Organs In Different Body Cavity

ORGANS IN DIFFERENT BODY CAVITIES

Body Cavity

Body cavities: spaces within the body that help protect, separate and support internal organs.

Body cavity is any fluid filled space in a multicellular organism.

Main Body Cavities

• The two major cavities of the body are
• The dorsal cavity
• The ventral body cavities.

The Dorsal Cavity

The dorsal body cavity is located near the posterior surface of the body and has two main subdivisions The vertebral canal that contains the spinal cord The cranial cavity that contains the brain

The Ventral Body Cavities

The ventral body cavity is located near the anterior surface of the body and has two subdivisions The thoracic cavity

The abdomino-pelvic cavity

The abdomino-pelvic cavity, which is separated by the diaphragm consists of two continuous cavities -The abdominal cavity

-The pelvic cavity

Organs-(Abdominal-Pelvic Cavity)

• Abdominal cavity contains
• Stomach
• Liver
• Gallbladder
• Pancreas
• Spleen
• small intestine
• Kidneys
• Appendix

part of the large intestine.

….

• The pelvic cavity contains
• Part of the large intestine
• Rectum
• Urinary bladder

Female reproductive organs (ovaries, uterine tubes, uterus, vagina)

Male reproductive organs (prostate, part of ductus deferens).

It is important to note that the testes and penis are not located in the ventral body cavity but are outside the body wall.

Thoracic Cavity and its Divisions

• Thoracic Cavity: Space enclosed by the ribs, sternum, and vertebral column
• The thoracic cavity is separated from the abdominal cavity by the diaphragm.
• This cavity contains three small cavities (potential spaces).
• The pericardial cavity (peri _around; cardia _ heart).
• Two pleural cavities (pleura _ side or rib).

The pericardial cavity surrounds the heart, and each pleural cavity contains a lung.

The Mediastinum

A broad central partition that separates the two laterally placed pleural cavities.

Extends from the sternum to the bodies of the vertebrae and from the superior thoracic aperture to the diaphragm.

The organs located in the mediastinum are the heart, thymus gland, oesophagus, trachea and bronchi.

The pleural cavities are located on either side of the mediastinum

Regions(subdivision) of mediastinum

• The middle mediastinum
• The superior mediastinum
• The anterior mediastinum

The posterior mediastinum

The middle mediastinum

• Centrally located in the thoracic cavity.
• Major Structures found
• heart,
• origins of the great vessels,
• various nerves

smaller vessels.

The superior mediastinum

The superior mediastinum is posterior to the manubrium of the sternum and anterior to the bodies of the first four thoracic vertebrae.

The superior mediastinum is continuous with the neck superiorly and with the inferior mediastinum inferiorly.

• The Major Structures found include:
• Thymus
• Right and left brachiocephalic veins
• Left superior intercostal vein
• Superior vena cava

Arch of the aorta with its three large branches

….

• Trachea
• Esophagus
• Phrenic nerves
• Vagus nerves
• Left recurrent laryngeal branch of the left vagus nerve
• Thoracic duct

Other small nerves, blood vessels, and lymphatics

The anterior mediastinum

• Posterior to the body of the sternum
• Anterior to the pericardial sac.
• The posterior mediastinum
• Posterior to the pericardial sac and diaphragm
• Anterior to the bodies of the mid and lower thoracic vertebrae.
• Major structures in the posterior mediastinum
• Esophagus and its associated nerve plexus
• Thoracic aorta and its branches
• Azygous system of veins
• Thoracic duct and associated lymph nodes
• Sympathetic trunks

Thoracic splanchnic nerves

Peritoneum and Peritoneal Cavity

The peritoneum is the largest serous membrane in the body The abdominal cavity is lined by peritoneum, which consists of an epithelial-like single layer of cells (the mesothelium) together with a supportive layer of connective tissue.

• Two layers
• Parietal peritoneum lines the abdominal wall.
• Visceral peritoneum covers suspended organs
• The peritoneal cavity is a potential space between the parietal peritoneum

Contains a small amount of serous fluid

CT

• Abdominal viscera are either intraperitoneal or retroperitoneal
• Intraperitoneal structures are suspended from the abdominal wall by mesenteries
• Stomach
• Liver
• Gallbladder
• Spleen

small intestine

….

• Appendix
• large intestine
• Rectum
• Urinary bladder
• Female reproductive organs (ovaries, uterine tubes, uterus, vagina)

Male reproductive organs (prostate, part of ductus deferens).

CT

Structures that are not suspended in the abdominal cavity by a mesentery and that lie between the parietal peritoneum and abdominal wall are retroperitoneal in position includes;

• The kidneys
• Ureters
• Pancreas

Great vessels ( aorta and venna cava)