Intro To Endocrine Systems Flashcards
What is endocrine transmission?
- Chemical secretions in low concentrations by cell(s)
- Sent to all parts of body via blood stream
- Hormone only acts on cell with correct membrane receptor (target cell)
Communication by hormones is:
- Coordinated
- Slow to act, but effect persists
Name the endocrine glands:
- Hypothalamus
- Pituitary gland
- (Para)Thyroid gland
- Pancreas (islets of langerhans)
- Adrenal glands
- Endocrine cells in GI tract
- Gonads: ovaries, testes
- Thymus
- Placenta
- Pineal Gland
What are the 2 classifications of hormones?
Steroids
Non-steroids
What are some steroid hormones?
- Cortisol
- Aldosterone
- Testosterone
- Oestrogen
- Progesterone
What are the 3 categories of non-steroid hormones?
- Amino acid derivatives
- Peptides
- Glycoproteins
What is a glycoprotein?
A class of protein with a carbohydrate group attached onto the polypeptide chain
What are some AMINO ACID DERIVATIVE non-steroid hormones?
- Adrenaline (epinephrine)
- Noradrenaline (norepinephrine)
- Melatonin
What are some PEPTIDE non-steroid hormones?
- Antidiuretic hormone (ADH)
- Somatostatin (GH inhibiting hormone)
- Parathyroid hormone
- Insulin, Glucagon
- etc..
What are some GLYCOPROTEIN non-steroid hormones?
- Prostaglandins
- Leukotrienes
- Thromboxanes
What are second messengers?
INTRACELLULAR signalling molecules released in response to an EXTRACELLULAR signalling molecule (first messenger) binding on the cells receptor
What is the overview of hormone action?
1) synthesis/storage of hormone
2) Release in response to stimulus
3) Transport in blood
4) Action on target cells (role of 2nd messengers)
5) Metabolism/excretion
What is the difference between steroid and non-steroid hormones when it comes to cell signalling?
Non-steroid hormones bind to extracellular receptors activating secondary messenger systems which cause effect inside the cell
(THEY CANT PASS THE CELLS MEMBRANE)
Steroid hormones can pass outer cell membrane and activate INTRACELLULAR receptors
What role does negative feedback control have on hormone systems?
Important role as most hormone systems are REGULATED by negative feedback
How can endocrine disorders arise?
Can be through hyper and hyposecretion of endocrine hormones
hyper - excess
hypo - decreased
