1. The Thyroid & Parathyroid Gland
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2. Overview of the Thyroid & Parathyroid Gland
The thyroid gland is located at the base of the neck.
It’s purpose is the release of the hormone thyroxin.
It also releases calcitonin.
The thyroid gland four smaller glands on the posterior side known as the parathyroid glands.
Their purpose is the release of the hormone parathormone.

3. Draw and label a picture of the thyroid gland from a posterior view:
Label the following:
Thyroid gland
Parathyroid gland
Trachea
Larynx

4. The Thyroid Gland

5. The Thyroid Gland
Releases the hormone calcitonin, which lowers calcium in blood.
Causes it to store in bones.

6. The Thyroid Gland Releases the hormone thyroxin.
Thyroxin causes an increase in metabolism.
Mechanism: Thyroxin causes cells to increase production of enzymes.
Thyroxin’s release is regulated by the hormone TSH. (recall?)

8. What happens if one gets too little thyroxin?

9. The Thyroid Gland Disorders of the thyroid gland:
Low levels of thyroxin = hypothyroidism.
If one gets too little thyroxin during development = cretinism.
Greek, “stupid”.

11. A form of hypothyroidism
Cretinism:
A form of hypothyroidism

12. Cretinism
After thyroxin treatment…

13. Cretinism
After thyroxin treatment…

14. The Thyroid Gland Disorders of the thyroid gland:
If one gets too little thyroxin after childhood: myxedema.
Greek, “Dry, cold skin”.
Causes low mental function, weight gain, dry skin.
After thyroxin treatment…

15. Myxedema: Hypothyroidism in elderly people

16. Hypothyroidism is a reduced output of thyroxin from thyroid:
This causes a rapid reduction in metabolism, leading to:
Weight gain
Sluggishness
Slower brain function/ loss of intelligence

17. Hypothyroidism
If young…
If old…
Cretinism
Myxedema

18. What happens if one gets too much thyroxin?

19. The Thyroid Gland Disorders of the thyroid gland:
High levels of thyroxin: Hyperthyroidism.
A common form is: Graves Disease.

20. Graves Disease: A form of Hyperthyroidism

21. After treatment to reduce thyroxin levels”
Grave’s Disease:
A form of hyperthyroidism
After treatment to reduce thyroxin levels”
Normal

22. Hypothyroidism Hyperthyroidism Cretinism Myxedema Grave’s Disease
Too little thyroxin…
Too much thyroxin…
Hypothyroidism
Hyperthyroidism
Cretinism
Myxedema
Grave’s Disease

23. Other disorders of the thyroid gland

24. The Thyroid Gland Disorders of the thyroid gland:
The thyroid gland requires iodine to manufacture thyroxin.
If too little iodine in diet: Goiter.

26. Goiter: Having too little iodine in diet

29. The Parathyroid Gland

30. The Parathyroid Gland
Releases the hormone parathormone, which increases calcium in the blood.
Releases calcium from bones.
Why is important?
Because we need calcium for nerve to function and cannot have too much calcium in bones.

31. Why do we need parathormone to lower calcium in bones?

32. Why do we need parathormone to lower calcium in bones?

33. Why do we need parathormone to lower calcium in bones?
Roy Lee “Rocky” Dennis

34. Review of Thyroid & Parathyroid Hormones
Thyroid Gland
Thyroxin
Increases metabolism of cells by causing an increase in enzyme production & activity.
Calcitonin
Lowers calcium in blood by storing it in bones.
Parathyroid Gland
Parathormone
Raises calcium in blood by removing it from bones.
(Posterior)