External links
- Anatomy photo:18:02-0105 at the SUNY Downstate Medical Center - "Thoracic Wall: The External Intercostal Muscle"
| Vertebral |
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| Thorax |
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| Pelvis |
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 | This human musculoskeletal system article is a stub. You can help Wikipedia by expanding it. |
| External intercostal membrane | |
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| Details | |
| Identifiers | |
| Latin | membrana intercostalis externa |
| TA | A03.3.01.002 |
| FMA | 10475 |
Unlike the other two intercostal muscles, the external intercostal muscle does not retain its muscular character all the way to the sternum, and so the tissue in this location is called the external intercostal membrane.
The fibers of the external intercostal muscles run downward and forward between adjacent ribs. Each muscle begins posteriorly at the tubercles of the ribs and extends anteriorly to the costochondral junction, the junction between the costal cartilage and the sternal end of the rib. The muscle between the costal cartilages is replaced by a membranous layer called the external intercostal membrane.
Links and References: Grant's: 1.15, 1.20 Netter: 176 Rohen/Yokochi: 193, 194
| | This human musculoskeletal system article is a stub. You can help Wikipedia by expanding it. |
The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates, that encloses and protects the heart and lungs. In humans, the rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human rib cage consists of 24 ribs in 12 pairs, the sternum and xiphoid process, the costal cartilages, and the 12 thoracic vertebrae.
The pleural cavity is the thin fluid-filled space between the two pulmonary pleurae of each lung. A pleura is a serous membrane which folds back onto itself to form a two-layered membranous pleural sac. The outer pleura is attached to the chest wall, but is separated from it by the endothoracic fascia. The inner pleura covers the lungs and adjoining structures, including blood vessels, bronchi and nerves. The pleural cavity can be viewed as a potential space because the two pleurae adhere to each other under all normal conditions. Parietal pleura projects up to 2.5 cm above the junction of the middle and medial third of the clavicle
The thorax or chest is a part of the anatomy of humans and various other animals located between the neck and the abdomen. The thorax includes the thoracic cavity and the thoracic wall. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. Many diseases may affect the chest, and one of the most common symptoms is chest pain.
The thoracic diaphragm, or simply the diaphragm, is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity and performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases, a negative vacuum is created which draws air into the lungs.
Intercostal muscles are several groups of muscles that run between the ribs, and help form and move the chest wall. The intercostal muscles are mainly involved in the mechanical aspect of breathing. These muscles help expand and shrink the size of the chest cavity to facilitate breathing.
An aponeurosis is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join muscles and the body parts they act upon, whether it be bone or other muscles. They have a shiny, whitish-silvery color, are histologically similar to tendons, and are very sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are papery and peel off by sections. The primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, and the palmar (palms) and plantar (soles) regions.
The rectus abdominis muscle, also known as the "abdominal muscle" or "abs", is a paired muscle running vertically on each side of the anterior wall of the human abdomen, as well as that of some other mammals. There are two parallel muscles, separated by a midline band of connective tissue called the linea alba. It extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of ribs V to VII superiorly. The proximal attachments are the pubic crest and the pubic symphysis. It attaches distally at the costal cartilages of ribs 5-7 and the xiphoid process of the sternum.
The transversus thoracis muscle lies internal to the thoracic cage, anteriorly. It is a thin plane of muscular and tendinous fibers, situated upon the inner surface of the front wall of the chest. It is in the same layer as the subcostal muscles and the innermost intercostal muscles.
The external intercostal muscles, or external intercostals are eleven in number on both sides.
The internal intercostal muscles are a group of skeletal muscles located between the ribs. They are eleven in number on either side. They commence anteriorly at the sternum, in the intercostal spaces between the cartilages of the true ribs, and at the anterior extremities of the cartilages of the false ribs, and extend backward as far as the angles of the ribs, hence they are continued to the vertebral column by thin aponeuroses, the posterior intercostal membranes.
The external oblique muscle is the largest and the outermost of the three flat muscles of the lateral anterior abdomen.
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum and differ from the anterior rami of the other spinal nerves in that each pursues an independent course without plexus formation.
The abdomen constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the frontal part of the abdominal segment of the trunk, the dorsal part of this segment being the back of the abdomen. The region occupied by the abdomen is termed the abdominal cavity. In arthropods it is the posterior tagma of the body; it follows the thorax or cephalothorax. The abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear.
Hemopneumothorax, or haemopneumothorax is the condition of having air in the chest cavity (pneumothorax) and blood in the chest cavity (hemothorax). A hemothorax, pneumothorax, or the combination of both can occur due to an injury to the lung or chest.
The intercostal space (ICS) is the anatomic space between two ribs. Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it.
The costocervical trunk arises from the upper and back part of the second part of subclavian artery, behind the scalenus anterior on the right side, and medial to that muscle on the left side.
The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the costocervical trunk, which is a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein.
The following outline is provided as an overview of and topical guide to human anatomy:
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Shaped roughly like a necktie, it is one of the largest and longest flat bones of the body. Its three regions are the manubrium, the body, and the xiphoid process. The word "sternum" originates from the Greek στέρνον, meaning "chest".
The pulmonary pleurae are the two pleurae of the invaginated sac surrounding each lung and attaching to the thoracic cavity. The visceral pleura is the delicate serous membrane that covers the surface of each lung and dips into the fissures between the lobes. The parietal pleura is the outer membrane which is attached to the inner surface of the thoracic cavity. It also separates the pleural cavity from the mediastinum. The parietal pleura is innervated by the intercostal nerves and the phrenic nerve.