Flashcards in Basic principles of endocrinology Deck (13)
What are the different types of action performed by the endocrine system? (give examples)
-Paracrine=the hormone acts locally by diffusing from its source to target cells in the neighborhood. e.g histamine from mast cells
-Autocrine= acts on the same cell that produced it e.g interleukins
-Neurocrine= The influence of nerves on endocrine tissue. e.g neurotransmitter noradrenaline.
-Endocrine= the hormone is distributed in blood and binds to distant target cells e.g insulin
-Neuroendocrine=released by neurons and carried by blood or other bodily fluids and act on distant cells e.g dopamine inhibition of prolactin release
What are the main characteristics of hormones?
- synthesised and secreted by specialised cells
-released into circulation
-exert effects on target cells distant from release site
- act either on one cell type ( eg GnRH) or many cells types (e.g oestrogen)
What is the role of the endocrine system?
-responds to changes in the environment( food,stress etc)
- important role in control of: growth, development,puberty,sexual maturation
Which hormones are derived from tyrosine?
What are the different classes of hormones?
Describe the structure of glycoprotein hormones
Alpha and Beta chains with carbohydrate
The alpha chain= species specific- common to all 4 glycoprotein hormones
The beta chain= hormone specific- responsible for specificity
Give eg's of glycoprotein hormones.
LH, FSH, hCG, TSH.
How does GnRH control release of LH& FSH
-Pulsatile release of GnRH release LH and FSH
-Sustained release of GnRH inhibit LH& FSH
What are the different types of hormone release?
- Pulsitile e.g GnRH pulse generator
-Circadian based on 24hour cycle e.g cortisol
-Diurnal synchronised to day/night cycle
-Infradian based on longer than 24hour cycle e.g menstrual cycle
-Seasonal e.g prolactin
What use can radioimmunoassay ( RIA) have in endocrinology
We can use RIA to assess hormone levels. As the conc. of hormone increases, the amount of antibody bound decreases. We can also use enzyme-linked immunosorbant assay (ELISA)
What is the function of oestrogen receptor alpha
What is the function of oestrogen receptor beta