Hypothalamus and pituitary gland
In this lesson, we’ll begin exploring another essential component of neurochemistry: hormones. Although hormones are often discussed in terms of their effects on the body, they are closely linked to the brain—both as a major site of their production and as a key target of their action. Two especially important hormone-producing structures in the brain are the hypothalamus and the pituitary gland.
1) Start with this video:
2) Then, read these articles:
Know Your Brain - Hypothalamus
Know Your Brain - Pituitary Gland
Know Your Brain - HPA Axis
3) Watch this video for a quick refresher:
4) Finally, answer these questions to test your understanding:
1. This part of the brain is known for its role in regulating homeostasis throughout the body. Through its connections to the autonomic nervous system and endocrine system, as well as its ability to influence behavior, it is involved in the regulation of thirst, hunger and feeding, body temperature, and circadian rhythms, among many other things:
- A. amygdala
- B. hypothalamus
- C. hippocampus
- D. cerebellum
Show Answer
Correct answer: B
The hypothalamus is involved in many processes that are critically important to maintaining homeostasis across various bodily systems. Some of the major functions generally attributed to the hypothalamus include the regulation of: thirst and drinking behavior, fluid and electrolyte balance, hunger and feeding, body temperature, stress responses, aggressive behaviors, reproductive behaviors, circadian rhythms, the sleep-wake cycle, and more.
2. Which of the brain regions below has the most prominent role in the direct regulation of body temperature?
- A. thalamus
- B. hypothalamus
- C. amygdala
- D. hippocampus
Show Answer
Correct answer: B
The hypothalamus plays a direct role in the regulation of body temperature. It constantly monitors the temperature of the body and, when temperature gets too high or too low, enacts mechanisms to bring it back to baseline. For example, if your body is too hot, the hypothalamus can cause perspiration to cool it off. The hypothalamus is involved a long list of other functions as well.
3. The hypothalamus controls the secretion of hormones from the anterior pituitary gland through the use of:
- A. neurotransmitters that are secreted into the bloodstream
- B. neurotransmitters that travel directly from the hypothalamus to pituitary gland
- C. hormones called releasing hormones that are secreted by the hypothalamus
- D. hormones called intermediate hormones that are secreted by the pituitary gland
Show Answer
Correct answer: C
The hypothalamus is connected to the anterior pituitary gland via a network of blood vessels called the hypophyseal portal system. The hypothalamus secretes a releasing hormone into the hypophyseal portal system, and the releasing hormone binds to receptors on anterior pituitary cells, prompting the release of a specific hormone from the anterior pituitary into the bloodstream in response.
4. Which of the following hormones is NOT produced in the anterior pituitary gland?
- A. thyroid-stimulating hormone
- B. growth hormone
- C. oxytocin
- D. adrenocorticotropic hormone
Show Answer
Correct answer: C
Oxytocin is made in the hypothalamus and released from the posterior pituitary gland. The anterior pituitary contains cells that produce several important hormones: adrenocorticotropic hormone, thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, growth hormone, and prolactin.
5. The HPA axis involves a cascade of hormones that results in the release of cortisol from the adrenal glands. What is the first hormone in the cascade?
- A. corticotropin-releasing hormone (CRH)
- B. corticosterone
- C. adrenocorticotropic hormone (ACTH)
- D. beta-endorphin
Show Answer
Correct answer: A
When we experience something stressful, the hypothalamus releases a hormone called corticotropin-releasing hormone (or CRH). This starts the cascade by signaling the pituitary gland to secrete a hormone called adrenocorticotropic hormone, or ACTH into the bloodstream. ACTH travels to the adrenal glands where it prompts the release of a hormone called cortisol from the adrenal glands.
