The endocrine system is a network of glands that secrete chemical messengers called hormones directly into the bloodstream to regulate distant target organs.
: The ultimate goal of these hormonal interactions is to maintain a constant, balanced internal environment regardless of external changes. Endocrine Physiology
: Hormones like insulin and glucagon (from the pancreas) and thyroid hormones ( T3cap T sub 3 T4cap T sub 4 ) manage energy use and blood sugar levels. The endocrine system is a network of glands
: While the "classical" pathway involves hormones traveling through the blood, they can also act on nearby cells ( paracrine ) or even the secreting cell itself ( autocrine ). : While the "classical" pathway involves hormones traveling
: Most endocrine functions are controlled by negative feedback , where the body's response to a hormone signal eventually turns off the original stimulus to maintain stability.