Chapter 22 Study Guide

Question 1

1) What does the respiratory system do?
2) What other system works closely to deliver oxygen?
3) What other system works with respiratory to help regulate acid-base balance?

Answer 1

1) The respiratory system consists of a system of tubes that delivers air to the lungs
2) Works with the cardiovascular system to deliver oxygen.
3) Works with urinary system to help regulate acid-base balance.

Question 2

What are the 8 functions of the respiratory system?

Answer 2

1) Gas exchange
2) Communication
3) Olfaction
4) Acid-base balance
5) Blood pressure regulation
6) Blood and lymph flow
7) Blood filtration
8) Expulsion of abdominal contents

Question 3

1) What are the principal organs of the respiratory system?
2) What is conducting division consist of?
3) What does the respiratory division consist of?

Answer 3

1) Major organs include the nose, pharynx, larynx, trachea, and lungs.
2) The conducting zone includes passages that serve only for airflow (no gas exchange)
3) The respiratory zone is where gas exchange takes place (alveoli)

Question 4

What is considered the upper respiratory tract? Lower respiratory tract?

Answer 4

The upper respiratory tract is in the head and neck, the lower respiratory tract is in the thorax.

Question 5

1) What are some of the functions of the nose? (3)
2) What type of cartilage makes up the nose?
3) The nose extends from _______ to the posterior nasal ____________.
4) What divides the nasal cavity?

Answer 5

1) 3 functions of the nose:
a) Warms, cleanses, and humidifies inhaled air
b) Detects odors
c) Serves as a resonating chamber that amplifies voice
2) Made of hyaline cartilage
3) The nose extends from nostrils (nares) to posterior nasal apertures (choanae)
4) The nasal septum divides the nasal cavity.

Question 6

1) What is a meatus? What is the function of the meatus?
2) What are the conchae?
3) What is the scientific name of the wineglass-shaped cells in the respiratory epithelium and what do they secrete?

Answer 6

1) A meatus is the narrow air passage/ indent beneath each concha; it cleans, warms, and moistens air due to its narrowness and turbulence.
2) The conchae are the bumps between the meatuses.
3) Goblet cells, which secrete mucus.

Question 7

Are the cilia in the nasal cavity mobile?

Answer 7

Cilia in this area are mobile; they propel mucus posteriorly towards the pharynx to be swallowed

Question 8

1) What are the 3 regions of the pharynx?
2) Which region receives the auditory (eustachian) tubes from the middle ears and houses the pharyngeal tonsil?
3) Which region is a space between the posterior margin of the soft palate and the epiglottis?
4) Which region lies mostly posterior to the larynx, extending from the superior margin of the epiglottis to the inferior margin of the cricoid cartilage, where the esophagus begins?

Answer 8

1) Nasopharynx, oropharynx, and laryngopharynx
2) Nasopharynx
3) Oropharynx
4) Laryngopharynx

Question 9

1) What two regions of the pharynx pass air, food, and fluids?
2) What are they lined by?

Answer 9

1) Oropharynx and laryngopharynx
2) Stratified squamous epithelium

Question 10

1) The larynx, or ____ ____, is a cartilaginous chamber. What is the primary function of the larynx?
2) What is the flap of tissue that guards the opening of the larynx called? What is its purpose?

Answer 10

1) Voice box; to keep food and drink out of the airway and sound production.
2) Epiglottis; closes the airway and directs food to esophagus behind it

Question 11

1) The framework of the larynx consists of how many cartilages?
2) The _________ cartilage, the most superior, is a spoon-shaped supportive plate in the epiglottis.
3) The largest, the _________cartilage, is named for its shield-like shape. It covers the anterior and lateral aspects and forms the “Adam’s apple,” which is larger in males.
4) The ring-like _________ cartilage is located inferior to the thyroid cartilage.

Answer 11

1) 9 cartilages.
2) The epiglottic cartilage, the most superior
3) The largest, the thyroid cartilage
4) The ring-like cricoid cartilage is located inferior to the thyroid cartilage

Question 12

1) What are the two folds located in the larynx?
2) What purpose do they serve?
3) Where is the glottis located?

Answer 12

1) The superior vestibular fold and inferior vocal fold. 2) The vestibular fold plays no role in speech and just closes the larynx during swallowing, and the vocal fold allows for speech.
3) The glottis is the two folds and the space between them

Question 13

1) The __________, or “windpipe,” is a rigid tube anterior to the esophagus. 2) It is supported by 16 to 20 C-shaped rings of __________ cartilage.
3) The open part of the C faces __________.
4) What does the gap in the C allow for?

Answer 13

1) The trachea
2) It is supported by hyaline cartilage.
3) The open part of the C faces the esophagus.
4) The gap in the C allows for the esophagus to expand into the trachea when swallowing food.

Question 14

1) The inner lining of the trachea is what type of tissue?
2) The________ traps inhaled particles, and the upward beating of the __________ moves mucus toward the pharynx, where it is swallowed.

Answer 14

1) Ciliated pseudostratified columnar epithelium.
2) Mucous; Cilia

Question 15

The outermost layer of the trachea, the ______________, is fibrous connective tissue that blends into that of other organs of the mediastinum.

Answer 15

Adventitia

Question 16

1) What does the trachea fork into at its most inferior? The lowermost tracheal cartilage has an internal median ridge called the ________ that directs airflow right and left.
2) The bronchi subdivide in the lungs to form the___________ tree.

Answer 16

1) Carina
2) Bronchial

Question 17

1) The lungs are somewhat conical with a broad, concave base resting on the diaphragm and a blunt peak called the _________ projecting slightly above the clavicle.
2) The mediastinal surface exhibits a slit called the _________ through which the lung receives the main bronchus, blood vessels, lymphatics, and nerves.

Answer 17

1) Blunt peak called the apex
2) The hilum

Question 18

1) Why is the right lung shorter than the left?
2) Why is the left lung, although taller, narrower than the right?

Answer 18

1) The right lung is short to make room for the liver
2) The left lung is narrower to make room for the apex of the heart

Question 19

1) If an object is aspirated, which lung would it lodge in and why?
2) What do we call the indentation on the medial surface of the left lung?

Answer 19

1) An aspirated object would lodge in the right lung because the right bronchiole is more vertical, shorter, and wider.
2) The indentation on the medial surface of the left lung is the cardiac impression

Question 20

1) How many lobes does the right lung have and what fissures separate which lobes?
2) The left lung has only a _______ and ___________ and a single oblique fissure.

Answer 20

1) The right lung has 3 lobes; the horizontal fissure separates the superior and middle lobes, and the oblique fissure separates the middle and inferior lobes.
2) The left lung has only a superior lobe and inferior lobe and a single oblique fissure.

Question 21

The bronchial tree is a branching system of air tubes within each lung; it extends from the main bronchus to about 65,000 _________ __________

Answer 21

terminal bronchioles

Question 22

1) How many branches does the right lung give off?
2) In both lungs, the lobar bronchi branch into ___________ (tertiary) bronchi.
3) The main bronchi are supported, like the trachea, with C-shaped rings of hyaline cartilage, whereas the _________ and ___________ bronchi are supported by overlapping crescent-shaped cartilaginous plates.

Answer 22

1) 3
2) In both lungs, the lobar (secondary) bronchi branch into segmental (tertiary) bronchi.
3) Lobar (secondary) and segmental (tertiary) bronchi are supported by overlapping crescent-shaped cartilaginous plates.

Question 23

1) Does the pulmonary artery carry to the alveoli or away from the alveoli?
2) What does the bronchial artery serve?
3) Is the blood in the bronchial artery oxygenated or deoxygenated?
4) What muscle is located here, skeletal or smooth?

Answer 23

1) To the alveoli
2) Bronchial artery from aorta services bronchial tree with systemic blood
3) Oxygenated blood
4) Smooth muscle

Question 24

What determines when you call a vessel in the bronchial tree bronchioles? Is cartilage here? What does the bronchiole enter?

Answer 24

Bronchioles are 1 mm or less in diameter and have no cartilage support, and each bronchiole enters a Pulmonary lobule

Question 25

1) What is a terminal bronchiole, i.e., when do you change from bronchiole to terminal bronchiole?
2) What branches off a terminal bronchiole? What is considered the beginning of the respiratory zone?

Answer 25

1) Terminal bronchioles have no mucous glands or goblet cells but still have cilia; they’re the final branches of the conducting zone
2) They branch off into respiratory bronchioles, which is the beginning of the respiratory zone.

Question 26

What 3 things are located after the respiratory zone starts?

Answer 26

Respiratory bronchiole, alveolar ducts, and alveolar sacs

Question 27

What is the path of airflow in the conducting division starting with the nasal cavity and ending with the terminal bronchiole?

Answer 27

1) Nasal cavity
2) Nasopharynx
3) Oropharynx
4) Laryngopharynx
5) Larynx
6) Trachea
7) Primary bronchi
8) Secondary bronchi
9) Tertiary bronchi
10) Bronchioles
11) Terminal bronchioles

Question 28

1) How many alveoli are in each lung?

Answer 28

150 million

Question 29

What are the three type of alveoli cells? What are their functions?

Answer 29

1) Squamous (type I) alveolar cells
a) Thin cells that allow for rapid gas diffusion between alveolus and bloodstream
b) Cover 95% of alveolus surface area; most numerous
2) Great (type II) alveolar cells
a) Round to cuboidal cells that cover the remaining 5% of alveolar surface
b) Repair the alveolar epithelium when the squamous (type I) cells are damaged
c) Secrete pulmonary surfactant
3) Alveolar macrophages (dust cells)
a) Wander the lumens of alveoli and the connective tissue between them
b) Keep alveoli free from debris by phagocytizing dust particles
c) 100 million dust cells die each day as they ride up the mucociliary escalator to be swallowed and digested

Question 30

1) What are the most numerous of all cells in the lungs and what do they do?
2) Which alveolar cell type secretes surfactant?
3) Which alveolar cell type helps repair the alveolar epithelium?
4) Which cell type does phagocytosis?

Answer 30

1) Squamous (type I) alveolar cells are the most numerous; they’re thin cells that allow for rapid gas diffusion between alveoli and bloodstream
2) Great (type II) alveolar cells
3) Great (type II) alveolar cells
4) Alveolar macrophages (dust cells)

Question 31

1) What supplies the web of blood capillaries around each alveoli?
2) What makes up the respiratory membrane barrier? What is the barrier between?

Answer 31

1) A pulmonary artery
2) It’s a thin barrier between the alveolar air and blood that consists of squamous alveolar cells, endothelial cells of the blood capillary, their shared basement membrane, and the thin layer of moisture inside the alveolus.

Question 32

1) What happens to keep fluid from accumulating in the alveoli?
2) Why don’t you want fluid to accumulate in the alveoli?

Answer 32

1) Low capillary pressure is maintained to keep low filtration (prevents membrane rupture), excess liquid is absorbed by the blood capillaries, and the lungs have the most extensive lymphatic drainage in the body
2) If fluid accumulates in the alveoli, then gasses diffuse too slowly through liquid to sufficiently aerate the blood

Question 33

1) At the hilum of the lungs, the visceral pleura turns back on itself and forms the ________ pleura.
2) The space between the parietal and visceral pleurae is called the _________ cavity.

Answer 33

1) At the hilum, the visceral pleura turns back on itself and forms the parietal pleura.
2) The space between the parietal and visceral pleurae is called the pleural cavity.

Question 34

What are functions of the pleurae and pleural fluid of the lungs? (3)

Answer 34

1) Reduce friction
2) Create pressure gradient: Lower pressure than atmospheric pressure; allows the two layers to stick to each other (assists lung inflation)
3)Compartmentalization: Prevents spread of infection from one organ to another

Question 35

1) Breathing, or pulmonary ventilation, consists of a repetitive cycle of _________ (inhaling) and ___________ (exhaling).
2) What does a respiratory cycle consist of?
3) What is quiet respiration? What is forced respiration?

Answer 35

1) Inspiration; expiration
2) One complete inspiration (inhaling) and expiration (exhaling)
3) Quiet expiration is a passive process occurring at rest, whereas forced expiration is an active process that occurs during exercise.

Question 36

1) Can you name the muscles of respiration?
2) Which is the prime mover of inhalation? Which are synergist muscles for inhalation?

Answer 36

1) The diaphragm, external intercostals, and scalenes are typically used for respiration
2) The prime mover of inhalation is the diaphragm; the synergists are the external intercostals and scalenes

Question 37

1) Which muscles are used for forced inhalation?
2) Which muscles are used for forced expiration?

Answer 37

1) Forced inhalation: The erector spinae, sternocleidomastoid, pectoralis major, pectoralis minor, and serratus anterior muscles are used
2) Forced expiration: The rectus abdominis and the internal intercostals are used.

Question 38

1) When do you use the Valsalva maneuver?
2) How is the maneuver performed?

Answer 38

1) Used during childbirth, urination, defecation, vomiting
2) Consists of taking a deep breath, holding it by closing the glottis, and then contracting the abdominal muscles to raise abdominal pressure and push organ contents out

Question 39

1) Automatic neural control of breathing requires the VRG and the DRG found in which organ?
2) Which sets the basic respiratory rhythm?

Answer 39

1) The medulla
2) The VRG sets the basic respiratory rhythm of 12 breaths/minute

Question 40

1) Which respiratory group modifies the rate and depth of breathing?
2) Which receives influences from external sources?

Answer 40

1) The DRG modifies the rate and depth of breathing
2) The DRG uses influences from external sources

Question 41

1) The PRG is in what organ?
2) What is the purpose of the PRG?

Answer 41

1) The PRG is in the pons.
2) It modifies rhythm of the VRG by outputs to both the VRG and DRG. It does this to adapt breathing to special circumstances such as sleep, exercise, vocalization, and emotional responses

Question 42

What would be examples of voluntary control of breathing?

Answer 42

Holding your breath, playing an instrument, swimming, etc

Question 43

1) Where are central chemoreceptors located?
2) They respond to changes in which fluid, blood or cerebrospinal fluid? They respond mostly to changes in CO2, O2 or pH?

Answer 43

1) The central chemoreceptors are in the medulla
2) They respond to changes in the pH of cerebrospinal fluid which reflects the CO2 level in the blood. They aren’t sensitive to oxygen levels.

Question 44

1) Where are the peripheral chemoreceptors located?
2) They respond to changes in which fluid, blood or cerebrospinal fluid? Are they sensitive to changes in CO2, O2 or pH, some combination of those, all of those or none of those?

Answer 44

1) In the carotid and aortic bodies
2) They respond to changes in the the O2 and CO2 content and the pH of blood

Question 45

1) What are the purposes of stretch receptors?
2) What would irritant receptors respond to?
3) Voluntary control of breathing involves which lobe of the cerebrum? This is known as a ________________ influence.

Answer 45

1) Stretch receptors are important to the inflation; they cause the (Hering-Breuer) reflex, which prevents over-inflation
2) Irritant receptors respond to smoke, dust, pollen, chemical fumes, cold air, and excess mucus
3) Voluntary control of breathing involves the cerebral cortex; this is known as cortical influences. This part of the cerebrum is called the frontal lobe

Question 46

1) Respiratory flow is very similar to what other flow in the body?
2) If resistance does up, does the flow of air go up or down?
3) Is this inversely proportional or directionally proportional?

Answer 46

1) Blood flow
2) If resistance goes up, airflow goes down.
3) This is inversely proportional.

Question 47

1) What is atmospheric pressure in mmHg and in atm?
2) What does it mean to have positive respiratory pressure? What does it mean to have negative respiratory pressure?

Answer 47

1) 760mmHg or 1atm.
2) Positive respiratory pressure means the respiratory pressure is above that of the atmosphere, and negative respiratory pressure means it’s below atmospheric pressure.

Question 48

1) What does Boyle’s law state?
2) If lung volume increases, what does this do to intrapulmonary pressure? Does it increase or decrease? Does air move into the lungs or out of the lungs?

Answer 48

1) That at a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume
2) If the volume increases, intrapulmonary pressure decreases, and air moves into the lungs if it falls below atmospheric pressure

Question 49

1) If lung volume decreases, what does this do to intrapulmonary pressure? Does air move into the lungs or out of the lungs?
2) When does air flow stop moving?

Answer 49

1) If the volume decreases, intrapulmonary pressure increases, and air moves out of the lungs.
2) When intrapulmonary pressure is equal to the atmospheric pressure

Question 50

Which profession uses cm of water for pressure unit measurements and why?

Answer 50

Respiratory physiologists because it’s more sensitive than mmHg, since Hg (mercury) is a heavy liquid

Question 51

1) As the thoracic cage expands, the two layers of pleura do what?
2) And what are the two reasons the pleural membranes do the thing they do?
3) Is air flowing in or out of the lungs?

Answer 51

1) The two layers of pleura stick together
2) Because:
a) Cohesion of water in the pleural cavity
b) Slightly negative Intrapleural pressure
-Recoil of lung tissue and tissues of thoracic cage causes lungs and chest wall to be pulling in opposite directions
-About −5 cm H_2 O of intrapleural pressure results
3) Air is flowing into the lungs; elastic coil of the thoracic cage compresses the lungs

Question 52

When the prime mover of inspiration contracts, in what direction does it move? What does this do to the volume in the thoracic cavity?

Answer 52

It moves downward, which increases the volume of the thoracic cavity

Question 53

In quiet breathing, how much is the total volume increased by?

Answer 53

500ml

Question 54

1) What is expiration? Is air flowing in or out of the lungs?
2) What muscles are involved?
3) When the prime mover of inspiration, relaxes, in what direction does it move? What does it do to the volume in the thoracic cavity when it is relaxed?

Answer 54

1) Exhaling; air is moving out of the lungs
2) No muscles are involved in relaxed exhalation, in forced exhalation the internal intercostals and rectus abdominis are involved
3) The prime mover of inspiration moves upwards towards the lungs when it relaxes, which decreases the volume of the thoracic cavity

Question 55

Define pneumothorax, hemothorax and atelectasis

Answer 55

1) Pneumothorax: Thoracic wall is punctured allowing air into pleural cavity
2) Hemothorax: A collection of blood in the space between the chest wall and the lung
3) Atelectasis: Collapse of part or all of a lung

Question 56

1) What happens to airflow if you increase resistance?
2) What two factors influence airway resistance?

Answer 56

1) Increasing resistance decreases airflow
2) Bronchiole diameter and pulmonary compliance

Question 57

1) What is bronchodilation; what hormones are involved and what happens to airflow?
2) What is bronchoconstriction; what hormones are involved and what happens to airflow?

Answer 57

1) Dilation of bronchiole diameter; controlled by epinephrine and sympathetic stimulation. Increases airflow.
2) Constriction of bronchiole diameter; controlled by histamine, parasympathetic nerves, cold air, and chemical irritants

Question 58

1) What is pulmonary compliance?
2) What are reasons that pulmonary compliance be reduced?

Answer 58

1) The ease with which the lungs or thoracic wall can expand
2) Degenerative lung diseases (TB, black lung disease) that cause scar tissue or increased surface tension due to lack of surfactant

Question 59

What is the purpose of surfactant?

Answer 59

Surfactant disrupts hydrogen bonds between water molecules and thus reduces the surface tension; reducing surface tension increases compliance

Question 60

1) Define anatomic dead space. Can it be altered; if so, how?
2) Define physiologic (total) dead space.

Answer 60

1) Anatomic dead space is the dead space taken up by the conducting zone of the airway; can be altered somewhat by sympathetic and parasympathetic stimulation (sympathetic dilation increases dead space but allows greater flow)
2) Physiologic (total) dead space is the sum of anatomic dead space and any pathological alveolar dead space

Question 61

Give the definitions and the respiratory volumes of the following:
1) Tidal volume
2) Inspiratory reserve volume
3) Expiratory reserve volume
4) Residual volume.

Answer 61

1) Tidal volume: The volume of one breath inhaled or exhaled. ~500ml/breath.
2) Inspiratory reserve volume: The amount of air that can be forcefully inhaled after a normal tidal volume inhalation (3,000ml)
3) Expiratory reserve volume: The amount of air that can be forcefully exhaled after a normal tidal volume exhalation (1,200ml)
4) Residual volume: The amount of air remaining in the lungs after maximum exhalation (1300ml)

Question 62

1) What is a spirometer?
2) What is vital capacity?
3) Do males or females have greater vital capacity?

Answer 62

1) A device that measures rate and depth of breathing, speed of expiration, and rate of oxygen consumption
2) The maximum amount of air that can be exhaled after maximum inspiration (4700ml); decreases with age
3) Males have a higher vital capacity

Question 63

Define:
1) Eupnea
2) Apnea
3) Hyperventilation
4) Hypoventilation

Answer 63

1) Eupnea: relaxed, quiet breathing
2) Apnea: temporary cessation of breathing
3) Hyperventilation: increased pulmonary ventilation in excess of metabolic demand
4) Hypoventilation: reduced pulmonary ventilation leading to an increase in blood CO2

Question 64

Relaxed, quiet breathing, or eupnea, is typically characterized by a TV of _____ mL and a respiratory rate of ___ to ____ breaths/min.

Answer 64

500; 12-15

Question 65

1) What is air is composed of?
2) What is the most abundant gas in the atmosphere?
3) The total atmospheric pressure is a sum of?

Answer 65

1) 78.6% nitrogen, 20.9% oxygen, 0.04% carbon dioxide, 0% to 4% water vapor, depending on temperature and humidity, and minor gasses argon, neon, helium, methane, and ozone
2) Nitrogen
3) The contributions of the individual gasses

Question 66

1) What is partial pressure?
2) How do you calculate it?

Answer 66

1) Partial pressure is the separate contribution of each gas in a mixture toward pressure.
1) Percent of mixture x total pressure = partial pressure.

Question 67

What is Dalton’s law?

Answer 67

Total atmospheric pressure is the sum of the contributions of the individual gasses

Question 68

1) What is alveolar gas exchange?
2) Each gas diffuses ______ its pressure gradient until the partial pressure of each gas in the air is equal to its partial pressure in the water, namely the water film on the surface of alveoli.

Answer 68

1) Alveolar gas exchange is the swapping of O2 and CO2 across the respiratory membrane
2) down

Question 69

1) Explain what it means to load oxygen or unload carbon dioxide?
2) Do respiratory gasses come in contact with water?

Answer 69

1) It means oxygen is entering the blood and carbon dioxide is leaving it.
2) Yes; there is a film of water on the outside of the alveolar films.

Question 70

1) When does a gas stop diffusing down its partial pressure gradient?
2) What does Henry’s law state?

Answer 70

1) Until the partial pressure of each gas in the air is equal to its partial pressure in water
2) For a given temperature, the amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in air

Question 71

1) Which is more soluble, CO2 or O2?
2) What gas is mostly insoluble in plasma?

Answer 71

1) CO2 is 20 times more soluble than O2
2) N2 is practically insoluble in plasma

Question 72

The greater the PO2 in alveolar air, the _______ O2 the blood picks up; and the greater the PCO2 in the blood, the ______ CO2 is released into alveolar air.

Answer 72

more; more

Question 73

In gas exchange, as partial pressures are different, is the amount of O2 and CO2 exchanged the same or different? Why?

Answer 73

Equal amounts of O2 and CO2 are exchanged; the CO2 gradient might not be as steep as the oxygen gradient, but it’s more soluble.

Question 74

List the four factors that can change the rate of gas exchange and describe them

Answer 74

1) Pressure gradient: increased pressure gradient between alveoli and blood increases rate of gas exchange
2) Respiratory membrane surface area: decreased surface area decreases the rate of gas exchange
3) Respiratory membrane thickness: increased respiratory membrane thickness decreases the rate of gas exchange
4) Ventilation-perfusion coupling: the ability to match air flow and blood flow to each other

Question 75

1) What are reasons that could result in decreased lung surface area?
2) What are reasons the membrane thickens?

Answer 75

1) Emphysema, lung cancer, and tuberculosis decrease surface area for gas exchange
2) Pneumonia, pulmonary edema (left ventricular heart failure), etc. can cause the membrane to thicken

Question 76

Which term ventilation or perfusion refers to the alveolus? Which term ventilation or perfusion refers to the capillaries?

Answer 76

Ventilation refers to the alveolus, perfusion refers to the capillaries

Question 77

1) What is necessary for good gas exchange?
2) Poor ventilation causes local ___________ of the pulmonary arteries, redirecting blood to better-ventilated alveoli.
3) Good ventilation stimulates ________ of the arteries and increases perfusion so that most blood is directed to regions where it can pick up the most oxygen.
4) This is the opposite from the reactions of systemic arteries, where oxygen deficiency causes ___________.

Answer 77

1) Gas exchange requires both good ventilation of alveolus and good perfusion of the capillaries
2) Constriction
3) Dilation
4) Perfusion

Question 78

1) What is the number one way oxygen is transported in the body?
2) Define:
a) Oxyhemoglobin
b) Deoxyhemoglobin
c) Carbaminohemoglobin

Answer 78

1) Bound to hemoglobin
2a) Oxyhemoglobin (HbO2): O2 bound to hemoglobin
2b) Deoxyhemoglobin (HHb): hemoglobin with no O2
2c) Carbaminohemoglobin (HbCO2): hemoglobin with CO2

Question 79

1) How many molecules of oxygen can bind to one hemoglobin?
2) What percent of bound oxygen is unloaded in the tissues?
3) Why is carbon monoxide poisonous?

Answer 79

1) 4 molecules of O2
2) 25% is unloaded in the tissues
3) If hemoglobin is given a choice between binding to oxygen or carbon monoxide, it will bind to carbon monoxide every single time

Question 80

1) What are the three forms carbon dioxide is found in the body?
2) In the transport of CO2 and in exchange of CO2, the majority is in the form of what acid?

Answer 80

1) Most is carbonic acid, some is carbaminohemoglobin, some as dissolved gas
2) Carbonic acid

Question 81

Write out and interpret the carbon dioxide plus water reaction through dissociation into bicarbonate and free hydrogen

Answer 81

1) CO2 + H2O > H2CO3 > HCO3- + H+.
2) Carbon dioxide plus water can lead to the formation of carbonic acid, which can then dissociate into bicarbonate and free hydrogen.

Question 82

1) In CO2 loading, is CO2 diffusing into cells or diffusing into blood?
2) What enzyme catalyzes the reaction?
3) Explain how the chloride shift is working. What is being exchanged for chloride?

Answer 82

1) CO2 is diffusing into the blood
2) Then carbonic anhydrase from the RBC catalyzes the reaction of carbon dioxide and water into carbonic acid, which then disassociates into bicarbonate and free hydrogen.
3) Then hydrogen bonds to hemoglobin, making it release O2, bicarbonate diffuses out of the RBC and is exchanged for chloride (chloride shift)

Question 83

1) In CO2 unloading, what is loading onto the Hb as CO2 is dissociating?
2) Explain how the reverse chloride shift is working. What is being exchanged for chloride?

Answer 83

1) As hemoglobin loads O2, its affinity for H+ decreases, so H+ dissociates from hemoglobin and binds with bicarbonate.
2) Then bicarbonate diffuses back into RBC to be exchanged for Cl−, free CO2, that is generated and diffused into alveolus to be exhaled

Question 84

What are the factors that adjust the rate of oxygen unloading to meet the body’s needs?

Answer 84

1) Ambient PO2: active tissue has a decreased pressure of oxygen, so oxygen is released from Hb
2) Ambient pH (Bohr effect): active tissue has an increased amount of CO2, which lowers pH of blood; promoting O2 unloading
3) Temperature: Active tissue has an increase temp; promotes O2 unloading

Question 85

1) What is the range of blood pH?
2) What is the most potent stimulus for breathing? What is the second most potent stimulus for breathing? What is the last most potent stimulus for breathing?

Answer 85

1) 7.35-7.45
2) Most important is pH, followed by CO2, and least significant is O2

Question 86

1) What is used to maintain the pH of the brain?
2) Central chemoreceptors are located in what organ and what fluid do they monitor?
3) Peripheral chemoreceptors monitor what fluid?
4) Which produces most of the response?

Answer 86

1) The adjustment of pulmonary ventilation (breathing)
2) Central chemoreceptors are in the medulla; monitor CSF
3) Peripheral chemoreceptors; monitor blood
4) Central chemoreceptors produce 75% of the response

Question 87

Define acidosis, alkalosis, hypocapnia and hypercapnia. Relate hypocapnia and hypercapnia with acidosis and alkalosis.

Answer 87

1) Acidosis: blood pH lower than 7.35
2) Alkalosis: blood pH higher than 7.45
3) Hypocapnia: PCO2 less than 37 mm Hg (normal 37 to 43 mm Hg)
-Most common cause of alkalosis
4) Hypercapnia: PCO2 greater than 43 mm Hg
-Most common cause of acidosis

Question 88

1) When is a respiratory imbalance considered respiratory acidosis? What is happening to CO2 and what is happening to the pH number?
2) Would hypoventilation or hyperventilation be the correct corrective function?

Answer 88

1) When here’s a pH imbalance (low pH) resulting from a mismatch between the rate of pulmonary ventilation and the rate of CO2 production; there is too much CO2 produced, so pH goes down.
2) Hyperventilation would be the corrective function

Question 89

1) When is a respiratory imbalance considered respiratory alkalosis? What is happening to CO2 and what is happening to the pH number?
2) Would hypoventilation or hyperventilation be the correct corrective function?

Answer 89

1) A pH imbalance (high pH) resulting from a mismatch between the rate of pulmonary ventilation and the rate of CO2 production; there is too little CO2 produced, so pH goes up.
2) Hypoventilation would be the corrective function

Question 90

1) What is hypoxic drive? 2) What are situations that could cause this to occur?

Answer 90

1) Respiration driven more by low PO2 than by CO2 or pH
2) Emphysema, pneumonia, or high elevations after several days

Question 91

1) Define COPD.
2) What are the two major COPDs?
3) What is the most common habit associated with COPD?

Answer 91

1) Long-term obstruction of airflow and substantial reduction in pulmonary ventilation
2) Chronic bronchitis and emphysema
3) Smoking

Question 92

1) What are symptoms of chronic bronchitis?
2) What are symptoms of emphysema?
Consider: Which reduces surface area? Which results in chronic inflammation and infections?

Answer 92

1) Chronic bronchitis: Hypoxemia and cyanosis; severe, persistent inflammation of lower respiratory tract; excessive mucus produced, develops into a chronic cough
2) Emphysema: Alveolar walls break down reducing surface area, which makes lungs fibrotic and less elastic. Air passages collapse (obstructs outflow of air), which causes air to be trapped in lungs, so the person becomes barrel-chested. Weakens thoracic muscles and takes 3-4x the amount of energy just to breathe

Question 93

1) What does COPD due to vital capacity?
2) What are other symptoms that COPD causes?

Answer 93

1) It reduces vital capacity
2) It causes hypoxemia, hypercapnia, and respiratory acidosis
Hypoxemia stimulates erythropoietin release from kidneys, and leads to polycythemia

Question 94

What is Cor pulmonale?

Answer 94

Hypertrophy and potential failure of right heart due to obstruction of pulmonary circulation

Question 95

1) What cancer accounts for more deaths than any other form of cancer?
2) What is the cause of people getting this type of cancer?
3) How many carcinogenic compounds are in cigarette smoke?

Answer 95

1) Lung cancer
2) Smoking
3) At least 60