Endocrine and Exocrine Flashcards
Function of the Endocrine system
- Cellular communication throughout the body
- maintains homeostasis by regulating cell activity
Anatomy of the Endocrine system
- Consists of a group of glands that control organs by sending hormones into the blood
What is exocrine
Secretes contents through tiny tubes or ducts outside the body
e.g: sweat and tears
What is endocrine
Glands secrete hormones by sending chemical messages directly into the blood stream, which then delivers them to their specific target cells/tissues
Define homeostaisis
The state of steady internal, physical and chemical living conditions maintained by living systems
Define saturation
Receptors reach their maximum capacity
- all receptor molecules are occupied by hormone molecules
Describe protein/amine hormone
- water soluble
- they attach to receptor proteins in the membrane
- combination of the hormone with the receptor causes a secondary messenger substance to diffuse through the cell to activate particular enzymes
- e.g: insulin, glycogen
Describe steroid hormones
- enters through plasma membrane into the cytoplasm to bind to cells
- lipid soluble
- e.g: estrogen, progesterone
How is hormone secretion regulayted
- Negative feedback
Define enzyme amplification
A hormone triggers a cascading effect. The number of reacting hormones involved increased hundreds/thousands of times for each step along the metabolic pathway
therefore a small stimulus can cause a very large effect
Define hormone clearance
- breaking down hormone molecules
- some are broken down by target cells, most are broken down by liver and kidneys
Describe structure/function of the hypothalamus
- Conection between endocrine and nervous system
What is a chemical messenger
hormone that sends a message throughout the body
