Chapter 17 Flashcards
Gases exert a partial pressure when they are in gaseous form or when they are dissolved in liquid. True or False?
True
Carbon dioxide is approximately 20 times more soluble in liquid than oxygen. True or False?
True
If the partial pressure of oxygen in a pulmonary capillary is 100 mm Hg and the partial pressure of oxygen in the alveoli is 100 mm Hg, the net flow of oxygen from the alveoli to the blood would be zero. True or False?
True
At equilibrium, the concentration of oxygen will be the same in the alveolus as it is in the capillary surrounding the alveolus. True or False?
False. At equilibrium the partial pressures will be equal between the alveolus and its associated capillary. This does not mean that the concentration of oxygen will be equal between the two locations.
Blood in the \_\_\_\_\_\_\_\_\_\_ will have the same PO2 as the blood in the aorta. A. right ventricle B. pulmonary veins C. pulmonary arteries D. systemic veins
The PULMONARY VEINS deliver oxygenated blood to the left side of the heart. Since no gas exchange occurs while inside the left atrium or left ventricle, the blood in the pulmonary veins will have the same amount of oxygen as in the aorta. (B)
Blood in the \_\_\_\_\_\_\_\_\_\_ will have the same PO2 as the blood in the pulmonary arteries. A. right ventricle B. pulmonary veins C. aorta D. systemic veins
The SYSTEMIC VEINS deliver deoxygenated blood to the right atria. This deoxygenated blood is then pumped through the right ventricle to pulmonary arteries going to the lungs to be oxygenated. (D)
The partial pressure of oxygen in atmospheric air at sea level is about 160 mm Hg. The partial pressure of oxygen in the alveoli is less than that. Why?
A. The barometric pressure of air decreases as air moves into the lungs.
B. The cells of the upper respiratory tract absorb some of the oxygen that is breathed in, removing it from the air that reaches the alveoli.
C. Water vapor is added to the air that is breathed in, which decreases the fraction of air that is oxygen.
D. The cells of the upper respiratory tract secrete carbon dioxide into the lumen of the airways, thereby increasing the fraction of carbon dioxide and decreasing the fraction of oxygen.
C. Water vapor is added to the air that is breathed in, which decreases the fraction of air that is oxygen. If another gas is added to a gaseous mixture, the fractional composition of the other gases will necessarily decrease.
In order to diffuse from the blood into the alveoli, oxygen and carbon dioxide have to cross __________ cell layer(s) and a basement membrane.
Two (alv & cap)
Oxygen is transported in the blood by which methods? (Multiple answers) A. attached to platelets B. dissolved in plasma C. converted to bicarbonate D. bound to hemoglobin
dissolved in plasma & bound to hemoglobin (B & D)
Carbon dioxide is transported in the blood by which methods? (Multiple answers) A. attached to platelets B. dissolved in plasma C. converted to bicarbonate D. bound to hemoglobin
B. dissolved in plasma
C. converted to bicarbonate
D. bound to hemoglobin
Carbonic anhydrase is an enzyme involved in the conversion of \_\_\_\_\_\_\_\_\_\_ to \_\_\_\_\_\_\_\_\_\_. A. carbon dioxide; bicarbonate B. carbon dioxide; oxygen C. carbon dioxide; carbaminohemoglobin D. oxygen; oxyhemoglobin
Carbonic anhydrase is an enzyme involved in the conversion of CARBON DIOXIDE to BICARBONATE. (A)
The concentration gradient of oxygen is affected by the \_\_\_\_\_\_\_\_\_\_ and solubility of oxygen. A. temperature B. transpulmonary pressure C. concentration of carbon dioxide D. partial pressure
The concentration gradient of oxygen is affected by the PARTIAL PRESSURE and solubility of oxygen. (D)
The venous blood in the right ventricle is referred to as “mixed” because the blood that enters the heart..
A. has a high PCO2.
B. contains a mixture of oxygen and carbon dioxide.
C. comes from tissue with differing metabolic activities.
D. has a low PO2.
The venous blood in the right ventricle is referred to as “mixed” because the blood that enters the heart… C. comes from tissue with differing metabolic activities.
Which of the following causes a decrease in the PO2 of air as it enters the conducting zone of the lungs? A. warming of the air B. humidifying the air C. the consumption of oxygen D. the increasing PCO2
B. humidifying the air
When the PO2 immediately surrounding the hemoglobin is high, this facilitates oxyhemoglobin dissociation. True or False?
False. Actually, when PO2 is high, this facilitates the formation of oxyhemoglobin.
The majority of oxygen in the blood does not directly contribute to the PO2 of the blood. True or False?
True
A leftward shift in the hemoglobin-oxygen dissociation curve can be caused by an increase in blood pH. True or False?
True
A leftward shift in the hemoglobin-oxygen dissociation curve can be interpreted that hemoglobin is more saturated at a given PO2. True or False?
True
A leftward shift in the hemoglobin-oxygen dissociation curve can be interpreted that oxygen loading onto the hemoglobin is increased. True or False?
True
A leftward shift in the hemoglobin-oxygen dissociation curve can be interpreted that affinity for oxygen is increased. True or False?
True
A leftward shift in the hemoglobin-oxygen dissociation curve can be interpreted that affinity for oxygen is decreased. True or False?
False. Left shift = Higher affinity for O2
A right shift in the hemoglobin-oxygen dissociation curve can be interpreted that affinity for oxygen is decreased. True or False?
True
A right shift in the hemoglobin-oxygen dissociation curve can be interpreted that affinity for oxygen is increased. True or False?
False. Right shift = Lower affinity for O2.
A right shift in the hemoglobin-oxygen dissociation curve can be interpreted that increase/decrease in O2 unloading.
Increase O2 unloading d/t lower affinity for O2.
A left shift in the hemoglobin-oxygen dissociation curve can be interpreted that increase/decrease in O2 unloading.
Decrease in O2 unloading d/t higher affinity for O2.
A right shift in the hemoglobin-oxygen dissociation curve can be interpreted that oxygen loading onto the hemoglobin is increased. True or False?
False. Lower affinity for O2 means harder to bind or load onto hemoglobin. Unloading of O2 is increased.
A right shift in the hemoglobin-oxygen dissociation curve can be caused by an increase in blood pH. True or False?
False. Decrease in blood pH causes a right shift in the hemoglobin-oxygen dissociation curve.
A right shift in the hemoglobin-oxygen dissociation curve can be caused by an increase in PCO2. True or False?
True
A leftward shift in the hemoglobin-oxygen dissociation curve can be caused by an increase in PCO2. True or False?
False. Left shift can be caused by a decrease in PCO2
Respiratory acidosis can occur during.. A. hypoventilation B. hyperventilation C. hypocapnia D. hypernea
A. hypoventilation - a condition in which ventilation is insufficient to meet the metabolic demands of the body.
What is the primary function of the central pattern generator?
The central pattern generator (CPG) is responsible for generating the cycle of inspiration and expiration.
The diaphragm is the most important muscle of respiration. It is innervated by the __________ nerve.
The diaphragm is the most important muscle of respiration. It is innervated by the PHRENIC nerve.
Peripheral chemoreceptors respond to all EXCEPT which of the following? A. small changes in PCO2 B. small changes in H+ ion concentration C. small changes in PO2 D. small changes in pH
C. small changes in PO2
Henry's law determines the \_\_\_\_\_\_\_\_ of gases. A. solubility B. partial pressure C. resistance D. temperature
Henry’s law determines the SOLUBILITY of a gas in a liquid. (A)
Dalton's law determines the \_\_\_\_\_\_\_\_ of gases. A. solubility B. partial pressure C. resistance D. temperature
Dalton’s law determines the PARTIAL PRESSURE of a gas in a mixture of gases. (B)
Normal air is comprised of \_\_\_\_\_\_\_\_\_\_ percent nitrogen and \_\_\_\_\_\_\_\_\_\_ percent oxygen. A. 90;10 B. 79;21 C. 59;41 D. 50;50
Normal air is comprised of ___79___ percent nitrogen and ___21___ percent oxygen. (B)
According to (Henry’s/Dalton’s) law, the partial pressure of a gas in a mixture of gases is equal to the percent of the gas present in the mixture multiplied by the total combined pressure of all the gases in the mixture of gases. PP of certain gas = (% of certain gas in mixture/100) x (total combined pressure of all the gases in the mixture)
Dalton’s law
At sea level, the atmospheric pressure is \_\_\_\_\_\_\_\_\_\_ mm Hg. According to Dalton’s law, \_\_\_\_\_\_\_\_\_\_ would have the highest partial pressure in Earth’s atmosphere. A. 1,000 mm Hg; oxygen B. 760; oxygen C. 760; carbon dioxide D. 760; nitrogen
D. 760; nitrogen
(Henry’s/Dalton’s) law determines how much a certain gas will dissolve in a certain liquid. The formula states that the molar concentration ‘c’ of a gas that will dissolve in a liquid is equal to the partial pressure of the gas above the liquid ‘P’ times a constant.
Henry’s
The Henry’s law constant ‘k’ is experimentally derived; it depends on the particular chemical properties of a certain gas and chemical properties of a certain liquid. Thus, a low value for Henry’s constant reflects that a certain gas has a \_\_\_\_\_\_\_\_\_\_ solubility in a certain liquid. A high value reflects that a certain gas has a \_\_\_\_\_\_\_\_\_\_ solubility in a certain liquid. A. low; low B. low; high C. high; low D. high; high
B. low; high
Though __________ is the major gas in the atmosphere, it does not dissolve easily into blood plasma because of a low Henry’s constant. However, it can be forced into the blood if there is an increase in its partial pressure.
A. oxygen
B. carbon dioxide
C. nitrogen
C. nitrogen
For every \_\_\_\_\_\_\_\_\_\_ feet that a diver descends under water, the pressure increases by 1 atmosphere (760 mm Hg). This increased pressure can drive nitrogen into the blood. Because nitrogen is minimally soluble in blood, it forms bubbles in the bloodstream, just as carbon dioxide does when forced (pushed) into a beverage to make it carbonated. A. 10 B. 100 C. 33 D. 50
For every ___33___ feet that a diver descends under water, the pressure increases by 1 atmosphere (760 mm Hg).
The nitrogen bubbles will lodge in joints and cause cramps and pain known as \_\_\_\_\_\_\_\_\_\_. When the bubbles move into the nervous system they may cause a loss or decrease in consciousness known as nitrogen narcosis. A. nitrogen toxicity B. respiratory alkalosis C. respiratory acidosis D. the bends
D. the bends
Nitrogen bubbles in the circulation may cause an air \_\_\_\_\_\_\_\_\_\_. One treatment that drives the nitrogen bubbles back into solution is to place the person in a \_\_\_\_\_\_\_\_\_\_. A. embolism; hyperbaric chamber B. thrombus; hyperbaric chamber C. thrombus; hypobaric chamber D. embolism; hypobaric chamber
A. embolism; hyperbaric chamber
Hypoventilation can lead to \_\_\_\_\_\_\_\_\_\_ levels of CO2 and respiratory \_\_\_\_\_\_\_\_\_\_. A. decreased; alkalosis B. increased; acidosis C. decreased; acidosis D. increased; alkalosis
Hypoventilation can lead to INCREASED levels of CO2 and respiratory ACIDOSIS. (B)
How does hemoglobin (Hb) act as a blood buffer?
A. Hb does not act as a buffer in the blood.
B. Hb binds the majority of CO2, preventing it from being converted into carbonic acid.
C. Hb can desensitize the central chemoreceptors so they are less responsive to increases in arterial PCO2.
D. Hb can bind H+ following the dissociation of carbonic acid.
D. Hb can bind H+ following the dissociation of carbonic acid. As soon as carbonic acid dissociated, it becomes H+ and a bicarbonate anion. If that H+ were left unchecked, it would cause a significant decrease in blood pH.
Hyperventilation can lead to \_\_\_\_\_\_\_\_\_\_ levels of CO2 and respiratory \_\_\_\_\_\_\_\_\_\_. A. decreased; alkalosis B. increased; acidosis C. decreased; acidosis D. increased; alkalosis
Hyperventilation can lead to __________ levels of CO2 and respiratory __________. A. decreased; alkalosis
What is the difference between ventilation and respiration?
Ventilation is mechanical rxn and Respiration is chemical rxn - exchange of gases.
Distinguish between respiration at the biochemical level between animals and plants.
In the biochemistry of animals, O2 is consumed as covalent bonds are broken to yield energy, and CO2 is produced. In plants, CO2 is consumed in the process of trapping energy to form the covalent bonds of more complex molecules during photosynthesis.
Distinguish the difference between hypoxia and hypoxemia.
Hypoxia is the deficiency of O2 in the tissues. Hypoxemia is the deficiency of O2 in the blood.
Hyper/Hypocapnia is an excess/deficiency of what in the blood?
Hyper/Hypocapnia is an excess/deficiency of CO2 in the blood
Define hyperpnea.
Increase in ventilation to meet an increase in the metabolic demands of the body.
How do the terms dyspnea and apnea relate to breathing?
Dyspnea describes labored or difficult breathing.
Apnea describes a temporary cessation of breathing.
Define tachypnea.
Rapid, shallow breathing.
Describe the conditions of hyperventilation.
Ventilation exceeds the metabolic demands of the body.
Describe the conditions of hypoventilation
Ventilation is insufficient to meet the metabolic demands of the body.
What is inspiration initiated by?
Neural stimulation
Contraction of diaphram + contraction of external intercostals = rivs pivot up and out, expanding wall
What does 2, 3-DPG do? What does carbon monoxide do?
decreases affinity of Hb for O2 - enhancing O2 unloading
hemoglobin loves CO more than O2
CO prevents O2 binding to Hb
What is the role of carbonic anhydrase? how does the law of mass action relate? equation?
enzyme that converts carbon dioxide and water to carbonic acid.
increased CO2 = increased bicarbonate and H+ ions
CO2 + H2O H2CO3
where does the generation of breathing rhythm come from? what type of input goes to the respiratory centers?
brainstem
peripheral
What kind of neural and muscular control is involved in inspiration? expiration?
phrenic nerve -> diaphragm
external intercostal nerve -> external intercostal muscles
internal intercostal nerve -> internal intercostal muscles
Components of neural control of breathing?
phrenic internal/external intercostal nerves medulla pons central pattern generator
What are the 2 respiratory control centers of the medulla? 2 main functions?
ventral respiratory group: nucleus ambiguous
dorsal respiratory group: nucleus tractus solitarius
controls motor neurons to inpiratory/expiratory muscles
inhibition of inspiratory neurons
Describe the chain reactions of decreased O2.
Direct: increased O2 unloading
Haldane: increased CO2 loading
carbamino: decreased Hb affinity for O2
Describe the chain reactions of increased CO2.
Direct: increased CO2 loading
Bohr and carbamino: decreased Hb affinity for O2
Increased: H+ ions
How does the pons regulate breathing?
pontine respiratory group regulates transitions between inspiration and expiration
(superior to the VRG and DRG)
6 functions of respiratory system?
Regulation of blood pH Enabling vocalization Defense against pathogens and foreigns in airways Provides route for water and heat loss Enhances venous return Activates plasma proteins
What are the 2 primary expiratory muscles?
Internal intercostals and abdominal muscles
What is the function of the central pattern generator?
establishes respiratory cycle
5 types of receptors?
central peripheral pulmonary stretch irritant proprioceptors
Chemoreceptor control of ventilation?
detect O2 and CO2 blood levels
describe peripheral chemoreceptors.
respond to blood pH changes
located in carotid bodies near carotid sinus
have direct contact with arterial blood
communicate via chemical messenger
project to medullary respiratory controls
describe central chemoreceptors.
located on ventral surface of medulla
responds indirectly to CO2 via pH - not DIRECTLY responsive to CO2
increased CO2 = decreased pH
DOESN’T GIVE AN F ABOUT O2 CHANGES!!!!
what kind of feedback is hyperventilation?
negative.
increased CO2 and H+ ions, decreased O2 = more ventilation
Ventilation-perfusion ratios? where?
local ventilation and perfusion are regulated to match (pulmonary capillaries)
V= rate of air flow
P (Q) = rate of blood flow
V(alveoli)/Q = ventilation-perfusion ratio
Effects of increased CO2 and decreased O2 on bronchioles and pulmonary arterioles?
Bronchioles: decreased smooth muscle contractility bronchodilation decreased resistance increased ventilation
Pulmonary arterioles: increased smooth muscle contractility vasoconstriction increased resistance decreased perfusion
CO2 and O2 effects on bronchioles.
increased CO2: dilation
decreased CO2: constriction
increased O2: weak constriction
decreased O2: weak dilation
CO2 and O2 effects on arteries.
increased CO2: weak constriction
decreased CO2: weak dilation
increased O2: dilation
decreased O2: constriction
