The Respiratory System Flashcards
What is the thoracic inlet bounded by?
T1 posteriorly.
The 1st pair of ribs laterally.
The costal cartilage of rib 1 and the superior border of the manubrium anteriorly.
What is the thoracic outlet bounded by?
T12 posteriorly.
The 11th and 12th pairs of ribs laterally.
The costal cartilages of ribs 7-10 and the xiphisternal joint anteriorly.
Where is the sternum, and the sternal angle, located?
Sternum - lower border of T4.
Sternal angle - T5.
Describe the shape of the 1st rib.
Broad and flat.
Its surfaces look up and down.
Head - one articular facet, for the body of T1.
Describe the upper surface of the body of the 1st rib.
Marked by two shallow grooves, separated by the scalene tubercle (for attachment of the anterior scalene muscle).
What do the two grooves of the 1st rib lodge?
The anterior groove lodges the subclavian vein.
The posterior groove lodges the subclavian artery and the lowest trunk of the brachial plexus.
Describe the general features of a typical rib.
Head - two articular facets.
A costal groove.
A tubercle.
What are costovertebral joints?
The head of the rib articulates with the body of the thoracic vertebra of the same number, and the body of the vertebra above.
What are costotransverse joints?
The tubercle of the rib articulates with the transverse process of the thoracic vertebra of the same number.
What are the attachments of the diaphragm?
Peripherally at the lumbar vertebrae, arcuate ligaments, costal cartilages of ribs 7-12, and xiphoid process of the sternum.
Centrally at the central tendon.
What are the crura of the diaphragm?
Arises from the vertebrae.
Tendinous in structure.
Right crus - arises from L1-L3.
Left crus - arises from L1-L2 and their intervertebral discs.
What is the caval opening?
A diaphragmatic hiatus at T8.
Goes through the central tendon.
Transmits the inferior vena cava and the right phrenic nerve.
What is the oesophageal opening?
A diaphragmatic hiatus at T10.
Located through the muscular sling of the right crus.
Transmits the oesophagus and both vagus nerves.
What surrounds the oesophageal opening?
Fibres of the right crus help prevent the reflux of gastric contents back into the oesophagus.
What is the aortic opening?
A diaphragmatic hiatus at T12.
Located between the left and right crus.
Transmits the aorta, azygos vein, hemiazygos vein, and the thoracic duct.
Where are the roots of the phrenic nerve?
Found in the anterior rami of C3-C5.
Mainly C4 - both motor and sensory.
What does the phrenic nerve innervate?
Pierces and innervates the diaphragm interiorly via motor neurons.
Supplies the central part of the diaphragm via sensory neurons.
What innervates the peripheral portions of the diaphragm?
Sensory fibres of intercostal nerves.
T7-T12.
What are the different intercostal muscles?
External - /// (right).
Internal - \\ (right).
Innermost - vertical.
What is the arterial supply of the thoracic wall?
Posterior intercostal arteries (branch of mainly descending thoracic aorta).
Anterior intercostal arteries (branch of internal thoracic artery).
Branches of axillary arteries.
What is the venous drainage of the thoracic wall?
The azygos vein, accessory hemiazygos vein, and hemiazygos vein.
Internal thoracic veins.
Where does the left side of the chest wall drain to?
The thoracic duct and left subclavian vein.
Where does the right side of the chest wall drain to?
The right lymphatic duct and right subclavian vein.
Where does the breast drain to?
The axillary, parasternal, and abdominal lymph nodes.
