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 hormone axis physiology. And you can find written notes on this topic at

zero to finals.com slash hormone access physiology or in the endocrinology section of the zero to finals medicine book.

So let's get straight into it.

Hormones are messenger chemicals that travel in the blood between organs and tissues,

regulating many processes.

A hormone axis is a system that controls the amount of a hormone in the system.

Too much or too little of a hormone can have significant consequences. Let's start by talking about

the hypothalamus and the pituitary gland. The hypothalamus releases hormones that stimulate the pituitary gland. The pituitary gland. The hypothalamus releases hormones that stimulate the

pituitary gland. The pituitary gland has an anterior and a posterior part that releases

different hormones. The anterior pituitary gland releases thyroid stimulating hormone, shortened

to T-S-H, adrenocortogotropic hormone shortened to ACTH,

follicle stimulating hormone shortened to F-S-H, and lutanizing hormone shortened to LH,

growth hormone shortened to GH, and prolactin.

The posterior pituitary releases oxytocin and antidioretic hormone, shortened to ADH.

Let's talk about the thyroid axis.

The hypothalamus releases thyrotropin releasing hormone, shortened to TRH.

This stimulates the anterior pituitary to release thyroid-stimulating hormone, or T-S-H.

Thyroid stimulating hormone stimulates the thyroid gland to release triiodothyronine, or T3, and

thyroxene, or T4. The hypothalamus and the anterior pituitary respond to T3 and T4, the thyroid

hormones, by suppressing the release of thyrotropin releasing hormone

and thyroid stimulating hormone. In turn, reduced TRH and TSA results in lower amounts of T3

...