Physiology Flashcards
What are the main Endocrine Organs?
Pituitary gland Thyroid gland Adrenal glands Pancreas Ovary and testes
Example of Modified Amino Acid hormones (2)
adrenaline
thyroid hormones
Example of Steroid Hormones (3)
Progesterone
Testosterone
Cortisol
What are steroid hormones synthesised from?
Cholesterol
Example of Peptide hormones (3)
ATCH
ADH
Oxytocin
What are peptide hormones made from?
Larger precursor proteins
Example of a protein hormone (1)
Insulin
Give an example of complimentary hormone action
adrenaline + glucagon + cortisol = prevent hypoglycaemia in short term high intensity exercise
Give an example of antagonistic hormone action
Insulin + glucagon
Insulin inhibits gluconeogenesis + increases glucose uptake in muscle and fat cells
Glucagon promotes gluconeogenesis but has no effect on glucose tissue uptake
How are Amine hormones synthesised and stored?
Pre-synthesised and in vesicles
When are Amine hormones released?
In response to stimuli by Ca++ dependant exocytosis
How do Amines travel in blood?
Transport free in plasma because they are hydrophilic
How are Peptide/Protein hormones synthesised and stored?
Pre-synthesised and in vesicles
When are Peptide/Protein hormones released?
In response to stimuli by Ca++ dependant exocytosis
How do Peptide/Protein hormones travel in blood?
Transport free in plasma because they are hydrophilic
How are Steroid hormones synthesised and stored?
Cholesterol enters cell and hormone is made via pregnenolone in lots of steps
When hormone is made it is immediately released. It is not stored
How do steroid hormones travel in blood?
Bound to plasma proteins because they are hydrophobic
Function of carrier proteins (4)
Transport in blood
Provide reservoir of hormone
Extend half-life of hormone
Maintain a constant conc of free lipophilic hormone in blood
Comment on rate of secretion of hormones
Not constant and fluctuates diurnally
e.g cortisol increases while sleep and decreases during day
What is the action of Gs protein?
Acts on adenylyl cyclase enzyme to up regulate production of cAMP
What hormones activate GPCRs?
amines and some peptide/proteins
What is the action of Gi protein?
Acts on adenylyl cyclase enzyme to down regulate production of cAMP
What is the action of Gq protein?
Acts to increase activity of phospholipase C enzyme
What hormones are linked to Gs protein? (2)
Adrenaline and glucagon
What hormone is linked to Gi protein?
Melatonin
What hormone is linked to Gq protein?
Angiotensin II
What type of ligand acs on GPCR?
Hydrophilic
What type of ligand acts on Receptor Kinases?
Hydrophobic
What hormone acts on a kinase receptor?
Insulin
Name 3 types of hormone receptors
GPCR
Receptor kinases
Nuclear receptors
