Which system is considered a parallel communication system to the nervous system in the body with its secretions passing directly into the bloodstream or lymph system?

Endocrine.

Explanation:

The nervous system is one of the most important system of the body that regulates the sensory information and coordination of the other system of the body.

The nervous system together with the endocrine system work together to maintain the homeostasis of the body. The endocrine system releases hormone upon the nerve stimulation by the nervous system of the body. The changes in the environment are sensed by the sensory receptor that stimulates the production of specific hormone.

Thus, the answer is endocrine.