Diaphragm Pleurae Flashcards
Mediastinum
- A movable median partition of the thoracic cavity that extends superiorly to the thoracic outlet/root of the neck & inferiorly to the respiratory diaphragm.
- It extends anteriorly to the sternum and pos
Respiratory Diaphragm
skeletal muscle diaphragm lined by pleura (superiorly) and peritoneum (inferiorly) that separates the thoracic and abdominal viscera.
What is the mediastinum divided into?
- Superior
- Anterior
- Middle
- Posterior
Superior mediastinum
bounded anteriorly by the manubrium & posteriorly by vertebral bodies of T1-T4
Anterior mediastinum
space between the pericardium and the sternum
Middle mediastinum
pericardium & heart
Posterior mediastinum
between the pericardium and the vertebral column
What is the inferior mediastium and what makes up it?
bounded anteriorly by the body of the sternum and posteriorly by the vertebral bodies of the lower 8 thoracic vertebrae.
- Subdivided into: Anterior, middle, posterior mediastinum
Respiratory diaphragm
- most important muscle of respiration.
- Thin muscular & tendinous septum that separates the thoracic cavity from the abdominal cavity.
- pierced by structures that pass between the thorax & abdomen.
- dome-shaped (convex superiorly)
attachments of the respiratory diaphragm (4)
- right crus and left crus
- median arcuate ligament
- medial arcuate ligament
- lateral arcuate ligament
right crus
larger and longer (L1-L3/L4);
median arcuate ligament
unites the crura and forms the aortic hiatus
medial arcuate ligament
thickening of fascia (psoas major)
lateral arcuate ligament
thickening of fascia (quadratus lumborum)
what arise from the anterior surface of L1-3/IVDs & the anterior longitudinal ligament
crura of the diaphragm
Diaphramatic Apertures (openings)
- (Inferior) Caval hiatus –T8
- Esophageal hiatus –T10
- Aortic hiatus –T12
- “I ate ten eggs at noon”
what is the respiratory diaphragm innervated by?
(somatic motor) by the phrenic nerve (C3-5)
What also carries sensory information (pain & proprioception)?
phrenic
what do peripheral parts of the diaphragm also receive?
some sensory innervation from lower intercostal nerves
vasculature of the respiratory diaphragm
arterial supply and venous drainage
superior surface of arterial supply
Musculophrenic & Pericardiacophrenic (br. ITA)and Superior Phrenic (br. Thoracic Aorta)
inferior surface of arterial supply
Inferior Phrenic (br. Abdominal Aorta)
superior surface of venous drainage
Musculophrenic & Pericardiacophrenic (drain into ITV) and R. Superior Phrenic (drain into IVC), some veins from posterior curvature drain into azygos and hemiazygos veins
inferior surface of venous drainage
R. inferior phrenic (IVC) & L inferior phrenic (IVC and/or suprarenal vein)
Pleura or Pleural membrane
lining of the thoracic cavity
general features of the pleural membrane
- serous membranes forming closed sacs
2. two layers ( visceral and parietal pleura)
visceral pleura
adheres to lung, continuous with parietal pleura at root of lung
parietal pleura
lines the thoracic cavity
pleural cavity
- potential space b/t pleura layers
- contains small amount of serous pleural fluid
- lubricates pleural surfaces and allows layers to slide smoothly over one another during respiration
pleural reflections
lines, usually projected onto thoracic wall surface, indicating abrupt change in parietal pleura direction as it passes from one wall of the pulmonary cavity to another
does the lung completely fill the pleural cavity, why?
no; therefore there are places where parietal pleurae can appose each other
what is pleural recesses? and what 2 recesses are there?
- occupied by lungs only on (forced) deep inspiration
- Costodiaphragmatic and costomediastinal recesses
Costodiaphragmatic recesses
split like space b/t space between costal and diaphragmatic pleurae, along the interior border of the lung, which enters through it in deep inspiration
costomediastinal recesses
slit like space b/t costal and mediastinal pleurae, along the anterior border of the lung which enters into it in deep inspiration
Thoracentesis
- procedure where a needle is inserted into the pleural space between the lungs and the chest wall.
- remove excess fluid, known as a pleural effusion, from the pleural space to help you breathe easier.
pleural effusion
- excess fluid in pleural space
- “water on the lungs,” is the build-up of excess fluid between the layers of the pleura outside the lungs.
empyema
pus in the pleural space
hemothorax
haemorrhagic pleural effusion
pneumothorax
air filled the pleural space, between the layers of parietal pleura lining the chest wall and the visceral pleura covering the lung
what is pneumothorax caused by?
a blunt or penetrating chest injury, certain medical procedures,or damage from underlying lung disease.
Or it may occur for noobvious reason
pneumothorax symptoms
include sudden chest pain and shortness of breath
pneumothorax treatment
involves inserting a flexible tube or needle between the ribs to remove the excess air. However, a small pneumothorax may heal on its own.
blood supply of pleurae
- visceral and parietal pleura
bronchial arteries arise from what?
athoracic aorta; 1-2 for each lung
role of bronchial arteries
- Supply oxygenated blood to the nonrespiratory tissues of the lung & visceralpleura
- Anastomoses occur between the capillaries of the bronchial and pulmonary systems.
bronchial veins
- Only two visible and named bronchial veins.
- Probably carry only about 13%ofbronchialvenous blood to systemic venous circuit.
- Remaining 87% of bronchial venous blood drains to pulmonary venous circuit desaturating the LA blood by about one percent from 100 to 99%.
arterial supply of the pleurae
- Arterial supply is from the branches of the bronchial and pulmonary arterial systems.
where do the veins drain in the blood supply of pleurae?
The veins drain to the azygos/hemiazygos veins & some to the pulmonary vein.
arteries supply pleurae, which cover the following structures (4):
- cervical pleura
- cost pleura
- diaphragmatic pleura
- mediastinal pleura
cervical pleura
intercostal vessels
cost pleura
intercostal vessels
diaphragmatic pleura
intercostal vessels (periphery) & pericardiacophrenic vessels (central tendon)
mediastinal pleura
pericardiacophrenic vessels
what would be the companion veins of the arterial supply?
venous drainage from parietal pleura
nerve supply to the pleurae
viscera and parietal pleura
viscera pleura of nerve supply
no nerve supply
parietal pleura of nerve supply
Identical to the vascular supply
parietal pleura of nerve supply also cover the following structures (4)
- cervical pleura
- costal pleura
- diaphragmatic pleura intercostal nerves & phrenic nerves (central tendon)
- mediastinal pleura
mediastinal pleura of nerves
phrenic nerves
