ANATOMY & PHYSIOLOGY II · MODULE 18
A pain married to the breath
Most chest pain is indifferent to breathing. Hers stabs with every inhalation, on one side, and then goes away. This module builds the respiratory systemThe organ system responsible for gas exchange (oxygen and carbon dioxide). and completes the serositis triad the case has been assembling since Module 1.
The findings this module reads together
Between attacks her lungs are unremarkable: clear breath sounds, normal gas exchange, arterial oxygen and carbon dioxide where they should be. During attacks she takes rapid shallow breaths and avoids filling her chest, and a small effusion may appear and then resolve.
Probably a muscle strain, the note said. But the pattern is recurrent, self-limited, unilateral pleuritic pain with transient effusion in a body with a documented history of pericarditis and peritonitis. The pleuraThe double-layered membrane surrounding the lungs and lining the thoracic cavity. is the third serous membrane, and it is taking its place in the triad.
PATIENT CHART · STINA · CHART CLUE #18
- Recurrent — Unilateral stabbing pain on inhalation
- Imaging — Small transient pleural effusionFluid accumulation between the layers of the pleura around the lungs.
- Between — Normal lungs, normal gases
- History — Prior pericarditis and peritonitis
Seven parts, one chart
Each part opens with a finding from Stina’s chart and asks you to commit to a prediction before any video plays, then alternates short videos with H5P activities. Work them in order.
18.1
A Pain That Stabs With Every Breath
Chest pain that tracks the breath, and what that localizes.
PLEURITIC PAIN
18.4
The Mechanics of Breathing
Pressure, complianceThe ease with which the lungs expand and contract during breathing., and why a deepAway from the surface of the body. breath hurts.
VENTILATION MECHANICS
18.6
The Pleura and the Serosal Fire
The pleura as serous membrane, inflamed like the others.
PLEURA
18.7
The Serositis Triad Completes
Pericardium, peritoneumThe membrane lining the abdominal cavity and organs., pleura — one signature.
CHART CLUE #18
◆
The Evidence Behind the Case
Every step of this module’s reasoning, paired with the peer-reviewed literature behind it.
REFERENCES
What you’ll be able to do
By the end of Module 18 you will be able to:
1
Trace the path of air from the nostril to the alveolus and identify the structures along it.
2
Describe the respiratory membrane and explain the requirements for efficient gas exchange.
3
Explain the pressureThe force exerted by gases in the respiratory system, affecting airflow and gas exchange. changes that drive inspirationThe process of inhaling, driven by diaphragm and external intercostal contraction. and expirationThe process of exhaling, which can be passive (relaxation of respiratory muscles) or active (involvi.
4
Describe oxygen and carbon dioxide transport and the respiratory contribution to pH.
5
Identify the pleural membranes and explain the mechanism of pleuritic pain.
6
Recognize recurrent serositis across pericardiumThe membrane surrounding the heart., peritoneum, and pleura as one process.
List of terms
- respiratory system
- pleura
- pleural effusion
- compliance
- deep
- pH
- peritoneum
- pressure
- inspiration
- expiration
- pericardium