Endocrine Flashcards
What are the 4 main processes controlled by hormones?
- Digestion, storage of nutrients and their metabolism
- Salt and water balance
- Growth and development
- Reproductive function
What 3 things control hormone release?
- Plasma concentration of ions or nutrients
- Neurotransmitters
- Another hormone
What is the mechanism of the action of a water soluble hormone
- Hormone diffuses out of the blood and attaches to the receptor on the cell membranes surface, and forms an activated hormone-receptor complex
- This activates a G-protein which in turns activates Adenylyl Cyclase that causes ATP to become cAMP
- This activates protein kinases to phosphorylate one or more cellular proteins
- This then creates a physiological response (specific to the protein/ type of hormone)
- Phophodiesterase inactivates cAMP to end the hormonal response
What is the mechanism of action of a lipid soluble hormone?
- The lipid soluble hormone diffuses in to the target cell (detaching itself from the carrier protein)
- The hormone binds onto a receptor inside the cell creating an activated hormone-receptor complex.
- This now can alter gene expression of cellular DNA, by turning genes on or off.
- During DNA transcription new mRNA is created, which then leaves the nucleus and enters the cytosol.
- The new mRNA undergoes protein synthesis on one of the ribosomes forming a new protein.
- This new protein alters the activity of the cell causing a physiological response typical to that protein/ hormone that was first used.
What are the 3 types of hormone?
- Polypeptides (e.g. insulin, glucagon) Fast breakdown - receptors on plasma membrane
- Amino acid derivatives (e.g. adrenaline, melatonin)
- Steroids (e.g. testosterone, cortisol) Slow breakdown - intracellular receptors
Name 4 pancreatic hormones
- Insulin
- Glucagon
- Somatostatin
- Pancreatic Polypeptide
Name some Adrenal Cortex hormones?
- Aldosterone
- Cortisol
- Androgens
Name the Adrenal Medulla hormones
- Epinephrine
- Norepinephrine
Where is Calcitonin released from?
And what other hormones are released from there?
Thyroid gland
- Thyroxine (T4)
- Triiodothyronine (T3)
What hormones are released from the hypothalamus?
And what is their primary target?
Tropic hormones
- Anterior pituitary
Where is melatonin released from?
Pineal Gland
How are peptide hormones released?
Via exyocytosis
How are peptide hormones stored and synthesised?
Made in advance and stored in secretory vesicles
What is an example of a steroid hormone?
Estrogen
Androgens
Cortisol
What type of hormones are water-soluble?
Amine, protein, peptide and eicosanoid hormones
What type of hormones are lipid-soluble?
Steroid and thyroid hormones
What is a C-peptide?
When is it released?
Connecting part of insulin when it was proinsulin.
Released when insulin is release is activated
What hormones do each cells of the pancreatic islets produce? (Alplha, Beta, Delta and F cells)
Alpha - Glucagon
Beta - Insulin
Delta - Somatostatin
F - Pancreatic Polypeptide
What is glycogenolysis?
Conversion of glycogen to glucose
What is gluconeogenesis?
The formation of glucose from lactic acid and certain amino acids
What is glycogenisis?
Conversion of glucose and glycogen
