36. Endocrine 1 Flashcards
Give 3 examples of endocrine glands.
Thyroid
parathyroid
Adrenal
What 2 categories can hormones fall in to?
Steroids or non steroids
Give 3 steroid hormones
cortisol
testosterone
oestrogen
Give an example of a group of non-steroid hormones and an example of this.
Amines - adrenaline, noradrenaline
In what form are many peptide hormones produced? What is the name given to them?
Produced in an inactive, precursor form
called pro-hormones
Where is pre-pro-hormone converted?
Pre-pro-hormone is converted to pro-hormone in the endoplasmic reticulum
What are glycoproteins?
Carbohydrate groups attached to amino acids
How do most non-steroid hormones act?
Via second messenger systems eg cyclic AMP.
Can steroid hormones pass through the outer membrane of cells?
Yes
How do steroid hormones alter DNA?
They enter the cell and nucleus then bind to a HORMONE RECEPTOR which alters DNA
How do non-steroid hormones act?
Bind to a 1st messenger which activates G-proteins. Adenyl cyclase breaks down ATP to cAMP which activates protein kinases. Specific enzymes convert substrate to product.
What regulates most hormone systems?
Negative feedback
Name 2 functions which can cause endocrine disorders.
Hypersecretion
Hyposecretion
What is the sensitivity of a cell related to?
The number of membrane receptors -
- more receptors > more sensitivity > up regulation
- fewer receptors > decreased sensitivity > down regulation