p.37
Gas Transport in Blood
What is the primary function of red blood cells (RBCs) in gas transport?
To transport O2 to and CO2 from peripheral tissues.
p.37
Gas Transport in Blood
Can blood plasma carry enough O2 and CO2 for physiological needs?
No, it cannot carry enough.
p.10
Alveoli and Gas Exchange
What is the function of Type II pneumocytes?
They secrete surfactant to reduce surface tension in the alveoli.
p.3
Organization of the Respiratory System
What does the upper respiratory system include?
Structures above the larynx.
p.28
Pulmonary Ventilation Mechanics
What should you feel in your chest during quiet breathing?
Your chest expanding and contracting.
p.68
Chemoreceptors and Respiratory Reflexes
What do central chemoreceptors monitor?
Cerebrospinal fluid (CSF).
p.21
Pulmonary Ventilation Mechanics
What is pulmonary ventilation?
The process that causes volume changes in the thoracic cavity, leading to pressure changes.
p.31
Pulmonary Ventilation Mechanics
How does the diaphragm contribute to exhalation?
It is forced upward during exhalation.
p.65
Control of Respiration
What is the primary function of the complex nervous system in respiration?
To control the process of breathing.
p.13
Respiration Processes: External and Internal
What are the two integrated processes of respiration?
External respiration and internal respiration.
p.58
Control of Respiration
What part of the brain sets the pace of respiration?
The respiratory centers of the medulla oblongata.
p.5
Organization of the Respiratory System
What does the conducting portion of the respiratory tract include?
From the nasal cavity to the terminal bronchioles.
p.22
Pulmonary Ventilation Mechanics
What happens to the rib cage during inhalation?
The ribs and sternum elevate.
p.21
Pulmonary Ventilation Mechanics
What causes changes in the volume of the thoracic cavity during pulmonary ventilation?
The expansion or contraction of the diaphragm or rib cage.
p.69
Control of Respiration
What is the function of carotid sinuses?
To monitor blood pressure in the carotid arteries.
p.65
Control of Respiration
How does the nervous system influence respiration?
By regulating the rate and depth of breathing.
p.23
Structure of the Respiratory Tract
What is the function of pleural fluid?
It reduces friction between the pleurae during breathing.
p.18
Pulmonary Ventilation Mechanics
What does Boyle's law define?
The relationship between gas pressure (P) and volume (V), expressed as P = 1/V.
p.18
Pulmonary Ventilation Mechanics
What happens to gas molecules in a contained gas when external pressure increases?
The external pressure forces molecules closer together.
p.51
Gas Transport in Blood
How is 7% of CO2 transported in the blood?
As CO2 dissolved in plasma.
p.48
Oxygen and Carbon Dioxide Transport
What is the effect of temperature on oxyhemoglobin saturation?
Higher temperatures lead to lower saturation at a given partial pressure of oxygen.
p.20
Pulmonary Ventilation Mechanics
What is the principle of airflow to the lungs?
Air flows from an area of higher pressure to an area of lower pressure.
p.49
Gas Transport in Blood
How does carbon dioxide bind to hemoglobin?
It binds within red blood cells.
p.17
Pulmonary Ventilation Mechanics
What is pulmonary ventilation?
The physical movement of air in and out of the respiratory tract.
p.37
Gas Transport in Blood
Why can't blood plasma transport enough O2 or CO2?
Because it cannot meet physiological needs.
p.15
Respiration Processes: External and Internal
What is diffusion?
The movement of anything from an area of higher concentration to an area of lower concentration.
p.2
Functions of the Respiratory System
What is one function of the respiratory system related to gas exchange?
Provides extensive gas exchange surface area between air and circulating blood.
p.3
Organization of the Respiratory System
What does the lower respiratory system include?
Structures below the larynx.
p.22
Pulmonary Ventilation Mechanics
What is the effect of elevating the rib cage on thoracic cavity volume?
It increases the volume of the thoracic cavity.
p.46
Oxygen and Carbon Dioxide Transport
What is the effect of pH on oxygen-hemoglobin saturation?
A decrease in pH leads to increased oxygen release, while an increase in pH leads to decreased oxygen release.
p.11
Alveoli and Gas Exchange
How does surfactant prevent lung collapse?
By reducing surface tension in the alveoli.
p.12
Alveoli and Gas Exchange
How do charges affect the behavior of surfactant molecules?
Similar charges repel each other, while opposite charges attract, influencing the stability of the surfactant layer.
p.34
Respiration Processes: External and Internal
What are the two main circuits of the cardiovascular system?
Systemic circuit and Pulmonary circuit.
p.58
Control of Respiration
What are the two groups of respiratory centers in the medulla oblongata?
Dorsal respiratory group (DRG) and Ventral respiratory group (VRG).
p.32
Alveoli and Gas Exchange
What factors does gas exchange depend on?
1. Partial pressures of the gases 2. Diffusion of molecules between gas and liquid.
p.40
Oxygen and Carbon Dioxide Transport
What environmental factors affect hemoglobin saturation?
P O2 of blood, blood pH, temperature, and metabolic activity within RBCs.
p.22
Pulmonary Ventilation Mechanics
What occurs when the diaphragm contracts?
The volume of the thoracic cavity increases.
p.63
Control of Respiration
What are the two main respiratory centers influenced by chemoreceptors?
Dorsal Respiratory Group (DRG) and Ventral Respiratory Group (VRG).
p.14
Respiration Processes: External and Internal
What is the second process of external respiration?
Gas diffusion across membranes and capillaries.
p.9
Structure of the Respiratory Tract
What type of epithelium makes up the alveolar epithelium?
Simple squamous epithelium.
p.62
Chemoreceptors and Respiratory Reflexes
What do chemoreceptors respond to in the respiratory system?
They are sensitive to P CO2, P O2, or pH of blood or cerebrospinal fluid.
p.14
Respiration Processes: External and Internal
Where does gas diffusion occur in external respiration?
Across membranes and capillaries.
p.7
Structure of the Respiratory Tract
What is the role of elastic fibers in the alveolar structure?
They provide support to the alveoli.
p.14
Gas Transport in Blood
What is transported between alveolar capillaries?
Oxygen (O2) and carbon dioxide (CO2).
p.55
Control of Respiration
How does the brainstem influence the rate of respiration?
By sending signals to the respiratory muscles.
p.24
Pulmonary Ventilation Mechanics
What is the relationship between outside pressure and inside pressure during inhalation?
Outside pressure is greater than inside pressure (P outside > P inside).
p.3
Organization of the Respiratory System
What are the two main divisions of the respiratory system?
Upper respiratory system and lower respiratory system.
p.68
Chemoreceptors and Respiratory Reflexes
Where are central chemoreceptors located?
On the ventrolateral surface of the medulla oblongata.
p.69
Control of Respiration
Where are aortic sinuses located?
In the aorta, near the heart.
p.39
Oxygen and Carbon Dioxide Transport
How does oxygen transport occur in the blood?
Oxygen binds to iron ions in hemoglobin (Hb) molecules.
p.8
Alveoli and Gas Exchange
What are alveoli?
Air-filled pockets within the lungs.
p.49
Gas Transport in Blood
How is carbon dioxide transported in the bloodstream?
Three ways: converted to carbonic acid, bound to hemoglobin, and dissolved in plasma.
p.7
Structure of the Respiratory Tract
What are the plural and singular forms of alveolus?
Alveoli (plural); alveolus (singular).
p.8
Alveoli and Gas Exchange
Why do alveoli have a large surface area?
To increase the diffusion rate.
p.57
Control of Respiration
What can inhibit respiration?
Factors such as high carbon dioxide levels, low oxygen levels, and certain drugs.
p.33
Alveoli and Gas Exchange
What causes O2 to enter the blood during gas exchange?
The concentration gradient.
p.32
Alveoli and Gas Exchange
Where does gas exchange occur?
Between blood and alveolar air across the respiratory membrane.
p.32
Gas Transport in Blood
What is partial pressure?
The portion of the total pressure exerted by the presence of a single gas molecule.
p.40
Oxygen and Carbon Dioxide Transport
What is the role of heme in hemoglobin?
Heme is an iron-containing molecule that binds oxygen.
p.14
Respiration Processes: External and Internal
What is the first process of external respiration?
Pulmonary ventilation (breathing).
p.11
Alveoli and Gas Exchange
What is surfactant?
An oily secretion that contains phospholipids and proteins.
p.46
Oxygen and Carbon Dioxide Transport
What occurs to the oxygen-hemoglobin saturation curve when pH increases?
Less oxygen is released; the curve shifts to the left.
p.28
Pulmonary Ventilation Mechanics
What should you observe about your muscles during deeper breathing?
You should feel the muscles working differently.
p.54
Control of Respiration
What part of the brain is involved in involuntary control of respiration?
The brainstem, specifically the respiratory centers of the pons and medulla oblongata.
p.41
Oxygen and Carbon Dioxide Transport
What does the oxygen-hemoglobin saturation curve represent?
A graph relating the saturation of hemoglobin to the partial pressure of oxygen.
p.45
Oxygen and Carbon Dioxide Transport
What is the relationship between CO2 concentration and hemoglobin's affinity for oxygen?
Hemoglobin's affinity for oxygen decreases as CO2 concentration increases.
p.36
Alveoli and Gas Exchange
What is the formula for calculating P O2?
P O2 = (P atm – P water) O2 % – (P CO2 / RQ)
p.24
Pulmonary Ventilation Mechanics
What occurs as the volume of the thoracic cavity increases?
Air flows into the lungs.
p.64
Chemoreceptors and Respiratory Reflexes
What stimulates the chemoreceptors in the aortic bodies?
Changes in blood pH or P O2.
p.64
Chemoreceptors and Respiratory Reflexes
What is the primary function of chemoreceptors in respiration?
To monitor changes in blood pH and P O2.
p.37
Gas Transport in Blood
How do red blood cells (RBCs) assist in gas exchange?
By removing O2 and CO2 from plasma, allowing gases to diffuse into blood.
p.15
Respiration Processes: External and Internal
Does diffusion require energy?
No, diffusion does not require energy.
p.69
Control of Respiration
What are baroreceptors?
Sensors that detect changes in blood pressure.
p.10
Alveoli and Gas Exchange
What role do alveolar macrophages play in the lungs?
They identify and eliminate bacteria in the lung area.
p.10
Structure of the Respiratory Tract
What are the components of the alveolar structure?
Type I pneumocytes, Type II pneumocytes, alveolar macrophages, endothelial cells of capillaries, and elastic fibers.
p.12
Alveoli and Gas Exchange
What role does surfactant play in the respiratory system?
Surfactant ensures a constant size of the alveoli, preventing them from collapsing due to pressure.
p.11
Alveoli and Gas Exchange
What is the primary function of surfactant in the lungs?
To coat alveolar surfaces and reduce surface tension.
p.27
Pulmonary Ventilation Mechanics
What are the pressure changes during inhalation and exhalation?
They can be measured inside or outside the lungs.
p.11
Alveoli and Gas Exchange
What happens if there is a problem with surfactant production?
It can lead to a collapsed lung.
p.51
Gas Transport in Blood
What happens to HCO3- when red blood cells reach the lungs?
HCO3- is transported back to RBC in exchange for Cl- ions.
p.44
Oxygen and Carbon Dioxide Transport
What happens to CO2 in red blood cells (RBC)?
CO2 diffuses into RBC and reacts with water.
p.20
Pulmonary Ventilation Mechanics
What are the two phases of a respiratory cycle?
Inspiration (inhalation) and expiration (exhalation).
p.41
Oxygen and Carbon Dioxide Transport
What happens to hemoglobin saturation as partial pressure of oxygen (P O2) increases?
Higher P O2 results in greater hemoglobin saturation.
p.53
Control of Respiration
What types of control do the respiratory centers of the brain have?
Both voluntary and involuntary components.
p.31
Pulmonary Ventilation Mechanics
What muscles are primarily used in exhalation?
Internal intercostal and transversus thoracis muscles.
p.31
Pulmonary Ventilation Mechanics
What is the role of abdominal muscles during exhalation?
They depress the ribs and compress the abdomen.
p.10
Alveoli and Gas Exchange
What is the relationship between capillaries and alveoli?
A single capillary may be involved in gas exchange with several alveoli simultaneously.
p.47
Oxygen and Carbon Dioxide Transport
In which tissues are temperature effects on hemoglobin significant?
In active tissues generating large amounts of heat.
p.28
Pulmonary Ventilation Mechanics
What type of breathing is encouraged after quiet breathing?
Deeper breaths or forced breathing.
p.65
Control of Respiration
What role do neural pathways play in respiration?
They transmit signals that initiate and control breathing patterns.
p.57
Control of Respiration
What is the primary function of the control of respiration?
To regulate the rate and depth of breathing.
p.62
Chemoreceptors and Respiratory Reflexes
Where are baroreceptors located and what do they detect?
In aortic or carotid sinuses; they are sensitive to changes in blood pressure.
p.9
Structure of the Respiratory Tract
What role do alveolar macrophages (dust cells) play?
They patrol the alveolar epithelium.
p.26
Pulmonary Ventilation Mechanics
What does compliance indicate in the context of the lungs?
It indicates the expandability or stretch and expand capability of the lungs.
p.64
Chemoreceptors and Respiratory Reflexes
What stimulates the chemoreceptors in the carotid bodies?
Changes in blood pH or P O2.
p.57
Control of Respiration
How does the body respond to increased carbon dioxide levels?
By increasing the rate and depth of breathing.
p.19
Pulmonary Ventilation Mechanics
What is the mathematical formula for Boyle's Law?
P1V1 = P2V2, where P is pressure and V is volume.
p.41
Oxygen and Carbon Dioxide Transport
Why is the oxygen-hemoglobin saturation curve not a straight line?
Because hemoglobin changes shape each time a molecule of O2 is bound.
p.29
Pulmonary Ventilation Mechanics
What role do accessory muscles play in breathing?
They assist in elevating the ribs.
p.16
Respiration Processes: External and Internal
What is internal respiration?
The exchange of gases between the blood and the tissues.
p.34
Control of Respiration
Why is P CO2 considered a good measure of respiratory function?
It indicates respiratory function and acid-base homeostasis.
p.13
Respiration Processes: External and Internal
What does external respiration involve?
Exchanging oxygen (O2) and carbon dioxide (CO2) with the environment.
p.13
Respiration Processes: External and Internal
What occurs during internal respiration?
Uptake of O2 and production of CO2 within individual cells.
p.60
Control of Respiration
What are the two types of breathing mentioned?
Quiet and forced breathing.
p.60
Control of Respiration
What is the role of intercostal muscles?
They are involved in forced breathing.
p.47
Oxygen and Carbon Dioxide Transport
What happens to hemoglobin when temperature increases?
Hemoglobin releases more oxygen.
p.21
Pulmonary Ventilation Mechanics
What is required for forced breathing?
Increased muscle activity to support the thoracic cavity.
p.46
Oxygen and Carbon Dioxide Transport
What happens to oxygen release when blood pH decreases?
More oxygen is released; the oxygen-hemoglobin saturation curve shifts to the right.
p.12
Alveoli and Gas Exchange
What happens to alveoli without surfactant?
They may collapse due to surface tension and pressure.
p.61
Control of Respiration
What do the VRG and DRG establish in respiration?
The basic pace and depth of respiration.
p.9
Alveoli and Gas Exchange
What are type I pneumocytes responsible for?
The majority of gas exchange in the alveoli.
p.23
Pulmonary Ventilation Mechanics
What happens at rest, prior to inhalation?
The pressures inside and outside the lungs are equal.
p.45
Oxygen and Carbon Dioxide Transport
How does acidity affect hemoglobin's oxygen binding affinity?
Increased acidity decreases hemoglobin's oxygen binding affinity.
p.24
Pulmonary Ventilation Mechanics
What effect does inhalation have on the size of the thoracic cavity?
It increases the size of the thoracic cavity.
p.26
Pulmonary Ventilation Mechanics
What is the relationship between compliance and force required for lung expansion?
Low compliance requires greater force, while high compliance requires less force.
p.62
Control of Respiration
What other sensations can affect respiration?
Pain, changes in body temperature, and abnormal visceral sensations.
p.16
Respiration Processes: External and Internal
What is external respiration?
The process of gas exchange between the lungs and the external environment.
p.19
Pulmonary Ventilation Mechanics
In which conditions does Boyle's Law apply?
When the temperature of the gas remains constant.
p.41
Oxygen and Carbon Dioxide Transport
How does binding of one O2 molecule affect the binding of subsequent O2 molecules?
Each O2 bound makes the next O2 binding easier.
p.59
Control of Respiration
How does quiet expiration occur?
It is a passive process that does not require expiratory neurons.
p.36
Respiration Processes: External and Internal
What does RQ stand for and what does it indicate?
RQ stands for respiratory quotient and indicates the ratio of CO2 eliminated to O2 consumed.
p.17
Pulmonary Ventilation Mechanics
What are the effects of pulmonary ventilation?
It has several important physiological effects.
p.5
Organization of the Respiratory System
What are the two main portions of the respiratory tract?
The conducting portion and the respiratory portion.
p.40
Oxygen and Carbon Dioxide Transport
What is hemoglobin saturation?
The percentage of heme units in a hemoglobin molecule that contain bound oxygen.
p.5
Organization of the Respiratory System
What comprises the respiratory portion of the respiratory tract?
The respiratory bronchioles and alveoli.
p.68
Chemoreceptors and Respiratory Reflexes
What do central chemoreceptors respond to?
P CO2 and pH of cerebrospinal fluid.
p.7
Structure of the Respiratory Tract
What surrounds each alveolus?
A network of capillaries supported by elastic fibers.
p.69
Control of Respiration
How do baroreceptors affect cardiac rate?
They increase cardiac rate when blood pressure drops.
p.51
Gas Transport in Blood
What percentage of CO2 binds to hemoglobin?
23% is bound to amino groups of globular proteins in the hemoglobin molecule.
p.7
Structure of the Respiratory Tract
What is the function of smooth muscle cells in respiratory bronchioles?
They can change the diameter of these airways.
p.45
Oxygen and Carbon Dioxide Transport
What is the Bohr effect?
The phenomenon where hemoglobin's oxygen binding affinity is inversely related to acidity and carbon dioxide concentration.
p.54
Control of Respiration
What do the motor neurons control in the respiratory system?
They control the respiratory muscles.
p.25
Pulmonary Ventilation Mechanics
What happens to the rib cage during exhalation?
It returns to its original position.
p.57
Control of Respiration
What role do chemoreceptors play in respiration control?
They detect changes in blood chemistry and help regulate breathing.
p.59
Control of Respiration
What is the function of the Dorsal Respiratory Group (DRG)?
It acts as the inspiratory center and functions in both quiet and forced breathing.
p.14
Structure of the Respiratory Tract
What is the role of capillaries in external respiration?
They wrap around the alveolar sacs for gas exchange.
p.38
Respiration Processes: External and Internal
What is the primary function of the systemic circuit?
To deliver oxygenated blood from the heart to the body and return deoxygenated blood back to the heart.
p.26
Pulmonary Ventilation Mechanics
What factors affect lung compliance?
Connective tissue structure of the lungs, level of surfactant production, and mobility of the thoracic cage.
p.20
Pulmonary Ventilation Mechanics
What is pulmonary ventilation?
The process of moving air in and out of the lungs.
p.67
Control of Respiration
Which cranial nerves are involved in diaphragm control?
N IX (Glossopharyngeal) and N X (Vagus).
p.56
Control of Respiration
How do the apneustic and pneumotaxic centers regulate respiration?
They regulate the respiratory rate and depth of respiration.
p.1
Oxygen and Carbon Dioxide Transport
How is oxygen transported in the blood?
Oxygen is primarily transported bound to hemoglobin in red blood cells.
p.53
Control of Respiration
What happens to cardiac output and respiratory rates when oxygen demand rises?
They increase under neural control.
p.2
Functions of the Respiratory System
How does the respiratory system facilitate air movement?
Moves air to and from exchange surfaces of the lungs.
p.2
Functions of the Respiratory System
What role does the respiratory system play in protecting the body?
Protects respiratory surfaces from the outside environment.
p.47
Oxygen and Carbon Dioxide Transport
What effect does a decrease in temperature have on hemoglobin?
Hemoglobin holds oxygen more tightly.
p.23
Structure of the Respiratory Tract
What is the role of the parietal pleura?
It lines the thoracic wall.
p.61
Control of Respiration
What are the two main respiratory centers involved in controlling respiration?
Ventral Respiratory Group (VRG) and Dorsal Respiratory Group (DRG).
p.65
Control of Respiration
What is the relationship between the nervous system and respiratory muscles?
The nervous system sends signals to respiratory muscles to facilitate breathing.
p.28
Pulmonary Ventilation Mechanics
What is happening while you are sitting and listening?
Nothing exciting is happening; it's a moment of quiet breathing.
p.61
Control of Respiration
What is the role of the pneumotaxic center?
It modifies the pace of respiration.
p.18
Pulmonary Ventilation Mechanics
What effect do gas molecules have in a container?
The movement of gas molecules exerts pressure on the container.
p.64
Chemoreceptors and Respiratory Reflexes
What nerve is associated with chemoreceptors from the carotid bodies?
Glossopharyngeal nerve (IX).
p.45
Oxygen and Carbon Dioxide Transport
What happens to oxygen transport when carbon dioxide concentration increases?
Oxygen transport increases as O2 binds to higher CO2 levels.
p.33
Alveoli and Gas Exchange
What causes CO2 to leave the blood during gas exchange?
The concentration gradient.
p.50
Gas Transport in Blood
What does carbonic acid (H₂CO₃) dissociate into?
H⁺ and bicarbonate (HCO₃⁻).
p.20
Pulmonary Ventilation Mechanics
What does a respiratory cycle consist of?
An inspiration and an expiration.
p.55
Control of Respiration
What role do chemoreceptors play in the control of respiration?
They detect changes in blood chemistry and influence breathing rate.
p.38
Respiration Processes: External and Internal
What is the primary function of the pulmonary circuit?
To carry deoxygenated blood from the heart to the lungs for oxygenation and return oxygenated blood to the heart.
p.1
Functions of the Respiratory System
What is the primary function of the respiratory system?
To facilitate gas exchange, supplying oxygen to the body and removing carbon dioxide.
p.41
Oxygen and Carbon Dioxide Transport
What advantage does the oxygen-hemoglobin saturation curve provide at low oxygen levels?
It allows hemoglobin to bind O2 when O2 levels are low.
p.16
Oxygen and Carbon Dioxide Transport
How is oxygen transported in the blood?
Primarily bound to hemoglobin in red blood cells.
p.52
Gas Transport in Blood
What is the chloride shift in relation to HCO3−?
HCO3− moves out of RBC in exchange for Cl−.
p.16
Oxygen and Carbon Dioxide Transport
How is carbon dioxide transported in the blood?
Dissolved in plasma, bound to hemoglobin, or as bicarbonate ions.
p.36
Organization of the Respiratory System
How is air modified before it reaches the lungs?
It is warmed and humidified by water (H2O).
p.30
Pulmonary Ventilation Mechanics
What is the function of the scalene muscles?
They assist in elevating the first two ribs during inhalation.
p.30
Accessory Respiratory Muscles
What is the role of the external oblique muscle in respiration?
It assists in forced exhalation.
p.2
Functions of the Respiratory System
How does the respiratory system contribute to the sense of smell?
Participates in olfactory sense.
p.63
Control of Respiration
Which cranial nerve is associated with chemoreceptor input from the pharynx?
Glossopharyngeal nerve (N IX).
p.23
Pulmonary Ventilation Mechanics
What does 'P outside = P inside' indicate?
Pressure outside and inside are equal, so no air movement occurs.
p.44
Oxygen and Carbon Dioxide Transport
What is the Bohr effect?
The effect of pH on the hemoglobin saturation curve, influenced by CO2.
p.19
Pulmonary Ventilation Mechanics
What does Boyle's Law state?
The pressure of a gas is inversely proportional to its volume when temperature is held constant.
p.61
Control of Respiration
How does the control of respiration relate to homeostasis?
It helps maintain homeostasis in the body.
p.43
Oxygen and Carbon Dioxide Transport
What happens to oxygen release when pH drops or temperature rises?
More oxygen is released and the curve shifts to the right.
p.43
Oxygen and Carbon Dioxide Transport
What does a leftward shift in the oxygen-hemoglobin saturation curve indicate?
Decreased oxygen release.
p.59
Control of Respiration
What type of breathing involves active manipulation?
Inhalation during exercise or work.
p.30
Accessory Respiratory Muscles
What is the role of the rectus abdominis muscle in respiration?
It aids in forced exhalation.
p.30
Accessory Respiratory Muscles
Which muscle is involved in both inhalation and exhalation?
Serratus anterior muscle.
p.30
Primary Respiratory Muscles
What are primary respiratory muscles responsible for?
They are primarily responsible for normal breathing.
p.4
Structure of the Respiratory Tract
What are bronchioles?
Small air passages that branch from the bronchi.
p.39
Oxygen and Carbon Dioxide Transport
How many hemoglobin molecules are present in each red blood cell (RBC)?
About 280 million Hb molecules.
p.12
Alveoli and Gas Exchange
What are the characteristics of surfactant?
Surfactant has hydrophobic tails that help reduce surface tension in the alveoli.
p.49
Gas Transport in Blood
What happens to carbon dioxide when it is converted to carbonic acid?
It helps regulate blood pH and transport CO2.
p.55
Control of Respiration
Which structures in the brainstem are involved in regulating breathing?
The medulla oblongata and pons.
p.43
Oxygen and Carbon Dioxide Transport
What is the standard condition for the oxygen-hemoglobin saturation curve?
pH 7.4 and temperature 37 °C.
p.51
Gas Transport in Blood
What is released from hemoglobin when HCO3- is transported back to RBC?
H+ is released from hemoglobin.
p.67
Pulmonary Ventilation Mechanics
What is the role of the diaphragm in respiration?
It is a primary muscle that facilitates breathing.
p.44
Oxygen and Carbon Dioxide Transport
What does carbonic acid dissociate into?
Hydrogen ion (H+) and bicarbonate ion (HCO3-).
p.67
Respiration Processes: External and Internal
What do stretch receptors in the lungs monitor?
They provide feedback on lung inflation.
p.59
Control of Respiration
What happens to the breathing rate at rest?
It is typically unconscious and involves quiet breathing.
p.38
Respiration Processes: External and Internal
What is internal respiration?
The exchange of gases between the blood in systemic capillaries and the interstitial fluid.
p.67
Pulmonary Ventilation Mechanics
What is the function of the phrenic nerve?
It controls the diaphragm's contraction.
p.4
Functions of the Respiratory System
What is the function of the nasal cavity?
To filter, warm, and humidify the air we breathe.
p.29
Pulmonary Ventilation Mechanics
Which muscles assist in inhalation by contributing to air movement?
External intercostal muscles.
p.54
Control of Respiration
What do the respiratory centers respond to?
Sensory information via respiratory reflexes.
p.42
Oxygen and Carbon Dioxide Transport
What is the relationship between partial pressure of O2 (P O2) and hemoglobin saturation?
As P O2 increases, hemoglobin binds oxygen better, but never reaches 100% saturation.
p.56
Control of Respiration
What is the role of the pneumotaxic center?
It inhibits the apneustic centers and promotes passive or active exhalation.
p.4
Organization of the Respiratory System
What structures are included in the Lower Respiratory System?
Larynx, trachea, bronchus, bronchioles, and alveoli.
p.35
Alveoli and Gas Exchange
What happens to the air during gas exchange in the alveoli?
It becomes warmer and moistened.
p.62
Chemoreceptors and Respiratory Reflexes
What types of stimuli can irritate the respiratory system?
Irritating physical or chemical stimuli in the nasal cavity, larynx, or bronchial tree.
p.54
Control of Respiration
Where are the nuclei that regulate respiratory muscles located?
In the reticular formation of the medulla oblongata and pons.
p.42
Oxygen and Carbon Dioxide Transport
What does the % saturation of Hb indicate?
The percentage of hemoglobin that is saturated with oxygen.
p.52
Gas Transport in Blood
What is formed when 23% of CO2 binds to hemoglobin (Hb)?
Carbaminohemoglobin (Hb•CO2).
p.57
Control of Respiration
What is the effect of low oxygen levels on respiration?
It stimulates an increase in breathing rate.
p.26
Pulmonary Ventilation Mechanics
How does fibrosis affect lung compliance?
It decreases compliance, making the lungs less expandable.
p.50
Gas Transport in Blood
How do bicarbonate ions (HCO₃⁻) move into plasma?
By an exchange mechanism known as the chloride shift.
p.1
Organization of the Respiratory System
What are the main components of the respiratory system?
Nasal cavity, pharynx, larynx, trachea, bronchi, lungs, and alveoli.
p.44
Oxygen and Carbon Dioxide Transport
How does the dissociation of carbonic acid affect pH?
Hydrogen ions can diffuse out of RBC, lowering pH.
p.1
Alveoli and Gas Exchange
What is the role of alveoli in the respiratory system?
Alveoli are the sites of gas exchange between air and blood.
p.25
Pulmonary Ventilation Mechanics
What is the effect of decreased volume on air flow during exhalation?
Air flows out of the lungs.
p.42
Oxygen and Carbon Dioxide Transport
What is the significance of the saturation curve for hemoglobin?
It illustrates how hemoglobin's affinity for oxygen changes with varying levels of oxygen pressure.
p.67
Control of Respiration
What are the two main groups of respiratory centers?
Dorsal respiratory group (DRG) and Ventral respiratory group (VRG).
p.4
Structure of the Respiratory Tract
What is the function of the esophagus?
To transport food from the mouth to the stomach.
p.30
Accessory Respiratory Muscles
What is the function of the transversus thoracis muscle?
It helps in forced exhalation by depressing the ribs.
p.4
Alveoli and Gas Exchange
What are alveoli?
Air sacs where gas exchange occurs.
p.16
Functions of the Respiratory System
What is the primary function of the lungs in respiration?
To facilitate gas exchange between the air and the blood.
p.59
Control of Respiration
What does the Ventral Respiratory Group (VRG) control?
It serves as both inspiratory and expiratory center, functioning only in forced breathing.
p.43
Oxygen and Carbon Dioxide Transport
What does a rightward shift in the oxygen-hemoglobin saturation curve indicate?
Increased oxygen release.
p.26
Pulmonary Ventilation Mechanics
How does emphysema affect lung compliance?
It increases compliance, allowing for easier expansion.
p.16
Pulmonary Ventilation Mechanics
What is pulmonary ventilation?
The process of moving air in and out of the lungs.
p.1
Control of Respiration
What regulates the rate of respiration?
The respiratory center in the brainstem, influenced by chemoreceptors.
p.1
Chemoreceptors and Respiratory Reflexes
What are chemoreceptors and their function?
Chemoreceptors detect changes in blood pH, carbon dioxide, and oxygen levels, influencing respiratory rate.
p.6
Alveoli and Gas Exchange
What are the tiny air sacs where gas exchange occurs?
Alveoli in a pulmonary lobule.
p.9
Alveoli and Gas Exchange
What is the function of surfactant in the alveoli?
To reduce surface tension of the liquid in which it is dissolved.
p.33
Alveoli and Gas Exchange
What does rapid exchange in the alveoli allow for?
Blood and alveolar air to reach equilibrium.
p.52
Gas Transport in Blood
How is H+ removed from the bloodstream?
By buffers, especially hemoglobin (Hb).
p.16
Alveoli and Gas Exchange
What role does gas diffusion play in respiration?
It allows oxygen to enter the blood and carbon dioxide to exit.
p.4
Structure of the Respiratory Tract
What is the role of the ribs in the respiratory system?
To protect the lungs and assist in breathing.
p.43
Oxygen and Carbon Dioxide Transport
What occurs when pH rises or temperature drops in relation to oxygen release?
Less oxygen is released and the curve shifts to the left.
p.59
Control of Respiration
What is the role of the DRG during quiet breathing?
The DRG fires out inspiratory neurons to facilitate inspiration.
p.56
Control of Respiration
What are the apneustic and pneumotaxic centers responsible for?
They adjust the output of respiratory rhythmicity centers.
p.56
Control of Respiration
What does the apneustic center do?
It provides continuous stimulation to the dorsal respiratory group (DRG) center.
p.59
Control of Respiration
When are expiratory neurons fired?
Only during deep expiration.
p.30
Pulmonary Ventilation Mechanics
Which muscle assists in elevating the ribs during inhalation?
External intercostal muscles.
p.56
Control of Respiration
What type of stimulus does the pneumotaxic center provide?
A negative stimulus for shallow respiration.
p.4
Structure of the Respiratory Tract
What is the primary function of the tongue?
To aid in the process of swallowing and tasting.
p.67
Chemoreceptors and Respiratory Reflexes
What type of receptors provide afferent signals to the respiratory centers?
Chemoreceptors and baroreceptors from carotid and aortic sinuses.
p.25
Pulmonary Ventilation Mechanics
What causes air to flow out of the lungs?
Increased pressure inside the lungs.
p.67
Control of Respiration
Where are the respiratory rhythmicity centers located?
In the medulla oblongata.
p.56
Control of Respiration
What is the relationship between the apneustic and pneumotaxic centers?
The apneustic center stimulates while the pneumotaxic center inhibits.
p.6
Organization of the Respiratory System
What is the functional unit of the lung that includes the alveoli?
Bronchopulmonary segment.
p.1
Pulmonary Ventilation Mechanics
What is pulmonary ventilation?
The process of moving air in and out of the lungs.
p.56
Control of Respiration
What type of stimulus does the apneustic center provide?
A positive stimulus for deep respiration.
p.67
Respiration Processes: External and Internal
What is the significance of stimulation and inhibition in respiratory control?
They regulate the activity of respiratory muscles.
p.30
Pulmonary Ventilation Mechanics
What role do the internal intercostal muscles play?
They assist in exhalation by depressing the ribs.
p.30
Pulmonary Ventilation Mechanics
Which muscle is involved in forced inhalation and is located in the neck?
Sternocleidomastoid muscle.
p.56
Control of Respiration
What is the overall goal of the apneustic and pneumotaxic centers?
To maintain homeostasis in respiration.
p.4
Structure of the Respiratory Tract
What is a cavity within the bone?
A space that can house air or other materials.
p.4
Structure of the Respiratory Tract
How many lungs do humans have?
Two (right lung and left lung).
p.4
Organization of the Respiratory System
What structures are included in the Upper Respiratory System?
Nose, nasal cavity, sinuses, and pharynx.
p.4
Structure of the Respiratory Tract
What is the role of the pharynx in the respiratory system?
To serve as a pathway for air and food.
p.4
Functions of the Respiratory System
What is the function of the larynx?
To produce sound and protect the trachea against food aspiration.
