DIAPHRAGM
T8 - L3
- The diaphragm is the primary muscle for inspiration.
Structure:
Origin:
The diaphragm has 3 origins:
- 1. Sternal part
- ↳ From back of xiphoid process.
- 2. Costal part:
- ↳ From Internal surfaces of lower costal cartilages & ribs 7-10
- 3. Lumbar part:
- A) right crus: anterolateral surface of first 3 lumbar vertebrae and IVDs. L1 - L3
- B) left crus: anterolateral surface of first 2 lumbar vertebrae and IVD. L1 - L2
- C) medial arcuate lig.: from body of vertebra to front of transverse process.
- D) lateral arcuate lig.: from transverse process to 12th rib.
* There is also the median arcuate ligament. Connecting the medial margins of the 2 crura.
Insertion : Central tendon of diaphragm.
- Has 2 surfaces . thoracic & abdominal
Innervation:
Phrenic nerves (C3-C5)
Blood Supply:
- Subcostal art.
- Sup. & Inf. phrenic arts.
Major openings of diaphragm:
- 1. Vena Caval
- At the level of T8 to the right
- It gives passage for:
- IVC
- Branches of right phrenic nerve.
- 2. Esophageal hiatus:
- At the level of T10 to the left
- passage for:
- esophagus
- Ant. & post. vagal trunks
- 3. Aortic
- At the level of T12 in the midline.
- passage for:
- Aorta
- Thoracic duct.