Chapter 13 Smartbook
The following are events that occur during inspiration. Place them in sequence, with the first at the top of the list.
-Diaphragm and inspiratory intercostals contract -Thorax expands -Pip becomes more subatmospheric -Increase in transpulmonary pressure -Lung expands -Palv becomes subatmospheric -Air flows into alveoli
Put the following steps in the order that they occur during expiration. Start with the earliest at the top of the list.
-Inspiratory muscles stop contracting. -Chest wall recoils inward and intrapleural pressure increases toward pre-inspiration value. -Intrapleural pressure increases and transpulmonary pressure decreases back toward pre-inspiration values. -Lungs recoil toward pre-inspiration size, compressing alveolar air. -Alveolar pressure increases above atmospheric pressure, and air flows out of lungs.
The total milliliters of oxygen dissolved and bound to hemoglobin in 1 liter of systemic arterial blood is approximately
200
Match the correct numbers to the physiological parameters under normal, resting conditions.
3 - milliliters of oxygen normally dissolved in 1 liter of systemic arterial blood 5 - typical cardiac output in liters per minute 197 - milliliters of oxygen normally bound to hemoglobin in 1 liter of systemic arterial blood 1000 - total milliliters of oxygen normally delivered by systemic arterial blood each minute
In a normal, healthy person at rest, the PO2 in alveolar air and the blood first reaches diffusion equilibrium when the blood has traveled approximately ______% of the length of the pulmonary capillary.
30
Consider the following data: Respiratory rate = 10 breaths/minute Tidal volume = 500 mL/breath Dead space = 150 mL The alveolar ventilation rate for this individual is
3500 mL/minute
What is the minute ventilation of a person who takes a breath every 5 seconds and has a tidal volume of 500 mL?
6000 mL
Red blood cells have an average diameter of approximately ______, and the thickness of the barrier separating alveolar air from pulmonary capillary blood is approximately ______
7 micrometers; 0.2 micrometers
Red blood cells have an average diameter of approximately ______, and the thickness of the barrier separating alveolar air from pulmonary capillary blood is approximately ______.
7 micrometers; 0.2 micrometers
According to the oxygen-hemoglobin dissociation curve, at a PO2 of 60 mmHg, approximately ______% of the total hemoglobin is combined with oxygen.
90
During a normal cycle of respiration, there is a pause prior to inspiring a breath, and a pause in between inspiring and expiring the breath. Which of these conditions is the SAME during those two pauses?
Air flow Atmospheric pressure The alveolar pressure
Which systemic blood compartment does not usually increase in PCO2 during exercise?
Arterial
What does the arterial PCO2 most directly influence?
Arterial pH
In this figure, the letters A, B and C represent the pressures in each region. Which of these equations defines the transpulmonary pressure (Ptp)?
B - C
Which of the following are possible in mountain sickness?
Both pulmonary edema and brain edema
The physical principle stating that gas pressure in a closed space increases as its volume decreases is known as _____'s law.
Boyle
_____ is represented by the equation P1P1V1V1= P2P2V2V2.
Boyle's law
Which of the following are non-respiratory functions of the lungs?
Defends against microbes Forms speech sounds Dissolves blood clots arising from systemic veins
______ has a much greater affinity for H+ than does _____, so it binds (buffers) most of the H+. In this form, hemoglobin is abbreviated ______.
Deoxyhemoglobin; oxyhemoglobin; HbH
Which is TRUE about alveolar and atmospheric pressures with regards to bulk flow of air in the respiratory system?
During an expiration alveolar pressure is greater than atmospheric pressure.
What disease is characterized by a loss of elastic tissue and the destruction of the alveolar walls leading to an increase in lung compliance?
Emphysema
Which of the following is the proper equation for calculating the bulk flow of air out of the lungs? (Where F = flow, Palv = alveolar pressure, Patm = atmospheric pressure, and R = resistance).
F = (Palv −- Patm)/R
True or false: The diaphragm and intercostal muscles contract mainly involuntarily, and are composed of smooth muscle.
False
Which is NOT one of the five main steps involved in respiration?
Gas exchange across pleural membranes
Carbon dioxide is a waste product that has toxicity in part because it generates
H+
______ refers to excessive buildup of carbon dioxide in the blood.
Hypercapnia
What is the term describing the condition in which there is a decreased arterial PCO2?
Hypocapnia
Describe the relationships between air flow, alveolar pressure, and airway resistance by identifying the true statements from the ones shown here.
Increasing pressure gradients will increase flow. Increasing resistance decreases flow. Flow is equal to pressure divided by resistance.
In the absence of other changes, which of the following would NOT increase the PO2 in the alveoli?
Increasing the rate of total body oxygen consumption
Which of the following is the term that describes the additional amount of air that can be inspired after a normal tidal volume is inhaled?
Inspiratory reserve volume
Which of the following statements is true?
Intracellular PO2 of a metabolizing tissue cell is lower than in arteriolar blood, and the intracellular PCO2 is higher than in arteriolar blood.
Which of these occurs during normal inspiration at rest?
Intrapleural pressure becomes more subatmospheric.
As carbon dioxide enters the blood in tissues and H+ and HCO3- are produced, what buffers the concentration of H+?
It binds to hemoglobin.
The following statements relate to the disease emphysema. Identify the ones that are true.
Marked ventilation-perfusion inequality Loss of elastic tissue in lung Decreases total surface area due to alveolar wall loss
What structure would air flow through next after passing through the nose?
Pharynx
What term describes the volume of gas remaining in the lungs after a maximum expiration?
Residual volume
The pressure of a gas within a closed, rigid-walled container depends on which two of these?
The concentration of the gas The temperature of the gas
What point of the respiratory cycle does the figure best represent?
The end of an unforced expiration when the muscles are relaxed and there is no airflow
Which three are the determinants of alveolar PO2?
The rate of total-body oxygen consumption The rate of alveolar ventilation The PO2 of atmospheric air
What are the two main determinants of lung compliance?
The surface tension at the air-water interfaces within the lungs The amount and distensibility of connective tissues making up the lung tissue
Which of the following best describes the oxygen-hemoglobin dissociation curve at blood PO2 values between 60 mmHg and 100 mmHg?
There is a plateau in which little change in oxygen saturation occurs.
Which of these would decrease the compliance of the lung?
Thickening of the connective tissues present in the lungs
What term describes the volume of gas inspired or expired in an unforced respiratory cycle?
Tidal volume
Which of these is a step occurring during normal resting expiration?
Transpulmonary pressure decreases back toward its pre-inspiration value.
During moderate exercise, the alveolar and arterial PCO2 do not change.
True
True or false: Blood leaving a pulmonary capillary normally has the same partial pressures of oxygen and carbon dioxide as that present in the alveolus perfused by that capillary.
True
Which of the following results from the fact that the oxygen-hemoglobin dissociation curve is sigmoid in shape while the relationship between PCO2 and arterial carbon dioxide content is linear?
Ventilation-perfusion abnormalities affect arterial oxygen levels more than they affect arterial carbon dioxide levels.
Most people who ascend rapidly to altitudes above 10,000 ft experience some degree of _____ _____, which may include breathlessness, headache, nausea, vomiting, insomnia, fatigue, and impairment of mental processes.
altitude sickness
The value that is calculated by the equation (Tidal volume −- Dead space) x Respiratory rate is the _____ _____ rate.
alveolar ventilation
The main sites of gas exchange between atmospheric air and the bloodstream are the
alveoli
The tiny air sacs of the lungs which mediate gas exchange with the blood are called
alveoli
The most important inputs to the medullary respiratory neurons come from chemoreceptors called the _____ and _____ bodies.
aortic carotid
For airflow into or out of the lungs, the gas _____ pressure at the nose and mouth is normally the pressure.
atmospheric
The factors that determine the precise value of alveolar PO2 are: 1) the PO2 of air; 2) the rate of alveolar ; and 3) the rate of total-body oxygen
atmospheric ventilation consumption
Net diffusion of oxygen occurs from ______, while net diffusion of carbon dioxide occurs from ______
blood to cells; cells to blood
Ventilation refers to the exchange of air between the atmosphere and alveoli by _____ ______. In contract, the exchange of O2 and CO2 between alveolar air and blood in lung capillaries occurs by diffusion.
bulk flow
The alveolar walls contain _____, which carry the RBCs, and a very small _____ space, which in many places is absent altogether.
capillaries interstitial
The respiratory quotient is greatest when tissues are metabolizing
carbohydrates
Receptors found between epithelial cells in the larynx, trachea, and bronchi typically cause _____ in response to irritants
cough
Receptors found between epithelial cells in the larynx, trachea, and bronchi typically cause _____ in response to irritants.
cough
What goes in the blank in this equation? Alveolar ventilation = (tidal volume −- ______) x respiratory rate
dead space
The relationship between O2 binding and partial pressure of oxygen is known as the oxygen-hemoglobin _____ _____
dissociation curve
There are two major determinants of lung compliance: 1) The _____ of the lung tissues, particularly their elastic connective tissues; 2) The surface _____ at the air-water interfaces within the alveoli.
elasticity tension
Some of the diseases that produce hypoxia also produce a condition characterized by carbon dioxide retention and an increased arterial PCO2. This condition is called _____.
hypercapnia
Ventilation-perfusion inequality is the most common cause of
hypoxic hypoxia
The two layers of pleura in each sac are separated by a layer of _____ _____, the total volume of which is only a few milliliters.
intrapleural fluid
The hydrostatic pressure responsible for causing the lungs and thoracic wall to move in and out together during normal breathing is the
intrapleural pressure
Irritant receptors located between epithelial cells in the wall of the ______ cause coughing when stimulated by irritants
larynx trachea bronchi
The _____ _____= tidal volume x respiratory rate.
minute ventilation
At a PO2 of 40 mmHg, the fetal isoform of hemoglobin binds ______ oxygen compared to the adult isoform
more
At a PO2 of 40 mmHg, the fetal isoform of hemoglobin binds ______ oxygen compared to the adult isoform.
more
Expiration at rest is passive, depending only upon the relaxation of the inspiratory _____ and the _____ _____ of the stretched lungs.
muscle elastic recoil
As blood flows through pulmonary capillaries, there is net diffusion of
oxygen into the blood and carbon dioxide out of the blood
The aortic bodies and carotid bodies are locations for ______ chemoreceptors involved in the automatic control of ventilation.
peripheral
During inspiration, air passes through the nose or the mouth (or both) into the _____, a passage common to both air and food.
pharynx
The structure that is posterior to the oral cavity, and which is a common pathway for food moving toward the esophagus and air moving toward the larynx, is called the _____.
pharynx
The extremely thin fluid layer that is between membranes surrounding the lungs and lubricates their surfaces is know as the _____ fluid.
pleural
By definition, if there is no airflow and the airways are open to the atmosphere, Palv must equal Patm. Because the lungs always have air in them, the transmural pressure of the lungs (Ptp) must always be ______; therefore, ______
positive; Palv > Pip
The substance 2,3-DPG, which is produced by ______, binds to hemoglobin and ______ its affinity to oxygen.
red blood cells; decreases
When airway radius decreases,
resistance to airflow increases
The ratio of CO2 produced to O2 consumed by tissue metabolism is known as the _____ _____
respiratory quotient
The factors that determine airway resistance are analogous to those determining vascular resistance in the circulatory system: tube _____, tube _____, and interactions between moving molecules (gas molecules, in this case)
size diameter
The diaphragm and intercostal muscles are _____ muscles and therefore do not contract unless motor neurons stimulate them to do so
skeletal
The diaphragm and intercostal muscles are _____ muscles and therefore do not contract unless motor neurons stimulate them to do so.
skeletal
The muscles of respiration are composed of
skeletal muscle
The muscles of respiration are composed of ______.
skeletal muscle
Receptors found between epithelial cells of the nose and pharynx cause a reflex called _____ when stimulated by irritant particles.
sneeze
The pressure a gas exerts is proportional to _____ and the _____ of the gas.
temperature concentration
Increasing the ______ of gas molecules increases their ______, and this ______ the pressure it exerts.
temperature; rate of movement; increases
The major cause of the slight ventilation-perfusion inequality observed in most healthy people at rest is
the differential effect of gravity on blood flow and airflow in the lung
At the end of an unforced expiration when the respiratory muscles are relaxed and there is no airflow,
the intrapleural pressure is less than atmospheric pressure
The most important determinant of airway resistance is
the radius of the airways
According to Boyle's Law, when the volume of a closed space increases at a constant temperature,
the total gas pressure within that space decreases
The total ventilation per minute—the minute ventilation—is equal to the _____ volume multiplied by the respiratory _____.
tidal rate
The difference in pressure between the alveolar and intrapleural spaces is known as the
transpulmonary pressure
List the five steps of respiration in the order that they occur when a molecule of oxygen from the environment is used by the body. Start with the earliest at the top
ventilation gas exchange between lungs and pulmonary capillary blood gas transport in the blood gas exchange between systemic capillary blood and tissues cellular respiration
A mismatch of alveolar airflow and capillary blood flow in the lung is known as _____-_____ inequality.
ventilation perfusion