mediastinal cavity

(noun)

The central compartment of the thoracic cavity. It contains the heart, the great vessels of the heart, the esophagus, the trachea, the phrenic nerve, the cardiac nerve, the thoracic duct, the thymus, and the lymph nodes of the central chest.

Related Terms

Examples of mediastinal cavity in the following topics:

  • Thoracic Aorta

    • The thoracic aorta is the section of the aorta that travels through the thoracic cavity to carry blood to the head, neck, thorax and arms.
    • Contained within the posterior mediastinal cavity, it begins at the lower border of the fourth thoracic vertebra where it is continuous with the aortic arch, and ends in front of the lower border of the twelfth thoracic vertebra at the aortic hiatus in the diaphragm.
    • In descending order these are the bronchial arteries, the mediastinal arteries, the esophageal arteries, the pericardial arteries, and the superior phrenic artery.

  • Body Cavities

    • Blood vessels are not considered cavities but may be held within cavities.
    • The dorsal cavity is a continuous cavity located on the dorsal side of the body.
    • The abdominoplevic cavity is the posterior ventral body cavity found beneath the thoracic cavity and diaphragm.
    • Humans have multiple body cavities, including the cranial cavity, the vertebral cavity, the thoracic cavity (containing the pericardial cavity and the pleural cavity), the abdominal cavity, and the pelvic cavity.
    • In mammals, the diaphragm separates the thoracic cavity from the abdominal cavity.

  • Lung Cancer

    • A hollow cavity and associated necrosis are commonly found at the center of the tumor.
    • If mediastinal lymph node involvement is suspected, mediastinoscopy may be used to sample the nodes and assist staging.

  • Great Vessels of the Heart

    • The inferior vena cava begins posterior to the abdominal cavity and travels to the heart next to the abdominal aorta.
    • It branches off into the bronchial, mediastinal, esophageal, and phrenic arteries.

  • Serous Membranes

    • 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.
    • Serous membranes line and enclose several body cavities, known as serous cavities, where they secrete a lubricating fluid which reduces friction from muscle movement.
    • 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 plays a greater role in the function of breathing.
    • Describe the function of the serous membranes in the pericardial, pleural, and peritoneal cavities

  • Serosa

    • Serous membranes line and enclose several body cavities, known as serous cavities, where they secrete a lubricating fluid that reduces friction from muscle movement.
    • 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.
    • 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.

  • Bilaminar Embryonic Disc Development

    • The floor of the amniotic cavity is formed by the embryonic disc.
    • The floor of the amniotic cavity is formed by the embryonic disc, which is composed of a layer of prismatic cells and the embryonic ectoderm.
    • As the embryo progresses in implantation, a small space appears in the embryoblast and forms the amniotic cavity.
    • The epiblast forms the floor of the amniotic cavity and is continuous with the amnion.
    • The hypoblast forms the roof of the exocoelomic cavity and is continuous with the thin exocoelomic membrane.

  • Injuries to the Phrenic Nerves

    • In the thorax, each phrenic nerve supplies the mediastinal pleura and pericardium.

  • Inspiration

    • Inspiration begins with the contraction of the diaphragm, which results in expansion of the thoracic cavity and the pleural cavity.
    • As the volume of air inside the lung increases, the lung pushes back against the expanded pleural cavity as a result of the drop in intrapleural pressure (pressure inside the pleural cavity).
    • External intercostal muscles: muscles located in between the ribs that help the thoracic cavity (and thus pleural cavity) to expand during quiet and forced inspiration.
    • The accessory muscles assist breathing by expanding the thoracic cavity in a similar way to the diaphragm.
    • However, they expand a much smaller part of the thoracic cavity compared to diaphragm.

  • Development of the Central Nervous System

    • The CNS is contained within the dorsal cavity, with the brain in the cranial cavity and the spinal cord in the spinal cavity.
    • The telencephalon differentiates into, among other things, the striatum, the hippocampus, and the neocortex, and its cavity becomes the first and second ventricles.
    • Diencephalon elaborations include the subthalamus, hypothalamus, thalamus, and epithalamus, and its cavity forms the third ventricle.
    • The tectum, pretectum, cerebral peduncle, and other structures develop out of the mesencephalon, and its cavity grows into the mesencephalic duct (cerebral aqueduct).
    • The metencephalon becomes, among other things, the pons and the cerebellum; the myelencephalon forms the medulla oblongata; and their cavities develop into the fourth ventricle.