Thyroid

Question 1

What does the Thyroid Gland produce?

Answer 1

Thyroid hormones T3 and T4, also Calcitonin

Question 2

Describe the structure of the thyroid gland.

Answer 2

• dense connective tissue capsule - follicules surrounded by single layer of secretory follicular cells on basement membrane - cell free follicle that store thyroid hormone - parafollicular cells that store calcitonin

Question 3

What does Calcitonin do?

Answer 3

Acts on bone by increasing osteoblast activity; increases Calcium storage but decreases Calcium serum levels.

Question 4

Who produces Calcitonin?

Answer 4

parafollicular cells / “C” cells

Question 5

Identify A and B

Answer 5

A = Thyroid glandB = Parathyroid gland

Question 6

Answer 6

A = calcitonin

Question 7

Answer 7

Thyroid

Question 8

Answer 8

Question 9

What do Follicular cells produce?

Answer 9

Thyroglobulin, it is iodinated and stored within the follicles.

In response to TSH, the thyroglobulin is endocytosed, processed into T3 and T4 and secreted into the blood. T3 and T4 are important regulators of metabolic activity.

Question 10

What do parafollicular cells do?

Answer 10

Make calcitonin (thyrocalcitonin), a peptide hormone that inhibits bone resorption by osteoclasts, thereby lowering calcium concentrations in blood.

Question 11

identify

Answer 11

Question 12

How is Thyroid hormone produced?

Answer 12

1. Iodine pump transports and concentrates iodide into colloid
2. & 3. Epithelial cells secrete thyroglobulin and thyroid peroxidase into colloid
3. Thyroglobulin becomes iodinated after thyroid peroxidase converts iodide to iodine
4. Proteolysis of iodothyroglobulin after uptake of colloid droplets and fusion with lysosomes
5. Release of thyroid hormones triiodotyrosine (T3) and thyroxine (T4) into the circulation

Question 13

Identify the structure

Answer 13

Question 14

Describe the function of thyronines

Answer 14

1. increase the basal metabolic rate
2. affect protein synthesis
3. help regulate long bone growth
4. neuronal maturation
5. increase the body’s sensitivity to catecholamines.
6. essential for proper development and differentiation of all cells of the human body.
7. Thyroid hormone stimulates heat generation.

Question 15

What are the thyroid hormones?

Answer 15

The thyroid hormones (thyronines) are:

• thyroxine (T4)
• triiodothyronine (T3)

Question 16

What is needed to produce the thyroid hormones?

Answer 16

They are produced using iodine

Question 17

What is thyroid hormone T4 converted to?

Answer 17

T4 is converted to T3 by deiodinases and further processed by decarboxylation and deionidation to produce T1a (iodothyronamine) and thyronamine (T0a).

Question 18

Describe the function of calcitonin

Answer 18

Parafollicular (C) cells secrete calcitonin which binds to receptors on osteoclast and inhibits bone resorption.

Question 19

What are Hyperthyroidism symptoms?

Answer 19

Symptoms:

• nervousness
• irritability
• increased perspiration
• heart racing
• hand tremors
• anxiety
• difficulty sleeping
• muscular weakness (main-upper arms)

Question 20

Why does Hyperthyroidism occur?

Answer 20

Excess thyroid hormones overstimulate metabolism and enhance the effect of the sympathetic nervous system, causing “speeding up” of various body systems and symptoms resembling an overdose of epinephrine (adrenaline).

Question 21

What is Graves Disease?

Answer 21

• It’s the most common form of hyperthyroidism.

Question 22

What is this disease?

Answer 22

Graves Disease

Question 23

What is Hypothyroidism?

Answer 23

• is a Iodine deficiency
• In the US the most common cause is Hashimoto’s thyroiditis.
• B cells produce autoantibodies against thyroid antigens

Question 24

What is this disease?

Answer 24

Hashimoto’s Thyroiditis

Question 25

What is this disease?

Answer 25

Graves Disease/hyperthyroidism

Question 26

What happens in Hyperthryoidism?

Answer 26

There is an overproduction of thyroid hormone causes overstimulation of the metabolism and enhacing sympathetic nervous system

Question 27

What causes Grave's Disease?

Answer 27

- It's caused by autoantibodies binding and stimulating the TSH receptor

Question 28

What other disease accompanies Grave's Disease?

Answer 28

- usually is accompanied with myasthenia gravis

Question 29

What are the symptoms of Graves Disease?

Answer 29

- symptoms: eyes may look enlarged because the eye muscles swell and push the eye forward and swelling of the front of the neck from an enlarged thyroid gland (goiter)

Question 30

What is the most common form of Hypothyroidism?

Answer 30

Hashimoto’s thyroiditis.

Question 31

What happens in Hashimoto's thyroiditis?

Answer 31

B cells produce autoantibodies against thyroid antigens

Question 32

What is this disease?

Answer 32

Grave's Disease