Week 34/ Respiratory Flashcards
Q: What are the 5 main functions of the respiratory system?
A:
Gas exchange – Oxygen (O₂) in, Carbon dioxide (CO₂) out
pH regulation – By controlling CO₂ levels in blood
Defence against pulmonary pathogens – Protects lungs from infections (e.g. asthma, COPD, CF, advanced infections)
Vocalisation – Speech via the larynx
Sense of smell – Facilitates olfaction through airflow to nasal receptors
Q: Why is respiration important for the human body?
A:
Provides a constant supply of oxygen (O₂) for:
Metabolic reactions
ATP generation
Breakdown and conversion of molecules
Removes carbon dioxide (CO₂) waste products
The process of providing O₂ and removing CO₂ is called respiration
The respiratory system carries out this process
What are the 5 Stages of Respiration?
- Ventilation (breathing)
- Pulmonary gas exchange
- Transport of O2 and CO2 by the
blood. - Systemic gas exchange
- Cellular respiration
Q: What are the components of the Upper Respiratory Tract?
A:
Nose & Nasal Cavity
Pharynx (throat)
Larynx (voice box)
Epiglottis
Q: What are the components of the Lower Respiratory Tract?
A:
Trachea (windpipe)
Lungs
Bronchi
Alveoli
Diaphragm
What type of bones protect the lungs?
The Rib Bones
Q: What is the Pleural Membrane?
A:
A thin mesothelial layer
Double membrane
Adherent to and surrounds the lungs
Q: What are the two layers of the pleura?
A:
Visceral layer – against the lungs
Parietal layer – against the surrounding tissues
Q: What is the Pleural Cavity?
A:
A potential space
Contains pleural fluid
Q: What is Pneumothorax?
A:
Air in the pleural cavity
Can lead to a collapsed lung
Q: What is Pleural Effusion?
A:
Fluid in the pleural cavity
Can cause difficulty in breathing
Q: What is Haemothorax?
A:
Blood in the pleural cavity
Can lead to a collapsed lung and requires immediate medical attention
Q: What are the branches in the airway branching of the respiratory system?
A:
Trachea
Primary bronchi
Smaller bronchi
Conducting zone:
Bronchioles
Respiratory bronchioles
Respiratory zone:
Alveolar ducts
Alveolar sacs
Q: What structures are seen in an anteromedial view of the lungs?
A:
Hilum
Bronchi
Pulmonary arteries
Pulmonary veins
Right lung
Left lung
Q: What are alveoli and what is their function?
A:
Small air sacs of the lungs
The place where gases exchange from air into blood
Each alveolus has its own blood supply
Alveoli increase surface area to allow more gas exchange
Q: What are the key pressures involved in lung ventilation, and how do they change during breathing?
A:
Atmospheric Pressure: The pressure of air in the atmosphere. It remains relatively constant unless affected by altitude (e.g., climbing a mountain or deep-sea diving).
Alveolar Pressure: The pressure of air within the alveoli. It increases during inspiration (breathing in) and decreases during expiration (breathing out).
Intrapleural Pressure: The pressure within the pleural cavity. This is influenced by diaphragm movement.
Q: What role does the diaphragm play in ventilation?
A:
Shape & Location: The diaphragm is a dome-shaped muscle that separates the thoracic and abdominal cavities.
Primary Function: It is the primary muscle active in inspiration.
Mechanism:
Contraction: When the diaphragm contracts, it flattens, which increases the volume of the thoracic cavity.
Pressure Change: The increased volume decreases the intrathoracic pressure, allowing the lungs to expand and facilitating inspiration.
Q: Do the lungs have muscles to inflate and deflate?
A:
No, the lungs do not have their own muscles.
Lung volume is controlled by changes in pressure within the thoracic cavity.
Q: What controls the pressure changes that affect lung volume?
A:
The diaphragm and other respiratory muscles (e.g., intercostal muscles) control cavity pressure.
These muscles influence how much the lungs expand or contract during breathing.
Q: What regulates the rate of contraction of respiratory muscles?
A:
Respiratory centres in the brainstem (medulla and pons) control the rate and rhythm of respiratory muscle contraction.
Q: How much oxygen does the body use at rest vs during strenuous exercise?
A:
At rest: ~200 mL of O₂/minute
During exercise: O₂ use can increase 15- to 20-fold in healthy adults
Q: What part of the brain controls breathing?
A:
The Respiratory Centre, located in the pons and medulla oblongata of the brainstem, regulates breathing.
Q: Why does breathing need to adjust during exercise?
A:
To match breathing effort with metabolic demand as oxygen consumption and CO₂ production rise.
Q: What do chemoreceptors monitor to modulate ventilation?
A:
They respond to changes in CO₂, H⁺ (pH), and O₂ levels in body fluids.
Q: Where are central chemoreceptors located?
A:
In the medulla oblongata of the central nervous system.
Q: Where are peripheral chemoreceptors located?
A:
In the aortic bodies and carotid bodies.
Q: Why is the respiratory system highly responsive to gas level changes?
A:
To maintain correct levels of O₂ and CO₂, especially during exercise, illness, environmental changes, or drug therapy.
Q: How do chemoreceptors modulate ventilation?
A:
Chemoreceptors detect changes in CO₂, O₂, or pH, and adjust ventilation by increasing or decreasing the respiratory response via the respiratory muscles.
Q: What role does the respiratory centre in the brainstem play in ventilation?
A:
The respiratory centre in the brainstem is key for CO₂ removal. It controls the diaphragm and ribs to increase ventilation based on PaCO₂ (partial pressure of CO₂).
Q: What is the respiratory quotient (RQ) and how does it reflect fuel usage?
A:
The RQ is the ratio of CO₂ production to O₂ consumption, reflecting the relative contributions of fat, carbohydrate, and protein to the oxidation fuel mixture.
RQ for carbohydrates: 1 (CO₂ produced = O₂ consumed)
RQ for fats/proteins: lower than 1
Use in lung disorders: Adjusting the diet to produce less CO₂ can reduce stress on the lungs.
Formula:
RQ = CO₂ eliminated / O₂ consumed
Q: What is partial pressure in the context of gases?
A: Partial pressure refers to the contribution of an individual gas to the total gas mixture, such as in air.
Q: What do Arterial Blood Gases (ABGs) measure?
A: ABGs measure the effectiveness of oxygen (O₂) and carbon dioxide (CO₂) exchange in the blood.
Q: How do gases move in the lungs during exchange?
A: Gases move from areas of high pressure to low pressure:
High PO₂ in alveoli → moves into blood
High PCO₂ in blood → moves into alveoli
Q: What is PaCO₂?
A: PaCO₂ is the partial pressure of CO₂ in arterial blood, reflecting how well CO₂ is being removed from the body.
Q: How does foetal haemoglobin (HbF) differ from maternal haemoglobin?
A: HbF has a slightly different structure and a higher affinity for oxygen (O₂) than maternal Hb.
Q: Why is the higher affinity of HbF for oxygen important?
A: It allows the foetus to effectively extract oxygen from the mother’s blood, even when O₂ levels are low.
Q: How much more oxygen can foetal Hb carry compared to maternal Hb?
A: Foetal Hb can carry up to 30% more oxygen than maternal Hb.
Q: Are foetal haemoglobins affected by natural Hb inhibitors?
A: No, naturally occurring inhibitors of haemoglobin do not affect foetal Hb.
Q: What protein do muscles use to transport oxygen?
A: Myoglobin, not haemoglobin.
Q: How many haem groups does myoglobin have?
A: One haem group (vs. four in haemoglobin).
Q: How does myoglobin’s oxygen affinity compare to haemoglobin?
A: Myoglobin has a higher affinity for oxygen, even at lower O₂ levels.
Q: What is the role of myoglobin in muscle?
A: To store and release oxygen directly to muscle cells when needed.
Q: What is the primary role of haemoglobin?
A: To carry and release oxygen throughout the entire bloodstream to various tissues.
Q: How does increased acidity (lower pH) affect haemoglobin’s affinity for oxygen?
A: It decreases haemoglobin’s affinity for O₂, causing oxygen to dissociate more readily.
Q: What is the effect of increased partial pressure of CO₂ on oxygen binding?
A: CO₂ binds to haemoglobin, reducing its affinity for O₂ and enhancing oxygen release.
Q: What effect does an increase in temperature have on haemoglobin’s oxygen affinity?
A: It causes more oxygen to be released from haemoglobin.
Q: Why are changes in pH, CO₂, and temperature important in disease states?
A: Because they can alter haemoglobin’s oxygen affinity, affecting oxygen delivery during conditions like drug overdose, lung disease, or other pathologies.
Q: What is the key role of O₂ in the body?
A: Oxygen is essential for aerobic respiration, enabling ATP production.
Q: In what two forms does oxygen exist in the blood?
A: As unbound O₂ (dissolved in plasma) and O₂ bound to haemoglobin (Hb).
Q: Why is haemoglobin concentration important?
A: It determines how much oxygen can be carried in the blood.
Q: What does PO₂ represent?
Q: What does PaO₂ represent?
Q: What does SO₂ represent?
Q: What does SaO₂ represent?
A: The partial pressure of oxygen in general (plasma).
A: Partial pressure of oxygen in arterial blood.
A: The oxygen saturation of haemoglobin.
A: The oxygen saturation of haemoglobin in arterial blood.
Q: What does a pulse oximeter measure and how?
A: It measures SaO₂ (not CO₂) using a simple, non-invasive finger probe.
Q: What are the three main forms in which CO₂ is transported in the blood?
A:
Dissolved CO₂ in plasma (~7%)
Bound to haemoglobin as carbaminohaemoglobin (~23%)
As bicarbonate ions (HCO₃⁻) in plasma (~70%)
Q: What happens to the 7% of CO₂ that is dissolved in blood plasma?
A: It diffuses into alveolar air and is exhaled through the lungs.
Q: What is CO₂ called when it binds to haemoglobin?
A: Carbaminohemoglobin (Hb-CO₂), making up ~23% of transported CO₂.
Q: What enzyme facilitates the conversion of CO₂ to carbonic acid in red blood cells?
Q: How much CO₂ is transported as bicarbonate ions?
A: Carbonic anhydrase.
A: About 70%.
Q: What does Hb stand for?
Q: What is an erythrocyte?
Q: What enzyme is essential for converting CO₂ to carbonic acid in RBCs?
A: Haemoglobin
A: A red blood cell (RBC)
A: Carbonic Anhydrase
Q: What is the key buffering equation that controls blood pH?
Q: What enzyme is involved in this buffering process?
Q: How does the respiratory system affect blood pH?
A:
CO₂ + H₂O ⇌ H₂CO₃ ⇌ HCO₃⁻ + H⁺
Carbon dioxide (CO₂) reacts with water to form carbonic acid (H₂CO₃), which dissociates into bicarbonate (HCO₃⁻) and hydrogen ions (H⁺).
A: Carbonic Anhydrase
A:
Promotes Acidic Conditions: Increases CO₂, leading to more H⁺ (lower pH).
Promotes Alkali Conditions: Decreases CO₂, leading to fewer H⁺ (higher pH).
Q: What is hypoxia?
Q: What are common causes of hypoxia?
Q: What are some conditions that lead to hypoxia?
Q: Why is hypoxia important for pharmacists to understand?
A: Hypoxia occurs when tissues receive inadequate oxygen to support aerobic respiration, leading to insufficient energy production and potential tissue damage.
A:
Impaired oxygenation (e.g., due to lung diseases).
Impaired blood supply (e.g., due to circulatory issues).
A:
Acute and chronic lung conditions (e.g., asthma, COPD, pulmonary edema).
Impaired lung function or blood flow.
A:
Lung Function Testing is crucial to monitor oxygenation and respiratory health.
Pharmacists need to be aware of medications that may impact oxygen delivery or interact with respiratory function (e.g., sedatives, respiratory depressants).
Pharmacists may recommend treatments or interventions that support lung function or correct oxygenation levels.
Q: What happens in chronic bronchitis?
Q: What occurs in asthma?
Q: What is emphysema?
A:
Air tubes (bronchi) narrow due to swelling and excessive mucus production.
Enlarged submucosal glands contribute to mucus production.
Inflammation of the epithelium worsens airflow.
A:
Smooth muscle constriction in the airways leads to narrowing.
Mucus accumulation and hyperinflation of alveoli.
Edema of respiratory mucosa and excessive mucus production obstructs the airways.
A:
Enlargement and destruction of alveolar walls, leading to loss of surface area for gas exchange.
Mucus plugs contribute to airway blockage.
Hyperinflation of alveoli occurs as the walls are damaged and cannot be repaired, resulting in fused large air spaces.
