The Endocrine System (Hormone System)

Endocrine systems, also referred to as hormone systems, are found in all mammals, birds, fish, and many other types of living organisms. They are made up of:

  • Glands located throughout the body;
  • Hormones that are made by the glands and released into the bloodstream or the fluid surrounding cells; and
  • Receptors in various organs and tissues that recognize and respond to the hormones.

Why are Hormones Important?

Hormones act as chemical messengers that are released into the blood stream to act on an organ in another part of the body. Although hormones reach all parts of the body, only target cells with compatible receptors are equipted to respond. Over 50 hormones have been identified in humans and other vertebrates.

Hormones control or regulate many biological processes and are often produced in exceptionally low amounts within the body. Examples of such processes include:

  • blood sugar control (insulin);
  • differentiation, growth, and function of reproductive organs (testosterone (T) and estradiol); and
  • body growth and energy production (growth hormone and thyroid hormone).

Much like a lock and key, many hormones act by binding to receptors that are produced within cells. When a hormone binds to a receptor, the receptor carries out the hormone’s instructions, either by altering the cell’s existing proteins or turning on genes that will builld a new protein. The hormone-receptor complex switches on or switches off specific biological processes in cells, tissues, and organs.

Some examples of hormones include:

Estrogens are the group of hormones responsible for female sexual development. They are produced primarily by the ovaries and in small amounts by the adrenal glands.

Androgens are responsible for male sex characteristics. Testosterone, the sex hormone produced by the testicles, is an androgen.

The thyroid gland secretes two main hormones, thyroxine and triiodothyronine, into the bloodstream. These thyroid hormones stimulate all the cells in the body and control biological processes such as growth, reproduction, development, and metabolism.

The endocrine system, made up of all the body’s different hormones, regulates all biological processes in the body from conception through adulthood and into old age, including the development of the brain and nervous system, the growth and function of the reproductive system, as well as the metabolism and blood sugar levels. The female ovaries, male testes, and pituitary, thyroid, and adrenal glands are major constituents of the endocrine system.


Where are Endocrine Glands Located in the Human Body?

Hypothalamus – The hypothalamus links our endocrine and nervous systems together. The hypothalamus drives the endocrine system.

Pituitary gland – The pituitary gland receives signals from the hypothalamus. This gland has two lobes, the posterior and anterior lobes. The posterior lobe secretes hormones that are made by the hypothalamus. The anterior lobe produces its own hormones, several of which act on other endocrine glands.

Thyroid gland – The thyroid gland is critical to the healthy development and maturation of vertebrates and regulates metabolism.

Adrenal glands – The adrenal gland is made up of two glands: the cortex and medulla. These glands produce hormones in response to stress and regulate blood pressure, glucose metabolism, and the body’s salt and water balance.

Pancreas – The pancreas is responsible for producing glucagon and insulin. Both hormones help regulate the concentration of glucose (sugar) in the blood.

Gonads – The male reproductive gonads, or testes, and female reproductive gonads, or ovaries, produce steroids that affect growth and development and also regulate reproductive cycles and behaviors. The major categories of gonadal steroids are androgens, estrogens, and progestins, all of which are found in both males and females but at different levels.


How Can Chemicals Affect the Endocrine System?

Scientific research on human epidemiology, laboratory animals, and fish and wildlife suggests that environmental contaminants can disrupt the endocrine system leading to adverse-health consequences. It is important to gain a better understanding of what concentrations of chemicals found in the environment may cause an adverse effect. Various types of scientific studies (epidemiology, mammalian toxicology, and ecological toxicology) are necessary to resolve many of the scientific questions and uncertainty surrounding the endocrine disruptor issue. Many such studies are currently underway by government agencies, industry, and academia.

Source: US Environmental Protection Agency


DIRTY DOZEN ENDOCRINE DISRUPTORS – 12 Hormone-Altering Chemicals and How to Avoid Them . . . . .

Hong Kong Style Baked Pork Chop and Fried Rice

Ingredients

400 g cooked rice
1 egg, beaten
1/2 tsp salt
2 tbsp water
2 pieces pork chop, about 240 g
1/2 onion, shredded
1 tomato, cut into chunks
1 tbsp green peas
1 egg
1/2 cup all-purpose flour

Marinade

1/4 tsp salt
1/2 tsp sugar
1 tsp cornstarch
1 tsp light soy sauce
1 tsp water
dash ground white pepper

Sauce

1 cup canned tomato soup
1/4 cup water
2 tbsp ketchup
1/4 tsp salt
2 tsp sugar
dash ground white pepper
1/2 tbsp cornstarch

Method

  1. Pound pork chops with mallet. Mix with marinade and set aside for 20 minutes. Coat with beaten egg and flour.
  2. Deep-fry pork chop in medium hot oil until cooked. Remove and set aside.
  3. Heat 2 tbsp in the wok. Lightly fry beaten egg. Add rice and toss well. Sprinkle salt and water. Stir-fry to combine. Remove fried rice to a baking dish.
  4. Heat 1 tbsp oil in the wok. Saute onion briefly. Add tomato and green peas. Mix in sauce ingredients and bring to a boil.
  5. Place pork chops on rice. Pour sauce over to cover the pork and rice. Bake in a preheated 180ºC oven until the sauce is browned.

Makes 2 servings.

Source: Rice and Noodles – Delicious Recipes

In Pictures: Cute Foods and Latte Decorated with Bird-shaped Templates

The pictures were created by placing the templates on top of the food or the cups. Just sprinkle cocoa powder or powdered sugar through the templates.

Shapes of Birds Available

Eating More Whole Grains Linked with Lower Risk of Death

Eating at least three servings of whole grains every day could lower your risk of death, according to new research in the American Heart Association’s journal Circulation.

Although dietary guidelines around the world have included whole grains as an essential component of healthy eating patterns, people aren’t eating enough, according to the analysis. In the United States average consumption remains below one serving a day, despite the long-time recommendation of three servings a day.

In the first meta-analysis review of studies reporting associations between whole grain consumption and death, researchers noted that for about every serving (16 grams) of whole grains there was a:

  • 7 percent decreased risk in total deaths;
  • 9 percent decline in cardiovascular disease-related deaths; and
  • 5 percent decline in cancer-related deaths.

The more whole grains consumed, the lower the death rate. According to researchers, when three servings (48 grams) were consumed daily the rates declined:

  • 20 percent for total deaths;
  • 25 percent for cardiovascular deaths; and
  • 14 percent for cancer-related deaths.

“Previous studies have suggested an association with consumption of whole grains and reduced risk of developing a multitude of chronic diseases that are among the top causes of deaths, although data linking whole grain intake and mortality were less consistent,” said Qi Sun, M.D., Sc.D., senior author of the study and assistant professor at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts. “These findings lend further support to the U.S. government’s current Dietary Guidelines for Americans, which suggest higher consumption of whole grains to facilitate disease prevention.”

Whole grains, such as whole wheat, oats and brown rice, contain dietary fiber, which may help improve blood cholesterol levels, and lower the risk of heart disease, stroke, obesity and type 2 diabetes. Dietary fiber can also make you feel full longer, so you may eat fewer calories.

This analysis included 12 studies published through February 2016 and unpublished results from the National Health and Nutrition Examination Survey (NHANES) III, conducted from 1988 to 1994, and NHANES 1999-2004. Of the reviewed studies, 10 were conducted in U.S. populations, three in Scandinavian countries and one in the United Kingdom.

The combined studies involved 786,076 men and women with 97,867 total deaths, 23,597 deaths from cardiovascular disease, and 37,492 deaths from cancer.

A potential drawback of the analysis may be the use of questionnaires to assess respondents’ intake of whole grains. However, Sun said questionnaires were validated against respondents’ diet records to ensure reliability.

Sun noted that low-carbohydrate diets that ignore the health benefits of whole grains foods “should be adopted with caution,” as they may be linked to higher cardiovascular risk and mortality.

“Based on the solid evidence from this meta-analysis and numerous previous studies that collectively document beneficial effects of whole grains, I think healthcare providers should unanimously recommend whole grain consumption to the general population as well as to patients with certain diseases to help achieve better health and perhaps reduce death,” Sun said.

The American Heart Association recommends a heart-healthy dietary pattern emphasizing fruits, vegetables, whole grains and other nutritious foods and specifically that at least half of grain consumption should be whole grains. Whole grains provide many nutrients, such as fiber, B vitamins, and minerals, which are removed during the refining process.

Source: American Heart Association


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