The Endocrine System
The endocrine system works alongside the nervous system to facilitate cellular
communication and control in the body. The endocrine system consists of endocrine
glands that secrete hormones directly into the bloodstream, resulting in slower and
longer-lasting effects compared to the rapid and specific actions of the nervous system.
Over 200 different hormones are secreted by the endocrine glands.
Glands that function exclusively as endocrine glands include the pituitary, pineal,
thyroid, parathyroid, and adrenal glands. Other tissues and organs, such as the
hypothalamus, thymus, pancreas, testes, and ovaries, also secrete hormones while
performing other functions.
Hormones act on target cells that possess specific receptor proteins for the respective
hormones. Most hormones are distributed through the bloodstream to target cells,
where they bind to their receptor proteins, initiating specific cellular changes.
Chemical Signals: Steroid & Water-Soluble Hormones
The endocrine system works alongside the nervous system to facilitate cellular
communication and control in the body. The endocrine system consists of endocrine
glands that secrete hormones directly into the bloodstream, resulting in slower and
longer-lasting effects compared to the rapid and specific actions of the nervous system.
Over 200 different hormones are secreted by the endocrine glands.
Glands that function exclusively as endocrine glands include the pituitary, pineal,
thyroid, parathyroid, and adrenal glands. Other tissues and organs, such as the
hypothalamus, thymus, pancreas, testes, and ovaries, also secrete hormones while
performing other functions.
Hormones act on target cells that possess specific receptor proteins for the respective
hormones. Most hormones are distributed through the bloodstream to target cells,
where they bind to their receptor proteins, initiating specific cellular changes.
Chemical Signals: Steroid & Water-Soluble Hormones