Cortisol and Stress Flashcards
What is cortisol?
A lipid soluble hormone which is produced as it is required
How does cortisol travel?
Carried in the blood bound to a carrier protein
Where does cortisol travel?
To the target cell and passes through the cell membrane
What does cortisol do once it has passed through the cell membrane?
Binds to a specific receptor which is usually found in the cytoplasm
What does cortisol don once bound to the specific receptor?
The receptor hormone complex moves into the nucleus
What does cortisol do once in the nucleus?
Activates specific genes
What does cortisol do once it has activated specific genes?
Produces mRNA and then a protein
What happens once the protein has been produced?
The protein has an effect
What is the stimulus for cortisol?
Stress and non-stress neural inputs (day-night rhythm, low blood glucose concentration)
What does stress and non-stress neural inputs cause?
The hypothalamus to secrete corticotropin releasing hormone (CRH)
What does corticotropin releasing hormone do?
Causes the anterior pituitary to secrete adrenocorticotropic hormone (ACTH)
What does adrenocorticotropic hormone do?
Causes the adrenal cortex to secrete cortisol
What effects does cortisol have?
Metabolic effects and other effects
What cells does cortisol effect metabolically?
Muscle, fat and liver
What does cortisol do to muscle cells?
Increase protein breakdown and decrease glucose uptake
What does cortisol do to fat cells?
Increase fat breakdown and decrease glucose uptake
What does cortisol do to liver cells?
Increase glucose synthesis (gluconeogenesis from the fat and protein which have been broken down by the muscle and fat cells)
What are the other effects of cortisol?
Helps one to cope with stress, long term it suppresses the immune system and is essential for maintaining normal blood pressure
What is cortisol secretion controlled by?
Negative feedback during the non-stress stimulus. Negative feedback does not occur when the stimulus is stress
What happens in the negative feedback of cortisol?
Cortisol goes and acts on the hypothalamus and anterior pituitary to prevent release of corticotropin releasing hormone and adrenocorticotropic hormone
What is the daily pattern of cortisol?
Pulses during the day in response to specific conditions in the body which the highest peak upon waking