Diaphragm Flashcards
1
Q
Diaphragm
A
- Boundary of the posterior abdominal region
- A musculotendinous sheet
- Separated abdominal and thoracic cavities
- Central tendinous part into which circumferentially arranged muscle fibres attach
- Anchored to lumbar vertebrae by muculotendinous crura which blend with the anterior ligament of the vertebral column
- Three parts: pars sternalis, pars costalis and pars lumbalis
2
Q
Three parts of the diaphragm
A
- Pars sternalis - runs from the dorsal side of the xiphoid process and the dorsal layer of the rectus sheath
- Pars costalis - runs from the inferior margin of the inferior aperture (lower 6 ribs)
- Pars lumbalis - consists of the right and left crura
3
Q
Pars lumbalis (crura of the diaphragm)
A
- Right crus - longer and broader, attaches to bodies of vertebrae LI to LIII and the intervening intervertebral discs
- Left crus - attaches to bodeis of LI and LII and associated IVD
- The crura are connected across the midline by the median arcuate ligament, whcih passes anterior to the aorta
- There are two more arcuate ligaments: medial and lateral
4
Q
Arcuate ligaments of the diaphragm
A
- Median - connects crura across midline, passes anterior to aorta
- Medial - lateral to the crura, formed by fascia covering the upper part of the psoas major, attached medially to the sides of vertebrae LI and LII and laterally to the transcerse process of vertebra LI
- Lateral - formed by a thickening of the fascia that covers the quadratus lumborum muscle, attached medially to the transverse process of vertebra LI and laterally to rib XII
- Medial and arcuate ligaments serve as points of origin for some of the muscular components of the diaphragm
5
Q
Domes of the diaphragm
A
- Pericardium is centrally attached - causing flattening
- Produced on the right by the liver (+right kidney and its suprarenal gland)
- On the left by the fundus of the stomach and spleen (+the left kidney and its suprarenal gland)
- Left dome is usually at the fith intercostal space and the right dome at the 5th rib (slightly higher than left)
6
Q
Aortic hiatus
A
- Posterior to diaphragm, anterior to vertebral bodies at the lower end of TXII
- Between the crura
- Posterior to median arcuate ligament, just to the left of the midline
- Contents: aorta, thoracic duct and sometimes the azygoud vein
7
Q
Oesophageal hiatus
A
- Pases through the musculature of the right crus at the level of TX, just to the left of the aortic hiatus
- Contents: oesophagus, anterior and posterior vagal trunks, oesphageal branches of the left gastric artery and vein and a few lymphatic vessels
8
Q
Foramen of the inferior vena cava (caval opening)
A
- At approximately the level of TVIII, through the central tendon
- Contents: inferior vena cava and the right phrenic nerve
9
Q
Passage of the left phrenic nerve
A
- Passes through muscular part of the diaphragm, just anterior to the central tendon on the left side
10
Q
Passage of the splanchnic nerves
A
- The greater, lesser and least splanchnic nerves pass through crura on either side
11
Q
Passage of the hemi-azygous vein
A
- Passes through the left crus
12
Q
Passage of the sympathetic trunks
A
- Pass anterior to medial arcuate ligament on either side
13
Q
Passage of superior epigastric vessels
A
- Anterior to diaphragm, deep to ribs
14
Q
Passage of the musculophrenic and intercostal nerves
A
- through the diaphragm at various points
15
Q
Weakening of the diaphragm
A
- Trigonum sternocostale - between pars sternalis and pars costalis of the diaphragm
- Trigonum lumbocostale - between pars costalis and pars lumbalis - site of lumbar hernias
