The main function of the hypothalamus is to connect the nervous system and the endocrine system, through the pituitary gland. It controls many of the nervous system functions like sleep, hunger, blinking, and body temperature. It controls the hormones that the rest of the body and the brain need to function. The best way to envision how it works is if the hypothalamus is viewed as a control tower for an airport. There are many hormones that are like airplanes ready to take off to various locations around the body. The Hypothalamus tells each batch of hormones when to take off. Those hormones carry the information to perform some function like telling the brain it needs sleep, or telling the stomach to growl because it’s hungry.
Every vertebrate animal on the planet has a hypothalamus, and has the various hypothalamus functions. It responds to daylight and what’s called the photoperiod. The hypothalamus functions in this regard. By measuring the extent of light and dark it encounters. The hypothalamus also responds to scents that it encounters, including pheromones. These pheromones trigger many vertebrate animals to mate, however in humans this instinct isn’t as strong. We use visual cues more so then the sense of smell, when it comes to mating, but the hypothalamus is also responsible for this basic biological function as well. The hypothalamus also has the ability to receive information from other parts of the body including the stomach, the reproductive tract, and the major one, the heart. One of the hypothalamus functions is to make sure that the heart, and its regular beat, stays regular, and constant. It also tells the stomach when to send the signal that the person is hungry, which is a very powerful instinct that is triggered by hormones.
When a person is sick from some form of micro-organism, the hypothalamus has a function that we are all familiar with, a fever. It raises the body temperature in order to kill off the organism that has invaded the body. Unfortunately for the human that has to deal with this temperature increase, the uncomfortable nature of this is almost too much to handle. In some cases where the temperature get’s out of control, this defense becomes a hindrance, and can cause severe damage to the brain and heart.
One of the most interesting parts about the hypothalamus is that it looks and acts slightly different between the sexes. Most parts of the brain are the same in both male and female, however the hypothalamus physically looks different in each sex. One of the functions of the hypothalamus that stems from it being different in males and females is the excretion of growth hormones, which usually ends up making the male of the species larger than the females. In females the differences in shape seem to make them more attracted to the scent of males, and prefer their company as opposed to other females. This helps continue the species. Oddly enough, if the hypothalamus is scared or damaged in a particular way, then females will prefer the company of other women. This has nothing to do with sexual orientation, more that it will cause the female to seek out other females. This hypothalamus function is also present in males, but it’s interesting that the same damage will cause the opposite effect on the sexes.
The hypothalamus is a fascinating part of the brain, it regulates the body, it releases pheromones, and various chemicals to other parts of the body. It can make us large or small, and attracted to one sex or the other. If that little control tower in the brain wasn’t there directing the traffic, human history would have been a vastly different lineage. A part of the brain the size of an almond is what keeps us alive, and it doesn’t stop there. It causes the species to continue, and even is responsible for who we prefer to spend time with. The hypothalamus and its functions are part of what makes us who we are, and without it, life as we know it, simply vanishes.