Serous membrane - wikipedia Serous membrane Serous Membrane Stomach. ( Serosa is labeled at far right, and is colored yellow. ) Details Precursor mesoderm Identifiers Latin tunica serosa MeSH D012704 FMA 9581 Anatomical terminology ( edit on Wikidata ) This article is one of a series on the Gastrointestinal wall General structure Epithelium Mucosa Submucosa Circular muscle Longitudinal muscle Serosa Adventitia Specific Meissner 's plexus Auerbach 's plexus Organs Esophagus Stomach Intestines In anatomy, serous membrane ( or serosa ) is a smooth tissue membrane consisting of two layers of mesothelium, which secrete serous fluid. The inner layer that covers organs ( viscera ) in body cavities is called the visceral membrane. A second layer of epithelial cells of the serous membrane, called the parietal layer, lines the body wall. Between the two layers is a potential space, mostly empty except for a few milliliters of lubricating serous fluid that is secreted by the two serous membranes. The Latin anatomical name is tunica serosa. Serous membranes line and enclose several body cavities, known as serous cavities, where they secrete a lubricating fluid which reduces friction from muscle movement. Serosa is entirely different from the adventitia, a connective tissue layer which binds together structures rather than reducing friction between them. The serous membrane covering the heart and lining the mediastinum is referred to as the pericardium, the serous membrane lining the thoracic cavity and surrounding the lungs is referred to as the pleura, and that lining the abdominopelvic cavity and the viscera is referred to as the peritoneum. Contents 1 Structure 1.1 Visceral and parietal layers 1.2 Examples 1.3 Development 2 Additional images 3 See also 4 References 5 External links Structure A serous membrane ( also referred to as a serosa ) is one of the thin membranes that cover the walls and some organs of the thoracic and abdominopelvic cavities. Serous membranes have two layers. The parietal layers of the membranes line the walls of the body cavity ( pariet - refers to a cavity wall ). The visceral layer of the membrane covers the organs ( the viscera ). Between the parietal and visceral layers is a very thin, fluid - filled serous space, or cavity. Visceral and parietal layers Each serous membrane is composed of a secretory epithelial layer and a connective tissue layer underneath. The epithelial layer, known as mesothelium, consists of a single layer of avascular flat nucleated cells ( simple squamous epithelium ) which produce the lubricating serous fluid. This fluid has a consistency similar to thin mucus. These cells are bound tightly to the underlying connective tissue. The connective tissue layer provides the blood vessels and nerves for the overlying secretory cells, and also serves as the binding layer which allows the whole serous membrane to adhere to organs and other structures. For the heart, the layers of the serous membrane are called the parietal pericardium, and the visceral pericardium ( sometimes called the epicardium ). Other parts of the body may also have specific names for these structures. For example, the serosa of the uterus is called the perimetrium. Schematic diagram of an organ invaginating into a serous cavity The pericardial cavity ( surrounding the heart ), pleural cavity ( surrounding the lungs ) and peritoneal cavity ( surrounding most organs of the abdomen ) are the three serous cavities within the human body. While serous membranes have a lubricative role to play in all three cavities, in the pleural cavity it has a greater role to play in the function of breathing. The serous cavities are formed from the intraembryonic coelom and are basically an empty space within the body surrounded by serous membrane. Early in embryonic life visceral organs develop adjacent to a cavity and invaginate into the bag - like coelom. Therefore, each organ becomes surrounded by serous membrane - they do not lie within the serous cavity. The layer in contact with the organ is known as the visceral layer, while the parietal layer is in contact with the body wall. Examples There are three serous cavities and their associated membranes. Serous membrane lines the pericardial cavity and reflects back to cover the heart -- much the same way that an underinflated balloon would form two layers surrounding a fist. The pericardium is a two - layered sac that surrounds the entire heart except where the blood vessels emerge on the heart 's superior side. The pleura is the serous membrane that surrounds the lungs in the pleural cavity ; the pericardium is the serous membrane that surrounds the heart in the pericardial cavity The peritoneum is the serous membrane that surrounds several organs in the abdominopelvic cavity. The serous fluid produced by the serous membranes reduces friction between the walls of the cavities and the internal organs when they move, such as when the lungs inflate or the heart beats, that could otherwise lead to inflammation of the organs. The serous membranes have two layers, parietal and visceral, surrounding a fluid filled space. Development All serous membranes found in the human body formed ultimately from the mesoderm of the trilaminar embryo. The trilaminar embryo consists of three relatively flat layers of ectoderm, endoderm ( also known as `` entoderm '' ) and mesoderm. As the embryo develops, the mesoderm starts to segment into three main regions : the paraxial mesoderm, the intermediate mesoderm and the lateral plate mesoderm. The lateral plate mesoderm later splits in half to form two layers bounding a cavity known as the intraembryonic coelom. Individually, each layer is known as splanchnopleure and somatopleure. The splanchnopleure is associated with the underlying endoderm with which it is in contact, and later becomes the serous membrane in contact with visceral organs within the body. The somatopleure is associated with the overlying ectoderm and later becomes the serous membrane in contact with the body wall. The intraembryonic coelom can now be seen as a cavity within the body which is covered with serous membrane derived from the splanchnopleure. This cavity is divided and demarcated by the folding and development of the embryo, ultimately forming the serous cavities which house many different organs within the thorax and abdomen. Additional images Layers of stomach wall Section of duodenum of cat See also This article uses anatomical terminology ; for an overview, see Anatomical terminology. Adventitia References This Wikipedia entry incorporates text from the freely licensed Connexions ( 1 ) edition of Anatomy & Physiology ( 2 ) text - book by OpenStax College Jump up ^ `` The Anatomy of Lining and Covering Tissues - Membranes ! ''. McGraw - Hill Companies. Retrieved September 2, 2017. ^ Jump up to : `` Anatomy & Physiology ''. Openstax college at Connexions. Retrieved November 16, 2013. External links UIUC Histology Subject 844 Parsons, Frederick Gymer ( 1911 ). `` Coelom and Serous Membranes ''. Encyclopædia Britannica. 6 ( 11th ed. ). pp. 642 -- 644. Anatomy of the gastrointestinal tract, excluding the mouth Upper Pharynx Muscles Spaces peripharyngeal retropharyngeal parapharyngeal retrovisceral danger prevertebral Pterygomandibular raphe Pharyngeal raphe Buccopharyngeal fascia Pharyngobasilar fascia Piriform sinus Esophagus Sphincters upper lower glands Stomach Curvatures greater lesser Angular incisure Cardia Body Fundus Pylorus antrum canal sphincter Gastric mucosa Gastric folds Microanatomy Gastric pits Gastric glands Cardiac glands Fundic glands Pyloric glands Foveolar cell Parietal cell Gastric chief cell Enterochromaffin - like cell Lower Small intestine Microanatomy Intestinal villus Intestinal gland Enterocyte Enteroendocrine cell Goblet cell Paneth cell Duodenum Suspensory muscle Major duodenal papilla Minor duodenal papilla Duodenojejunal flexure Brunner 's glands Jejunum No substructures Ileum Ileocecal valve Peyer 's patches Microfold cell Large intestine Cecum Appendix Colon Ascending colon Hepatic flexure Transverse colon Splenic flexure Descending colon Sigmoid colon Continuous taenia coli haustra epiploic appendix Rectum Transverse folds Ampulla Anal canal Anus Anal columns Anal valves Anal sinuses Pectinate line Internal anal sphincter Intersphincteric groove External anal sphincter Wall Serosa / Adventitia Subserosa Muscular layer Submucosa Circular folds Mucosa Muscularis mucosa Anatomy of the lower respiratory tract Respiratory tree Trachea Tracheal rings Annular ligaments Carina Bronchi Main left right Secondary eparterial Tertiary Lungs General Landmarks Base Apex Root Hilum Fissures Horizontal Oblique Superior lobe Lingula of left lung Middle lobe of right lung Inferior lobe BP segment Bronchiole : Conducting zone ( Terminal bronchiole ) Respiratory zone ( Respiratory bronchiole Alveolar duct Alveolus Blood - air barrier ) Cells Alveolar cells Type I Type II Club cell Goblet cell Anatomy of the peritoneum and mesentery General Peritoneum cavity Mesentery Abdominal From ventral mesentery Lesser omentum Hepatoduodenal ligament Hepatogastric ligament Liver Coronary ligament ( Left triangular ligament Right triangular ligament Hepatorenal ligament ) Falciform ligament Round ligament of liver Ligamentum venosum From dorsal mesentery Greater omentum Gastrophrenic ligament Gastrocolic ligament Gastrosplenic ligament Mesentery Splenorenal ligament Phrenicocolic ligament Folds Umbilical folds Supravesical fossa Medial inguinal fossa Lateral umbilical fold Lateral inguinal fossa Ileocecal fold Abdominal cavity Greater sac Lesser sac Omental foramen General Cystohepatic triangle Hepatorenal recess of subhepatic space Abdominal wall Inguinal triangle Peritoneal recesses Paracolic gutters Paramesenteric gutters Pelvic Uterus / ovaries Broad ligament of the uterus Mesovarium Mesosalpinx Mesometrium ) Ovarian ligament Suspensory ligament of ovary Recesses Male Recto - vesical pouch Pararectal fossa Female Recto - uterine pouch Recto - uterine fold ( Uterosacral ligament ) Vesico - uterine pouch Ovarian fossa Paravesical fossa Retroperitonium Spaces Extraperitoneal space Retroperitoneal space Retropubic space Retrieved from `` https://en.wikipedia.org/w/index.php?title=Serous_membrane&oldid=825191760 '' Categories : Membrane biology Tissues ( biology ) Hidden categories : Pages with unresolved properties Wikipedia articles incorporating a citation from the 1911 Encyclopaedia Britannica with Wikisource reference Talk Contents About Wikipedia Azərbaycanca Беларуская Català Deutsch Eesti Español Esperanto فارسی Français Íslenska Italiano עברית Lietuvių 日本 語 Polski Português Русский Simple English Svenska 11 more Edit links This page was last edited on 12 February 2018, at 00 : 24. 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Question: two thin membranes surround the lungs. what are these membranes known as
Answer: pleura