Respiratory Flashcards
What is the function of the respiratory system?
To supply the body with oxygen and dispose of carbon dioxide.
What are the four main processes of the respiratory system?
- Pulmonary ventilation
- External respiration
- Transport of respiratory gases
- Internal respiration
What does pulmonary ventilation refer to?
Air is moved in and out of the lungs so the gases are continuously refreshed.
What is external respiration?
Oxygen diffuses from the lungs to the blood and carbon dioxide diffuses from the blood to the lungs.
Define internal respiration.
Oxygen diffuses from blood to tissues, and carbon dioxide diffuses from the tissues to blood.
Which process refers to the exchange of carbon dioxide and oxygen between systemic tissues and systemic capillaries?
C. Internal respiration
What is the conducting zone?
All structures relating to conduction of the air to the respiratory zone; no gas exchange occurs here.
What is the function of the conducting zone?
To cleanse, warm, and humidify the incoming air.
What is the respiratory zone?
All structures relating to gas exchange between air and blood.
Which of the following is NOT a function of the conducting zone?
C. Gas exchange
What is the histology of the nasal cavity?
- Olfactory mucosa
- Respiratory mucosa (pseudostratified ciliated columnar epithelium)
What type of epithelium lines the nasopharynx?
Pseudostratified ciliated columnar epithelium.
What type of epithelium is found in the oropharynx?
Stratified squamous epithelium.
What is the structure of the larynx?
An intricate arrangement of nine cartilages connected by membranes and ligaments.
What is the function of the respiratory membrane?
A blood-air barrier where gas exchange occurs by diffusion.
What features of the alveoli suit them for gas exchange?
Very thin walls and a very large surface area.
What do alveolar type I cells do?
Make up the respiratory membrane.
What do alveolar type II cells secrete?
Surfactant.
Surfactant helps to prevent the alveoli from collapsing by ________.
C. interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid.
What maintains the negative intrapleural pressure?
The adhesive force between the parietal and visceral pleurae.
Describe the process of ventilation.
Ventilation occurs by changing the volume of the thorax, which creates pressure changes that move air.
Air moves out of the lungs when the pressure inside the lungs is ________.
B. greater than the pressure in the atmosphere.
What are the three factors that affect ventilation?
- Resistance
- Surface tension
- Compliance
The local matching of blood flow with ventilation is ________.
D. ventilation-perfusion coupling.
Which of the following represents the function(s) of pulmonary surfactant?
- Prevents alveolar collapse
- Reduces alveolar surface tension
- Increases lung compliance
- Is secreted by type II alveolar cells
How do respiratory gases diffuse across membranes?
Partial pressure gradients of O2 and CO2 drive the diffusion of these gases.
By what two mechanisms is O2 carried in the blood?
- Dissolved in the plasma (1.5%)
- Carried by hemoglobin (98.5%)
By what three mechanisms is CO2 carried in the blood?
- Dissolved in the plasma (7-10%)
- Carried in hemoglobin (20%)
- Carried as bicarbonate ions (HCO3-) (~70%)
In the plasma, the quantity of oxygen in solution is ________.
A. only about 1.5% of the oxygen carried in blood.
What is the main factor determining how saturated hemoglobin is?
The partial pressure of O2.
What factors influence the carrying capacity of O2 in the blood?
- Temperature
- pH (H+ concentration)
- PCO2
- BPG concentration
Describe how the Bohr and Haldane effects alter the affinity of hemoglobin for CO2.
The Bohr Effect decreases Hb’s affinity for O2 in high CO2 and H+ environments; the Haldane Effect allows deoxygenated Hb to bind CO2 more easily.
How are the unloading of O2 and loading of CO2 in tissues linked?
As O2 is unloaded, reduced hemoglobin binds CO2 more readily.
How are the loading of O2 and unloading of CO2 in the alveoli linked?
O2 binding to hemoglobin releases H+, which combines with bicarbonate to form CO2 for exhalation.
With the Bohr effect, more oxygen is released because a(n) ________.
B. decrease in pH (acidosis) weakens the hemoglobin-oxygen bond.
What is the Bohr Effect?
The phenomenon where increased CO2 and decreased pH result in more oxygen being released from hemoglobin
It describes how blood pH affects the oxygen-binding affinity of hemoglobin.
What happens to hemoglobin’s affinity for CO2 during oxygenation of blood?
Hemoglobin loses its affinity for CO2
This is known as the Haldane Effect.
With the Bohr effect, more oxygen is released because a(n) ________.
decrease in pH (acidosis) weakens the hemoglobin-oxygen bond
What is bronchitis?
A chronic inflammation of the bronchi; results in inflamed and fibrosed mucosae
This condition can lead to chronic cough and mucus production.
What is emphysema?
Condition in which the septa between the alveoli are destroyed, decreasing surface area; expiration becomes difficult
It is often associated with smoking and results in shortness of breath.
What is lung cancer?
Uncontrolled growth of cells in the lungs; most often caused by smoking
Early detection is key to improving survival rates.
What is asthma?
Chronic inflamed bronchioles which become hypersensitive to irritants
It can cause wheezing, coughing, and difficulty breathing.
What is pneumothorax?
Collapsed lung caused by loss of negative pressure in the lungs – usually caused by air entering the pleural cavity
This condition can lead to respiratory distress and requires immediate medical attention.
True or False: Increased temperature results in increased O2 unloading from hemoglobin.
True
True or False: The functions of the nasal conchae are to enhance the air turbulence in the cavity and to increase the mucosal surface area exposed to the air.
True
True or False: The olfactory mucosal lining of the nasal cavity contains the receptors for the sense of smell.
True
True or False: As carbon dioxide enters systemic blood, it causes more oxygen to dissociate from hemoglobin (the Haldane Bohr effect), which in turn allows more CO2 to combine with hemoglobin and more bicarbonate ions to be generated (the Bohr Haldane effect).
False
True or False: Oxygenated hemoglobin releases oxygen more readily when the pH is more acidic.
True
