3.11.T - Lesson: Body Systems Part V - Endocrine (Study Guide)

The __________ is a section of the brain that produces many of the body's hormones, and those hormones control body temperature, thirst, hunger, sleep, mood, sex drive, and the release of other hormones.

Hypothalamus

The __________ is the inner part of the adrenal gland, and it produces adrenaline for your body's fight or flight reaction.

Adrenal Medulla

There are nine different glands in the endocrine system:

Adrenal glands (above the kidneys) Pineal gland (in the brain) Pituitary gland (in the brain) Thyroid gland (in the throat region) Parathyroid glands (near the thyroid gland) Hypothalamus (in the brain) Thymus (in the upper chest near the top of the breastbone) Pancreas (within the abdomen near the stomach) Ovaries (female reproductive) and testes (male reproductive)

Hypothalamic hormones include which of the following?

Growth hormone-releasing hormone Somatostatin Dopamine Thyrotropin-releasing hormone Corticotrophin-releasing hormone Gonadotropin-releasing hormone

The primary function of the hypothalamus is to regulate the inner workings of your body; this is called __________.

Homeostasis

The pineal gland is involved in several functions of the body, including which of the following?

Influencing sexual development and maturation Releasing melatonin Causing tiredness or sleepiness

Although the names are similar, the thyroid and parathyroid are __________ related.

Not

In the endocrine system, what is the female counterpart of the testes?

Ovaries

The endocrine system is made up of which of the following?

Pineal gland Adrenal glands Thyroid gland Thymus Pancreas Hypothalamus Ovaries (in females) Testes (in males) Pituitary gland Parathyroid glands

The __________ controls how most of the glands in the endocrine system function and is therefore sometimes called the master gland. Group of answer choices

Pituitary Gland

The Endocrine System

The endocrine system is made up of a group of glands, and these glands produce hormones that help regulate your mood, metabolism, sleep patterns, growth and development, tissue function, reproduction, and many other things. The endocrine system has an impact on almost every organ and cell in your body. It also gets some help from organs that are not part of the endocrine system: the heart, kidneys, and liver. The heart, kidneys, and liver are considered secondary endocrine organs.

Hypothalamus

The hypothalamus is part of your brain, and it makes many of the hormones that are in your body. The hormones the hypothalamus produces regulate body temperature, thirst, hunger, sleep, mood, sex drive, and the release of other hormones. Although this section of your brain is not very big, it helps with many different bodily processes, including metabolism, growth and development, and behavior. The main function of the hypothalamus is regulating the inner workings of your body and regulating the release of hypothalamic hormones; this is called homeostasis. The hypothalamic hormones are dopamine, somatostatin, corticotrophin-releasing hormone, gonadotropin-releasing hormone, growth hormone-releasing hormone, and thyrotropin-releasing hormone. These hormones are released into your blood via small blood vessels (capillaries), and they then travel to the pituitary gland.

Pancreas

The pancreas is located behind your stomach in the upper left part of your abdomen. Your small intestine, liver, and spleen are close to and surround the pancreas. The pancreas is about 6-20 inches long, is spongy, and is shaped kind of like a flat fish or a pear; it extends across your abdomen horizontally. The pancreas is essential for converting the food you eat into fuel. It has two main functions, including an exocrine function (which helps with digestion) and an endocrine function (which helps regulate blood sugar levels). Almost all of the pancreas (95%) is made up of tissues that produce pancreatic enzymes for digestion; these tissues are called exocrine tissues. The rest of the tissues in the pancreas are made up of endocrine cells (which are called islets of Langerhans). These are little clusters of cells that look like grapes. These cells produce hormones that regulate your blood sugar levels, and they regulate secretions from the pancreas.

Parathyroid Glands

The parathyroid glands are small glands located behind the thyroid gland in your neck. These glands control the calcium that is in your body's bones and blood. There are four parathyroid glands. Normally, each gland is about the size of a grain of rice and is the color of spicy yellow mustard. Once in a while, a person can have a normal parathyroid gland that is as large as a pea.

Pineal Gland

The pineal gland is a small gland in the endocrine system that is shaped like a pinecone. As part of your brain, the pineal gland produces the sleep hormone called melatonin. Melatonin influences sexual development and sleep-wake cycles. The pineal gland serves to connect the endocrine system to the nervous system by converting some of the signals from nerves into hormone signals.

Pituitary Gland

The pituitary is a gland that is about the size of a pea. This gland is inside the bony structure at the base of your brain called the sella turcica. The sella turcica protects the pituitary, but there is very little room inside it for the pituitary gland to expand. The pituitary gland controls how most of the glands in the endocrine system function. Because of this powerful control, the pituitary gland is often called the master gland. The pituitary gland works with the hypothalamus to detect how much of the different hormones are being produced by glands the pituitary controls (which are called target glands). These glands can then determine if those target glands need to be stimulated and how much stimulation they may need. The pituitary gland becomes highly active upon puberty.

Thymus

The thymus is part of the endocrine system, but it is much more closely associated with the immune system. The thymus does have glandular tissue and produces several hormones. It serves a very important role along with the white blood cells in your body called T-lymphocytes, or T cells. T cells help protect your body from fungi, bacteria, and viruses that could otherwise be deadly. The thymus is a soft organ that almost looks like a triangle. It is behind your sternum (breastbone) but in front of your heart. The thymus has two lobes that are identical, but the two lobes are distinct (they can be easily identified), and each lobe has strong fibrous tissue around it. While most organs grow until maturity, the thymus gets bigger throughout childhood but slowly shrinks once an individual reaches puberty, and continues to shrink throughout adulthood. As the thymus shrinks, its tissues are replaced by tissues that are stored in fat cells (called adipose tissue). The reason the thymus shrinks is that it has a reduced role during adulthood.

Thyroid Gland

The thyroid gland is located at the base of your neck; this organ or gland is shaped like a butterfly and is about two inches long. It is at the front of your throat in the area that is often called the "Adam's apple." The butterfly shape gives the thyroid gland two distinct sides (which are called lobes). The thyroid releases hormones that regulate your metabolism. A few other bodily functions the thyroid regulates are your heart rate, breathing, weight, muscle strength, cholesterol levels in your blood, body temperature, and menstrual cycles (in females).

Adrenal Glands

There are two adrenal glands in your body, each situated above a kidney. The adrenal glands have two distinct parts: the adrenal cortex and the adrenal medulla. The adrenal cortex is the outer part of the adrenal gland, and it produces hormones that are very important for living. Two of the hormones the adrenal cortex produces are cortisol (which helps regulate your metabolism and helps your body respond to stress) and aldosterone (which helps control your blood pressure). The adrenal medulla is the inner part of the adrenal gland, and it produces adrenaline for your body's fight or flight reaction.

The __________ serves a very important role along with the white blood cells in your body called T-lymphocytes, or T cells. T cells help protect your body from fungi, bacteria, and viruses that could otherwise be deadly.

Thymus