The clinical anatomy of the musculotendinous part of the diaphragm

Abstract

The thoracoabdominal diaphragm is a composite musculotendinous structure, separating the thoracic and abdominal cavities. Reemphasis of the already well-delineated variations of the muscular and tendinous portions, and blood and nerve supply of the diaphragm is becoming apparent. Scientific reports concerning reconstruction of the pericardium, activation of the muscle and the phrenic nerves by use of laparoscopically placed intramuscular electrodes, and repair of congenital and traumatic hernias reemphasize the importance of the muscular to tendinous relationships. The objective of this study, therefore, was to measure the ratio of the surface area of the tendinous central region to the muscular region of the diaphragm and provide a clear description across various specimens. We classified diaphragmatic measurements from 104 adult human diaphragms into six classes (I-VI) based on the ratio of surface area between its tendinous and muscular components. The majority of specimens, 56.7%, was attributed to class II and indicated a tendon-to-muscle ratio of between 10 and 15%; however, a small number of specimens indicated a very large tendon area at the expense of muscle bulk. Future research should be geared toward assessing the relationship between surface area of the musculature and its motor points with focus on interventions for herniation repair and recovery. Our results have shown that surgical interventions should be tailored to the individual, as diaphragm size may not necessarily predict tendon-to-muscle ratio.

A review of analgesic and emotive breathing: a multidisciplinary approach

“…The diaphragm has a phrenic center, consisting of a strong “V”-shaped connective component having a variable percentage of the amount of contractile tissue. 32 The fascial system is richly innervated by proprioceptors, which may become a source of afferent pain, transforming in turn into nociceptors. 33 The crural and connective area is populated by proprioceptors, and we can assume that alteration of the position and function of the respiratory muscle creates a condition of irritability of these proprioceptors and consequent occurrence of painful afferents.…”

“… 2 The right phrenic nerve penetrates the diaphragm at the level of the connective tissue of the phrenic center, while the left phrenic nerve penetrates the muscle area of the muscle; the right nerve has a faster electro conductivity than the left. 32 , 34 We might suppose that if the position of the diaphragm is not physiological, the phrenic nerve will be stretched or irritated in different ways, causing nociceptive afferents, in the same way as irritation of a peripheral nerve from the surrounding tissues. 35 , 36 …”

Failed back surgery syndrome: review and new hypotheses

“…The diaphragm has a phrenic center, consisting of a strong “V” shaped connective component with a variable percentage in respect to the amount of contractile tissue. 50 The fascial system is richly innervated by proprioceptors, which can become a source of painful afferents that can transform into nociceptors. 26 The crural and connective tissue areas are populated by proprioceptors and it can be assumed that an alteration to the position and function of the respiratory muscle creates a state of irritability of these proprioceptors and subsequent presence of painful afferents.…”

Tissue Doppler Imaging of the Diaphragm: A New Kid on the Block?

“…Ultrasound measures of the diaphragm dome evaluate its caudal motion, whereas ultrasound measures of the diaphragm in the ZOA allow the clinician to directly assess diaphragm musculature. The following two factors should be considered when assessing motion of the diaphragm dome: first, the visualized image is the intensely echogenic lung–diaphragm interface and not the diaphragm muscle itself, and second, as much as 35% of the diaphragm dome may be central tendon ( 3 ). Despite these considerations, several studies have documented that caudal dome motion of more than 1–1.7 cm reasonably predicts extubation success in mechanically ventilated patients ( 4 – 6 ).…”