Body Cavities and Membranes
Thoracic cavity, also called chest cavity, the second largest hollow space of the body. It is enclosed by the ribs, the vertebral column, and the sternum, or breastbone, and is separated from the abdominal cavity (the body’s largest hollow space) by a muscular and membranous partition, the diaphragm. It contains the lungs, the middle and lower airways—the tracheobronchial tree—the heart, the vessels . Apr 28, · The thoracic cavity is actually composed of three spaces each lined with mesothelium, a special film-like tissue that separates vital organs. The pleural cavities surround the lungs, while the pericardial cavity surrounds and protects the heart. These Estimated Reading Time: 5 mins.
The body is internally divided into two major body cavitiesdorsal and ventral fig. The organs within them are called the viscera VISS-er-uh singular, viscus9. Various membranes line the cavities, cover the viscera, and hold the viscera in place table A.
The dorsal body cavity has two subdivisions: 1 the cranial CRAY-nee-ul cavity, which is enclosed by the cranium braincase and contains the brain, and 2 the verte bral canal, which is enclosed by the vertebral column backbone and contains the spinal cord.
The dorsal body cavity is lined by three membrane layers called the meninges meh-NIN-jeez. Among other functions, the meninges protect the delicate nervous tissue from the hard protective bone that encloses it. During embryonic development, a space called the coelom SEE-loam forms within the trunk and eventually gives rise to the ventral body cavity.
This cavity later becomes partitioned by a muscular sheet, the diaphragm, into a superior thoracic cavity and an inferior abdominopelvic cavity. The thoracic and abdominopelvic cavities are lined with thin serous membranes. These membranes secrete a lubricating film of moisture similar to blood serum hence the name serous. The thoracic cavity is divided into right, left, and medial portions by a partition called the mediastinum10 ME-dee-ass-TY-num fig.
The right and left sides contain the lungs and are lined by a two-layered membrane called the pleura11 PLOOR-uh fig. The outer layer, etal12 pa-RY-eh-tul pleura, lies against the inside of the. Cranial cavity. Pelvic cavity. Figure A. Pleural cavities 2. Digestive organsspleen, kidneys. The narrow, moist space between the visceral and parietal pleurae is called the pleural cavity see fig. It is lubricated by a slippery pleural fluid.
The medial portion, or mediastinum, is occupied by the esophagus and trachea, a gland called the thymus, and the heart and major blood vessels connected to it. The heart is enclosed by a two-layered membrane called the pericardium. This space is lubricated by pericardial fluid. The abdominopelvic cavity consists of the abdominal cavity above the brim of the pelvis and the pelvic cavity below the brim see fig.
The abdominal cavity contains most of the digestive organs as well as the kidneys and ureters. The pelvic cavity is markedly narrower and its lower end tilts posteriorly see fig. It contains how to unclog your bathtub drain naturally distal part of the large intestinethe urinary bladder and urethra, and the reproductive organs.
The parietal peritoneum lines the walls of the cavity, while the visceral peritoneum covers the external surfaces of most digestive organs. The peritoneal cavity is what is the meaning of schedule in pipe space between the parietal and visceral layers.
It is lubricated by peritoneal fluid. Some organs of the abdominal cavity lie between the peritoneum and dorsal body wall outside of the peritoneal cavityso they are said to have a retroperitoneal15 position fig. These include the kidneys, ureters, adrenal glandsmost of the pancreas, and abdominal portions of two major blood vessels—the aorta and inferior vena cava see fig. The intestines are suspended from the dorsal abdominal wall by a translucent membrane called the mesentery16 MESS-en-tare-eea continuation of the peritoneum.
The membrane then wraps around the intestines and some other viscera, forming a moist membrane called the serosa seer-OH-sa on their outer surfaces fig.
The mesentery of the large intestine is called the mesocolon. The visceral peritoneum consists of the mesenteries and serosae. It is unattached at its inferior border and can be lifted to reveal the intestines. A smaller lesser omentum extends from the superomedial border of the stomach to the liver.
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Home Made Cures and Remedies. Recommended Natural Healing for Heart Disease. Related Category Spinal Cord. Responses mildred What moist serous membrane lines the abdominopelvic cavity?
Trahand What is the two layered membrane of the abdominopelvic cavity called? URHO What major body cavity called the dorsal cavity of the heart? Quintino What is the moist membrane that wraps around the intestines and other viscera?
The thoracic cavity conjointly contains the gorge, the channel through that food is passed from the throat to the abdomen. The bodily/chest cavity is lined with a membrane that exudes a skinny fluid. That portion of the chest membrane is named the Parietal usloveescort.comted Reading Time: 6 mins. Dec 23, · The thoracic and abdominopelvic cavities are lined with thin serous membranes. These membranes secrete a lubricating film of moisture similar to blood serum (hence the name serous). Thoracic Cavity. The thoracic cavity is divided into right, left, and medial portions by a partition called the mediastinum10 (ME-dee-ass-TY-num) (fig. A.7). The right and left sides contain the lungs and are Estimated Reading Time: 4 mins. parietal layer which lines the thoracic wall, covers the thoracic surface of the diaphragm and the lateral aspect of the mediastinum, and extends into the root of the neck to line the undersurface of the suprapleural membrane at the thoracic outlet.
Thoracic cavity , also called chest cavity , the second largest hollow space of the body. It contains the lungs , the middle and lower airways—the tracheobronchial tree—the heart , the vessels transporting blood between the heart and the lungs, the great arteries bringing blood from the heart out into general circulation, and the major veins into which the blood is collected for transport back to the heart.
The heart is covered by a fibrous membrane sac called the pericardium that blends with the trunks of the vessels running to and from the heart.
The thoracic cavity also contains the esophagus , the channel through which food is passed from the throat to the stomach. The chest cavity is lined with a serous membrane, which exudes a thin fluid. That portion of the chest membrane is called the parietal pleura. The membrane continues over the lung, where it is called the visceral pleura, and over part of the esophagus, the heart, and the great vessels, as the mediastinal pleura, the mediastinum being the space and the tissues and structures between the two lungs.
Because the atmospheric pressure between the parietal pleura and the visceral pleura is less than that of the outer atmosphere, the two surfaces tend to touch, friction between the two during the respiratory movements of the lung being eliminated by the lubricating actions of the serous fluid.
The pleural cavity is the space, when it occurs, between the parietal and the visceral pleura. The pleura is a continuous sheet of endothelial, or lining, cells supported by a thin base of loose connective tissue. The membrane is well supplied with blood vessels , nerves, and lymph channels. The vessels of the visceral part of the pleura are intimately related with those of the lungs and bronchi; its arteries are branches of the bronchial arteries, and its veins mingle with the pulmonary network of capillaries.
Beneath its inner side is a network of tiny lymph channels, or capillaries, that penetrate the lung substance, or parenchyma , and drain to the lymph nodes at the hilus of each lung, the point of entrance and departure for bronchi, blood vessels, and nerves.
Diseases affecting the pleura and pleural cavity, other than primary tumours , are brought by the blood vessels or may spread from contiguous structures. The pleural cavity may be contaminated by the rupture of either the visceral pleura or the parietal pleura.
Accumulation of fluid in the pleural cavity is called hydrothorax. If the fluid is bloody, the condition is described as hemothorax; if it contains pus , pyothorax.
The accumulation of fluid may or may not be accompanied by air. When air is present, the affix - pneumo - is inserted into each of the names mentioned—e. The penetration of air into the pleural cavity from outside, as from a penetrating wound of the chest, or from within, by rupture of dilated alveoli air sacs of the lung or of a cyst , will produce a pneumothorax , converting this cavity into a positive pressure chamber and collapsing the lung, which in turn will lead to decreased oxygenation of the venous blood.
The collapse may also have a deleterious effect on the heart. Inflammation of the pleura, usually diffuse, affecting one or both sides, is called pleurisy. Two forms are distinguished: 1 simple, dry, or fibrinous pleurisy; and 2 exudative pleurisy, in which the membrane gives off excessive fluid. Since the pleura is well supplied by nerves, pleurisy can be extremely painful, especially as the lung moves in respiration.
Common symptoms are pain , shortness of breath, and fever. Treatment is directed toward evacuation of fluid and alleviation of the underlying condition, often an infected lung but more rarely a diffuse inflammatory condition such as rheumatoid arthritis. Rupture of the thoracic duct , the main channel for lymph, gives rise to chylothorax, characterized by escape of lymph into the pleural space.
Epidemic pleurodynia , or Bornholm disease, is an acute infection of the various tissues of the pleural cavity by group B coxsackieviruses or certain other enteroviruses.
The disease is characterized by a general feeling of ill health and by pain in the chest muscles and the upper part of the abdomen. That pain is usually increased by respiration and cough , and pain in other muscles is often present.
The condition subsides in two to five days but sometimes may take weeks to disappear. Thoracic cavity. Additional Info. Contributors Article History. Print Cite verified Cite. While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. Facebook Twitter. Give Feedback. Let us know if you have suggestions to improve this article requires login. External Websites. The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree See Article History.
The lungs serve as the gas-exchanging organ for the process of respiration. Get a Britannica Premium subscription and gain access to exclusive content.
Subscribe Now. Chest scan showing a large hydropneumothorax from pleural empyema on the right side of the chest cavity A is air; B is fluid. Learn More in these related Britannica articles:. Rib , any of several pairs of narrow, curved strips of bone sometimes cartilage attached dorsally to the vertebrae and, in higher vertebrates, to the breastbone ventrally, to form the bony skeleton, or rib cage, of the chest.
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