Therefore, there needs to be a certain amount of inherent stability to the thorax. The process of ventilation depends on the mobility of the bony rib thorax and the ability of the muscles of ventilation to move the thorax. Anterior A and posterior B views of the thorax are shown, including its component parts: the sternum, 12 pairs of ribs and their costocartilages, and the thoracic vertebrae. Function, especially ventilatory function, can be affected when pathology interferes with the structure of the bony thorax.
For example, scoliosis is a pathological lateral curvature of the spine frequently associated with rotation of the vertebrae. The coupled rotation in a typical right thoracic scoliosis causes the bodies of the vertebrae to rotate to the right and the spinous processes to rotate to the left.
The right transverse processes of the vertebrae rotate posteriorly, carrying the ribs with them Fig.
This is the mechanism that causes the classic posterior rib hump of scoliosis. On the concave side of the scoliotic curve, the effects are just the opposite. The transverse processes of the vertebrae move anteriorly, bringing the articulated ribs forward.
The rib distortion that results from the vertebral rotation is evident bilaterally in Figure 5—2A and 5—2B. These musculoskeletal abnormalities limit the range of motion of the rib cage and the spine and, therefore, decrease ventilatory abilities. The bodies of the thoracic vertebrae in a right scoliosis typically rotate to the right, resulting in posterior displacement of the right transverse process and the attached right rib, as well as anterior displacement of the opposite transverse process and left rib.
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Learn More. Don't have an account? The thorax is the region of the body commonly known as the chest between the neck and the abdomen. The thoracic cavity is the hollow in the thorax that is occupied by the thoracic viscera, the heart and its associated vessels in the midline, and the lungs laterally. The thoracic viscera are enclosed by the bony and muscular thoracic cage.
The bony components of the cage are the 12 thoracic vertebrae posteriorly, the 12 pairs of ribs and their anterior cartilaginous extensions, the costal cartilages that meet the sternum anteriorly. The intercostal muscles fill the intercostal spaces between the ribs and are involved in ventilation. Another muscle involved in ventilation is the diaphragm, a sheet of muscle that separates the thoracic from the abdominal cavity. If you are not familiar with the basic outline and arrangements of the circulatory and respiratory systems, refer back to Chapters 4 and 5 before reading this section.
A good way to appreciate where these structures lie in relation to each other is to examine their surface anatomy, the position of internal organs related to features that can be observed or palpated felt on the surface of the body. Relating surface anatomy to deeper structures is a clinical skill essential not only to the study of the thorax, but also of structures in the head and neck important in dental practice.
In the clinical examination of the living subject, the position of the internal thoracic organs is defined with reference to a set of vertical and horizontal lines running through the surface of bony landmarks.
The significant vertical lines are shown in Figure 9. Mid-sternal line—in the median plane anteriorly; 2. Mid-clavicular line—through the midpoint of the clavicle; 3. Mid-axillary line—midway between the anterior and posterior axillary folds, formed from skin overlying muscles. The vitality of the organs, vessels, and nerves located within the thoracic cavity predispose it to be a location of high clinical significance.
The chest wall deformities, including pectus excavatum and pectus carinatum, are one of the most common congenital chest wall defects seen in young people. Surgical correction is needed in some people to avoid complications which may lead to heart and lungs dysfunction. However, these techniques require aggressive resection of the cartilage and rib cage, leading to severe post-operational complications such as infections, and delayed healing.
The Thorax; Anterior View. Contributed by Gray's Anatomy Plates. This book is distributed under the terms of the Creative Commons Attribution 4. To arrive at the top five similar articles we use a word-weighted algorithm to compare words from the Title and Abstract of each citation.
Cited by: 0 articles PMID: Barberini F , Brunone F. Ital J Anat Embryol , 3 , 01 Jul Cited by: 1 article PMID: Safarini OA , Bordoni B. Yasui T. No Shinkei Geka , 12 9 , 01 Aug Contact us. Europe PMC requires Javascript to function effectively. Recent Activity. Search life-sciences literature Over 39 million articles, preprints and more Search Advanced search. Abstract Free full text Similar Articles. Hussain A 1 ,.
Burns B 2. Affiliations 1 author 1. Xavier University School of Medicine. Share this article Share with email Share with twitter Share with linkedin Share with facebook. Abstract The thoracic wall consists of a bony framework that is held together by twelve thoracic vertebrae posteriorly which give rise to ribs that encircle the lateral and anterior thoracic cavity.
Free full text StatPearls [Internet]. StatPearls [Internet]. Introduction The thoracic wall consists of a bony framework that is held together by twelve thoracic vertebrae posteriorly which give rise to ribs that encircle the lateral and anterior thoracic cavity.
Structure and Function The thoracic cavity subdivides into three compartments; the mediastinum and two pleural cavities, one on each side. Embryology The formation of somite begins as the paraxial mesoderm starts to spiral into an organized cell called somitomere. Blood Supply and Lymphatics Three arteries supply each intercostal space; the posterior intercostal artery and two branches of anterior intercostal arteries. Nerves The thoracic wall is primarily innervated by the intercostal nerves, which are the anterior rami of spinal nerves of T1-T11 and the anterior ramus of T12 is a subcostal nerve.
Muscles There are three intercostal muscles; externally intercostal, internal intercostal and innermost intercostal muscles.
Physiologic Variants The difference in size of the sternum in both genders may provide essential clues in determining the skeletal remains during forensic evaluation. Surgical Considerations Understanding the anatomy of the thorax is vital, as it provides access to the heart, great vessels, lungs, diaphragm, and mediastinum. The intercostal nerve block is a procedure through which local anesthetic agent is injected around the intercostal nerve between the paravertebral line and the area of required anesthesia for different surgical procedures.
However, the surgeon needs to anesthetize the adjacent nerve as well because of considerable overlapping of contiguous dermatomes occurs. Median sternotomies are the most commonly performed osteotomy in the world and a standard incision for thoracic and cardiac surgery. The median sternotomy is a critical procedure in which the surgeon splits the sternum in the median plane to gain access to the heart, great vessels, as well as the lungs.
Flail chest is an extremely painful injury affecting the respiration, often caused by blunt chest trauma, resulting in multiple successive rib fractures. Today, flail chest management is through pain control, pulmonary toilet, and early ambulation.
It is not common to surgically repair the ribs. Clinical Significance The vitality of the organs, vessels, and nerves located within the thoracic cavity predispose it to be a location of high clinical significance. The sternum is a commonly used site for bone marrow aspiration because it possesses hematopoietic marrow throughout life.
However, the surgeon needs to exercise great care because if the sternal puncture is improperly executed, the needle can pierce the structures related to the posterior surface of the manubrium such as the left brachiocephalic vein in the upper part and aortic arch in the lower part. Thoracentesis is a diagnostic procedure that is performed by the surgeon to remove excess fluid from the thoracic cavity for both diagnostic or therapeutic purposes.
This procedure can be performed in two positions depending on the comfort of the patient. If the patient is lying supine, the needle placement is typically in the midaxillary line between the 6th- 8th ribs, and if the patient is in an upright or seated position, then the needle is placed between the 9th- 10th rib posteriorly in the midscapular line.
Pericardiocentesis is also a necessary procedure as it can be life-saving in a patient with cardiac tamponade. The needle is inserted cm lateral to the apex beat within the fifth, sixth or seventh intercostal space to remove excess fluid from the pericardial sac. The needle is advanced over the superior border of the rib to avoid intercostal nerves and vessels. If this performed improperly, the needle can puncture left ventricle or causes pneumothorax.
In patients with the thoracic outlet syndrome TOS , there is compression of the neurovascular structures in the thoracic outlet, resulting in pain, numbness, weakness, muscle wasting, fatigue in the upper limbs as well as ischemia. The brachial plexuses of nerves C5, C6, C7, C8, and T1 and subclavian vessels artery and vein are closely related to the first rib as well as the clavicle as they enter the upper limb. These structures may undergo compression between the scalene muscles and the first rib.
Pancoast tumors, as well as the presence of a rudimentary cervical rib, are among the potential causes of TOS.
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