The diaphragm is one of the most important muscles in the human body - it plays a significant role in the breathing process. Typically it is associated with breathing, but in practice the diaphragm also has other functions, because it is involved, among others, in into processes such as urination and defecation. But how is the diaphragm constructed? What symptoms may indicate a diaphragm problem?
The diaphragm(Latindiaphragma , English diaphragm) is the most important muscle related to breathing. In addition, this process involves, inter alia, intercostal muscles (external and internal) or muscles that are referred to as auxiliary respiratory muscles, which are, for example, the sternocleidomastoid muscles, the levator scapula or the subclavian muscles. This proves that not only proper lung function is important in the breathing process, but also that of other structures in the chest.
Diaphragm: structure
The diaphragm is a striated muscle. It is located between the chest and the abdominal cavity and separates these two spaces. It has the shape of the letter C. This muscle stretches transversely and it is slightly asymmetrical - the right dome of the diaphragm (due to the presence of the liver) is slightly higher than the left part of this muscle.
There are three parts of the diaphragm, which are:
- lumbar part: it consists of the limbs of the diaphragm and three arcuate ligaments (medial, medial and lateral); the right diaphragm starts at the level of the first three lumbar vertebrae, and the left one is attached to the upper two lumbar vertebrae of the spine. Both branches cross at the level of the twelfth thoracic vertebra, and this is where the aortic hiatus appears. Then the branches separate again and in this location there is an esophageal hiatus in the diaphragm
- rib part: starts on the inside surface of ribs 7-12
- sternum part: its beginning is located on the xiphoid process of the sternum
All three parts of the diaphragm all end up in one place, which is the tendon. At the same time, they do not connect at this point, and therefore two triangles are formed: lumbar-costal and sternocostal.
Three are present in the diaphragmhiatuses, which are places through which important structures pass down towards the abdominal or thoracic cavity. They are:
- aortic hiatus: it is located at the level of the twelfth thoracic vertebra and in this place the aorta and thoracic duct pass through the diaphragm
- esophageal hiatus: located at the level of the tenth thoracic vertebra, the esophagus and vicious trunks pass through the diaphragm here
- inferior vena cava: located at the level of the eighth thoracic vertebra, the inferior vena cava passes through it
Diaphragm: innervation and vascularization
Movementally, the diaphragm is innervated by the phrenic nerve, which originates from the third, fourth and fifth cervical nerves. In turn, sensory stimuli are received from the diaphragm mainly through the afferent fibers of the phrenic nerve, and it is also sensually innervated by the intercostal and subcostal nerves.
The arterial vascularization of the diaphragm comes from the internal thoracic arteries, the upper diaphragmatic arteries, and the internal intercostal and lower diaphragmatic arteries. Venous blood flows from the diaphragm through the following veins: brachiocephalic, odd and to the inferior vena cava and left adrenal vein.
Diaphragm: functions
The diaphragm's primary function is to participate in the breathing process.
During inhalation, this muscle contracts - this causes the diaphragm to lower, which increases the volume of the chest. This results - simply put - in that the lungs then have room to expand. Then, the pressure inside the chest is also reduced, which in turn causes the lungs to increase their volume.
When exhaling, the opposite occurs - the diaphragm relaxes, as a result of which the volume of the chest decreases, the pressure in it increases, and ultimately leads - along with the activity of the lungs - to remove air from the respiratory tract.
Participation in the gas exchange is the basic, but not the only function of the diaphragm. It has been mentioned above that this muscle has an influence on the pressure in the chest - it can also influence the pressure in the abdominal cavity.
The work of the diaphragm may result, among other things, in increase in pressure in the abdominal cavity, which is important, for example, during defecation, urination or vomiting, the diaphragm function is also important during childbirth.
In addition, the muscle also prevents the occurrence of gastroesophageal reflux. At the point where the esophagus passes through the diaphragm - that is, vwithin the hiatus - controlled pressure is exerted on it, which reduces the possibility of human food regurgitation or acid reflux into the esophagus.
Diaphragm: diseases
We do not pay more attention to the diaphragm and its function on a daily basis, but when there are pathological processes that lead to dysfunction of this muscle, we are beginning to realize how important this structure is . Symptoms that may appear in patients who develop a diaphragm-related disease may be:
- shortness of breath (especially during exercise or lying down)
- pain in the shoulder, chest, arms or lumbar
- feeling of flutter in the abdomen
- frequent hiccups
- swallowing impairment
- reflux
In what kind of pathologies, however, the above-mentioned ailments may appear?
One of such diseases is paralysis of the diaphragm. It can be caused both by damage to the phrenic nerve and to the centers related to this nerve located within the brain stem or spinal cord.
The diaphragmatic nerve may be damaged due to the experience of some trauma, but also during a traffic accident.
Another possible cause of its dysfunction are lung tumors (in this case, abnormalities in the functioning of the phrenic nerve appear primarily when the tumor infiltrates this nerve).
Though less frequent, diaphragmatic paralysis is also seen in the course of systemic lupus erythematosus and Guillain-Barré syndrome.
Another diaphragmatic disease is a diaphragmatic hernia. It can be a congenital condition, as well as acquired during life - an acquired diaphragmatic hernia is found, among others, in in people who have had some trauma. In the course of the disease, certain organs are abnormally displaced, e.g. the stomach may move from the abdominal cavity to the chest.