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Questions and Answers
The left crus of the diaphragm transmits the hemiazygous vein.
The left crus of the diaphragm transmits the hemiazygous vein.
True
The sympathetic trunks pass through the lateral arcuate ligament.
The sympathetic trunks pass through the lateral arcuate ligament.
False
The diaphragm is the chief muscle of expiration.
The diaphragm is the chief muscle of expiration.
False
The right dome of the diaphragm ascends to the 5th rib during expiration.
The right dome of the diaphragm ascends to the 5th rib during expiration.
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The diaphragm contracts during expiration.
The diaphragm contracts during expiration.
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The subcostal nerves and vessels pass through the medial arcuate ligament.
The subcostal nerves and vessels pass through the medial arcuate ligament.
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The left phrenic nerve passes through the right crus of the diaphragm.
The left phrenic nerve passes through the right crus of the diaphragm.
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The diaphragm's movement during inspiration decreases the volume of the thoracic cavity.
The diaphragm's movement during inspiration decreases the volume of the thoracic cavity.
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The right crus is shorter and smaller than the left crus.
The right crus is shorter and smaller than the left crus.
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The lateral arcuate ligament is a thickening of the fascia covering the psoas major.
The lateral arcuate ligament is a thickening of the fascia covering the psoas major.
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The diaphragm has only two major openings.
The diaphragm has only two major openings.
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The aortic hiatus is formed by the union of the left and right crura.
The aortic hiatus is formed by the union of the left and right crura.
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The caval opening perforates the peripheral part of the diaphragm.
The caval opening perforates the peripheral part of the diaphragm.
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Some of the muscle fibres of the left crus pass up to the right crus and surround the oesophageal orifice in a sling-like loop.
Some of the muscle fibres of the left crus pass up to the right crus and surround the oesophageal orifice in a sling-like loop.
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The diaphragm is attached to the lateral and medial lumbar vertebrae.
The diaphragm is attached to the lateral and medial lumbar vertebrae.
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The sternocostal foramina transmit the inferior epigastric vessels.
The sternocostal foramina transmit the inferior epigastric vessels.
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The descent of the diaphragm decreases the intrathoracic pressure and decreases the intra-abdominal pressure.
The descent of the diaphragm decreases the intrathoracic pressure and decreases the intra-abdominal pressure.
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The abdominal lymph vessels are compressed during diaphragmatic contraction, hindering the passage of lymph within the thoracic duct.
The abdominal lymph vessels are compressed during diaphragmatic contraction, hindering the passage of lymph within the thoracic duct.
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The right side of the superior surface of the diaphragm is drained by the pericardiacophrenic and musculophrenic veins.
The right side of the superior surface of the diaphragm is drained by the pericardiacophrenic and musculophrenic veins.
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The motor nerve supply of the diaphragm is by the lower intercostal nerves (T5-T11).
The motor nerve supply of the diaphragm is by the lower intercostal nerves (T5-T11).
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Hiccup is a symptom of a normal individual and occurs as a result of gastric irritation of the vagus nerve endings.
Hiccup is a symptom of a normal individual and occurs as a result of gastric irritation of the vagus nerve endings.
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A single dome of the diaphragm may be paralyzed by crushing or sectioning of the vagus nerve in the neck.
A single dome of the diaphragm may be paralyzed by crushing or sectioning of the vagus nerve in the neck.
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The thoracoabdominal pump is responsible for increasing the intrathoracic pressure and decreasing the intra-abdominal pressure.
The thoracoabdominal pump is responsible for increasing the intrathoracic pressure and decreasing the intra-abdominal pressure.
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The inferior phrenic arteries are branches of the internal thoracic artery.
The inferior phrenic arteries are branches of the internal thoracic artery.
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Study Notes
Diaphragmatic Openings
- Two openings in the right crus: transmit greater and lesser splanchnic nerves
- Three openings in the left crus: transmit greater and lesser splanchnic nerves, and hemiazygous vein
- Opening for sympathetic trunks: under the medial arcuate ligament
- Opening for subcostal nerves and vessels: under the lateral arcuate ligament
- Opening for the left phrenic nerve: located in the left dome of the diaphragm
Movements of the Diaphragm
- The level of the domes of the diaphragm varies according to the phase of respiration, posture, and size and degree of distention of the abdominal viscera
- The diaphragm is the chief muscle of inspiration, and expiration is largely passive
- When the diaphragm contracts, its domes are pulled inferiorly, increasing the volume of the thoracic cavity and decreasing intrathoracic pressure, resulting in air being taken into the lungs
Movement of the Diaphragm and Circulation
- Movements of the diaphragm are also important in circulation
- When the diaphragm contracts, intra-abdominal pressure increases, and intrathoracic pressure decreases, compressing the abdominal viscera, widening the caval opening, and dilating the IVC
Crura of the Diaphragm
- The right crus is larger and longer than the left crus and can arise from the first three or four lumbar vertebrae
- The left crus can arise from the first two or three lumbar vertebrae
- Some of the muscle fibers of the right crus pass up to the left crus and surround the esophageal orifice in a sling-like loop, acting as a sphincter to prevent regurgitation of stomach contents into the thoracic part of the esophagus
Arcuate Ligaments of the Diaphragm
- The diaphragm is attached on each side to the medial and lateral arcuate ligaments
- The medial arcuate ligament is a thickening of the fascia covering the psoas major
- The lateral arcuate ligament is on the quadratus lumborum
Diaphragmatic Openings
- The diaphragm has three major openings: foramen for inferior vena cava, foramen for esophagus, and foramen for aorta
- Additional smaller openings include sternocostal triangle, openings for splanchnic nerves, hemiazygous vein, phrenic nerve, subcostal neurovascular structures, and sympathetic trunks
Neurovascular Supply of the Diaphragm
- Arterial supply: mainly from the inferior phrenic arteries, which arise directly from the abdominal aorta
- Venous drainage: superior surface of the diaphragm is drained by pericardiacophrenic and musculophrenic veins, and the right side is drained by the superior phrenic vein
- Innervation: motor nerve supply is by the right and left phrenic nerves (C3, 4, 5), and sensory nerve supply is by the phrenic nerve (C3-C5) and lower intercostal nerves (T5-T11) and subcostal nerves (T12)
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Description
This quiz covers the various openings in the diaphragm, including those for the splanchnic nerves, hemiazygous vein, sympathetic trunks, subcostal nerves, and phrenic nerve. Learn about the locations and structures involved.
