15. Hormones Flashcards
How many humans post-mortem posess pituitory tumours?
1/6
What are features of an endocrine gland (3)?
- Highly vascularised.
- Highly organised.
- Many mitochondria.
What structures are classed as endocrine glands (12)?
- Pineal.
- Pituitory.
- Hypothalamus.
- Thyroid.
- Parathyroid.
- Adrenals.
- Testis.
- Ovaries.
- Skin.
- Fat.
- Bone.
What is a hormone?
A substance secreted into the blood by specialized cells in response to a stimulus.
What was the first hormone identified?
Secretin - regulates secretions from intestine.
What is a neurocrine hormone?
Hormone released into synaptic cleft adjacent to where the neurone contacts the target cell.
What are the 4 main groups of hormones?
- Peptide.
- Steroid.
- Tyrozine derivatives.
- Eicosanoids.
What are peptide hormones synthesized from?
Amino acids.
What size are peptide hormones?
Variable.
Give examples of peptide hormones?
Thyrotropin releasing hormone. Gonadotrophin releasing hormone.
What size are glycoprotein peptide hormones?
Large molecules.
Give examples of glycoprotein peptide hormones?
Gonadotrophins from the anterior pituitory: Leutenising hormone. Follicle stimulating hormone.
Where are steroid hormones synthesized?
* Adrenal cortex. * Testis. * Ovary. * Placenta.
What are adrenalin, noradrenaline, dopamine and the thyroid hormones derived from?
Tyrozine.
What are the thyroid hormones?
Thyroxine. Triodothyronine.
Name some lipid insoluble hormones - do not enter cells?
* Adrenaline. * Noradrenaline. * Dopamine.
Are the thyroid hormones lipid soluble?
Yes.
What are the 2 types of eicosanoid messengers?
Prostaglandins. Leukotrienes.
What kind of hormone is the growth hormone?
Peptide.
What happens when growth hormone is activated?
Receptor and protein phosphorylation and downstream signalling cascades.
What kind of receptor is the growth hormone receptor?
Cell-surface.
What is IGF?
Insulin growth factor.
What stimulates the production of IGF in the liver?
Growth hormone.
Name 2 lipid soluble hormones ?
* Thyroxine. * Triiodothyronine.
What kind of receptor is the thyroid hormone receptor?
Intracellular - member of the nuclear receptor family.
What happens when triiodothyronine and the thyroide hormone receptor bind?
Formation of homo or hetero-dimers.
What are the gonadotrophins?
Leutenising hormone. Follicle stimulating hormone.
Where do the gonadotrophins bind?
G-protein coupled receptors at cell surface of gonadal cells.
What is steroidogenesis?
Biological synthesis of steroids.
What is the function of a hormone?
Regulate the activity of it’s target cells in a specific manner.
What is important for endocrine glands to maintain their function?
Receive constant rapid information about the state of systems being regulated.
