Body Cavities and Subdivisions

Cranial Cavity

Where the brain is enclosed within the skull.

Vertebral cavity

Where the spinal cord is protected in the vertebral column.

Thoracic Cavity

Where the heart and lungs (protected by the ribcage) are housed.

Abdominal Cavity

Houses the stomach, liver, intestines, and other organs.

• Superior to the pelvic cavity.

• Part of the abdominopelvic cavity (divided into anatomical left and right quadrants).

• Also divided into nine regions.

Pelvic Cavity

Houses the reproductive organs, bladder, and rectum—all partially enclosed by the pelvic bone.

• Inferior to the abdominal cavity.

• Part of the abdominopelvic cavity (divided into anatomical left and right quadrants).

• Also divided into nine regions.

Serosa or Serous membrane

The walls of the ventral body cavity and the organs' outer surfaces are coated with this.

• Produces a thin lubricating fluid that allows the visceral (internal) organs to slide over one another/the body wall without friction.

Parietal serosa

Part of the membrane lining the cavity walls.

Visceral serosa

Part of the membrane that covers the external surface of the organs.

Umbilical region

The centermost region of the abdominopelvic region.

Epigastric region

Immediately superior to the umbilical region; overlies most of the stomach.

Hypogastric (pubic) region

Immediately inferior to the umbilical region; encompasses the pubic area.

Iliac (inguinal) regions

Lateral to the hypogastric region, overlaying the superior parts of the hip bones.

Lumbar regions

Between the ribs and the flaring parts of the hip bones; superior to the iliac regions.

Hypochondriac regions

On the left and right of the epigastric region; superior to the lumbar regions.

Oral cavity

AKA the mouth; contains the tongue and the teeth and is continuous with the rest of the digestive tube, which opens to the exterior of the anus.

Nasal cavity

Located within and posterior to the nose; it is part of the passages of the respiratory system.

Orbital cavities

Houses the eyes and presents them in an anterior position.

Middle ear/tympanic cavities

Lie medial to the eardrums and is carved into the skull.

• Contain tiny bones that transmit sound vibrations to the organ of hearing.

Synovial cavities

Joint cavities that are enclosed within fibrous capsules that surround the movable joints of the body.

• Membranes lining these cavities secrete a lubricating fluid that reduce friction as the structures move across each other.