Briefly explain the ventral and dorsal body cavities and the membranes which line the ventral cavities. What is a mesentery? Solution The ventral body cavity is a body cavity that is in the anterior (front) aspect of the body. It is made up of the thoracic cavity, and the abdominopelvic cavity. The abdominopelvic cavity is further divided into the abdominal cavity and pelvic cavity, but there is no physical barrier between the two. The abdominal cavity contains digestive organs, the pelvic cavity contains the urinary bladder, internal reproductive organs, and rectum. The thoracic cavity is separated from the abdominopelvic cavity by the diaphragm. The thoracic cavity is further separated into the pleural cavity which contains the lungs and the superior mediastinum which includes the pericardial (heart) cavity. The organs within the ventral body cavity are called the viscera. The walls of the ventral body cavity and outer covering of its organs contain a thin covering called the serosa (also called serous membrane). It is a double-layered membrane made up of two parts called the “parietal serosa” (lines the cavity walls) and “visceral serosa” (covers organs in the cavity). The serous membranes are separated by a thin layer of fluid called “serous fluid“. Serous fluid is secreted by both membranes and acts as a lubricant, allowing organs to slide in the cavity without causing friction. The dorsal body cavity is located along the dorsal (posterior) surface of the body, where it is subdivided into the cranial cavity housing the brain and the spinal cavity housing the spinal cord. The two cavities are continuous with one another. The cranial cavity is a large, bean-shaped cavity filling most of the upper skull where the brain is located.The vertebral cavity is a very narrow, thread-like cavity running from the cranial cavity down the entire length of the spinal cord. Just as the brain and spinal cord make up a continuous, uninterrupted structure, the cranial and spinal cavities that house them are also continuous. The brain and spinal cord are protected by the bones of the skull and vertebral column and by cerebrospinal fluid, a colorless fluid produced by the brain, which cushions the brain and spinal cord within the posterior (dorsal) cavity. The covering and protective membranes for the dorsal body cavity are called meninges..

1. Briefly explain the ventral and dorsal body cavities and the membranes which line the ventral
cavities. What is a mesentery?
Solution
The ventral body cavity is a body cavity that is in the anterior (front) aspect of the body. It is
made up of the thoracic cavity, and the abdominopelvic cavity. The abdominopelvic cavity is
further divided into the abdominal cavity and pelvic cavity, but there is no physical barrier
between the two. The abdominal cavity contains digestive organs, the pelvic cavity contains the
urinary bladder, internal reproductive organs, and rectum.
The thoracic cavity is separated from the abdominopelvic cavity by the diaphragm. The thoracic
cavity is further separated into the pleural cavity which contains the lungs and the superior
mediastinum which includes the pericardial (heart) cavity.
The organs within the ventral body cavity are called the viscera.
The walls of the ventral body cavity and outer covering of its organs contain a thin covering
called the serosa (also called serous membrane). It is a double-layered membrane made up of two
parts called the “parietal serosa” (lines the cavity walls) and “visceral serosa” (covers organs in
the cavity). The serous membranes are separated by a thin layer of fluid called “serous fluid“.
Serous fluid is secreted by both membranes and acts as a lubricant, allowing organs to slide in
the cavity without causing friction.
The dorsal body cavity is located along the dorsal (posterior) surface of the body, where it is
subdivided into the cranial cavity housing the brain and the spinal cavity housing the spinal cord.
The two cavities are continuous with one another.
The cranial cavity is a large, bean-shaped cavity filling most of the upper skull where the brain is
located.The vertebral cavity is a very narrow, thread-like cavity running from the cranial cavity
down the entire length of the spinal cord. Just as the brain and spinal cord make up a continuous,
uninterrupted structure, the cranial and spinal cavities that house them are also continuous. The
brain and spinal cord are protected by the bones of the skull and vertebral column and by
cerebrospinal fluid, a colorless fluid produced by the brain, which cushions the brain and spinal
cord within the posterior (dorsal) cavity.
The covering and protective membranes for the dorsal body cavity are called meninges.