The Endocrine System summary

THE ENDOCRINE SYSTEM


What Is Chemical Coordination?

Definition of Chemical Coordination

●​ A slow, long-lasting method of communication in the body​

●​ Uses chemical messengers called hormones​

●​ Involves the endocrine system, which works closely with the nervous system​


Hormones

●​ Organic chemical substances secreted by endocrine glands​

●​ Travel through the bloodstream to target organs/tissues​

●​ Regulate metabolic reactions in the body​

●​ Usually made of proteins, but can also be steroids​


Target Organs/Tissues

●​ Hormones only affect specific cells with matching receptor sites​

●​ These are called target tissues or target organs​

●​ May be a single organ, gland, or scattered cells in the body​


Endocrine Glands

●​ Ductless, vascular glands (rich in blood vessels)​

●​ Secrete hormones directly into the bloodstream​

●​ Example: Adrenal glands​


Endocrine vs Exocrine Glands

,●​ Endocrine glands:​

○​ No ducts​

○​ Secrete hormones into the bloodstream​

●​ Exocrine glands:​

○​ Have ducts​

○​ Secrete substances onto a surface or into a cavity​

, ○​ Examples: Salivary glands, liver, pancreas​




The Hypothalamus & Pituitary Gland