HORMONES - TYPES, DISEASES

 INTRODUCTION

For a healthy life, both physically and mentally the human body requires secretion of certain hormones for maintaining good health, development and functioning of the body parts. Hormones are necessary for this. There are about 50 hormones secreted from our body. Let us see few or some of them.

WHAT ARE HORMONES?

Hormones are the bearers or carriers, secreted by the organs of the body in to the blood stream. It travels and carries messages via blood stream to different organs and tissues of the body for the proper functioning of the parts.

The term hormone derived from the Greek word ‘hormao’ meaning ‘I excite’. 

If there is any imbalance in secretion of hormones, some of the hormones act slowly i.e., it takes time to affect the body parts whereas some may shows the result of affecting the parts quick. Hormones are responsible for all the functions of the body parts. Some of them are:

• Growth and development
• Metabolism
• Sexual Functions
• Mood
• Reproduction
• Cognitive functions
• Maintenance of body temperatures

There are several types of hormones, which has a specific function on the particular body parts rather than as a whole body. The glands secrete the hormones.

TYPES OF HORMONES

Since there are several hormones secreted by the glands in the human body, they classified in to three types based on their chemical structure. They are :

• AMINO ACID DERIVED HORMONES
• LIPID DERIVED (LIPID-SOLUBLE) HORMONES or STEROID
• PEPTIDES

AMINO ACID DERIVED HORMONES

These are small molecules derived from the amino acids tyrosine and tryptophan. If the hormone is amino acid derived, its chemical name ends in ‘...ine’. E.g.: epinephrine (Adrenal gland), norepinephrine (Adrenal gland), Triiodothyronine (Thyroid gland), Thyroxine (Thyroid gland), Dopamine (located in the mid brain), Melatonin (Pineal gland).

LIPID DERIVED (LIPID-SOLUBLE) HORMONES or STEROID

The steroid hormones are fat-soluble and thus, pass through plasma membranes of cells. The steroid hormones derived from cholesterol.  Its chemical names ends in “-ol” for alcohols or “-one” for ketones. Eg Estradiol, Aldosterone, Estrone, Estriol, Cortisol etc. Steroid hormones are insoluble in water. Proteins in the blood carry these hormones, so they remain in the circulation for a longer time than peptide hormones.

PEPTIDES

Peptide hormones constitutes amino acids ie., the structure of Peptide hormones is like polypeptide chain (chain of amino acids). Peptide hormones are water-soluble and they do not pass through plasma membranes of cells. E.g. antidiuretic hormone and oxytocin (pituitary gland), Insulin (Pancreas).

SIGNALS

The consequences of the hormones rely on how they released from the glands. The cell signals classified as

• AUTOCRINE : The hormone performs or reacts on the cell in which it got secreted.

• PARACRINE : The hormone performs or reacts on the neighbour cells without entering in to the blood circulation.

• INTRACRINE : The hormone performs or reacts intracellular, which means inside the same cell.

• ENDOCRINE : The hormone performs or reacts on the target cells once it released from the respective glands in to the blood stream.

Now let us see some of the hormones secreted by our body. As said before the glands secrete the hormones, the Glands are of two types Exocrine Gland and Endocrine Gland. 

EXOCRINE GLAND

Exocrine glands are glands with openings - duct (passage or a tube). 

This gland secretes the chemicals on the extrinsic surface of the body parts via the ducts.

The  exocrine glands found in the human body are salivary glands, mammary glands, sweat glands, lacrimal glands, sebaceous glands, prostate  glands and mucous.

 SECRETION OF EXOCRINE GLAND ?

• The Serous cells of exocrine ejects proteins.

• The Mucous cells of exocrine ejects mucus.

• The mixed gland of exocrine ejects both proteins and mucus eg Salivary Glands.

• The Sebaceous glands of exocrine ejects sebum. This gland also referred as Oil glands.

ENDOCRINE GLAND

Image : List of hormones found in the endocrine glands on the nervous system

Image Source : Wikimedia Commons

The endocrine system is a major communication system of the body since it links the nervous system and the nervous system controls the endocrine glands. The hormones are a carrier between the nervous system and rest of the organs of the body. This system comprises of glands like Hypothalamus, Pituitary gland, Pineal gland, Thymus Gland, Thyroid Gland, Parathyroid Gland, Adrenal Gland, Pancreas and Gonads.

The hormones secreted by this glands are :

HYPOTHALAMUS - HORMONES

Growth-hormone-releasing hormone (GHRH) : Triggers growth hormone, which released from the anterior pituitary.

Gonadotropin-releasing hormone (GnRH) : Triggers follicle stimulating hormone (FSH) and luteinizing hormone (LH), which released from the anterior pituitary.

PITUITARY GLAND - HORMONES

Growth Hormone (GH) : The different name of GH is  Somatotrophic hormone. GH is a protein hormone it has 190 amino acids. This hormone helps in cell reproduction, cell regeneration and stimulates the growth of bones, muscles and other organs by synthesizing protein.

Disorders:  If there is less secretion of this hormone in child, it affects the child’s growth (pituitary dwarf).

An excess secretion in child leads to tall or gigantic appearance, abnormal growth of bones and soft tissues results in heart problems and sleep apnoea.

Follicle stimulating hormone (FSH) : This hormone in male stimulates sperm production and in female it helps in egg production and maturation.

Disorders : Lack of FSH leads to decrease in libido, irregular menses, erectile dysfunction, and mood changes.

Excess secretion results in infertility and irregular menstruation.

Luteinzing hormone (LH) : LH and FSH works together. In females it helps in ovulation and prepares uterus for pregnancy, in males it triggers the secretion of testosterone.

Disorders: It is same as like FSH. Lack of LH leads to decrease in libido, irregular menses, erectile dysfunction, and mood changes.

Excess secretion results in infertility and irregular menstruation.

Antidiuretic hormone (ADH) : This hormone preserves water content in the body. This hormone helps the tissues to retain as much water as possible. ADH released once the pituitary recognizes that the blood is insufficient of water.

Disorders : Insufficient amounts of ADH results in  excessive water loss in the urine.

PINEAL GLAND - HORMONES

Melatonin : Melatonin regulates our daily sleep cycle. The production of melatonin based on how human eyes affected by light. The presence of light stops the secretion of melatonin whereas in the absence of light (during night) produces more melatonin. This helps in sleep.This hormone helps in the development and functions of ovaries and testes.

THYMUS GLAND - HORMONES

Thymosin  :  Thymosin helps in the development of immune system i.e. development of T-cells.

THYROID GLAND - HORMONES

• T3 : Tri-iodothyronine

• T4 : Thyroxine (tetraiodothyronine)

T3 and T4 hormone controls the rate of metabolism of carbohydrates, fats, and proteins in the body. These hormones are crucial for the betterment of the normal growth and metabolism. Thyroxine controls size of the body. Both the hormones have iodine. About 95 percent of the thyroid gland is thyroxine, and remaining 5 percent is Tri-iodothyronine. 

Disorders : The disorders or diseases occurs at any age group because of injury, dietary deficiency, abnormal thyroid growth, levels of secretion (hypo or hyper), thyroid cancer, nodules within the thyroid.

PARATHYROID GLAND - HORMONES

Parathyroid hormone (PTH) or parathormone : This hormone regulates the calcium and phosphorous levels in the blood. PTH stimulates the breakdown of bones i.e. releasing of calcium from the bones. PTH increases the reabsorption of calcium from the food. PTH retains the calcium from the kidneys. PTH orders the kidneys to transform the inactive Vitamin D in to the active form.  PTH decreases the phosphate levels in the blood serum. The balance of calcium level in the blood makes the heart, kidneys, nervous system and bones to function properly else, it leads to diseases.

Disorders : The disorders or diseases are hyperparathyroidism, hypoparathyroidism, Osteoporosis.

ADRENAL GLANDS - HORMONES

Aldosterone : Aldosterone helps in the retention of sodium and the excretion of potassium. Lack of aldosterone is made when the body is under stress. Its symptoms vary from fatigue to dizziness and chronic nausea, low blood pressure and low salt levels.

 

Cortisol (Hydrocortisone) : This hormone responds during physical, psychological stress and when the bodies’ sugar level drops down. This also regulates conversion of fats, proteins, and carbohydrates to energy. Cortisol balances blood pressure and cardiovascular function.

Disorders : If cortisol secreted more than the requirement it causes ulcer, blood pressure, anxiety, increase of cholesterol. Similarly, a low level causes alcoholism, chronic fatigue syndrome. It also subdues immune system and bone formation.

 

Androgens : The adrenal cortex releases small amounts of male and female sex hormones. The changes occur once the puberty starts. The changes might be pubic hair growth, Adam’s apple formation, muscle and hair growth.

Epinephrine : This hormone also referred as adrenaline. It controls blood sugar level by transforming glycogen to glucose in the liver. This hormone responds quickly by increasing the heartbeat, rushes blood into the muscles and brain. It affects both alpha and beta receptors in the nervous system.

Norepinephrine : This hormone also referred as noradrenaline. This hormone works along with epinephrine. This hormone can cause narrowing of blood vessels (vasoconstriction) resulting in high blood pressure. This affects only the alpha-receptors of the nervous system.

  

PANCREAS - HORMONES

Gastrin : This hormone helps in digestion by triggering certain cells to produce acid in the stomach.

Glucagon : This hormone stimulates the liver to convert glucagon to glucose thus increasing the blood glucose level in the body.

Insulin : The role of insulin is to make the body tissue cells to absorb the glucose from carbohydrates that are present in the food and use it as energy or it stores the glucose for future. Insulin drops the glucose level in the body.

Somatostatin : The role of this hormone is to balance the sugar and salt level in the body when insulin and glucagon level varies.

Vasoactive intestinal peptide (VIP) : The role of this hormone is to trigger the intestinal cells to release water and salt in to the intestine when required by the body.

Disorders : The disorders or diseases are the most common Diabetes (Type 1, Type 2).

GONADS - HORMONES
Testosterone : This hormone is present only in the male human beings. This hormone is responsible for controlling the development of male sex organ and characteristics of male like change in voice, growth of muscles, moustache, body hair and beard.

Disorders : The disorders or diseases is Hypogonadism lack of Testosterone secretion. This results in weakness of bones, infertility, and loss of body hair. The mild form affects the testicles and the severe form affects the pituitary gland, which in turn affects the secretion of Testosterone.

(O)Estrogen : This hormone is responsible for growth of reproductive organs and female characteristics like voice, soft skin, mammary glands, reproduction, menstruation, menopause etc. This hormone alerts the pituitary gland to release oxytocin (for contraction of uterine) during the end of pregnancy period.

Progesterone : Corpus luteum a temporary gland secretes this hormone once the egg reaches fallopian tube.  The role of this hormone is to prepare the body for pregnancy by preventing the contraction of uterine, which may disturb the nourishing embryo, preparing the breasts for lactation. This helps in proper menstrual cycle and pregnancy.

Disorders : The disorders or diseases are Osteoporosis, Ovarian Cancer, Ovarinan Cysts.

CONCLUSION

Hormones are essential factor of life. They play a vital role for proper functioning and development of the body. It is one’s personal responsibility to keep the secretion of hormone in balanced level by consuming right food at right time since there are many factors, which affects the health of one’s life like environment, junk foods, job stress, gadgets etc. Therefore, it is self-responsibility to maintain the body healthy.