What are hormones?
Dr. Uma Lerner is a practicing Psychiatrist based in San Francisco, CA. Dr. Lerner utilizes a combination of cognitive-behavioral, mindfulness, and psychodynamic techniques in addition to medication management and specializes in reproductive mental health. Please see an important disclosure at the end of this post.*
Hormones are messengers produced by the body’s endocrine glands. They can be transported all over the body via the bloodstream to instruct or regulate cells and tissues. There are 8 major endocrine organs: hypothalamus, pituitary, pineal, thyroid, parathyroids, adrenals, pancreas, ovaries/testes. There are also other organs which produce hormones, though they have different primary functions (such as the stomach, intestines, and the heart).
Each part of your body, from your brain to your skin, takes direction from hormones. Hormones affect fundamental processes such as metabolism, sexual development, reproduction, mood, and growth.
How are hormones regulated?
Most hormones are regulated via a negative feedback loop system. A feedback mechanism is a loop in which the product (hormone) signals (feeds back) to the original organ to limit its own production. This keeps the concentration of the hormone within a narrow range. An example of a hormone controlled through negative feedback is the thyroid. Your thyroid hormones influence your body temperature, amongst many other things, so it makes sense that thyroid, along with safe and tolerable body temperature, would have a very narrow range.
Some hormones, such as oxytocin during labor, are managed via a positive feedback loop. In a positive feedback loop, the hormone signals to the gland to release even more of itself. In the case of oxytocin and labor, this results in stronger and stronger contractions to push the baby through the birth canal.
Oxytocin is also an important part of orgasm. Now that you know about positive feedback loops, that makes sense. As I’m thinking about it, it seems it would be worth having an entire blog post on the hormonal and neurological aspects of the orgasm. It’s an exciting topic!
Can hormones be regulated by both positive and negative feedback loops?
Estrogen is a particularly complex hormone because it works through a negative feedback loop, causing its own production to decrease to stay within a narrow range during the 1st half of the menstrual cycle. But then… (drum roll please) around day 14 the body switches to have a positive feedback response to estrogen. We still don’t know how or why the body knows to make this abrupt switch! The positive feedback loop causes a surge in estrogen and in-turn a surge in other reproductive hormones, thereby initiating ovulation. Women’s bodies never cease to amaze me! How do we do it all?!
What happens to these feedback loops when we don’t take care of our health?
Sometimes when our lifestyle, diet, body, and hormones are not in balance with each other, problems such as diabetes, weight gain or loss, mood difficulties, or weak bones can result. Type 2 diabetes is a condition that affects the way that the body processes blood sugar. It’s a condition that is worth bringing up here because it is a good example of how hormones work through feedback loops and also how those loops can get off balance.
Glucose (a type of sugar) is an important source of energy for muscles, brain cells, as well as other organs. The body obtains glucose from two main sources, food and its own storage. Your body stores glucose in the liver and fat cells as glycogen. Glucose moves through the body via the bloodstream and it is absorbed by the tissues which need it. Insulin, which is produced by the pancreas, is the hormone which signals to the organs to take in the glucose. There is a negative feedback loop between blood glucose and insulin. That means when blood sugar rises, the pancreas produces more insulin to move glucose into cells to keep blood sugar levels in check.
In type 2 diabetes, the body is resistant to (ignores) insulin’s signals. This means that cells cannot effectively absorb glucose. This leaves too much sugar in the bloodstream and not enough in the cells. Without the sugar to provide energy to the cells, a person can feel tired and hungry. In type 2 diabetes, the body’s glucose feedback loop is constantly asking the pancreas to produce more insulin because of high amounts of sugar in the bloodstream, and over time, the body’s insulin production wears out and a person might even stop making insulin all together. The level of glucose in the bloodstream is too high. The elevated glucose levels can be toxic, causing blindness, kidney damage, and nerve damage, among other things.
As you can see, hormones carefully calibrate many basic bodily functions. When the negative and positive feedback loops dysregulate, disorders such as diabetes can occur.
It’s incredible what a delicate and dynamic balance our bodies are capable of achieving.
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Dr. Uma Lerner is a practicing Psychiatrist based in San Francisco. Dr. Lerner utilizes a combination of cognitive-behavioral, mindfulness, and psychodynamic techniques in addition to medication management and specializes in depression, anxiety, bipolar disorder, ADHD, life transitions, grief, and loss. Dr. Lerner is an Assistant Clinical Professor of Psychiatry at the University of California, San Francisco Medical School, where she teaches and supervises medical students and psychiatry residents.
She has expertise in managing psychiatric and emotional challenges during pregnancy and while breastfeeding. You can learn more about Dr. Lerner’s practice here.
*No information on this post should be relied upon to make a medical diagnosis, or determine treatment for a medical condition. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. Though I am a physician, my blog posts are for information purposes only and shouldn’t be seen as medical advice. Different people react to hormones differently, and it is important to be clinically evaluated and talk about your specific situation with your doctor.
