• Pineal Gland
• Pituitary Gland
• Pancreas
• Ovaries
• Testes
• Thyroid Gland
• Parathyroid Gland
• Hypothalamus
• Adrenal Glands

1. What Is Pineal Gland?

The pineal gland is a small endocrine gland which shape looks like a pinecone and is located in the middle of the brain.

The pineal gland is made of cells known as pinealocytes that secrete the hormone melatonin involved in the control of the wake-sleep pattern [2].

2. What Is Pituitary Gland?

The pituitary gland or hypophysis is a gland a size of a pea that sits on a saddle-shaped bony structure known as sella turcica in the middle of the brain.

The pituitary gland is divided into the anterior lobe, intermediate lobe, and posterior lobe.

The anterior lobe secretes several hormones and polypeptides involved in growth, reproduction, stress, pain, and metabolism:

• Adrenocorticotropic hormone (ACTH)

This hormone stimulates the adrenal gland to secrete glucocorticoids, mineralocorticoids, and sex corticoids.

• Thyroid-Stimulating Hormone (TSH)

This hormone stimulates the thyroid gland to secrete thyroid hormones, thyroxine (T4), and triiodothyronine (T3).

• Follicle-Stimulating Hormone (FSH)

This hormone is involved in regulating the growth of the reproductive system by targeting the gonads (ovaries and testes).

• Luteinizing Hormone (LH)

This hormone promotes the production of sex hormones by the gonads.

• Growth Hormone (GH)

This hormone is involved in the metabolism of carbohydrates and lipids by regulating the function of the liver adipose tissue.

• Prolactin

This hormone stimulates the ovaries to secrete estrogen and progesterone and the mammary glands to produce milk.

• Beta-endorphin

Beta-endorphin is an endogenous opioid that binds and blocks opioid receptors resulting in the inhibition of pain perception.

The intermediate lobe of the pituitary gland secretes the melanocyte-stimulating hormone (MSH) also known as melanotropin.

• Melanocyte-Stimulating Hormone (MSH)

MSH stimulates the production of the skin and her pigment, melanin through a process known as melanogenesis.

The posterior lobe of the pituitary gland does not produce hormones but rather stores and secrete the hypothalamus hormones oxytocin and vasopressin.

• Oxytocin is a hormone that acts on other parts of the brain to regulate social bonding, on the mammary gland for milk ejection, and on the uterus for cervical dilatation during labor.

• Vasopressin is a hormone that acts on the kidney to reabsorb free water which is recirculated in the blood.

3. What Is Pancreas?

The pancreas is an organ of the digestive system situated behind the stomach and has both endocrine and exocrine functions.

As an endocrine gland, the pancreas secretes inulin, glucagon, somatostatin, and pancreatic polypeptide.

• Insulin is a hormone produced by the beta cells of the pancreatic islets and is involved in the absorption of blood glucose be the liver, adipose tissue, and muscles.

• Glucagon is a hormone produced by the alpha cells of the pancreas and is involved in converting stored glycogen into glucose that is released in the bloodstream.

• Somatostatin is an inhibitor of the secretion of insulin, glucagon secretion, prolactin, growth hormone, thyroid stimulating hormone, and adenyl cyclase (enzyme).

• Pancreatic polypeptide is involved in the storage of glycogen by the liver and in the regulation of pancreatic secretion in the gastrointestinal system.

The exocrine function of the pancreas is associated with the secretion of the pancreatic juice that helps with the digestive process.

4. What Are Ovaries?

The ovaries are organs of the female reproduction system involved in the regulation of the menstrual cycle and fertility.

The ovaries secrete the hormones estrogen, progesterone, androgen, and inhibin.

• Estrogen are sex hormones that promote the development of the female reproductive system and secondary sexual characteristics such as breast and thickening of the inner layer of the uterus.

• Progesterone is a sex hormone involved in the regulation of female reproductive systems, such menstrual cycle, pregnancy, breastfeeding, and male reproductive system through its role in spermatogenesis and testosterone production.

• Androgens are involved in libido and sexual arousal in female and are precursors of estrogen.

5. What Are Testes?

Testes are organs of the male reproductive system which produce sperm, androgen (testosterone)

Androgen is a hormone involved in the development and maintenance of male characteristics (testosterone).

The release of testosterone is regulated by the pituitary gland hormones, follicle-stimulating hormone (FSH), and luteinizing hormone (LH).

6. What Is Thyroid Gland?

The thyroid gland is situated in the neck and produces the thyroid hormones, thyroxine (T4), triiodothyronine (T3), and calcitonin.

Thyroxine (T4), triiodothyronine (T3), and calcitonin are involved in the regulation of cellular metabolism, growth, and heartbeat rate.

7. What Is Parathyroid Gland?

The parathyroid gland is situated in the neck at the back of the thyroid gland and produces the parathyroid hormone involved in the maintenance of calcium and phosphate levels in the body through its effect on the bone, gut, and kidneys.

8. What Is Hypothalamus?

The hypothalamus is a gland at the interface between the nervous system and the endocrine system, represented by the pituitary gland.

The hypothalamus secretes hormones known as releasing hormones that regulate the secretions of hormones by the pituitary gland.

It is divided into three regions, the anterior region (supraoptic), the middle region (tuberal), and the posterior region (mammillary). Each region is involved in the secretion of hormones.

• Gonadotropin-Releasing Hormone (GnRH)

GnRH is secreted by the supraoptic region to stimulate the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by the pituitary gland.

• Vasopressin

• Oxytocin

• Thyrotropin-Releasing Hormone (TRH)

TRH is secreted by the supraoptic region to stimulate the release of thyroid-stimulating hormone (TSH) and prolactin by the pituitary gland.

• Corticotropin-Releasing Hormone (CRH)

CRH is secreted by the supraoptic region to stimulate the release of adrenocorticotropic hormone (ACTH) and beta-endorphin by the pituitary gland.

• Somatostatin

• Growth Hormone-releasing Hormone (GHRH)

GHRH is secreted by the tuberal region to stimulate the release of growth hormone (GH) by the pituitary gland.

9. What Are Adrenal Glands?

Adrenal glands are found on the top of the kidneys and secrete the hormones, epinephrine, (adrenaline), norepinephrine, cortisol, and aldosterone.

• Epinephrine

Epinephrine or adrenaline is involved in regulating blood pressure and smooth muscle constriction.

• Cortisol

Cortisol is a steroid hormone involved in many functions in the human body, the inflammatory response, regulating metabolism, and immune function.

Cortisol mediates the stress response as part of the “fight-or-flight” response mediated by the hypothalamus-pituitary gland-adrenal gland (HPA) axis.

• Aldosterone

Aldosterone is a steroid hormone involved in the regulation of blood pressure and the homeostasis of sodium and potassium plasma levels.

• Norepinephrine

Norepinephrine is a hormone and chemical messenger associated with the “fight-or-flight” response mediated by the hypothalamus-pituitary gland-adrenal gland (HPA) axis.

Conclusion

The endocrine system involves communication and coordination between different glands situated in different tissues and organs. It can be regarded as the body messenger that delivers instructions to control essential functions such as growth, reproduction, metabolism, homeostasis, immune response, and stress response.

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1. Physiological Mechanisms of Headaches and Migraines

Migraine can be due to a genetic complex familial disorder that is most likely governed by several genes, however, both headache and migraine are caused by trigeminal nerve activation and calcitonin gene-related peptide (CGRP) release from the trigeminovascular system.

The trigeminal nerve transmits sensations of touch and pain in the face and motor functions. These sensations are transmitted through the nerve’s three major branches: the ophthalmic, maxillary, and mandibular nerves [1].

Calcitonin gene-related peptide (CGRP) is a neuropeptide produced and secreted by the thyroid C cells and stored in the trigeminovascular system, which consists of a complex of sensory neurons that innervate cerebral blood vessels, pial vessels, dura mater, and large venous sinuses.

Once released from these neurons, CGRP has been associated with nociceptive transmission (perception or sensation of pain), and release from perivascular nerve endings causing neurogenic vasodilatation [2]. 

2. Causes of Headaches and Migraines

Several causes trigger a headache and migraine, and among these, stress, environment, diet, hormones, lack of sleep, and gallbladder disorders, are the main ones.

A. Stress and Migraines

Migraines and headaches are often caused by stress. When a person is stressed, the body releases certain hormones which can trigger migraines and headaches. These hormones can cause the blood vessels in the head to dilate, leading to pain [3].

Additionally, stress can lead to tension headaches, which are caused by muscle contractions in the neck and head. Tension headaches are the most common type of headache, and they can be triggered by stress, fatigue, poor posture, and eyestrain.

B. Diet and Migraines

Many experts believe that diet may play a role. Some foods are known to trigger migraines and headaches, including aged cheeses, processed meats, nuts, and chocolate. Drinking too much alcohol or caffeine can also bring on these unpleasant symptoms [4].

If you suffer from migraines or headaches, it’s important to keep track of what foods seem to aggravate them. Try eliminating suspected triggers from your diet for a few weeks and see if your symptoms improve. You may also want to try eating smaller meals more often throughout the day instead of three large meals. Getting enough sleep and regular exercise can also help reduce the likelihood of migraines and headaches.

C. Gall Bladder and Migraines

The association between the gall bladder and migraines has been shown by a study of 20,427 patients who were diagnosed with gallbladder stone disease (GSD) between 2000 and 2011 from Taiwan’s National Health Insurance Research Database (NHIRD). The study reported a greater cumulative incidence of migraines in patients with GSD compared with those without GSD [5].  

D. Environmental Factors and Migraines

Environmental factors that cause headaches and migraines are associated with seasonal allergies and weather changes that can affect the sinuses.

E. Hormones and Migraines

A link between hormones such as estrogens and migraines has also been reported. This is reflected by the increased frequency of migraines during menstruation [6].

F. Sleep and Migraines

Finally, a lack of sleep is another cause of headaches and migraines. This interaction was shown by a study of 50 migraineurs which confirmed previous observations that sleep is a common way of ending the headache phase [7].

3. Headaches and Migraines treatment

Migraines can be debilitating and frustrating. Many people do not know how to treat them. There are many treatments for migraines, but what works for one person may not work for another. Some people find that over-the-counter medications work well (e.g., Ibuprofen or Aspirin), while others need prescription medication.

Some people find that they need to see a neurologist to get help with their migraines. Several alternative treatments can help, including acupuncture and chiropractic care.

4. Frequently Asked Questions About What Causes Headaches and Migraines

What causes headaches and migraines?

Headaches and migraines can be caused by various factors, including stress, tension, dehydration, lack of sleep, hormonal changes, certain foods, environmental factors, and underlying health conditions.

Can weather changes cause headaches and migraines?

Yes, some people are sensitive to changes in weather patterns, such as barometric pressure changes, which can trigger headaches and migraines.

Are headaches and migraines hereditary?

There is evidence to suggest that genetics play a role in predisposing individuals to migraines. If one or both parents have a history of migraines, there’s an increased likelihood of experiencing them.

Can food and drinks trigger headaches and migraines?

Yes, certain foods and drinks, such as aged cheeses, processed meats, caffeine, alcohol, and artificial sweeteners, can trigger headaches and migraines in susceptible individuals.

Can stress cause headaches and migraines?

Yes, stress is a common trigger for both tension headaches and migraines. Managing stress through relaxation techniques, exercise, and mindfulness can help reduce the frequency and severity of headaches.

Are there any specific environmental factors that can trigger headaches and migraines?

Yes, environmental factors such as bright lights, loud noises, strong odors, and changes in altitude or air pressure can trigger headaches and migraines in some people.

Can hormonal changes trigger headaches and migraines?

Yes, hormonal fluctuations, such as those occurring during menstruation, pregnancy, or menopause, can trigger migraines in some individuals.

Are there certain medical conditions that can cause headaches and migraines?

Yes, underlying medical conditions such as high blood pressure, sinus infections, temporomandibular joint (TMJ) disorder, and intracranial abnormalities can cause headaches and migraines.

How can I determine what triggers my headaches and migraines?

Keeping a headache diary can help identify triggers by tracking factors such as food and drink intake, sleep patterns, stress levels, weather changes, and menstrual cycles, along with headache occurrence.

When should I see a doctor about my headaches and migraines?

You should see a doctor if you experience severe or frequent headaches, headaches that worsen over time, headaches accompanied by other symptoms such as vision changes, numbness, weakness, or difficulty speaking, or if your headaches interfere with daily activities despite over-the-counter treatments.

Conclusion

Although some headaches and migraines appear to be due to a hereditary genetic complex familial disorder, most are due to stress and diet that can be individually controllable through a healthy lifestyle.

Other types of headaches and migraines are periodic due to menstruation in women and environmental changes. However, treatment for gallbladder stone disease is required for related headaches and migraines.

References

[1] https://teachmeanatomy.info/head/cranial-nerves/trigeminal-nerve/

[2] Benemei, S., Nicoletti, P., Capone, J.G. and Geppetti, P., 2009. CGRP receptors in the control of pain and inflammation. Current opinion in pharmacology, 9(1), pp.9-14.

[3] Sauro, K.M. and Becker, W.J., 2009. The stress and migraine interaction. Headache: The journal of head and face pain, 49(9), pp.1378-1386.

[4] Finocchi, C. and Sivori, G., 2012. Food as trigger and aggravating factor of migraine. Neurological Sciences, 33(1), pp.77-80.

[5] Chen, C.H., Lin, C.L. and Kao, C.H., 2018. Gallbladder stone disease is associated with an increased risk of migraines. Journal of clinical medicine, 7(11), p.455.

[6] MacGregor, A., 2000. Migraine associated with menstruation. Functional neurology, 15, pp.143-153.

[7] Blau, J.N., 1982. Resolution of migraine attacks: sleep and the recovery phase. Journal of Neurology, Neurosurgery & Psychiatry, 45(3), pp.223-226.

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