Revision lecture endocrinology Flashcards
Name four types of hormones
P-Gas
Peptides
Glycoproteins
Amino Acid derivatives
Steroids
Example of peptide hormones (3). What are the properties of these hormones (Solubility)
Insulin, Glucagon, GH
Small and soluble, so don’t have to be bound to a carrier in the blood
Example of glycoprotein hormones (3). What are the properties of these hormones (Solubility)
LH, FSH, TSH
Water soluble
Example of Amino Acid derivatives hormones (2). What are the properties of these hormones (Solubility)
Adrenaline, thyroxine
From adrenal medulla, water soluble
From thyroid, lipid soluble
Example of steroid hormones(4). what are these hormones derived from? Solubility?
Cortisol, aldosterone, testosterone, oestrogen
Cholesterol
Lipid soluble
What two Amino Acids is adrenaline produced from? What metabolic disease can affect its production?
Tyrosine and Phenylalanine
Phenylketouria
How does the solubility of a hormone affect how it is transported? Give examples.
Lipophilic hormones are transported whilst bound to a carrier
eg. Thyroxine (T3) bound to thyroxine binding globulin
Cortisol to transcortin
how does the solubility of a hormone affect how and where it binds to its target receptor?
soluble hormones cannot pass through the cell membrane so binds to receptors of membrane–> So acts through a secondary messenger
Insoluble hormones diffuse through the cell membrane and act on intracellular receptors
Examples of positive feedback?
Oestrogen levels high–>Increased LH
Also blood clotting whereby clotting factors tend to stimulate other substances
Describe the negative feedback loop of cortisol
Stress–>CRH production from the hypothalamus
CRH acts on the pit gland to produce ACTH
ACTH acts on the adrenal cortex to secrete cortisol
Cortisol has a negative feedback effect on the pit gland (Stops secreting ACTH) and the hypothalamus (Stops secreting CRH)
So decreases cortisol production
Why are some hormonal effects faster than others?
If effect is altering the activity of enzymes or proteins, response is rapid
If its altering gene expression, can take longer
Where is the appetite control centre?
Arcuate nucleus
Name four chemicals responsible for appetite
PYY
Ghrelin
Leptin
Insulin
Describe the effect (Promote hunger or inhibit hunger) of the four chemicals responsible for appetite
PYY- inhibit hunger
Ghrelin- Stimulate hunger
Leptin- Inhibits hunger
Insulin- Inhibits hunger
Explain how we get the feeling of euphoria and tiredness after eating
Full stomch–>release of POMC–>Broken down into products including β endorphins–>euphoria and tiredness
