. Prolonged high FIO2 (> ________) increases the _________ shunt and can result in “absorption atelectasis,” a complete collapse of alveoli with previously low V/Q once all O2 within the alveoli is absorbed.
8. There is no other gas left in the alveoli to keep it open (ie nitrogen)

Answer 56

1. Increased
2. hypoventilation
3. Increased
4. Increased
5. venous admixture (physiologic shunt)
6. vasoconstriction
7. 0.5; absolute

Question 57

Central Respiratory Centers

1. ________ = origin of basic breathing rhythm
2. _________ respiratory group
   * Primarily active during inspiration
3. _________ respiratory group
   * Active during expiration

1. Respiratory rate and rhythm are “fine tuned” by 2 _________ areas (i.e., “pons” in the brainstem)
2. Influence _______ medullary center
3. Lower pontine (_________ ) center is considered “_________.”
4. Upper pontine (__________) center is considered “___________.”

Answer 57

1. Medulla
2. Dorsal
3. Ventral

1. pontine
2. dorsal
3. apneustic, excitatory
4. pneumotaxic, inhibitory

Question 58

Central Sensors

1. Central chemoreceptors located on the surface of the __________.
2. Respond primarily to changes in -________
3. Elevated ________ elevates CSF H+ and activates the chemoreceptors
4. Secondary stimulation of the adjacent respiratory medullary centers increases alveolar ventilation
5. Very high PCO2 tension depresses the ventilatory response (“_________”)

Apneic threshold
1. PCO2 at which ventilation is _________
1. Awake state, cortical influences prevent apnea
1. ___________ depresses central chemoreceptor activity.

Answer 58

1. medulla
2. CSF H+
3. PCO2
5. CO2 narcosis

1. zero
2. Hypoxia

Question 59

Peripheral Chemoreceptors

1. Carotid bodies
2. Aortic bodies (surrounding the aortic arch)

Bifurcation of the common carotid arteries
1. Principal peripheral chemoreceptors
1. Sensitive to changes in:
1. Interact with central respiratory centers via the ____________ nerves

Reflex increases in alveolar ventilation in response to:
1. reduction in PO2, arterial perfusion
1. Elevations in H+ and PCO2
1. Most sensitive to PO2
1. Receptor activity does not increase until PO2 < _________ mmHg

Answer 59

• PO2, PCO2, pH, and arterial perfusion pressure
• glossopharyngeal
• 50 (60-65)

Question 60

Lung Receptors

1. Impulses carried centrally by the _________ nerve

Stretch receptors
* Distributed in ________ _______ of airways
* (Hering-Breuer inflation reflex): Inhibit inspiration when lung is inflated to excessive volumes

Deflation reflex
1. Shortening of ________ when lung is deflated
1. Normally plays a minor role

Irritant receptors
1. Tracheobronchial mucosa
1. React to noxious gases, smoke, dust, and cold gases
1. Reflex increase in RR, bronchoconstriction, coughing

Answer 60

• vagus

Stretch receptors
- smooth muscle

Deflation reflex
- exhalation

Question 61

Lung Receptors

_____________ receptors
* Located in interstitial space within alveolar walls
* Induce dyspnea in response to expansion of interstitial space volume and various chemical mediators following tissue damage

Other Receptors:
Muscle and joint receptors
* pulmonary muscles and chest wall
* Input probably important during exercise
* Pathological conditions associated with decreased compliance

Answer 61

• J (juxtacapillary)

Question 62

Effects of Anesthesia

General anesthesia:
- Promotes _____________

Dual mechanism:

Increased anesthetic depth:
- Apneic threshold __________ and slope of minute ventilation curve ________
- This is partially reversed by surgical stimulation

Answer 62

• hypoventilation

Dual mechanism:
* Central depression of the chemoreceptor
* Depression of external intercostal muscle activity

increases, decreases

Question 63

Effects of Anesthesia

The peripheral response to __________ is more sensitive than the central ________ response.

The peripheral response is nearly abolished by even sub-anesthetic doses of most inhalation agents, including N2O, and many IV induction agents.

Answer 63

• hypoxemia, CO2

Question 64

Effects of Anesthesia

Pulmonary Mechanics and Induction of anesthesia:
* Additional _____ to _______% reduction in FRC beyond that which occurs in the supine position alone (~ _____ml).
* _______ _______ part of the diaphragm moves cephalad when lying in the supine position.
* Rib cage moves _________ due to loss of muscle tone.
* Change in intrathoracic volume secondary to _________ blood volume in the lung.

Changes in chest wall shape
* __________ lung volume
* ___________ FRC
* Not related to ______________
* May persist for _____________.

Answer 64

• 15 - 20%; 400
• Dorsal (dependent)
• inward
• increased

Changes in chest wall shape
* Decrease lung volume
* Decreased FRC
* Not related to anesthetic depth
* May persist for several hours

Question 65

Effects of Anesthesia

Steep Trendelenburg > 30 degrees
* may reduce FRC even further as intrathoracic blood volume ____________

Airway Resistance
* The bronchodilating properties of inhaled agents tend to overcome increased resistance due to decreased FRC.

Effects of Anesthesia
Pathological factors
Tongue
Laryngospasm
Bronchoconstriction
Secretions

Equipment
Small ETT/connectors
Malfunction of valves
Obstruction of breathing circuit

Answer 65

• increases

Question 66

Oxygen

1. Carried in the blood in two forms:
   dissolved and combined with Hb
2. _________ Law (dissolved O2)

The amount dissolved is proportional to the partial pressure

• For each mmHg of PO2 –> ___________ ml O2/ 100 ml blood
• Arterial PO2 of 100 mmHg = __________ ml O2 / 100 ml blood

Answer 66

2. Henry’s

• 0.003
• 0.3

Question 67

Hemoglobin

Heme:
* Iron-porphyrin compound joined to the protein globin
* Consists of _______ polypeptide chains
* _____ and ______ chains

Amino acid sequence gives rise to various types of human Hb

A normal adult

F fetal, which is gradually replaced over the first year of postnatal life

S sickle, which has a _________ O2 affinity (shift in O2 dissociation curve to the right)
Deoxygenated form, which is poorly soluble and crystallizes within the RBC; cell changes from biconcave to sickle shape

Answer 67

Heme:
- 4
- Alpha and beta

• reduced

Question 68

Oxyhemoglobin Dissociation Curve

• The oxyhemoglobin dissociation curve describes the non-linear tendency for oxygen to bind to hemoglobin. At an SaO2 of _______% or less, small differences in hemoglobin saturation reflect large changes in PaO2.
• At pressures above _______ mmHg, the standard dissociation curve is relatively flat, which means that the oxygen content of the blood does not change significantly even with large increases in the oxygen partial pressure.
• This can be correlated clinically. When the SaO2 decreases to 90% (or 60mmHg pp of O2) the curve becomes very steep. You will have a very sudden dramatic decrease.

Answer 68

• 90%
• 60

Question 69

Oxyhemoglobin Dissociation Curve

Shift to the right  more unloading of O2 at a given PO2 into the tissue capillary
↓ O2 affinity of Hb
↑ H+ ion concentration
↑ PCO2
↑ Temperature
↑ Concentration of 2,3-DPG, which is the end product of RBC metabolism (hypoxia, high altitude chronic lung disease); may be depleted in bank blood (impaired unloading).
Shift to the left will have the opposite effect

It is common to use the concept of P50 to describe the affinity of hemoglobin for oxygen.
The P50 is the PO2 at which the hemoglobin becomes 50% saturated with oxygen.
As the P50 decreases, oxygen affinity increases and visa verse.

Answer 69

Question 70

Oxygen - Hemoglobin Affinity

The normal P50 is ____-_____ mmHg

• Remember, this is at a temperature of 37◦ C and a pH of 7.4
• Anything greater than 27 mmHg referred to as a shift to the right.
• Anything less than 26 mmHg is referred to as a shift to the left.

Answer 70

26 - 27

Question 71

Carbon Dioxide

• CO2 is ~ ______ x more soluble than O2
• Carried in the blood in 3 forms:

_________ Effect
* deoxygenation of blood increases its ability to carry CO2

Answer 71

• 20
  1. As bicarbonate (~ 60%)
  1. In combination with proteins (~ 30%)
  carbamino compounds (most important is carbaminohemoglobin)
  1. Dissolved (~10%)

Haldane

Question 72

Carbon Dioxide

Reduced Hb is less _______ than the oxygenated form
* ________ acceptor
* Presence of reduced Hb in the peripheral blood (deoxyhemoglobin) helps with the loading of CO2
* Oxygenation in the pulmonary capillary (oxyhemoglobin) assists in the unloading

Answer 72

acidic:
- Proton

Question 73

Oxygen Stores

1. O2 consumption ~ _______ ml/min with cardiac output (CO) of ____ L/min
2. During apnea, the patient relies on the O2 remaining in the lungs, dissolved in body fluids and bound to hemoglobin.
3. Most important source –> O2 contained in the lungs at ________
4. O2 content =
5. Room air 
   0.21 x 2300 ml = ~ 480 ml of O2 in the lungs
   Hypoxemia in ~ 90 seconds
6. Increase FIO2 prior to apnea
   FIO2 1.0 x 2300 ml = 2300 ml of O2
   Delays hypoxemia for 4 – 5 minutes

Answer 73

1. 250; 5
2. O2
3. FRC
4. FRC x FIO2

Question 74

Physiologic changes in respiratory function associated with aging:

Answer 74

• Dilation of alveoli
• Enlargement of the airspaces
• Decrease in exchange surface area
• Loss of supporting tissue
• Decreased lung recoil leads to an increase in residual volume and FRC.

Question 75

Physiologic Dead Space:

The part of the tidal volume not participating in alveolar gas exchange is known as _______ dead space.

Composed of:
Anatomic Deadspace: gases in non-respiratory airways
Alveolar Deadspace: non-perfused alveoli
Approximately _____ mL/kg or ______ mL/lb

Answer 75

• physiologic
• 2 or 1

Question 76

Intrapleural pressure:

• Between the parietal pleura of chest wall and visceral pleura covering the lung
• Usually slightly subambient (_____-_______ mmHg) because lungs recoil inward and chest wall recoils outward
  **Inward and outward forces are equal at _______
  **During inspiration: intrapleural pressures become more _________ as the chest wall expands

Intrapulmonary pressure
* Zero at ___________;
* negative at start of inspiration (air enters lungs because intrapulmonary pressure is less than atmospheric pressure).

Answer 76

• -2 to -3
  ** FRC
  ** negative

• end-expiration

Question 77

The amount of gas inspired or expired with each breath.

Answer 77

Tidal Volume (TV).

Question 78

Maximum amount of additional air that can be inspired from the end of a normal inspiration.

Answer 78

Inspiratory Reserve Volume (IRV).

Question 79

The maximum volume of additional air that can be expired from the end of a normal expiration.

Answer 79

Expiratory Reserve Volume (ERV).

Question 80

denotes the lung volume from the beginning of airway closure to the end of maximum expiration, the residual volume.

Answer 80

Closing Volume (CV)

Question 81

The volume of air remaining in the lung after a maximal expiration. This is the only lung volume which cannot be measured with a spirometer.

Answer 81

Residual Volume (RV).

Question 82

Lung capacities are subdivisions of total volume that include two or more of the 4 basic lung volumes.
Two or more volumes represent a _______.

Answer 82

capacity

Question 83

Lung Capacities

The volume of air contained in the lungs at the end of a maximal inspiration. Called a capacity because it is the sum of the 4 basic lung volumes.

Answer 83

Total Lung Capacity (TLC).

TLC = RV+IRV+TV+ERV

Question 84

The maximum volume of air that can be forcefully expelled from the lungs following a maximal inspiration. Called a capacity because it is the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume.

Answer 84

Vital Capacity (VC).

VC = IRV+TV+ERV=TLC-RV

Question 85

The volume of air remaining in the lung at the end of a normal expiration. Called a capacity because it equals residual volume plus expiratory reserve volume.

Answer 85

Functional Residual Capacity (FRC).
FRC = RV+ERV

Question 86

Maximum volume of air that can be inspired from end expiratory position. Called a capacity because it is the sum of tidal volume and inspiratory reserve volume. This capacity is of less clinical significance than the other three.

Answer 86

Inspiratory Capacity (IC).
IC = TV+IRV

Question 87

1. ______________ is the lung volume at which the small airways in dependent parts (i.e., small airways lacking cartilaginous support) of the lung begin to close.
2. CC is the sum of ______ and _________.
3. It is normally well below FRC, but rises steadily with ________
4. Unlike FRC, closing capacity is unaffected by ___________.
5. When closing capacity (CC) exceeds FRC, there will be airway closure even during normal tidal breathing.
6. CC exceeds FRC in a person with normal lungs beyond age _____ when supine and beyond age ______ when standing.
7. As a result, there is airway closure during part of normal tidal breathing resulting in VQ mismatching and decreased arterial PaO2 in elderly.

Answer 87

1. Closing capacity (CC)
2. closing volume and residual volume
3. age
4. posture
5. -
6. 45; 65

Question 88

Question 89

forced expiratory volume 1 - the volume of air that is forcefully exhaled in one second.

Answer 89

FEV1

Question 90

the volume of air that can be maximally forcefully exhaled

Answer 90

FVC - forced vital capacity

Question 91

ratio of FEV1 to FVC, expressed as a %

Answer 91

FEV1/FVC

Question 92

forced expiratory flow - the average forced expiratory flow during the mid (25 - 75%) portion of the FVC

Answer 92

FEF25 - 75

Question 93

The peak flow rate during expiration

Answer 93

PEF - peak expiratory flow rate

Question 94

Pulmonary Function Test (PFTs)

Normal values:
FVC =
FEV1 =
Ratio =
Normal = you get _______% of the capacity out in 1 second

Answer 94

Normal values:
FVC = 5L
FEV1 = 4L/sec
Ratio = 0.8
Normal = you get 80% of the capacity out in 1 second

Question 95

Restrictive

FVC:
FEV1:
FEV1/FVC:
FEF 25-75:
FRC:
TLC:

Mechanical ventilation is better tolerated with:

Answer 95

FVC: very low
FEV1: very low
FEV1/FVC: normal
FEF 25-75: normal
FRC: very decreased
TLC: very decreased
Mechanical ventilation is better tolerated with smaller tidal volumes and higher respiratory rates

Question 96

Obstructive

FVC:
FEV1:
FEV1/FVC:
FEF 25-75:
FRC:
TLC:
Mechanical ventilation requires:

Answer 96

FVC: norm. to slight low
FEV1: normal to low
FEV1/FVC: very low
FEF 25-75: very low
FRC: Normal or increased
TLC: normal or increased
Mechanical ventilation requires higher volumes and lower rates to allow time for exhalation. Be cautious of barotrauma.

Question 97

High index of suspicion for markedly impaired pulmonary function

Answer 97

Any chronic disease involving lungs
Smokers
Chest wall or spinal deformities
Morbid obesity
Persistent cough or wheeze
Neuromuscular diseases
Requirement for one-lung ventilation or lung resection
Thoracic or upper abdominal surgery
Age > 60

Question 98

*

Answer 98

Question 99

Answer 99

Question 100

Question 101

Answer 101

Question 102

Answer 102

Flow–volume loops were formerly useful in the diagnosis of large airway and extrathoracic airway obstruction prior to the availability of precise imaging techniques. Imaging techniques such as MRI give more precise and useful information in the diagnosis of upper airway and extrathoracic obstruction and superseded the use of flow–volume loops for diagnosis of these conditions. Therefore, it is rare that flow–volume loops are useful for preoperative pulmonary evaluation in the modern era of imaging.

Question 103

Question 104

Airway obstructions:

Fixed: both inspiration and expiration are affected

Variable:
Extrathoracic: problems with __________
Intrathoracic: problems with __________

Answer 104

Fixed: both inspiration and expiration are affected

Variable:
Extrathoracic: problems with inspiration
Intrathoracic: problems with expiration

Question 105

• Patients who smoke should be advised to stop smoking at least __________ months prior to an elective procedure to decrease the risk of postoperative pulmonary complications (PPC).
• The operative site is one of the most important determinations of the risk of PPC. The highest risk is associated with non-laparoscopic upper abdominal cases followed by lower abdominal and intrathoracic operations.
• ___________ is the single most important consideration to prevent PPC.

Answer 105

• 2
• Early ambulation