Endocrine System

Mood, sleep, socialization:

 

Dopamine: 

• Known as the “feel good” hormone

• Regulates motivation and reward

• Low dopamine levels are linked to depression

 

Oxytocin: 

• Promotes socialization and maternal characteristics

• Also aids in childbirth as a reproductive hormone

 

Melatonin: 

• Promotes sleep 

• Regulates cycle of waking up and falling asleep

 

Serotonin

• Stabilizes mood by promoting tranquility

• Influences appetite and sleep

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Fluid and electrolyte cycle:

 

Calcitonin: 

• Triggers storage of calcium in bones to lower blood calcium levels

 

Parathyroid hormone: 

• Increases blood calcium levels

 

Antidiuretic hormone: 

• Promotes reabsorption of water by kidneys to lower urine output

 

Aldosterone: 

• Promotes kidneys to reabsorb sodium 

• Affects potassium, blood pressure, and fluid balance 

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Stress and flight or fight:

 

Adrenaline

• AKA epinephrine

• Increases heart rate, blood pressure, and flow to muscles

 

Cortisol: 

• “Stress hormone” 

• Increases blood sugar levels

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Reproduction:

 

Estrogen: 

• Regulates menstrual cycle

 

Testosterone: 

• Sperm production

• Regulates male development

 

Prolactin: 

• Stimulates milk production after childbirth

 

Luteinizing hormone: 

• Triggers ovulation in women

• Produces testosterone in men

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Metabolism and energy balance:

 

Insulin: 

• Lowers blood glucose levels

• Promotes cells to uptake glucose

• Excess glucose stored as glycogen

 

Glucagon: 

• Releases glucose from glycogen stored in liver into blood

 

Thyroid hormone: 

• Increases energy production by cells

 

Leptin: 

• Reduces appetite

• Leads to satiety 

 

Grehlin:

• Promotes hunger

Hypothalamus:

The hypothalamus is located in the brain. It is the link between the nervous and the endocrine system as it sends signals to the pituitary gland to release hormones. 

The key hormones it triggers in the pituitary gland are responsible for regulating homeostasis through body temperature, hunger and thirst, and sleep. 
 

Pituitary gland: 

The pituitary gland is located at the base of the brain below the hypothalamus. It contains two lobes: 

 

• The anterior pituitary is responsible for producing and releasing hormones

• The posterior pituitary is responsible for storing hormones from the hypothalamus

 

Key hormones that are released from the pituitary gland include: 

 

• Growth hormone

• Thyroid stimulating hormone

• Prolactin

• Oxytocin

• Luteinizing hormone

• Follicle-stimulating hormone

• Antidiuretic hormone

 

Thyroid gland:

The thyroid gland can be found below the Adam's apple. This gland regulates the efficiency and speed of the body’s cells. They influence the rate in how energy is used in the body. 

 

Key hormones: 

• Calcitonin

• Thyroxine

 

Parathyroid (back of thyroid gland)

This gland releases the parathyroid hormone which increases blood calcium. 

 

Adrenal gland:

Found at the top of the kidneys. 

 

Produces hormones for immune function, stress, and blood pressure. 

 

The adrenal cortex produces cortisol and aldosterone. The adrenal medulla produces epinephrine and norepinephrine. 

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Pancreas:

Located behind the stomach. The pancreas are key to regulating blood sugar through digestive enzymes. The production and release of insulin and glucagon are key to maintaining homeostasis. In addition, somatostatin is released to inhibit the production of both glucagon and insulin. 

 

Gonads:

The gonads are the testes in men and the ovaries in women. Gonads produce different sex hormones to regulate reproduction. 

 

Key hormones: 

• Estrogen 

• Progesterone

• Testosterone

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Pineal gland:

The pineal gland can be found in the center of the brain. It regulates the sleep and wake cycle by secreting melatonin. 

 

Thymus gland:

The thymus gland is found in the chest. The key hormone it produces is thymosin. This regulates the development and differentiation of T lymphocytes. 

Diabetes type 1:

Diabetes type 1 is an autoimmune disease. The body’s own immune cells start to attack beta producing insulin cells. 

 

This results in high blood sugar, extreme thirst, and weight loss. 

 

Most treatments include insulin therapy, healthy diet, and regular exercise. 

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Diabetes type 2:

Diabetes type 2 can be developed. The body becomes resistant to insulin and this gradually occurs over time due to heavy sugar or unhealthy diets. In addition, the body tries to compensate by producing more insulin, but eventually this does not have an effect. 

 

Symptoms are similar to type 1 such as high blood sugar, extreme thirst, and weight loss. 

 

Management includes lifestyle changes and medications. 
 

Hypo and Hyperthyroidism:

 

Hypothyroidism results from the thyroid gland producing insufficient amounts of thyroid hormones. On the other hand, hyperthyroidism results from an excessive amount of thyroid hormone production. 

 

Causes: 

 

Hypothyroidism

• Cold intolerance

• Slow heart rate

• Fatigue

 

Hyperthyroidism

• Rapid heart rate 

• Increased appetite

• Sweating

 

Treatments include thyroid hormone replacement for hypothyroidism and antithyroid medications or surgery for hyperthyroidism. 

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Growth hormone deficiency:

 

The growth hormone is produced by the pituitary gland. It is essential for growth of bones, cartilage, and more in children. It also regulates metabolism and repairs tissue. It usually occurs due to injury or disorders. 

 

Causes: 

• Low muscle mass

• Short stature

• Increased body fat

 

It can be managed only through growth hormone replacement therapy. 

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Cushing’s syndrome:

Usually caused by tumors in adrenal or pituitary glands. This causes excess cortisol production.

 

Symptoms include: 

• Weight gain

• High blood pressure

• Osteoprosis

 

Can be managed with surgery or medications. 

 

Addison’s disease: 

Insufficient production of cortisol and aldosterone from adrenal glands. 

 

Symptoms: 

• Low blood pressure

• Dizziness

• Hyperpigmentation 

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Managed through hormone replacement therapy. 

Although most endocrine related disorders can be out of one’s control, nutrition is an important factor in ensuring preventative measures against many developing conditions. 

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Thyroid Health: 

The thyroid needs iodine to produce hormones, selenium to activate them, and zinc.
 

• Iodine can come from salt, dairy, eggs, and fish. 

• Selenium can come from seeds, eggs, and mushrooms. 

• Zinc comes from red meat, poultry, beans, and nuts. 

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Bone Health:

Calcium and vitamin D are essential to the formation and structure of bones. 

 

• Calcium can be found in dairy products, almonds, and leafy greens. 

• Vitamin D is in fatty fish, sunlight, and dairy.

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Reproductive Health:

Phytoestrogens (for women): 

Plant compounds that mimic estrogen in the body. 

• Soy products and legumes are good sources of phytoestrogens. 

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Zinc is essential for testosterone production and ovarian health:

• Oysters, red meat, and seeds are good sources. 

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Vitamin D (most commonly found in sunlight) is essential for hormone regulation. 

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Blood Sugar:

Chromium is necessary for effective action of insulin: 

• Can be found in broccoli, whole grains, and eggs. 

 

Magnesium supports insulin sensitivity: 

• Found in whole grains, nuts, darky leafy greens

 

Fiber can slow blood sugar absorption: 

• Fruits and vegetables are great sources of fiber

 

Cinnamon has been shown to improve insulin sensitivity. 
 

Adrenal Health:

Vitamin C:

Vitamin C is used to produce cortisol

• Found in citrus fruits, strawberries, and blueberries. 

 

B vitamins:

B vitamins (specifically B5, B6, B12) are necessary for reducing the effects of stress.

• They can be found in whole grains, eggs, nuts, and seeds. 

 

Healthy fats: 

Healthy fats like omega-3 fatty acids can reduce inflammation.

• The sources of this are fatty fish, flaxseeds, walnuts, and chia seeds.