Welcome to 2 minute neuroscience, where I simplistically explain neuroscience topics
in 2 minutes or less.
In this installment I will discuss the hypothalamus and pituitary gland.
The hypothalamus is a small region situated directly above the brainstem.
It is made up of a collection of nuclei with a variety of functions, but in general the
hypothalamus is involved in controlling the two H’s: homeostasis and hormones.
Homeostasis is a term used to describe the maintenance of balance or stability in a biological
The hypothalamus can maintain homeostasis either by exerting direct influence over the
autonomic nervous system, or by causing the release of hormones.
The hypothalamus manipulates hormone release primarily by controlling the pituitary gland.
The pituitary gland is a hormone-secreting gland that sits just below the hypothalamus.
It is sometimes called the “master gland” because it not only secretes many extremely
important hormones but it also regulates the activity of other hormone-secreting glands
throughout the body.
The pituitary gland consists of two lobes, called the anterior and the posterior pituitary.
The anterior pituitary is responsible for the release of a number of hormones that have
widespread effects throughout the body.
They include growth hormone, which is involved with growth, follicle-stimulating hormone,
which plays a role in development and reproduction, luteinizing hormone, which is essential to
testosterone production and reproduction, adrenocorticotropic hormone, which is involved
with the stress and fear responses, thyroid stimulating hormone, which is important to
healthy metabolism, and prolactin, which promotes milk production in females.
The release of these hormones is controlled by the hypothalamus, which sends signals in
the form of releasing hormones to tell the anterior pituitary when to secrete its hormones.
The posterior pituitary also secretes two hormones, but does not synthesize them.
Instead, they are synthesized by the hypothalamus and then sent to the posterior pituitary for
release into the bloodstream.
The names of these hormones are: oxytocin and vasopressin.
Oxytocin has important roles in facilitating childbirth and lactation, but is also thought
to have a role in compassion and social bonding.
Vasopressin's main functions are to control urine output and regulate blood pressure.