Basic Principles of Endocrinology Flashcards
Where do endocrine glands secrete?
Into circulation
Where do exocrine glands secrete?
Via a duct (i.e digestive system)
What is a hormone?
Chemical substance secreted without benefit of a duct
Directly into bloodstream
Acts at long range, slowly on distant organs or tissues
What are the 5 modes of release for a hormone?
Paracrine Autocrine Neurocrine Endocrine Neuroendocrine
Describe paracrine action + example
Acts of adjacent cells
Histamine from mast cells
Describe autocrine action + example
Acts on same cell
Interleukins
Describe neurocrine action + example
Acts in neurotransmission
Noradrenaline
Describe endocrine action + example
Secreted into the bloodstream
Insulin
Describe neuroendocrine action + example
Neuron releases hormone into blood vessel
Dopamine inhibition of prolactin release
What are the characteristics of hormones?
Synthesised and secreted by specialist cells
Released into circulation
Acts (slowly) on distant organs and tissues
What developmental processes does the endocrine system play a role in regulating?
Growth
Puberty
Sexual Maturation
What tyrosine derivatives are important in the endocrine system?
Dopamine
Adrenaline
Noradrenaline
Thyroxine
What is the structure of a glycoprotein hormone?
Alpha and beta chain + carbohydrate
What are some examples of glycoprotein hormones?
TSH = thyroid stimulating hormone
LH = lutenizing hormone
FSH = follicle stimulating hormone
hCG = human chorionic gonadotropin
What is the difference between the alpha and beta chain in a glycoprotein hormone?
The alpha chain is species specific and beta chain is hormone specific.
What do steroid hormones effect? + examples
Water and electrolyte balance via mineralocorticoids (like aldosterone)
Carbohydrate and protein metabolism via glucocosteroids (like cortisol)
Sexual characteristics via sex steroids (like oestrogen, progesterone and testosterone)
What do mineralocorticoids control? + example
Water and electrolyte balance such as aldosterone