BBB - The Endocrine System Lesson

Learning Target:

• Explain how the endocrine system transmits information and interacts with the nervous system.

Courtesy of the AP psychology course and exam description, effective fall 2024. (n.d.). Links to an external site.

 

Endocrine System

The endocrine system is the second communication system in your body, working in tandem with the nervous system to transmit information. Unlike the rapid signals of the nervous system, the endocrine system uses hormones as its messengers. Communication by hormones in the endocrine system is much slower than communication in the nervous system because they travel by blood through the body. These hormones, such as adrenaline, leptin, ghrelin, melatonin, and oxytocin, are released by glands and travel through the bloodstream to target tissues in the brain. When these hormones reach the brain, they impact our behavior, including our appetite, stress response, and social bonding.

One of the key players in the endocrine system is the pituitary gland, located at the base of the brain and regulated by the hypothalamus. The pituitary gland acts as a conductor, directing other endocrine glands to release their specific hormones into the bloodstream. This intricate dance of communication involves a feedback loop between the brain, pituitary gland, other glands, hormones, and the body itself, highlighting the close relationship between the nervous and endocrine systems. By understanding how these two systems interact, we gain insight into how our bodies regulate vital functions and respond to external stimuli.

Major Glands and Their Functions

The hypothalamus (an area in the forebrain responsible for both the autonomic nervous system and the pituitary gland) is a brain structure responsible for triggering hormone secretion. It is also the main link between the endocrine and nervous systems. The hypothalamus stimulates the pituitary gland to regulate the production of hormones. The pituitary gland, often called the "master gland," regulates the production of growth hormones and other endocrine glands.

The pineal gland is in the center of the brain and is responsible for producing melatonin, which is involved in feelings of sleep and wakefulness.

The thyroid gland controls how quickly the body burns energy, makes protein, and is sensitive to other hormones. The parathyroid consists of four small thyroid glands, which are responsible for adjusting calcium in the blood. The thymus produces thymosin, which aids in the development of the immune system.

The adrenal glands arouse the body in times of stress. They are located just above the kidneys and are particularly interesting to psychologists as they trigger flight or fight responses. The adrenal glands consist of the adrenal cortex, which is the outer region that interacts with the immune system, and the adrenal medulla or inner region, which releases epinephrine and norepinephrine.

The pancreatic gland regulates blood sugar levels. It releases insulin and glucagon, two opposing hormones that control sugar levels.

Gonads or sex organs influence both emotional and physical development. For women, the sex organs consist of the ovaries, and for men, the testes. The male testes secrete sex hormones called androgens, the most important testosterone. Females also secrete testosterone along with the hormones estrogen and progesterone. Sexual development at conception is affected by these important hormones. They are also involved in the development of secondary sexual characteristics during adolescence.

Complete the Endocrine System Questions activity below.

Important Hormones to Know for the AP Exam

Prior to moving on to the next sections in this module The Endocrine System and The Brain please take a moment to review this Crash Course video on The Nervous System.

 

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