Body Cavities - Introduction PDF

Tile Main Title Body Cavities Anatomy Department Mon. Aug. 21. 2024 BMC Topic/Subject Body Cavities  Body Cavities Dr. Waheeb Aggad Body Cavities and Membranes During embryonic development, the body is divided into 2 internal cavities  Posterior (dorsal) body cavity and the a...

Tile Main Title Body Cavities Anatomy Department Mon. Aug. 21. 2024 BMC Topic/Subject Body Cavities  Body Cavities Dr. Waheeb Aggad Body Cavities and Membranes During embryonic development, the body is divided into 2 internal cavities  Posterior (dorsal) body cavity and the anterior (ventral) body cavity. Each of these major cavities is then subdivided into smaller cavities. The cavities, as well as the organs in the cavities (called the viscera), are lined by membranes. Posterior (Dorsal) Body Cavity: The posterior body cavity is subdivided into 2 parts: (1) The cranial cavity, enclosed by the bony cranium, contains the brain. (2) The vertebral canal, enclosed by vertebrae, contains the spinal cord.  Thee two major body cavities and their subdivisions: a. Left lateral view. b. Frontal view.  Anterior (Ventral) Body Cavity The large anterior body cavity is subdivided into: Superior thoracic cavity. Inferior abdomino-pelvic cavity. A muscular partition called the diaphragm separates the 2 cavities. Membranes that line these cavities are called serous membranes because they secrete a fluid that has just about the same composition as serum.  To understand the relationship between serous membranes and an organ, imagine a ball that is pushed in on one side by your fist. Your fist would be covered by one membrane (called a visceral membrane), and there would be a small space between this inner membrane and the outer membrane (called a parietal membrane).  Thoracic Cavity The thoracic cavity is enclosed by the rib cage, and has 3 portions: the left, right, and medial portions. The medial portion, called the mediastinum, contains the heart, thymus gland, trachea, esophagus, and other structures. The right and left portions of the thoracic cavity contain the lungs. The lungs are surrounded by a serous membrane called the pleura. Similarly, in the mediastinum, the heart is covered by the two-layered membrane called the pericardium. The visceral pericardium which adheres to the heart is separated from the parietal pericardium by a small space called the pericardial cavity. This small space contains pericardial fluid. Abdomino-pelvic Cavity The abdomino-pelvic cavity has 2 portions: Superior abdominal cavity. Inferior pelvic cavity. The stomach, liver, spleen, gallbladder, and most of the small and large intestines are in the abdominal cavity. The pelvic cavity contains the rectum, the urinary bladder, the internal reproductive organs, and the rest of the large intestine.  Many of the organs of the abdominopelvic cavity are covered by the visceral peritoneum, while the wall of the abdominal cavity is lined with the parietal peritoneum. The abdomino-pelvic cavity is divided into four quadrants by running a transverse plane across the mid-sagittal plane at the point of the navel. The 4 quadrants are: Right upper quadrant. Left upper quadrant. Right lower quadrant. Left lower quadrant. Body Cavities and Membranes Serous Membranes Serous membranes line the cavities of the trunk and are reflected onto the mobile viscera lying within these cavities. The serous membrane lining the wall of the cavity is referred to as the parietal layer, and that covering the viscera is called the visceral layer. 3 serous membranes are identified: Pleura  around the lung. Pericardium  around the heart. Peritoneum  lining the abdominal cavity. Body Cavities  Organs of the respiratory, cardiovascular, digestive, urinary, and reproductive systems are housed in the ventral body cavity.  The diaphragm separates the ventral body cavity.  Ventral body cavity: protected and lubricated by a two- layer membrane system called serous membranes. Body Cavities ]Insert fig 1.13[ Thank You