SURFACE ANATOMY

Apex: lung apex and pleural cupola extend about 2–3 cm above the medial third of the clavicle into the root of the neck. 

Anterior margin (right): follows the right side of the sternum from about the 2nd to the 4th costal cartilages then slopes laterally to reach the 6th right costal cartilage. 

Anterior margin (left): similar but deviates laterally to form the cardiac notch and reaches approximately 3 cm lateral to the left sternal edge at the upper margin of the 6th costal cartilage (the cardiac notch produces the lingula). 

Inferior margins (costal landmark lines)

Mid-clavicular line: inferior border of lung at 6th rib (pleural reflection ~2 ribs lower). 

Mid-axillary line: inferior border of lung at 8th rib. 

Posteriorly (paravertebral): inferior border reaches roughly the 10th rib/vertebral level. 

Note: the parietal pleura extends ~2 ribs lower than the lung at these points, creating the costodiaphragmatic recess. 

miliary tb ct finding

Nodule size and number: Numerous micronodules usually 1–3 mm (sometimes up to ~4–5 mm) and often too many to count. 

Distribution: Random (hematogenous) distribution with no centrilobular clustering or polygonal secondary-lobule pattern; nodules are bilateral and diffuse across all lung zones (may show mild basilar predominance acutely and mild upper-zone predominance chronically). 

Margins and background: Nodules often sharply marginated but can be ill-defined; ground-glass attenuation or interlobular septal thickening/reticular change may be present superimposed on the nodules. 

Pulsus paradoxus

Paradoxical pulse refers to an inspiratory decline in systolic pressure greater than 10 mmHg. In normal circumstances, inspiration results in an increase in venous return as blood is ‘sucked into’ the thorax by the decline in intrathoracic pressure. This increases right ventricular stroke volume, but left ventricular stroke volume falls slightly (ventricular interdependence). When the heart is constrained in a ‘fixed box’ by a pericardial effusion (cardiac tamponade) or by thickened pericardium (pericardial constriction), the increased inspiratory right ventricular blood volume reduces left ventricular compliance, resulting in a more pronounced reduction in left ventricular filling stroke volume and systolic blood pressure during inspiration. ‘Pulsus paradoxus’ therefore represents an exaggeration of the normal inspiratory decline in systolic pressure and is not truly paradoxical. Pulsus paradoxus in acute severe asthma is thought to be due to negative pleural pressure increasing afterload and thereby impedance to left ventricular emptying. It is measured by inflating a blood pressure cuff until no sounds are heard. The pressure is then slowly decreased until systolic sounds are first heard during expiration but not during inspiration – note this reading. The pressure is slowly decreased further until sounds are heard throughout the respiratory cycle (inspiration and expiration) – note this second reading. If the pressure difference between the two readings is >10 mmHg, it can be classified as pulsus paradoxus. 

Ref- Hutchison's 24E

CARDINAL SYMPTOMS OF GASTROINTESTINAL SYSTEM

1. Dysphagia and odynophagia
2. Heartburn and reflux
3. Indigestion
4. Flatulence
5. Vomiting
6. Anorexia
7. Constipation
8. Diarrhoea
9. Alteration of bowel pattern
10. Abdominal pain
11. Abdominal distension
12. Weight loss
13. Haematemesis
14. Rectal bleeding
15. Melaena
16. Jaundice
17. Itching
18. Urinary symptoms

Ref- Hutchison's clinical methods 24E

What is pulsus paradoxus and what are its respiratory causes?

 Pulsus paradoxus is an exaggerated fall in systolic blood pressure during inspiration.

Normally during inspiration, systolic BP falls slightly (≤10 mmHg).

In pulsus paradoxus, the fall is >10 mmHg.

Despite the name, there is no true paradox. The “paradox” refers to the fact that:

Heart sounds may still be heard,

But the peripheral pulse becomes weak or disappears during inspiration.

Mechanism

During inspiration:

More venous blood enters the right ventricle.

In conditions with limited cardiac space/filling (e.g., tamponade), the RV expands at the expense of the LV.

LV filling decreases → stroke volume falls → systolic BP drops markedly.

Conditions causing pulsus paradoxus

Cardiac causes

Cardiac tamponade (classic)

Constrictive pericarditis (less common)

Severe heart failure

Respiratory causes

Severe asthma

Severe COPD exacerbation

Tension pneumothorax

Massive pulmonary embolism

Aggravating factors of cough

PDFCE 

Pollution, Pollen, Posture

Drugs, Diurnal, Dry air

Food

Cold weather, Common cold

Exercise

Normal cortisol levels, diurnal variation and it's significance in respiratory system

Serum cortisol levels

Normal levels

Morning -8am- 5-23 mcg/dL

Evening -4pm- 3-13 mcg/dl

Diurnal variation is maintained by suprachiasmatic nucleus of the hypothalamus.

Cortisol levels peak during early morning and gradually decline throughout the day reaching lowest point around midnight 

Effects on the respiratory system

Increased Inflammatory response when the levels of cortisol reach lowest at around midnight. 

Low cortisol levels at midnight lead to airway hyper responsiveness leading to morning dip in Peak expiratory flow rate.

During cortisol trough at around late night, eosinophil counts rise leading to influx of inflammatory cells into the airway mucosa, exacerbating conditions like Eosinophilic Bronchitis or severe asthma.

Cortisol is essential for surfactant production in fetus. It stimulates the maturation of Type II pneumocytes, which is why exogenous glucocorticoids are administered in cases of threatened preterm labor to prevent Respiratory Distress Syndrome (RDS).

Stridor vs wheeze

 Stridor – Definition

A harsh, high-pitched, monophonic sound produced by turbulent airflow through a narrowed upper airway (larynx or trachea), typically heard best over the neck.

 Wheeze – Definition

A continuous, musical, high-pitched sound caused by airflow through narrowed lower airways (bronchi/bronchioles), typically heard over the chest.

Stridor vs Wheeze – Key Differences

Anatomical site

Upper airway (larynx, trachea) -stridor 

Lower airway (bronchi, bronchioles) - wheeze 

Sound quality

Harsh, loud, non-musical -stridor

Musical, whistling - wheeze

Best heard over

Neck -stridor

Chest (lung fields) - wheeze

Mechanism

Extrathoracic airway narrowing -stridor

Intrathoracic airway narrowing - wheeze

Common causes

Croup, epiglottitis, foreign body (upper airway), laryngeal edema -stridor

Asthma, COPD, bronchiolitis - wheeze

Clinical significance

Often emergency (airway compromise) -stridor

Suggests airflow limitation, not always immediately life-threatening - wheeze

causes of bronchial breath sounds

Primary Causes

Pneumonia (consolidation from bacterial, viral, or fungal infection)

Lung abscess or cavitary lesions (e.g., necrotic tumor, tuberculosis cavity)

Bronchiectasis (dilated airways with chronic inflammation)

Pleural effusion (over compressed underlying lung)

Atelectasis or lung collapse (obstructive or compressive)

Secondary Causes

Pulmonary fibrosis (scarring stiffens parenchyma)

Pulmonary edema (fluid overload in alveoli)

Large tumors compressing airways

Sinusitis symptoms

 Major symptoms 

1.purulent anterior nasal discharge 

2.purulent or discolored posterior nasal discharge 

3.Nasal congestion or obstruction 

4.Facial congestion or fullness

5.Facial pain or pressure

6.Hyposmia or anosmia 

7.Fever

Minor symptoms 

1.Headache

2.Halitosis

3.Ear pain, pressure or fullness

4.Dental pain

5.Cough

6.Fever

7.Fatigue

Presence of atleast 2 major or 1 major and 2 minor criteria -diagnosis of Sinusitis is made.

Reference - IDSA 2012