Final answer:
The endocrine system is the body's slow chemical communication system responsible for secreting hormones that maintain homeostasis. It works in conjunction with the nervous system to regulate bodily functions over various time scales.
Step-by-step explanation:
The body's "slow" chemical communication system is the endocrine system, which is a set of glands that secrete hormones. Unlike the nervous system, which relies on rapid transmission of electrical messages, the endocrine system utilizes hormones as biological messengers that travel via the bloodstream to reach various cells throughout the body. Hormones act slowly compared to the rapid actions of the nervous system, but their effects can be body-wide due to the circulatory delivery method.
Maintaining homeostasis within the body requires the timing and coordination of regulated events, which is the joint responsibility of the nervous system and the endocrine system. While the nervous system controls immediate responses, the endocrine system governs longer-term changes through hormone release. The autonomic nervous system controls involuntary functions alongside the endocrine system, which adjusts hormonal levels to influence activity within organ systems, achieving dynamic homeostasis.
Organ systems, such as the cardiovascular system, are subject to the regulatory influence of both neural and endocrine signals. For instance, the heart's rate and force of contraction are influenced by both autonomic nerves and circulating hormones like epinephrine and norepinephrine.