Lungs and Pleura Flashcards
Describe the surfaces on the lung:
Apex - superior
Mediastinal surface - faces the center of the thorax
Costal Surface - faces the ribs and the lateral side of the thoracic cavity
Diaphragmatic surface - rests on the diaphragm,
Describe the right lung:
Superior lobe - extends from apex to horizontal fissure, uppermost lobe
Horizontal fissure - separates superior and middle lobe, only found in right lung
Middle lobe -
Oblique fissure - separates middle and superior lobes from inferior lobe
Inferior lobe - extends down to the diaphragm
Describe the hilum in the right lung:
Situated on the mediastinal surface of the right lung, slightly higher than the left due to the position of the heart
Bronchus
Pulmonary arteries
Pulmonary veins
Describe the trachea:
Rings of C-shaped cartilage
Trachaelis muscle posteriorly, creates complete circle, controls diameter by contracting
Sits anteriorly to the oesphagus
The trachea bifurcates at the level of T4/5
At the carina, formation of two primary/main bronchi
These enter the corresponding lung at the hilum
Primary role is to conduct air between the larynx and the bronch
Describe the bronchial tree
- Network of branching airways
- Conduct air from the trachea into the lungs and facilitate
gas exchange - Begins with the trachea
- Splits into the right and left main bronchi
- Further divide into the secondary/lobar bronchi (supply
a lobe of the lung) - Tertiary/segmental bronchi (supply bronchopulmonary
segments) - Eventually into the bronchioles (no cartilage)
- Terminal bronchioles
- Respiratory bronchioles
- Lead to alveoli, where gas exchange takes place
- Alveolar ducts
- Alveolar sacs
- Individual alveoli
Describe the pleura:
- Pleural sleeve surrounds the hilum
- Visceral and parietal layers of pleura become continuous
Parietal pleura – lines the
thoracic wall, mediastinum and
covers the diaphragm - Visceral pleura – lines the
surface of the lung and into the
fissures - Pleural cavity – space between
the visceral and parietal layers,
continaing pleural fluid
Describe the pulmonary ligament
Thin fold of visceral pleura located in the thoracic cavity
Stabilises lung position
Accommodates lung movement
Supports vasculature
structures
Describe the left lung:
Only has 2 lobes - superior and inferior
Slightly smaller than the right lung to accommodate the heart
Superior lobe - Larger than the inferior lobe, it contains the cardiac notch, a concavity that accommodates the heart
Extends from the apex of the lung down to the oblique fissure
Inferior lobe - separated from the superior lobe by the oblique fissure
Lingula - thin, tongue-like projection of the superior lobe, lies against cardiac notch, gas exchange
Describe the apical/ cervical and costal parietal divisions of the pleura:
Apical/Cervical parietal - covers apex of lung, apical parietal pleura is surrounded by the cervical fascia and is located in the suprapleural space
Costal parietal -
Lines thoracic wall’s inner surfaces, following rib contours.
Smooth, adheres closely to ribs and intercostal muscles.
Extensive surface extends from cervical pleura to diaphragm.
Allows frictionless movement during breathing, reducing friction between lungs and thoracic wall.
Describe the Mediastinal parietal and Diaphragmatic parietal divisions of the pleura:
Mediastinal parietal:
Lines the mediastinum, separating lungs.
* Interacts with heart, major blood vessels, trachea, and esophagus.
* More complex structure than costal and cervical pleurae
Diaphragmatic pleura:
Covers superior diaphragm surface and extends laterally to costal parietal pleura.
* Continuous with costal pleura at lateral margins.
* Smooth, allowing movement during respiration.
* Crucial in breathing mechanics, increasing thoracic cavity volume and allowing lungs expansion during inhalation
What are pleura recesses ?
Potential spaces within the pleural cavity
Parietal pleura folds back onto itself and extends beyond the margin of the lungs
The recesses allow for the expansion of the lungs during deep inhalation
Fluid can accumulate in
certain medical conditions
What are the 2 types of pleura recesses ?
Costodiaphragmatic:
Located between the costal pleura and the diaphragmatic pleura
Largest recess and most evident when the lungs are not fully inflated
Costomediastinal Recess
Found between the costal pleura and the mediastinal pleura
More pronounced on the left side due to the cardiac notch
What is pneumothorax ?
Medical condition characterised by the accumulation of air in the pleural space between visceral and parietal pleura
What are the different types of pneumothorax ?
Closed/ spontaneous - Pleural cavity pressure < atmospheric
pressure, internal injury e.g lung cancer
Open - pleural cavity pressure = atmospheric pressure, major open trauma
Tension;
Pleural cavity pressure > atmospheric pressure,
Small puncture-like hole that
forms a ‘one way valve’. Air
can enter but can’t escape.
Causes mediastinal
deviation
What are mediastinal impressions ?
In situ, the lungs are in
close association with
other structures
These leave impressions
on cadaveric lungs -
artefactual
Do not ‘exist’ in a living
person
