Anatomy Review (regions, cavities)

Axial Region

Head, neck ( cervical region) and trunk. The trunk is further divided into the thoracic region above the diaphragm and the abdominal region below it.

Thoracic cavity: Pericardium

A two layered serous membrane enclosing the heart. The inner layer forms the surface of the heart is called the visceral pericardium (epicardium). The outer layer is called the parietal pericardium (pericardial sac) which is separated from the visceral pericardium by a space called the pericardial cavity which is lubricated by pericardial fluid.

Peritoneum

A two layered serous membrane in the abdominopelvic cavity. The parietal peritoneum lines the cavity wall and the visceral peritoneum turns inward from the body wall, wraps around the abdominal viscera, binds to body wall and holds them in their place. The peritonial cavity is the space between the parietal and visceral layers and is lubricated by peritonial fluid.

Abdominopelvic cavity

Consists of the abdominal and pelvic cavity separated by a bony landmark called the brim of the pelvis. The abdominal cavity above the brim contains digestive organs, kidneys and ureters. The pelvic cavity below the brim contains the rectum, urinary bladder, urethra and reproductive organs.

Pleural cavity

Contain the lungs lined by a serous membrane called pleura. Pleura have visceral (inner) and parietal (outer) layers. Visceral pleura form the external surface of the lung and parietal pleura line the inside of the rib cage. The narrow space between them is called the pleural cavity which is lubricated by pleural fluid.

Thoracic cavity

During ebryonic development, a space called the coelom forms ventrally with the trunk and becomes partitioned into the diaphragm, superior thoracic cavity, and inferior abdominopelvic cavity which are lined with serous membranes that secrete a lubricating film similar to blood serum.

Cranial cavity

Enclosed by the cranium and contains the brain. The vertebral canal is enclosed the the vertebral column (backbone) and contains the spinal cord. There are two continuous with each other and lined by three membrane layers called meninges. Meninges protect the delicate nervous tissue from hard, protective bone that encloses it, and anchor the spinal cord to the vertebral column and limit it's movement.

Intraperitoneal

Organs encircled by peritoneum and connected posterior to the body wall by peritoneal sheets. The intestines are suspended from the posterior (dorsal) abdominal wall by a translucent membrane called the dorsal mesentery. The dorsal mesentary of the large intestine is called the mesocolon. The mesentary continues toward the anterior body wall as the ventral mesentary. The greater omentum is a fatty membrane which hangs from the inferolateral margin of the stomach and overlies the intersines. The lesser omentum extends from the superomedial border of the stomach and liver. The serosa is where the visceral peritoneum meets the organ such as the stomach or small intestine and divides and wraps around it.

Retroperitoneal

Organs in the abdominal cavity lie against the posterior body wall and are covered by peritoneum only on the side facing the peritoneal cavity. Include: kidneys, ureters, adrenal glands, most of the pancreas, abdominal portions of two major blood vessels - the aorta and inferior vena cava.

Quadrants

RUQ=Right upper quadrant. RLQ=Right Lower Quadrant. LUQ=left upper Quadrant. LLQ=Left Lower Quadrant.

Thoracic cavity: Mediastinum

Region between the lungs, extending from the base of the neck to the diaphragm, occupied by the heart, the major blood vessels connected to it, the esophagus, the trachea and beonchi, and a gland called the Thymus.