Thyroid gland functions

In this blog, I will give you information about thyroid gland functions. Once you understand functions than you don’t need to mug up topics like hyperthyroid or hypothyroid. So, understand normal functioning of thyroid gland is very important.

Thyroid gland controls our whole body. There are 18 functions of thyroid gland. We learn in specific manner so you can remember and understand better.

• Thyroid hormones acts on below nutrition
  Protein, vitamin, fat, carbohydrate

• Thyroid hormones acts on below body system & associated to body system
  Central nervous system, cardio vascular system, respiratory system, gastrointestinal system, sexual, Blood, skeleton muscle, sleep, plasma and liver fats

• Thyroid gland also acts on
  Body temperature,body weight,body growth,our Besal metabolic rate(BMR)

This way if you remember points that it will easier.Now we take points of thyroid gland functions one by one.

1. ACTION ON PROTEIN METABOLISM

Thyroid hormone increases the protein synthesis in our body cells.

2. ACTION ON VITAMIN METABOLISM

Thyroid hormone(thyroxine) increases formation of many enzyme and vitamin is essential part of enzyme. So,while making enzymes vitamins are normally used.

Do your reasoning, what happen if thyroid hormone secretion increases. Simply it utilise more vitamins & cause vitamin deficiency.

3. ACTION ON FAT METABOLISM

Thyroxine decreases fat storage in our body. It move the fats from fat depots and convert into fatty acid in our blood.

Make your logic here if thyroxine increase than it removes more fat causes weight loss and if thyroxine decreases than it can not remove fat causes weight gain.

4. ACTION ON CARBOHYDRATE

Thyroid hormone stimulates almost all processes involved in the metabolism of carbohydrate.

• It increases absorption of glucose from GI  tract
• It enhance glucose uptake by cells.
• Also increase the breakdown of glycogen into glucose
• It accelerates gluconeogenesis

5. ACTION ON CENTRAL NERVOUS SYSTEM
   

   

   This hormone is needed to do normal functioning of central nervous system.

This hormone promote growth during fetal life and first few years of postnatal life. So,if this hormone is not in sufficient quantity in infant than it may cause mental retardation to them.

Thyroxine is a stimulating factor for brain. So,brain need this hormone for normal functioning.If this hormone increases, it stimulate brain more and causes anxiety,worries or paranoid thoughts. If it decreases it may cause lethargy and excess sleep.

6. ACTION ON CARDIOVASCULAR SYSTEM
   

   

Thyroxine increases the overall activity of cardiovascular system.

Heart rate
Normally it maintains the heart rate.In hyperthyroidism heart rate increases called tachycardia and in hypothyroidism heart rate decreased called bradycardia.

Contraction of heart
This hormone increases the force of contraction of the heart. If hormone level increases than it causes more contraction to heart leads to weak heart. So, patient may die due to cardiac decompensation. Cardiac decompensation means failure of the heart to maintain adequate circulation associated with dyspnea,venous engorgement and oedema.

On arterial blood pressure
Thyroxine increases heart rate and force of contraction of the heart. This way it increases blood pressure. This is necessary for our body.

7. ACTION ON RESPIRATION 

Thyroxine increases the rate and force of respiration indirectly.

8. ACTION ON GASTROINTESTINAL TRACT
   

   

   Here you will get answer why thyroid patient suffering from diarrhoea or constipation. Generally, thyroxine increases food intake and also increases secretion and movement of GI tract.

So, hypersecretion of hormone causes more movement of intestine and causes diarrhoea. Similarly, hyposecretion of hormone causes less movement of intestine and causes constipation.

9. ACTION ON SEXUAL FUNCTION

For normal sexual function, normal thyroid hormone level is necessary. If it increases or decreases it may create problems.

In men
If hormone level increases it may cause impotence.
If hormone level decreases there is no question of sexual desire. Person lost his sexual drive.

In women
if hormone increases it may cause less menses or complete stopaage of menses.
If hormone level decreases it may cause more menses called menorrhagia and polymenorrhea.

10. ACTION ON BLOOD
    

    

    Thyroxine increases erythropoietic activity and increases blood volume. This way this hormone helps to make blood.

You can check your reasoning that what happen if this hormone increases. Simply it make more blood cells, this disease condition called polycythemia.

11. ACTION ON SKELETON MUSCLE

Thyroid hormone is necessary for normal activity of skeleton muscles.

If this hormone increases than muscle works vigorously but along with that more protein breakdown occur due to increasing hormone level. So, finally muscle become weak, it’s called thyrotoxic myopathy. Also hypersecretion causes fine muscular tremor.Tremor occurs at the frequency of 10 to 15 times per second. It is very characteristic point to diagnose hyperthyroidism.

If thyroid hormone level decreases than it makes the muscle more sluggish.

12. SLEEP
    

    

    For normal sleep, normal hormonal level is necessary.

If hormonal level increases than it causes more stimulation to muscle and brain. So, person feels tired and sleepy.He is sleepy but can not sleep because continuos stimulation to brain.

13. ACTION ON PLASMA AND LIVER FATS

Normally thyroxine decreases cholesterol, triglyceride,phospholipids level in plasma. So,logically you can think that what happen if thyroxine is not sufficient, obviously cholesterol increases in plasma causes artherosclerosis.

Thyroxine also increases liver fat, leading to fatty liver.

14. BODY TEMPERATURE
    

    

    Thyroid hormone metabolite nutrition like protein,fat,vitamin,carbohydrate and produces heat by that.            

If this hormone increases than it produces more and more heat, which patient feels as a mild fever and sweating. This all are important points in diagnosis of thyroid disease.

Similarly if hormonal level decreases, than less heat produce and patient feels cold and clammy skin.

15. BODY WEIGHT
    

    

    This is characteristic point for thyroid disease. Because if anyone have unexpected weight loss or weight gain than we must look at thyroid disease once.

This hormone maintains body weight. If hormonal level increases which causes fat loss as mention in point no.3,  by fat loss patient’s weight loss drastically. You can not believe weight loss down 4-5kg within few days.

Similarly if hormonal level decreases that causes more fat storage leads to weight gain drastically. This way weight loss or gain is important point in diagnosis of thyroid disease.

16. BODY GROWTH

For our body growth we need normal thyroid hormone level.If changes occurs to that will causes problem.

If hormonal level increases than it accelerates the growth of the body, especially in growing children.

If hormonal level decreases arrest the growth. It causes early closure of epiphysis.So, the height of the individual may be slightly less in hypothyroid.

17. ACTION ON BASAL METABOLIC RATE

Thyroxine increases the metabolic activities in most of the body tissue, except brain,ratina,spleen,testes and lungs. It increases BMR by increasing the oxygen consumption of the tissues.

If hormone secretion increases than BMR increases by 60% to 100%. If hormonal level decreases than BMR falls 20% to 40% below the normal level.

These are the points where normally thyroid gland acts. Slightly changes to their function either hyposecretion or hypersecretion of thyroid hormone will give rise to hypothyroidism or hyperthyroidism.

It will be easier to understand thyroid disease, once you understand normal thyroid gland functions. Hope this article is helpful to you.To watch video, click below link.