intro to endocrine system Flashcards
What is the primary function of the endocrine system?
To maintain internal homestasis in response to external and internal stimuli.
Do hormones work rapidly or at a slower pace?
They work slowly but last much longer as a result
For a target cell to respond to a hormone, what must it have?
The target cell must have the appropriate receptors.
Name the 6 major endocrine glands in the body
the hypothalamus, pituitary gland, thyroid gland, parathyroid gland, thymus and adrenal glands.
NOTE: these are just the endocrine glands, not organs.
What is humoral hormone release?
When factors in the blood, or changed conditions are detected by the endocrine gland and hormone release is triggered.
What is neural hormone release?
when either pre or postganglionic nerve fibres stimulate an endocrine gland to secrete a hormone.
What is traditional hormone based hormone release?
When an tropic hormone binds to and stimulates the endocrine gland to secrete more hormones.
What are tropic hormones? (Tropic not trophic hormones)
Hormones designed to target other endocrine glands.
what are sex hormones
Special hormones of the reproductive system that target reproductive organs and tissue.
What are anabolic hormones?
A hormone that promotes anabolism on its target cells. Anabolism causes increased cellular growth and build-up, consuming energy.
What is the difference between peptide and steroid hormones?
Composition- peptide hormones are protein based, like insulin. Steroid hormones are lipid based and derived from cholesterol.
With what mechanism do hormones bind to receptors?
They use the lock-and-key mechanism.
What is the relationship between steroid hormones and diffusion through cell membranes?
Steroid hormones are hydrophobic, just like the lipid membranes. Thus they diffuse across into the cell easily.
what is the aim of steroid hormones once in a cell?
Steroid hormones help regulate production of proteins inside the cell. It does this by controlling protein gene expression in the nucleus.
Do steroid hormones elicit this response quickly?
No. It is a slow process that can take days.
What are non-steroid hormones?
Basically, protein hormones (g-protein family) and gonadotrophins.
Which mechanism do non-steroid hormones use to stimulate target tissue?
They use the second messenger mechanism. They are hydrophilic and cannot diffuse into the cell directly.
So they bind to the fixed g-protein receptors on the cell membrane. The g-proteins then send the signal to the second messenger chemical.
Name 2 important second messengers in the cell.
cyclic AMP and calmodulin (calcium based)