5.1.4 - Hormonal Communication✅ Flashcards
Define endocrine glands?
Glands that release hormones directly into the blood - hormones produced in cells and secreted directly into blood capillaries
Define exocrine glands?
Glands that secrete chemicals into ducts which carry them to another place
Define hormones?
Molecules released by endocrine glands and acts as chemical messengers - carried in the blood
Define protein and peptide hormones?
Hormones made up of amino acids (eg adrenaline, insulin and glucagon) they cannot pass through the phospholipid bilayer
Define steroid hormones?
Hormones that are lipid-based (eg sex hormones) they pass through membrane and have direct impact on DNA
- binding to receptor proteins to form hormone-receptor complex (HRC)
- HRC acts as transcription factor which facilitates or inhibits specific gene
Eg oestrogen
define target cells and target tissue?
Cells that posses specific receptors that a specific hormone will bind to in order to have an effect on the cell
- tissues which contains a number of target cells grouped together are target tissue
Explain how non-steroid hormones work?
Bind to specific receptors on cell surface membrane - triggers a cascade reaction mediated by ‘second messengers’
- complementary shape
- eg adrenaline
Compare the hormonal system with the nervous system - give 6?
1) communication is by chemicals (hormones) instead of nerve impulses
2) transmission by blood system instead of by neruons
3) transmission relatively slow - where as transmission is very rapid
4) hormones travel to all parts of body (only target organs respond) nerve impulses travel to specific part of body
5) response is widespread where as response is localised
6) effect may be permanent and irreversible where as effect is temporary and reversible
What is the structure of the adrenal glands - what are the 2 parts and what is their function?
Two small glands located on top of each kidney - consist of 2 parts surrounded by capsule
- adrenal cortex (outer region) produces hormones like cortisol and aldosterone (vital for life)
- adrenal medial (inner region of gland) produces non-essential hormones - like adrenaline
What are the 3 main hormones produced by the adrenal cortex?
- glucocorticoids
- mineralocorticoids
- androgens
production of these hormones controlled by hormones released from pituitary gland
What are the hormones glucocorticoids produced by the adrenal cortex?
- include cortisol
- help regulate metabolism - controls how body converts fats, proteins and carbs to energy
- involved in regulation of BP and cardiovascular function
What are the hormones mineralocoricoids produced by the adrenal cortex?
- main one produced is aldosterone - controls BP by maintaining balance between salt and water conc in blood
What are the hormones androgen produced by the adrenal cortex?
- small amounts of M and F sex hormones released
- impact relatively small compared to that of sex organs (testes/ovaries)
Finnish notes - 385
What are the 2 functions of the pancreas?
- exocrine gland - to produce enzymes and release then via a duct in the duodenum
- endocrine gland - to produce hormones and release them into blood §