A) what serosal cavities have been penetrated by the 1st arrow? b) explain the location, the microscopic characteristics of the serous membrane, and the purpose of the serous membrane.

A. Chest cavity and thoracic cavity have been penetrated by the first arrow.

B. The serous membrane is termed as a thin membrane which is lined in the internal body cavities and some organs. For example, lungs, abdominal cavity, and heart.

In many organs, it allows frictionless movement.