Central tendon of diaphragm
The muscle fibers of the diaphragm converge and attach to the central tendon of the diaphragm. It is a thin but strong layer of aponeurosis which forms an intergral part of respiration.
On this page:
Gross Anatomy
The central tendon of the diaphragm is located near the center of the diaphragmatic muscle but lies more anteriorly than posteriorly, meaning the posterior muscle fibers are longer than the anterior fibers 1. It is shaped like a club on a deck of cards. It has three leafs which are separated by small indentations. The right leaf is the largest, the middle is the second largest and directed anteriorly towards the xiphisternum and the left leaf is the smallest.
Structure
The central tendon of the diaphragm is composed of interlaced fibers which join at various angles to form bundles which give it its strength. It lies just inferiorly to the fibrous pericardium to which it is embryonically identical and inseparable 2.
Relations
The vena caval foramen passes through the tendon at the level of the T8 vertebra, posterior to the 6th costal cartilage and to the right of the midline 1. The inferior vena cava and right phrenic nerve pass through this opening.
Innervation
The diaphragm is supplied by the phrenic and lower intercostal nerves 2.
Action
With inspiration the central tendon is drawn inferiorly by the diaphgram. This expands the chest cavity and creates negative inter-thoracic pressure allowing air to enter the lungs 3. The inferior vena cava is not compressed in the foramen due to its tendinous nature.
Related Radiopaedia articles
Anatomy: Thoracic
- thoracic skeleton
- thoracic cage
- thoracic spine
- articulations
- muscles of the thorax
- diaphragm
- intercostal space
- intercostal muscles
- variant anatomy
- spaces of the thorax
- thoracic viscera
- tracheobronchial tree
-
lungs
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
- left lung
- right lung
- variant anatomy
- lung parenchyma
- hilum
- pleura
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
-
heart
- cardiac chambers
- heart valves
- pectinate muscles
- cardiac fibrous skeleton
-
coronary arteries
- coronary arterial dominance
- myocardial segments
-
left main coronary artery (LMCA)
- ramus intermedius artery (RI)
-
circumflex artery (LCx)
- obtuse marginal branches (OM1, OM2, etc))
- Kugel's artery
-
left anterior descending artery (LAD)
- diagonal branches (D1, D2, etc)
- septal perforators (S1, S2, etc)
-
right coronary artery (RCA)
- conus artery
- sinoatrial nodal artery
- acute marginal branches (AM1, AM2, etc)
- inferior interventricular artery (PDA)
- posterior left ventricular artery (PLV)
- congenital anomalies
- innervation of the heart
- fetal circulation
-
pericardium
- pericardial space
- oblique pericardial sinus
- transverse pericardial sinus
-
pericardial recesses
- aortic recesses
- pulmonic recesses
- postcaval recess
- pulmonary venous recesses
- pericardial ligaments
- epicardial fat pad
- esophagus
- thymus
- breast
- blood supply of the thorax
- arteries
- veins
- superior vena cava (SVC)
- inferior vena cava (IVC)
-
coronary veins
- cardiac veins which drain into the coronary sinus
- great cardiac vein
- middle cardiac vein
- small cardiac vein
- posterior vein of the left ventricle
- vein of Marshall (oblique vein of the left atrium)
- anterior cardiac veins
- venae cordis minimae (smallest cardiac veins or thebesian veins)
- cardiac veins which drain into the coronary sinus
- pulmonary veins
- thoracoepigastric vein
- lymphatics
- innervation of the thorax