Body Cavities PDF

 What is Body Cavity? A body cavity is any fluid-filled space in a multicellular organism other than those of vessels (such as blood vessels and lymph vessels). The term usually refers to the space located between an animal's outer covering (epidermis), and the outer lining of the gu...

 What is Body Cavity? A body cavity is any fluid-filled space in a multicellular organism other than those of vessels (such as blood vessels and lymph vessels). The term usually refers to the space located between an animal's outer covering (epidermis), and the outer lining of the gut cavity, where internal organs develop.  What is Coelom? A coelom is a cavity lined by an epithelium derived from mesoderm. Organs formed inside a coelom can freely move, grow, and develop independently of the body wall while fluid cushions and protects them from shocks.  Embryos Mammalian embryos develop two cavities: the intraembryonic coelom and the extraembryonic coelom (or chorionic cavity). The intraembryonic coelom is lined by somatic and splanchnic lateral plate mesoderm, while the extraembryonic coelom is lined by extraembryonic mesoderm  Coelom The intraembryonic coelom is the only cavity that persists in the mammal at term, which is why its name is often contracted to simply coelomic cavity. Subdividing the coelomic cavity into compartments, for example, the pericardial cavity / pericardium, where the heart develops, simplifies discussion of the anatomies of complex animals. Organisms can be also classified according to the type of body cavity they possess. Human Body Cavities  MESENTERIES A MESENTERY is a double layer of peritoneum that begins as an extension of the visceral peritoneum covering an organ. The mesentery connects the organ to the body wall and transmits vessels and nerves to it Transiently, the dorsal & ventral mesenteries divide the peritoneal cavity into right & left halves The ventral mesentery disappears EXCEPT where stomach develops.  The diaphragm Divides the thoracic and the abdominal cavities. The abdominal cavity occupies the entire lower half of the trunk, anterior to the spine. Just under the abdominal cavity, anterior to the buttocks, is the pelvic cavity. The pelvic cavity is funnel shaped and is located inferior and anterior to the abdominal cavity. Together the abdominal and pelvic cavity can be referred to as the abdominopelvic cavity while the thoracic, abdominal, and pelvic cavities together can be referred to as the ventral body cavity. Subdivisions of the Posterior (Dorsal) and Anterior (Ventral) Cavities. The anterior (ventral) cavity has two main subdivisions: the thoracic cavity and the abdominopelvic cavity. The thoracic cavity is the more superior subdivision of the anterior cavity, and it is enclosed by the rib cage. The thoracic cavity contains the lungs and the heart, which is located in the mediastinum. The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity. The abdominopelvic cavity is the largest cavity in the body. Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.  The cavities include 1.Dorsal body cavity cranial cavity, enclosed by the skull and contains the brain spinal canal, enclosed by the spine and contains the spinal cord. 2.Ventral body cavity thoracic cavity, enclosed by the ribcage and contains the lungs and heart. 3.Abdominopelvic cavity abdominal cavity, enclosed by the ribcage and pelvis and contains the kidneys, ureters, stomach, intestines, liver, gallbladder, and pancreas pelvic cavity, enclosed by the pelvis and contains bladder, anus and reproductive system. Human body cavities and membranes Principal Membranous Name of cavity contents lining Cranial cavity Brain Meninges Dorsal body cavity Vertebral canal Spinal cord Meninges Pericardium Thoracic cavity Heart, Lungs Pleural cavity Digestive Abdominal Ventral body cavity organs, spleen, Peritoneum cavity Abdominopelvic kidneys cavity Bladder, Pelvic cavity reproductive Peritoneum organs  References Quick and Easy Medical Terminology, 7th Edition, Peggy C. Leonard, Elsevier, 2014. Page Number: 98-138.