Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be talking to you about cortisol and the adrenal axis.

And you can find written notes on this topic at zero to finals.com slash cortisol or in the endocrinology section of the second edition of the zero to finals medicine book.

And you can find flashcards and questions to train your knowledge on this content and help you remember the information for longer at

members.0.0 tofinals.com. So let's jump straight in. Cortisol is a glucocorticoid steroid hormone

secreted by the two adrenal glands. An adrenal gland sits above both kidneys in the abdomen. Cortisol is a stress hormone

released in response to stress and it helps the body to cope with the stress. It has several

actions within the body. It increases alertness.

It inhibits the immune system and reduces inflammation.

It inhibits bone formation.

It raises the blood glucose level.

It increases metabolism.

And it supports cardiovascular function, increasing the heart rate,

blood pressure and cardiac output. Cortisol is released in pulses throughout the day and in response

to stressful stimuli. It has diurnal variation, meaning that it's high and low at

different times of the day. Cortisol typically peaks in the early morning, triggering the person to

wake up and get going, and it's at its lowest late in the evening, helping the person to relax and fall asleep.

There might be additional spikes throughout the day in response to stressful stimuli.

Let's talk about glucocorticoids and mineralocorticoids.

There are two types of steroid hormone produced by the adrenal glands.

Cortisol, which is a type of glucocorticoid,

and aldosterone, which is a type of mineralocorticoid.

Glucocorticoids, for example, cortisol, help the body to cope with stress, they regulate the

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