1. The document discusses thyroid hormones, the thyroid gland, and thyroid disease. It describes how the thyroid gland produces thyroid hormones like T3 and T4 which regulate metabolism. 2. Symptoms of thyroid disease include changes in heart rate, weight, and mood. Hypothyroidism is caused by insufficient hormone production while hyperthyroidism is caused by excessive hormones. 3. Thyroid disease is diagnosed through blood tests measuring TSH, T3, and T4 levels. Treatment for hypothyroidism involves thyroid hormone replacement medication while hyperthyroidism may be treated with anti-thyroid drugs, radioactive iodine, surgery, or beta blockers.

1. KUVEMPU UNIVERSITY
SAHYADRI SCEINCE COLLAGE
DEPARTMENT OF BIOTECHNOLOGY
Seminar topic: Thyroid hormones
Guide:
Syeda Misba Fathima
Dept.of Biotechnology
Sahyadri science college
Shivamogga
By
Vikas T N
1st Msc 1st semester
Sahyadri science college
Shivamogga

2. Contents
1. Hormones
2. Glands and its types
3. Thyroid gland in cellular level
4. Thyroid hormone production
5. Action of thyroid hormones on cell
Heart
Skin
CNS
G.I
Muscle
6. Normal concentration of Hormones
7. Diseases
8. Diagnosis
9. Treatment
10. Conclusion
11. Reference

3. Hormones and Glands
A regulatory substance produced in an organism and transported in
tissue fluids such as blood or sap to stimulate specific cells or tissues into
action
An organ in the human or animal body which secretes particular
chemical substances for use in the body or for discharge into the
surroundings
Endocrine glands
These are ductless glands (no tube to carry to various parts).
Their secretions are directly released into the blood which carries
them to various parts of the body.
Exocrine glands
The exocrine glands have ducts.
The secretions from these glands are carried through the ducts.
The ducts may open outside the body to release the secretions
(e.g.sweat, milk) or may be released on to another surface within the
body (e.g. Digestive juices)

5. Thyroid gland
The thyroid gland is by far the largest gland in the neck. It is shaped
in the form of a butterfly, and it contains two lobes (one on each side
of the neck). The entire structure is about two inches long, lying just
below the Adam’s apple.
Glands come in endocrine and exocrine varieties. Since the
thyroid gland functions by releasing hormones directly into the
bloodstream, it is considered a key part of our endocrine system The
thyroid gland works primarily by absorbing iodine from our diets and
then using it to make thyroid hormones thyroxine (T4) and
triiodothyronine (T3). The thyroid gland is able to store these
hormones for later use, as they will be released as needed. These
hormones are then able to navigate through the entire body via the
bloodstream in order to reach their target cells.

7. Thyroid gland in cellular level and mechanisum of action

9. Thyroid hormone structure

10. Mechanism of action of thyroid hormone on cell

11. Normal concentration of TSH , TRH, Thyroid hormone and
Iodine
Thyroid-stimulating hormone (TSH) is produced in the pituitary gland and regulates the
balance of thyroid hormones –- including T4 and T3 -- in the bloodstream. This is usually the
first test your provider will do to check for thyroid hormone imbalance. Most of the time, thyroid
hormone deficiency (hypothyroidism) is associated with an elevated TSH level, while thyroid
hormone excess (hyperthyroidism) is associated with a low TSH level. If TSH is abnormal,
measurement of thyroid hormones directly, including thyroxine (T4) and triiodothyronine (T3)
may be done to further evaluate the problem. Normal test range for an adult: 0.40 - 4.50
mIU/mL (milli-international units per liter of blood).
T4: thyroxine tests for hypothyroidism and hyperthyroidism, and used to monitor treatment of
thyroid disorders. Low T4 is seen with hypothyroidism, whereas high T4 levels may indicate
hyperthyroidism. Normal range for an adult: 5.0 – 11.0 ug/dL (micrograms per deciliter of
blood).
FT4: Free T4 or free thyroxin is a method of measuring T4 that eliminates the effect of
proteins that naturally bind T4 and may prevent accurate measurement. Normal test range for
an adult: 0.9 - 1.7 ng/dL (nanograms per deciliter of blood)
T3: triiodothyronine tests help diagnose hyperthyroidism or to show the severity of
hyperthyroidism. Low T3 levels can be observed in hypothyroidism, but more often this test is
useful in the diagnosis and management of hyperthyroidism, where T3 levels are elevated.
Normal range: 100 - 200 ng/dL (nanograms per deciliter of blood).
FT3: Free T3 or free triiodothyronine is a method of measuring T3 that eliminates the effect
of proteins that naturally bind T3 and may prevent accurate measurement. Normal range: 2.3 -
4.1 pg/mL (picograms per milliliter of blood

13. Iodine is mostly concentrated in thyroid gland. A healthy adult body contains
15-20 mg of iodine, 70-80% of which is stored in the thyroid gland. Daily
intake of iodine by an individual amounts to 500 micrograms; daily
physiological requirement during adult life is 150 micrograms; during
pregnancy and lactation period is 200 micrograms; and during neonatal
period is 40 micrograms. Normally about 120 micrograms of iodide are taken
up by the thyroid gland for the synthesis of thyroid hormones

14. HYPOTHYRODISUM AND HYPERTHYRODISUM
Causes
The most common cause of hypothyroidism is Hashimoto's thyroiditis.
"Thyroiditis" is an inflammation of the thyroid gland. Hashimoto's
thyroiditis is an autoimmune disorder. With Hashimoto’s, your body
produces antibodies that attack and destroy the thyroid gland. Thyroiditis
may also be caused by a viral infection.
Other causes of hypothyroidism include:
Radiation therapy to the neck area. Treating certain cancers, such as
lymphoma, requires radiation to the neck. Radiation damages the cells in
the thyroid. This makes it more difficult for the gland to produce
hormones.
Radioactive iodine treatment. This treatment is commonly prescribed to
people who have an overactive thyroid gland, a condition known
as hyperthyroidism. However, radiation destroys the cells in the thyroid
gland. This usually leads to hypothyroidism.
.

15. Use of certain medications. Certain medicines to treat heart problems,
psychiatric conditions, and cancer can sometimes affect the production of
thyroid hormone. These include amiodarone (Cordarone, Pacerone),
interferon alpha, and interleukin-2.
Thyroid surgery. Surgery to remove the thyroid will lead to hypothyroidism.
If only part of the thyroid is removed, the remaining gland may still be able to
produce enough hormone for the body's needs.
Too little iodine in the diet. The thyroid needs iodine to produce thyroid
hormone. Your body doesn't make iodine, so you need to get it through your
diet. Iodized table salt is rich in iodine. Other food sources of iodine include
shellfish, saltwater fish, eggs, dairy products, and seaweed. Iodine
deficiency is rare in the U.S.
Problems with the thyroid at birth. Some babies may be born with a
thyroid gland that did not develop correctly or does not work properly. This
type of hypothyroidism is called congenital hypothyroidism. Most hospitals in
the U.S. screen babies at birth for this disease.
Pituitary gland damage or disorder.
Disorder of the hypothalamus

17. Symptoms

18. Diagnosis
Sometimes, thyroid disease can be difficult to diagnose because the symptoms
are easily confused with those of other conditions. You may experience similar
symptoms when you are pregnant or aging and you would when developing a
thyroid disease. Fortunately, there are tests that can help determine if your
symptoms are being caused by a thyroid issue. These tests include:
Blood tests.
Imaging tests.
Physical exams.

19. Treatment
If you have high levels of thyroid hormones (hyperthyroidism),
treatment options can include:
Anti-thyroid drugs (methimazole and propylthioracil): These are
medications that stop your thyroid from making hormones.
Radioactive iodine: This treatment damages the cells of your thyroid,
preventing it from making high levels of thyroid hormones.
Beta blockers: These medications don’t change the amount of
hormones in your body, but they help control your symptoms.
Surgery: A more permanent form of treatment, your healthcare
provider may surgically remove your thyroid (thyroidectomy). This will
stop it from creating hormones. However, you will need to take thyroid
replacement hormones for the rest of your life.
If you have low levels of thyroid hormones (hypothyroidism),
the main treatment option is:
Thyroid replacement medication: This drug is a synthetic (man-made)
way to add thyroid hormones back into your body. One drug that’s
commonly used is called levothyroxine. By using a medication, you can
control thyroid disease and live a normal life.

20. Conclusion

21. Reference
• Lafranchi, Stephen H, et al. “Follow-up of Newborns with Elevated
Screening T4 Concentrations.” The Journal of Pediatrics, vol. 143
• Olateju, Tolulope O, and Mark P J Vanderpump. “Thyroid Hormone
Resistance.” Annals of Clinical Biochemistry, vol.5
• Sarada Subramanyan, K. Madhavan, Textbook of human physiology,
page no 486-496, S Chand and company -new delhi
• https://www.hormone.org/your-health-and-hormones/glands-and-
hormones-a-to-z/hormones/thyroid-hormones
• https://www.webmd.com/women/understanding-thyroid-problems-
treatment