Chapter 3: Respiratory System of Man

Select the correct answer:

1. When blood leaves the capillary bed most of the carbon dioxide is in the form of

A. carbonate ions

B. bicarbonate ions

C. hydrogen ions

D. hydroxyl ions

Answer: B. bicarbonate ions

Explanation: About 70% of carbon dioxide is transported in the blood as bicarbonate ions (HCO₃⁻) dissolved in the plasma.

2. When you inhale, the diaphragm

A. relaxes and moves upward

B. relaxes and moves downward

C. contracts and moves upward

D. contracts and moves downward

Answer: D. contracts and moves downward

Explanation: During inhalation, the diaphragm contracts and flattens (moves downward), increasing the volume of the thoracic cavity and decreasing pressure, allowing air to enter the lungs.

3. With which other system do specialised respiratory systems most closely interface in exchanging gases between the cells and the environment?

A. the skin

B. the excretory system

C. the circulatory system

D. the muscular system

Answer: C. the circulatory system

Explanation: The respiratory system works closely with the circulatory system to transport gases. Oxygen diffuses into the blood and is carried to cells, while carbon dioxide is carried from cells to the lungs for exhalation.

4. Which of the following is the respiratory surface in human respiratory system:

A. larynx

B. trachea

C. bronchi

D. alveoli

Answer: D. alveoli

Explanation: The alveoli are tiny air sacs in the lungs where gas exchange occurs. Their thin walls and rich blood supply facilitate the

diffusion of oxygen and carbon dioxide.

5. How is most of the oxygen transported in the blood?

A. dissolved in plasma

B. bound to haemoglobin

C. as bicarbonate

D. dissolved in water

Answer: B. bound to haemoglobin

Explanation: About 98% of oxygen is transported in the blood bound to hemoglobin, forming oxyhemoglobin. Only a small amount dissolves in plasma.

6. The lateral walls of the chest cavity of man are composed of:

A. ribs

B. intercostal muscles

C. ribs and intercostal muscles

D. ribs, intercostal muscles and diaphragm

Answer: C. ribs and intercostal muscles

Explanation: The lateral walls of the thoracic cavity are formed by the ribs and the intercostal muscles between them. The diaphragm forms the floor of the cavity.

7. Which of the following factors is the most effective in accelerating the rate of breathing in man?

A. a lack of oxygen in the blood

B. a lack of oxygen in the tissues

C. an excess of carbon dioxide in the lungs

D. an excess of carbon dioxide in the blood

Answer: D. an excess of carbon dioxide in the blood

Explanation: The primary stimulus for breathing is the level of carbon dioxide in the blood. An increase in CO₂ (hypercapnia) triggers chemoreceptors to increase the rate and depth of breathing.

8. Which of the following changes will increase the body's rate of carbon dioxide excretion into the alveoli?

A. holding the breath

B. the breakdown of alveolar tissue as a result of disease

C. a decrease in the partial pressure of carbon dioxide in the alveolar air

D. a decrease in the pulmonary circulation

Answer: C. a decrease in the partial pressure of carbon dioxide in the alveolar air

Explanation: According to Fick's law of diffusion, a greater concentration gradient (lower CO₂ in alveoli) increases the rate of diffusion of CO₂ from the blood into the alveoli.

9. Breathing is an example of

A. counter current exchange

B. cellular respiration

C. ventilation

D. diffusion

Answer: C. ventilation

Explanation: Breathing (ventilation) is the mechanical process of moving air in and out of the lungs, distinct from cellular respiration, which is the metabolic process of ATP production.

10. Which sequence most accurately describes the sequence of airflow in the human respiratory system?

1. pharynx

2. bronchus

3. trachea

4. larynx

5. alveolus

6. bronchiole

A. 4, 1, 3, 2, 5, 6

B. 1, 4, 3, 2, 5, 6

C. 4, 1, 3, 2, 6, 5

D. 1, 4, 3, 2, 6, 5

Answer: C. 4, 1, 3, 2, 6, 5 (Note: The correct sequence is: Larynx (4) [source symbol unavailable] Pharynx (1) [source symbol unavailable] Trachea (3) [source symbol unavailable] Bronchus (2) [source symbol unavailable] Bronchiole (6) [source symbol unavailable] Alveolus (5). However, physiologically, the pharynx is above the larynx. The correct order should be Pharynx [source symbol unavailable] Larynx [source symbol unavailable] Trachea. Option B might be intended if we consider the path from the nose. Given the options, the correct sequence is Pharynx (1), Larynx (4), Trachea (3), Bronchus (2), Bronchiole (6), Alveolus (5). So the answer is D if we assume the sequence starts at the pharynx.) Let's re-evaluate: Air enters the pharynx, then larynx, then trachea, then bronchi, then bronchioles, then alveoli. So the correct order is 1, 4, 3, 2, 6, 5. Therefore, the answer is D.

11. Which one of the following changes takes place during inspiration?

A. Decrease in thoracic cavity

B. Relaxation in diaphragm

C. Relaxation in external intercostal muscles

D. Sternum moves towards ventral and anterior direction

Answer: D. Sternum moves towards ventral and anterior direction

Explanation: During inspiration, the external intercostal muscles contract, lifting the ribs and moving the sternum upward and

outward (ventral and anterior), increasing the volume of the thoracic cavity.

12. The volume of air that can be exhaled normally after exhalation is called

A. tidal volume

B. residual volume

C. inspiratory reserve volume

D. expiratory reserve volume

Answer: D. expiratory reserve volume

Explanation: Expiratory reserve volume (ERV) is the additional amount of air that can be forcibly exhaled after a normal tidal expiration.

13. Hemoglobin

A. combine reversibly with only oxygen

B. bound to haemoglobin

C. attach to the alveolar wall

D. all have four heme group

Answer: D. all have four heme group

Explanation: Hemoglobin is a tetrameric protein with four heme groups, each capable of binding one oxygen molecule. It also binds carbon dioxide and carbon monoxide.

14. The maximum volume of air contained in the lung by a full forced inhalation is called

A. Tidal volume

B. Vital capacity

C. Ventilation rate

D. Total lung capacity

Answer: D. Total lung capacity

Explanation: Total lung capacity (TLC) is the maximum amount of air the lungs can hold after a maximal inhalation. It is the sum of vital capacity and residual volume.

15. Dissociation of O₂ from oxyhaemoglobin is facilitated by:

A. decreased temperature

B. decreases H⁺

C. decreased PO₂

D. exercise

Answer: D. exercise

Explanation: During exercise, muscles consume more oxygen, lowering PO₂, and produce more CO₂ and H⁺, which lowers pH and increases temperature. All these factors (Bohr effect) facilitate the dissociation of oxygen from hemoglobin.

16. Which of these correctly orders the structures through which air passes during inhalation?

A. pharynx [source symbol unavailable] trachea [source symbol unavailable] larynx [source symbol unavailable] bronchi

B. pharynx [source symbol unavailable] larynx [source symbol unavailable] trachea [source symbol unavailable] bronchi

C. larynx [source symbol unavailable] pharynx [source symbol unavailable] bronchi [source symbol unavailable] trachea

D. larynx [source symbol unavailable] pharynx [source symbol unavailable] trachea [source symbol unavailable] bronchi

Answer: B. pharynx [source symbol unavailable] larynx [source symbol unavailable] trachea [source symbol unavailable] bronchi

17. The pharynx is also known as the:

A. windpipe

B. trachea

C. voice box

D. throat

Answer: D. throat

18. What is the correct path air takes when it enters the trachea on its way to the lungs?

A. bronchi / bronchioles / pulmonary capillaries / alveoli

B. bronchioles / bronchi / alveoli / pulmonary capillaries

C. bronchi / pulmonary capillaries / alveoli / bronchioles

D. bronchioles / bronchioles / alveoli / pulmonary capillaries

Answer: A. bronchi / bronchioles / pulmonary capillaries / alveoli (Note: The correct path is bronchi [source symbol unavailable] bronchioles [source symbol unavailable] alveoli. Option A includes pulmonary capillaries, which is not part of the airway. The best answer is bronchioles [source symbol unavailable] bronchi [source symbol unavailable] alveoli, but option B has bronchi and alveoli swapped. Option A is the closest if we ignore the capillaries.)

19. Which of the following is correct for the partial pressure of oxygen in alveoli?

A. less than carbon dioxide

B. less than the blood

C. more than the blood

D. equal to that of the blood

Answer: C. more than the blood

Explanation: The partial pressure of oxygen (PO₂) in the alveoli is about 104 mmHg, while in the deoxygenated blood entering the

pulmonary capillaries it is about 40 mmHg. This gradient drives oxygen into the blood.

20. Which of the following is the respiratory surface in human respiratory system:

A. larynx

B. trachea

C. bronchi

D. alveoli

Answer: D. alveoli

1. What is respiratory surface? Write the properties of respiratory surface.

Answer: The respiratory surface is the site where gas exchange occurs between the organism and its environment. In humans, it is the alveoli. Properties include:

1. Thin: The surface must be thin (one cell thick) for efficient diffusion.

2. Moist: It must be moist to allow gases to dissolve.

3. Large Surface Area: It must have a large surface area to maximize gas exchange.

4. Rich Blood Supply: It must be well-vascularized to transport gases.

5. Permeable: It must be permeable to gases.

2. What organs constitute the respiratory system?

Answer: The human respiratory system consists of:

Nose and Nasal Cavity: Filters, warms, and moistens air. Pharynx: Throat; passage for air and food. Larynx: Voice box; contains vocal cords. Trachea: Windpipe; conducts air to bronchi. Bronchi: Two main branches entering the lungs. Bronchioles: Smaller branches within the lungs. Lungs: Contains alveoli where gas exchange occurs. Diaphragm and Intercostal Muscles: Assist in breathing.

3. How nose and nasal cavity function in filtering the incoming air?

Answer: The nose and nasal cavity filter incoming air through several mechanisms. Hairs (vibrissae) at the entrance trap large particles. The nasal cavity is lined with ciliated epithelium and mucus-secreting cells. Mucus traps smaller particles, and cilia beat to move the mucus and trapped particles toward the pharynx to be swallowed. The nasal conchae increase surface area, and the rich blood supply warms and moistens the air. This filtration protects the lungs from debris and pathogens.

4. What is the role of pharynx in human respiration?

Answer: The pharynx (throat) is a muscular tube that serves as a passageway for both air and food. In respiration, it conducts air from the nasal cavity to the larynx. It is lined with mucous membrane that continues to filter and humidify the air. The pharynx also plays a role in swallowing, and the epiglottis prevents food from entering the airway during swallowing. It is a common pathway for the respiratory and digestive systems.

5. Describe function of human larynx.

Answer: The larynx (voice box) is located between the pharynx and trachea. Its functions include:

1. Airway: It provides a passage for air to and from the lungs.

2. Voice Production: It contains vocal cords that vibrate to produce sound.

3. Protection: The epiglottis, a flap of cartilage, prevents food and liquids from entering the trachea during swallowing.

4. Humidification: It continues to warm and moisten air. The larynx is supported by cartilages (thyroid, cricoid, arytenoid).

6. Describe the structure and function of alveoli.

Answer: Alveoli are tiny, balloon-like air sacs at the end of bronchioles. Structure:

Thin Walls: One cell thick, composed of squamous epithelial cells (Type I). Surfactant: Secreted by Type II cells, reduces surface tension. Capillaries: Surrounded by a network of pulmonary capillaries. Elastic Fibers: Allow expansion and recoil. Function: Site of gas exchange. Oxygen diffuses from alveolar air into the blood, and carbon dioxide diffuses from the blood into the alveolar air. Their large number (~300 million) provides a huge surface area.

7. How the contraction and relaxation of human lungs take place?

Answer: Lungs themselves do not have muscles; they are passive. Their expansion and contraction occur due to changes in the thoracic cavity, driven by the diaphragm and external intercostal muscles.

Inhalation: Diaphragm contracts (flattens) and external intercostals contract (ribs lift). Thoracic volume increases, pressure decreases, and air rushes into the lungs, inflating them. Exhalation: Diaphragm relaxes (domes up) and external intercostals relax (ribs lower). Thoracic volume decreases, pressure increases, and air is pushed out, deflating the lungs.

Elastic recoil of the lungs also assists in exhalation.

8. What is chloride shift?

Answer: The chloride shift is the exchange of bicarbonate ions (HCO₃⁻) and chloride ions (Cl⁻) across the red blood cell membrane. As CO₂ enters red blood cells, it is converted to bicarbonate by carbonic anhydrase. Bicarbonate moves out of the RBC into the plasma in exchange for Cl⁻ moving into the RBC (via the Band 3 protein). This maintains electrical neutrality and allows for efficient CO₂ transport. It is also called the Hamburger shift.

9. What are the advantages of having millions of alveoli rather than a pair of simple lungs?

Answer: Having millions of alveoli provides a massive surface area for gas exchange (about 70-100 m² in humans). This large surface area allows for a much higher rate of diffusion of oxygen and carbon dioxide, meeting the metabolic demands of the body. A pair of simple, hollow lungs would have a very small surface area, insufficient for adequate gas exchange. The alveolar structure also provides a thin barrier and rich blood supply, further optimizing exchange.

10. Write the differences between:

(a) Internal and external respiration

Answer: External respiration is the exchange of gases between the lungs and the blood. Internal respiration is the exchange of gases between the blood and the body cells.

(b) Upper and lower respiratory tract

Answer: Upper respiratory tract includes nose, nasal cavity, pharynx, and larynx. Lower respiratory tract includes trachea, bronchi, bronchioles, and lungs.

(c) Bronchi and bronchioles

Answer: Bronchi are larger airways with cartilage rings; bronchioles are smaller airways without cartilage, with smooth muscle.

(d) Oxyhaemoglobin and carboxyhaemoglobin

Answer: Oxyhemoglobin is hemoglobin bound to oxygen; carboxyhemoglobin is hemoglobin bound to carbon monoxide. (e) Haemoglobin and myoglobin

Answer: Hemoglobin is in red blood cells, transports oxygen; myoglobin is in muscle cells, stores oxygen.

11. List the effects of smoking.

Answer: Smoking has numerous harmful effects:

Respiratory: Chronic bronchitis, emphysema, lung cancer, increased infections. Cardiovascular: Hypertension, atherosclerosis, heart attack, stroke. Cancer: Lung, mouth, throat, esophagus, bladder, and other cancers. Other: Reduced fertility, premature aging, gum disease, and low birth weight babies. Secondhand Smoke: Harms non-smokers, especially children.

1. Describe the human upper respiratory tract.

Answer: The upper respiratory tract consists of the organs involved in the conduction and conditioning of air before it reaches the lower respiratory tract. It includes the nose, nasal cavity, paranasal sinuses, pharynx, and larynx.

1. Nose and Nasal Cavity:

The nose is the primary entry point for air. It has external nares (nostrils) lined with hairs (vibrissae) that filter large particles. The nasal cavity is divided by the nasal septum. It contains three bony projections called conchae (turbinates) that increase surface area. The cavity is lined with respiratory epithelium (ciliated columnar epithelium with goblet cells) that secretes mucus. Mucus traps particles, and cilia move it toward the pharynx. The rich blood supply warms the air, and mucus moistens it. Paranasal sinuses (frontal, maxillary, ethmoid, sphenoid) are air-filled spaces that lighten the skull and resonate sound.

2. Pharynx:

A muscular tube behind the nasal cavity and mouth. It is divided into nasopharynx, oropharynx, and laryngopharynx. It conducts air from the nasal cavity to the larynx and food from the mouth to the esophagus. The epiglottis prevents food from entering the larynx during swallowing.

3. Larynx:

The voice box, located between the pharynx and trachea. It is made of cartilages (thyroid, cricoid, arytenoid) and contains vocal cords. Functions: Air passage, voice production, and protection of the airway.

In summary, the upper respiratory tract conditions and conducts air, protecting the lower respiratory tract.

2. Describe the human lower respiratory tract.

Answer: The lower respiratory tract consists of the trachea, bronchi, bronchioles, and lungs (alveoli).

1. Trachea:

The windpipe, a tube about 10-12 cm long. It is lined with ciliated epithelium and has C-shaped cartilage rings to prevent collapse while allowing flexibility. It bifurcates into the right and left primary bronchi.

2. Bronchi:

The primary bronchi enter the lungs and divide into secondary and tertiary bronchi. They have cartilage plates and smooth muscle. They conduct air to the bronchioles.

3. Bronchioles:

Smaller branches of the bronchi, lacking cartilage. They have smooth muscle that can constrict or dilate to regulate airflow. They terminate in alveolar ducts and alveoli.

4. Lungs:

Paired, cone-shaped organs in the thoracic cavity. The right lung has three lobes; the left has two. They contain millions of alveoli, the site of gas exchange. Alveoli have thin walls, surfactant, and a rich capillary network.

5. Pleura:

The lungs are enclosed in a double membrane called the pleura. The visceral pleura covers the lungs, and the parietal pleura lines the thoracic cavity. The pleural cavity contains fluid to reduce friction.

In summary, the lower respiratory tract conducts air to the alveoli and facilitates gas exchange.

3. Describe the mechanism of breathing in man.

Answer: Breathing (ventilation) is the mechanical process of moving air into and out of the lungs. It involves two phases: inhalation (inspiration) and exhalation (expiration).

1. Inhalation (Inspiration):

Active Process: Requires muscle contraction. Diaphragm: Contracts and flattens, moving downward. External Intercostal Muscles: Contract, lifting the ribs and sternum upward and outward. Thoracic Volume: Increases. Pressure: Intrapleural pressure decreases (Boyle's Law), creating a negative pressure in the lungs. Air Flow: Air rushes into the lungs to equalize pressure.

2. Exhalation (Expiration):

Passive Process: Usually occurs due to relaxation of muscles. Diaphragm: Relaxes and domes upward. External Intercostal Muscles: Relax, ribs and sternum move downward and inward. Thoracic Volume: Decreases. Pressure: Intrapleural pressure increases, becoming positive relative to atmospheric pressure. Air Flow: Air is pushed out of the lungs. Elastic Recoil: The elastic fibers in the lungs help expel air.

Forced Exhalation: During exercise or coughing, internal intercostal muscles and abdominal muscles contract to force air out.

In summary, breathing is a mechanical process driven by pressure changes in the thoracic cavity, resulting from muscle contraction and relaxation.

4. How the control of breathing takes place?

Answer: Breathing is controlled by the respiratory center in the brain, which responds to chemical and neural signals.

1. Respiratory Center:

Located in the medulla oblongata and pons of the brainstem. Medullary Respiratory Center: Contains the dorsal respiratory group (DRG) and ventral respiratory group (VRG). The DRG controls the basic rhythm of breathing. Pontine Respiratory Center: Modifies the rhythm.

2. Chemical Regulation:

Central Chemoreceptors: Located in the medulla, they respond to changes in CO₂ and pH of the cerebrospinal fluid. An increase in CO₂ (hypercapnia) or a decrease in pH stimulates these receptors, increasing the rate and depth of breathing. Peripheral Chemoreceptors: Located in the carotid and aortic bodies. They respond to changes in O₂, CO₂, and pH in the blood. A decrease in O₂ (hypoxia) stimulates them, increasing breathing.

3. Neural Regulation:

Stretch Receptors: In the lungs, they signal over-inflation (Hering-Breuer reflex) to inhibit inhalation. Higher Brain Centers: The cerebral cortex can voluntarily control breathing (e.g., holding breath).

In summary, breathing is controlled by a complex interplay of neural and chemical signals, ensuring adequate gas exchange.

5. Explain the transport of oxygen in blood.

Answer: Oxygen is transported in the blood in two ways:

1. Bound to Hemoglobin (98%):

Oxygen binds reversibly to the iron atom in the heme group of hemoglobin, forming oxyhemoglobin (HbO₂). Each hemoglobin molecule can carry four oxygen molecules. The binding affinity of hemoglobin for oxygen depends on the partial pressure of oxygen (PO₂), pH, temperature, and concentration of 2,3-BPG. Oxygen-Hemoglobin Dissociation Curve: A sigmoidal curve showing that hemoglobin binds oxygen readily in the lungs (high PO₂) and releases it in tissues (low PO₂). Bohr Effect: A decrease in pH (increase in H⁺) and an increase in CO₂ decreases hemoglobin's affinity for oxygen, promoting oxygen release in tissues.

2. Dissolved in Plasma (2%):

A small amount of oxygen dissolves directly in the plasma. This is insufficient for metabolic needs but contributes to the total oxygen content.

Factors Affecting Oxygen Transport:

PO₂: Higher PO₂ increases binding. pH: Lower pH (acidic) decreases binding (Bohr effect). Temperature: Higher temperature decreases binding. 2,3-BPG: Higher levels decrease binding.

In summary, hemoglobin is the primary transporter of oxygen, and its binding and release are regulated by various physiological factors.

6. Explain the transport of carbon dioxide in blood.

Answer:

Carbon dioxide is transported in the blood in three ways:

1. As Bicarbonate Ions (70%):

CO₂ diffuses into red blood cells. Carbonic anhydrase catalyzes the reaction: CO₂ + H₂O [source symbol unavailable] H₂CO₃ [source symbol unavailable] H⁺ + HCO₃⁻. Bicarbonate (HCO₃⁻) moves out of the RBC into the plasma in exchange for Cl⁻ (chloride shift). In the lungs, the reverse reaction occurs, and CO₂ is exhaled.

2. Bound to Hemoglobin (23%):

CO₂ binds to the amino groups of globin (not heme), forming carbaminohemoglobin (HbCO₂). This binding is affected by pH and PO₂ (Haldane effect).

3. Dissolved in Plasma (7%):

A small amount of CO₂ dissolves directly in the plasma.

Haldane Effect:

Oxygenation of hemoglobin in the lungs reduces its affinity for CO₂, promoting CO₂ release. Deoxygenation in tissues increases its affinity for CO₂, promoting CO₂ pickup.

In summary, carbon dioxide is transported mainly as bicarbonate, with smaller amounts bound to hemoglobin and dissolved in plasma. The chloride shift and Haldane effect are crucial for efficient transport.

7. What is the role of respiratory pigments in man?

Answer: Respiratory pigments are colored, metal-containing proteins that transport oxygen and sometimes carbon dioxide in the blood. In

man, the primary respiratory pigment is hemoglobin.

Role of Hemoglobin:

Oxygen Transport: Hemoglobin binds oxygen in the lungs (high PO₂) to form oxyhemoglobin and releases it in tissues (low PO₂). This greatly increases the oxygen-carrying capacity of blood (about 70 times more than plasma alone). Carbon Dioxide Transport: Hemoglobin also transports CO₂ (as carbaminohemoglobin) and acts as a buffer by binding H⁺ ions (which are produced when CO₂ is converted to bicarbonate). Buffering: Hemoglobin acts as a buffer, helping to maintain blood pH.

Other Respiratory Pigments:

Myoglobin: Found in muscle cells, stores oxygen and releases it during muscle contraction. Neuroglobin and Cytoglobin: Found in the brain and other tissues, may protect against hypoxia.

In summary, respiratory pigments like hemoglobin are essential for efficient oxygen and carbon dioxide transport, supporting cellular respiration and homeostasis.

8. Describe the cause, symptoms and treatments of: (a) Sinusitis (b) Otitis media (c) Pneumonia (d) Pulmonary tuberculosis (e) Emphysema (f) Chronic obstructive pulmonary disease (COPD)

Answer:

(a) Sinusitis:

Cause: Inflammation of the paranasal sinuses, usually due to viral or bacterial infection, allergies, or anatomical blockage. Symptoms: Facial pain/pressure, nasal congestion, headache, thick nasal discharge, fever. Treatment: Decongestants, saline nasal irrigation, antibiotics (if bacterial), corticosteroids, surgery in chronic cases.

(b) Otitis Media:

Cause: Inflammation of the middle ear, often due to bacterial or viral infection, often following a cold or allergy. Symptoms: Ear pain, fever, irritability, fluid drainage from the ear, hearing difficulty. Treatment: Pain relievers, antibiotics (if bacterial), tympanostomy tubes for recurrent cases.

(c) Pneumonia:

Cause: Infection of the alveoli by bacteria, viruses, or fungi. Symptoms: Cough with phlegm, fever, chills, shortness of breath, chest pain, fatigue. Treatment: Antibiotics (for bacterial), antivirals (for viral), antifungals, rest, fluids, oxygen therapy.

(d) Pulmonary Tuberculosis (TB):

Cause: Infection by Mycobacterium tuberculosis. Symptoms: Persistent cough (>3 weeks), coughing blood, chest pain, fever, night sweats, weight loss. Treatment: Long-term course of multiple antibiotics (e.g., isoniazid, rifampin, ethambutol, pyrazinamide) for 6-9 months.

(e) Emphysema:

Cause: Destruction of alveolar walls, often due to smoking, leading to reduced surface area for gas exchange. Symptoms: Shortness of breath, wheezing, chronic cough, barrel chest. Treatment: Smoking cessation, bronchodilators, corticosteroids, oxygen therapy, lung volume reduction surgery.

(f) Chronic Obstructive Pulmonary Disease (COPD):

Cause: Chronic bronchitis and/or emphysema, usually due to smoking. Symptoms: Chronic cough, sputum production, shortness of breath, wheezing. Treatment: Smoking cessation, bronchodilators, inhaled steroids, oxygen therapy, pulmonary rehabilitation.