W1

Question 1

What is Ventilation?

Answer 1

exchange of air between atmosphere and alveoli – capillary network

Question 1

What is Alveolar pressure?

Answer 1

gas pressure in the alveoli

Question 2

What is Intrapleural (or intrathoracic) pressure

Answer 2

The pressure within the pleural cavity. At rest, intrapleural pressure is subatmospheric. This is due to the recoil of the chest and lungs away from each other.

Intrapleural pressure is important for maintaining the structure and stability of the lungs and thoracic cavity,

Inhalation = intrapleural pressure becomes more negative, reaching its lowest point at the end of inhalation

Exhalation = intrapleural pressure increased but remains negative compared to atmospheric pressure, helping to maintain the elasticity of the lungs and keep the airways open

Question 3

What is Transpulmonary (transmural) pressure

Answer 3

Transpulmonary pressure refers to the difference between the pressure inside the alveoli of the lungs and the pressure in the pleural cavity (intrapleural pressure).

This pressure gradient is what drives ventilation, causing air to flow into or out of the lungs during inhalation and exhalation.

Question 4

What is the dependent lung

Answer 4

the lowermost portion of the lung, so in an upright position this is the bases

Question 5

When do the lungs start to deteriorate?

Answer 5

Around the age of 35, lungs start to deteriorate.
Changes include alterations in alveoli shape, stiffening of rib bones, weakening of the diaphragm, and reduced sensitivity of nerves to irritants.

Question 6

At what age is peak lung function?

Answer 6

Lungs typically reach their peak function around 25 years of age.

Question 7

What factors can accelerate age-related changes to the lungs?

Answer 7

Smoking, air pollution, increased central body mass index (BMI), and prolonged bed rest can accelerate age-related changes in breathing.

Question 8

What controls breathing?

Answer 8

Under autonomic control with interruption from cortical commands- non-conscious

Breathing is primarily controlled by the autonomic nervous system, specifically the respiratory centers located in the brainstem. However it can be modulated or overridden by conscious effort or specific commands from the cortex.

Question 9

Where does the control of breathing originate, and what is the pathway involved?

Answer 9

The control of breathing originates in the brainstem (pons & medulla) in the respiratory center.
The pathway involves the ventral lateral tract, spinal cord, phrenic nerve, intercostal nerves, respiratory muscle contraction, movement of thorax & lungs, air entering alveoli, gas exchange across the alveolar-capillary membrane, and arterial blood.
Feedback mechanisms are present in the loops.

Question 10

What are mechanoreceptors and where are they located?

Answer 10

Mechanoreceptors are sensory receptors that detect stretch and movement in the thorax and lungs.
They are located in bronchial smooth muscles, trachea, and visceral pleura.

Question 11

What are chemo receptors and what do they monitor?
What are the two types?

Answer 11

Chemo receptors are sensory receptors that monitor the partial pressure of arterial blood.
There are two types:
1. Arterial chemo receptors, which monitor and respond to changes in the partial pressure of oxygen and carbon dioxide in the arterial blood.

2. Central chemo receptors in the brain, which respond to changes in the partial pressure of carbon dioxide in their immediate environment, specifically the hydrogen ion concentration ([H+]) in the cerebrospinal fluid (ECF).
   Front (Question):

Question 12

What are the effects of low oxygen or high carbon dioxide levels on chemo receptor activity?

Answer 12

Low oxygen or high carbon dioxide levels increase chemo receptor activity, leading to faster and deeper breathing to compensate.

Question 13

Where are peripheral chemoreceptors located?

Answer 13

Peripheral chemoreceptors are located in the carotid bodies (via glossopharyngeal nerve) and aortic bodies (via the vagus nerve).

Question 14

What is the pathway of blood flow in the cardiorespiratory system?

Answer 14

Mixed venous blood enters the right atrium via superior and inferior vena cava.
It then moves to the right ventricle via the tricuspid valve.
From there, it is pumped through the pulmonary valve into the pulmonary artery, which branches into the left and right pulmonary arteries which then further subdivide into smaller arteries and arterioles as they reach the lungs.
The capillary bed lies on the wall of the alveoli, facilitating gas exchange.
Oxygenated blood returns to the left atrium via the left and right pulmonary veins.
It then enters the left ventricle via the bicuspid valve and is pumped through the aortic valve into the aorta, circulating throughout the body.

Question 15

What does FRC stand for, and what does it represent?

Answer 15

FRC stands for Functional Residual Capacity.
It represents the volume of air remaining in the lungs after a normal expiration.
ERV + RV

Question 16

What does TV stand for, and what does it represent?

Answer 16

TV stands for Tidal Volume.
The volume of air moved into and out of the lungs during each ventilation cycle.
t measures around 500 mL in an average healthy adult male and approximately 400 mL in a healthy female.

Question 17

What does VC stand for, and what does it represent?

Answer 17

Vital capacity (VC) is the maximum amount of air a person can expel from the lungs after a maximum inhalation. It is about 3.5 – 4.5 litres in the human body.
It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. It is approximately equal to Forced Vital Capacity (FVC)

Question 18

What does CV stand for, and what does it represent?

Answer 18

CV stands for Closing Volume.
It represents the volume of air at which small airways close.
For adults, it’s around 10% of VC, while for older adults (65 years), it can be up to 40% of VC, with CV equaling FRC.
Closing capacity equals CV plus residual volume.
It indicates the rate at which lungs begin to collapse or close, increasing with age and occurring with asthma or pulmonary disease.

Question 19

What does TLC stand for, and what does it represent?

Answer 19

Total lung capacity: the volume in the lungs at maximal inflation.
IRV + TV + ERV + RV

Question 20

What does RV stand for, and what does it represent?

Answer 20

Residual volume: the volume of air remaining in the lungs after a maximal exhalation

Question 21

What does ERV stand for, and what does it represent?

Answer 21

Expiratory Reserve Volume. It refers to the additional volume of air that can be forcibly exhaled from the lungs after a normal exhalation.

Question 22

What does IRV stand for, and what does it represent?

Answer 22

Inspiratory Reserve Volume. It refers to the additional volume of air that can be inhaled into the lungs beyond a normal inhalation. In other words, after you’ve taken a normal breath, there’s still some extra air that you could inhale if needed. IRV represents the amount of air that you can breathe in forcefully beyond this normal inhalation.

Question 23

What does FEV1 stand for, and what does it represent?

Answer 23

Volume that has been exhaled at the end of the first second of forced expiration

Question 24

What does PEF stand for, and what does it represent?

Answer 24

Peak expiratory flow: The highest forced expiratory flow measured with a peak flow meter

Question 25

What is spirometry?

Answer 25

Spirometry is the measurement of flow and volume in the respiratory system.
It can be an objective measure to assess or monitor disease progression and to monitor a patient’s deterioration during an acute respiratory episode or the efficiency of a drug, such as a bronchodilator.

Question 26

What are the changes in lung volumes across different age groups and conditions?

Answer 26

Children: Increase in lung volumes up to age 20.
Older Adults: Decrease in vital capacity and tidal volume.
Conditions leading to decreased lung volumes in adults: Chest pain; Respiratory muscle weakness; Bony thorax deformity; Pleural effusions; Pneumothorax; Depressed respiratory drive; Occupational lung diseases.

Question 27

What is the process of spontaneous respiration?

Answer 27

Spontaneous respiration, also known as quiet respiration or unforced breathing, is the process by which air moves into and out of the lungs without conscious effort
Inhalation (Inspiration):

Diaphragm contracts, moving downward.
External intercostal muscles contract, expanding ribcage.
Thoracic cavity volume increases, pressure decreases causing air to flow into lungs.
Passive process driven by pressure gradient.

Exhalation (Expiration):

Inhalation muscles relax, allowing elastic recoil of lungs and chest wall.
Thoracic cavity volume decreases, increasing air pressure in lungs.
Air expelled passively as diaphragm and intercostal muscles relax.
Shorter duration than inhalation.
Gas Exchange:

Occurs in alveoli.
Oxygen diffuses into bloodstream, binds to hemoglobin.
Carbon dioxide diffuses into alveoli, exhaled.
Vital for cellular function and health.

Question 28

What is compliance?

Answer 28

Compliance measures the lung’s ability to stretch and expand, which is determined by lung volume, elastic recoil, surfactant, and the lung’s ability to stretch.
Low compliance is seen with oedema (ARDS), scar tissue (pulmonary fibrosis), deformity (kyphoscoliosis), muscle paralysis (polio) and restrictive lung conditions, while high compliance is seen in conditions like emphysema (COPD) initially (although hyperinflation causes decreased compliance)

Question 29

What is elastic recoil?

Answer 29

Refers to the ability of the lungs and chest wall to return to their original shape and size after being stretched during inhalation

Question 30

What is surfactant

Answer 30

Specialized cells in the alveoli produce a substance called surfactant. Surfactant acts like a detergent, reducing the surface tension of the fluid lining the alveoli. By lowering surface tension, surfactant prevents the alveoli from collapsing after each breath.

Question 31

What factors affect elastic recoil?

Answer 31

Elastic recoil is affected by collagen, elastane, and surface tension/surfactant.
Age and pathology, such as emphysema or pulmonary fibrosis, can alter elastic recoil.

Question 32

What is airway resistance?

Answer 32

Airway resistance refers to the resistance of the respiratory tract to airflow during inspiration and expiration.
It is affected by the calibre/patency of the airway, with smaller airways having greater resistance.
Conditions like asthma and bronchospasm can increase airway resistance.

Question 33

What is ventilation?
Which area of the lungs is better ventilated?

Answer 33

Ventilation is the movement of air into and out of the lungs.
Lower regions of the lung are ventilated better than upper zones due to the weight of the lung and pleural pressure gradient.

Question 34

What is perfusion?
Which area of the lungs receives better perfusion?

Answer 34

Perfusion refers to the blood flow reaching the lungs to pick up oxygen and release carbon dioxide.
Blood flow is greater in the gravity-dependent portion of the lung (bottom of lungs).

Question 35

What is ventilation-perfusion matching?

Answer 35

The bases of the lungs have a greater proportion of blood flow (perfusion) relative to air flow (ventilation).
The apex of the lungs has more ventilation relative to perfusion.
Mid-lung regions provide the most efficient gas exchange due to optimal ventilation-perfusion matching.

Question 36

How are the airways protected from particles?

Answer 36

Large particles (>10 µm) are filtered by the nose or removed by cough or sneeze reflex.
Smaller particles (2-10 µm) are deposited in conducting airways and removed by the Mucociliary Escalator.
Smallest particles (<2 µm) are deposited in alveoli and removed by macrophages.

Question 37

What are the effects of smoking and dust exposure on lung function?

Answer 37

Smoking and exposure to silica dust and asbestos fibers can injure macrophages and alveolar walls, making the lungs more susceptible to infections and promoting pulmonary fibrosis

Question 38

What are the general features of the lungs?

Answer 38

Each lung has an apex, base, mediastinal surface, and costal surface.
Lungs are divided into lobes by fissures.
Hilum of lung: area on the medial surface where structures enter and leave. It’s the area where the lung is attached to the mediastinum
Root of lung: = structures themselves that enter/exit the hilum
Attached the lung to the mediastinum
Icludes a primary bronchus; delivers air to the lung
Pulmonary artery; delivers deoxygenated blood from the right ventricle of the heart
Pulmonary veins; delivers oxygenated blood back to left atrium of the heart
Bronchial arteries; deliveries oxygenated blood to supply the lung tissue itself
Lymphatic vessels
Branches of pulmonary nerve plexus to innervate the lungs

Question 39

What structures make up the thorax?

Answer 39

Bony thorax: ribs, vertebral column, sternum
Joints: intervertebral, costovertebral, costochondral, manubrium sternum, sternocostal
Muscles: innervated by phrenic and intercostal nerves
Pleura: parietal and visceral pleura line the lungs

Question 40

What is pleural linkage?

Answer 40

The thoracic rib cage acts as a mechanical pump for the lungs.
Pleural linkage refers to the lungs sticking to the walls of the thoracic cavity to be pumped.
Muscles of respiration drive this pump.

Question 41

Visceral pleura

Answer 41

Covers the surface of the lungs

Question 42

Parietal pleura

Answer 42

Lines the inner surface of the thoracic cavity

Question 43

Pleural fluid

Answer 43

In between visceral and parietal pleura
Acts as a lubricant and allows smooth movement between the lungs and chest wall during breathing
Also assists in surface tension and pleural linkage

Question 44

What is pleural linkage?

Answer 44

Lungs stick to the inside of pulmonary cavities dueto:
Surface tension - created by fluid between parietal and visceral pleura
Negative pressure - found in pleural space also holds the surfaces together

Prevents separation of lungs and thorax during breathing.

Question 45

Which muscles are involved in respiration?

Answer 45

Increase Volume:

Diaphragm (main muscle of inspiration)
External intercostal muscles
Sternocleidomastoid
Scalenes
Pectoralis minor
Decrease Volume:

Internal intercostal muscles
Abdominal muscles (rectus abdominis, external oblique, internal obliques, transversus abdominis)

Question 46

What dimensions does the thorax change during breathing?

Answer 46

Antero-posterior (forwards & backwards): “Pump Handle” movement
Transverse: “Bucket Handle” movement
Vertical: Mainly by the diaphragm

Question 47

What defines the conducting zone of the respiratory system?
Function?
Structure?
Lining?

Answer 47

No gas exchange occours
Function = filter, warm and humidity air and conduct it into the lungs
Contains goblet cells that secrete mucus.
Features the mucociliary escalator, driven by cilia, which clears mucus and foreign particles.
Structures involved = Extends from trachea to terminal bronchioles.
Lining = simple columnar epithelium, pseudostratified ciliated epithelial cells

Question 48

What characterizes the respiratory zone?
Function?
Structure?
Lining?

Answer 48

Function = Gas exchange occurs, site of O2 and CO2 exchange with the blood
Structures involved = Respiratory bronchioles to alevoli
Lining = simple squamous eplithium (flat cells that permit gas exchange)

Makes up 2.5L of lung volume.
Comprises the terminal lung unit.

Question 49

What are the types of dead space in the respiratory system?

Answer 49

Anatomical dead space: air in conducting zones (~150ml).
Alveolar dead space: air in alveoli with little or no blood supply. - Enters & leaves lungs but does not participate in gas exchange
Physiological dead space = anatomical + alveolar.
Increases with age and lung disease.

Question 50

What is minute ventilation?

Answer 50

Total volume of gas entering the lungs each minute.
Calculated as Tidal Volume (TV) × Respiratory Rate (RR).

Question 51

What is alveolar ventilation?

Answer 51

Total volume of fresh air entering the alveoli per minute.
Calculated as (TV - Anatomical dead space) × RR.

Question 52

What are alveoli and how are they stabilized?

Answer 52

300-500 million hollow sacs in the lungs.
Stabilized (reduces risk of collapse) by pulmonary surfactant secreted by type II alveolar cells.
Surfactant reduces surface tension, improving stability and compliance.

Question 53

What is pulmonary surfactant?
What is it secreted by?

Answer 53

Reduces surface tension at the air-liquid interface within the alveoli, preventing alveolar collapse during exhalation and enhancing lung compliance. This allows for easier lung expansion during inhalation and prevents lung collapse at the end of exhalation.

Secreted by type II alveolar cells.

Question 54

What does the velocity of gas flow in the respiratory system depend on?

Answer 54

Volume of gas flow in/out of alveoli is
Directly proportional to pressure difference between atmosphere and alveoli
Inversely proportional to airway resistance

Question 55

Describe the processes of inhalation

Answer 55

Intercostal muscles & diaphragm CONTRACT & pull thoracic wall out
~ pull parietal pleura (lungs) with it

Lungs inflate ~ alveoli inflate & stretched open
~ pressure drops = air rushes in (inspiration)

Rib moves superior/anterior = bucket handle movements

ACTIVE ~ Uses chemical energy = ATP

Question 56

Describe the processes of exhalation

Answer 56

Muscles relax

Pleural linkage causes thoracic wall to follow
~ increases pressure = air rushes out (expiration)

PASSIVE ~ Elastic recoil of lungs causes them to deflate (elastin “rubber band”)

Question 57

What are the types of respiration and their characteristics?

Answer 57

Quiet respiration: Active inspiration, passive expiration
Forced respiration: Active inspitation and expiration, involving accessory muscles.

Question 58

What is the patient position for a Postero-Anterior (PA) view, and what are the effects on the film?

Answer 58

Patient Position: Standing, arms abducted.
Effect on Film: Accurate proportions.
Advantage: More accurate heart size on film.
Disadvantage: Unable to use this position if the patient is unable to stand.

Question 59

What is the patient position for an Antero-Posterior (AP) view, and what are the effects on the film?

Answer 59

Patient Position: Supine, sitting up in bed.
Effect on Film: Enlarged heart. May be able to see more of the medial border of the scapula.
Advantage: Easy position to get into.
Disadvantage: Tends to magnify the mediastinum, harder to get full inspiration film.

Question 60

What is the patient position for a Lateral view, and what are the effects on the film?

Answer 60

Patient Position: Standing lateral with arms outstretched in front.
Effect on Film: Views of fissures. Can be difficult to decipher changes at the height of the hemidiaphragm.
Advantage: Middle lobe pathology clearer.
Disadvantage: Unable to use this position if the patient is unable to stand or lift arms up.

Question 61

What is the patient position for an Oblique view, and what are the effects on the film?

Answer 61

Patient Position: Standing/sitting, PA/AP, rotated 45° away from the film. One arm on hip and one at shoulder level resting on.
Effect on Film: Clear picture of mediastinum.
Advantage: Mostly used for looking at heart and mediastinum. Lung fields, apices, oblique and horizontal fissures more discernible.
Disadvantage: Must stand or sit independently in a difficult position.

Question 62

What does the Rotation check involve in chest X-rays?

Answer 62

Ensure the length of the clavicles is equal on both sides.
This check ensures that the patient was not rotated during the imaging process, which can affect the anatomical accuracy.

Question 63

What does the Inspiration check involve in chest X-rays?

Answer 63

Confirm the visibility of 5-6 anterior ribs above the diaphragm.
Check visibility of costophrenic angles and lung apices.
Indicates the X-ray was taken at full inspiration, essential for optimal lung and pleural space visualization.

Question 64

What does the Exposure check involve in chest X-rays?

Answer 64

Ideal exposure shows vertebrae just visible behind the heart.
Underexposed X-rays appear too white, obscuring details.
Overexposed X-rays appear too black, losing finer details like lung markings.

Question 65

What should you look for in soft tissues and bones in chest X-rays?

Answer 65

Check ribs, sternum, spine, clavicle, and glenohumeral joint for abnormalities.
Note on ribs: Posterior ribs are calcified and more visible; anterior ribs contain more cartilage and are less visible.
Rib angles should descend from the chest; deviation may indicate a barrel chest.

Question 66

What are key features to assess in the airways on a chest X-ray?

Answer 66

Trachea should be central; check for deviations.
Carina is the bifurcation point of the trachea.
Right main bronchus: wider, shorter, more vertical.
Left main bronchus: longer, about twice the size of the right.

Question 67

What should you examine in the breathing category of a chest X-ray?

Answer 67

Follow an ‘infinity figure’ pattern to inspect lungs and pleura.
Look for increased or reduced lung markings, opacities, and asymmetry.
Ensure lung markings extend to the borders of the chest.

Question 68

What are key circulation-related features to assess on a chest X-ray?

Answer 68

Heart should be centrally located with slight left extension.
Heart size should not exceed half the thoracic width.
Check for visible cardiophrenic angles and congestion around pulmonary vessels.

Question 69

What should you look for in the diaphragm on a chest X-ray?

Answer 69

Shape should be dome-shaped; look for tenting or flattening.
Right side typically higher than the left due to liver position.
Check for sharply defined cardiophrenic and costophrenic angles.
Look for the presence of a gastric bubble indicating air in the stomach.

Question 70

What does atelectasis look like on an X-ray?

Answer 70

Increased Density: The collapsed area appears denser due to the lack of air.
Volume Loss: Key feature, leading to shifting of the mediastinum towards the affected side, elevation of the corresponding hemidiaphragm, and rib crowding.
Displacement of Internal Structures: The trachea, heart, and nearby lung tissue may shift towards the affected area.

Question 71

What does consolidation look like in an X-ray?

Answer 71

Increased Opacity: The affected area becomes opacified with relatively homogenous density.
Air Bronchograms: These are often visible within the consolidation because the bronchi remain air-filled while surrounded by fluid-filled alveoli.
Well-defined Borders: The opacity may respect anatomical boundaries such as fissures, particularly in lobar pneumonia.
No Significant Volume Loss: Unlike atelectasis, consolidation does not typically cause a significant shift in mediastinal structures or diaphragm position.
Silhouette Sign: Adjacent structures may be obscured if they share a border with the consolidated area.

Question 72

At what rib levels should be the right and left hemi-diaphragms sit on a P.A. chest X-ray?

Answer 72

The right hemi-diaphragm usually sits at a slightly higher level than the left due to the liver’s position beneath it. 5 th rib level on the right and 7th rib level on the left

Question 73

What do elevated WBC counts indicate in pathology results?

Answer 73

High WBC indicates potential infection or inflammation; low counts could suggest immunosuppression

Question 74

What does an elevated CRP level indicate?

Answer 74

High CRP levels are markers of inflammation and can indicate infection, autoimmune disorders, or other inflammatory conditions.

Question 75

What does the level of haemoglobin indicate in a patient’s pathology results?

Answer 75

High Hb could suggest polycythemia, often seen in chronic hypoxic conditions; low levels might indicate anemia, affecting patient energy and healing.
Low haemoglobin may limit exercise tolerance due to decreased oxygen delivery to tissues, requiring adjusted activity levels during therapy.

Question 76

What do changes in platelet counts indicate in medical tests?

Answer 76

Platelets are essential for clotting; abnormal counts can indicate bleeding disorders or thrombotic risks.

Low platelet counts can increase bleeding risk, important to consider during manual therapies or exercises that could cause bruising or injury.

High counts may increase thrombosis risk, low counts may lead to excessive bleeding.

Question 77

What does an abnormal INR value signify?

Answer 77

INR is a measure of blood clotting; deviations can indicate coagulation issues.
High INR suggests blood thinning which is excessive, increasing bleeding risk; a low INR indicates quicker clotting times.

Question 79

What does an elevated CK level indicate in a pathology report?

Answer 79

High CK levels often suggest muscle damage, which can occur from myocardial infarction, muscle diseases, or physical trauma.

Question 80

What is the significance of elevated troponin levels?

Answer 80

Troponin is highly specific to cardiac muscle injury and is a critical marker in diagnosing myocardial infarctions.

Question 81

What does Pneumothorax look like on a X-ray?

Answer 81

Visible visceral pleural edge, absence of vascular markings.
May appear as area of translucency in supine position

Question 82

What does DRSABCDE stand for in reading X-rays

Answer 82

Details: Correct patient and correct X-ray, no previous X-rays
RIPE
Rotation: clavicles are equal distance from the midline, minimal rotation
Inspiration: Inspiratory effort is goof, 5-6 anterior ribs, costophrenic angles visible on both sides
Projection: PA
Exposure: Good, Able to see the vertebral bodies behind the heart
Soft tissues and bones
- No rib fractures, no clavicle fractures
- Erosion of 2-3 right ribs behind the mass in apical right lung
Airways
- Trachea is deviated towards the right side
- Bronchi are obscured and difficult to visualise
Breathing
- Left lung looks normal; no obvious consolidation or opacities
- Right lung; large and well defined opacity in apical zone of right lung
- Pleura; Normal, no evidence of thickening
Circulation
- Cardiac shadow is well defined and of a normal size
- Easily visualise the arch of aorta, left ventricle and right atrium
Diaphragm
- Small bulge in diaphragm on the right side - could be normal for the patient, difficult to know with no previous X-rays
- No Costophrenic blunting or evidence of fluid
- Fundus of stomach is visible on left hand side
Extra

Question 83

What do normal breath sounds indicate?

Answer 83

Cause: Normal breathing.
Mechanism: Air flows smoothly through the tracheobronchial tree without obstruction, sounding like a light breeze. Indicates healthy lung function and airway patency.

Question 84

What causes reduced breath sounds?

Answer 84

Cause: Small Tidal Volumes - less air flow.
Mechanism: Inflated lung mutes sounds because minimal air enters the lung, often heard in conditions like hyperinflation in chronic obstructive pulmonary disease (COPD).

Question 85

What are the causes and mechanisms behind absent breath sounds?

Answer 85

Causes: Pneumothorax or lobar atelectasis.
Mechanism:

Pneumothorax: Air in the chest cavity reduces breath sounds over the affected area.
Lobar Atelectasis: Obstruction from sputum or a foreign body blocks air entry, leading to absence of breath sounds over the affected lobe.

Question 86

What causes bronchial breath sounds and how do they sound?

Answer 86

Causes: Consolidated lung or large pleural effusion.
Mechanism:
Consolidation: Solid lung tissue transmits air movement more clearly, producing harsh sounds on both inspiration and expiration.
Pleural Effusion: Fluid mutes normal lung sounds but may cause harsh bronchial breathing if it compresses lung tissue.

Question 87

What are fine crackles and what causes them?

Answer 87

Cause: Acute pulmonary oedema.
Mechanism: Crackles are heard late in inspiration, typically basally and gravity-dependent as air moves through fluid-filled alveoli. Not altered by coughing, indicating fluid within the lung tissues.

Question 88

What are coarse crackles and when are they heard?

Answer 88

Cause: Sputum in the airways.
Mechanism: Coarse crackles occur throughout the breathing cycle as air bubbles through or opens sputum-blocked airways, indicating increased secretions or mucus in the airways.

Question 89

What causes a wheeze and what does it sound like?

Answer 89

Cause: Airway narrowing due to bronchoconstriction, foreign bodies, tumors, or airway collapse.
Mechanism: Wheezing is a musical sound, high or low-pitched, heard during expiration and/or inspiration as the air vibrates in the narrowed airways.

Question 90

What is a pleural rub and what causes it?

Answer 90

Cause: Inflammation, infection, or tumors of the pleural surfaces.
Mechanism: Friction between inflamed or roughened pleural surfaces creates creaking or grating sounds during both inspiration and expiration, indicating pleural pathology.