Thyroid

Question 1

Location and structure of thyroid

Answer 1

sits anterior to the Trachea and inferior to the Thyroid cartilage

• “butterfly-shaped” gland
• 2 lobes joined by isthmus
• deep red in color due to being vascular
• consists of clusters of follicles

Question 2

Cells of thyroid

Answer 2

• Follicular cells produce thyroid hormones: T3 and T4

- c-cells produce calcitonin

Question 3

Tri-iodothyronine (T3) has how many iodine

Answer 3

3 iodine atoms

Question 4

Thyroxine (T4) has how many iodine

Answer 4

4 iodine atoms

Question 5

Calcitonin

Answer 5

reduces calcium plasma concentration by inhibiting osteoclast activity and stimulating osteoblasts to deposit calcium in bone( takes Ca out of blood plasma therefore reducing blood plasma concentration

Question 6

Functions of T3 and T4

Answer 6

Target cells are most body cells

• increase BMR (basel metabolic rate), increasing cell O2 uptake and heat production (maintains body temp and adapts to cold)
• regulates cellular metabolism- necessary for normal body growth and dev. (Especially children) of bones, muscles, and tissues of NS

Question 7

Goitre

Answer 7

Enlargement of thyroid gland due to insufficient thyroid hormone production

Endemic (colloid ) goitre – occurs when there is inadequate intake of dietary iodine

Treatment – administer iodine (iodised salt is effective prophylactic)

Question 8

what does hypothyroidism in an infant do

Answer 8

Cretinism (inadequate skeletal and nervous system development: mental deficiency, growth retarded and delayed puberty)

Question 9

what does hypothyroidism in an adult do

Answer 9

Myxoedema:
Common in elderly
Lethargic, low body temperature, cold intolerant
Swelling of hands and face
Dry, thickened skin
Hair  loss
Constipation, heavy prolonged menstrual bleeds
Mental sluggishness

Question 10

Hashimoto’s thyroiditis

Answer 10

Autoimmune thyroiditis
Most common cause of hypothyroidism
Common in women
Treatment – Levothyroxine (T4)

Question 11

Therapeutic hypothyroidism

Answer 11

• Result from radioactive iodine therapy

- Surgery for hyperthyroidism or goitre

Question 12

what is hyperthyroidism and symptoms

Answer 12

-Occurs when excess thyroid hormone is produced (overactive thyroid gland)

Symptoms:
Metabolic rate increases
Skin flushed and sweaty
elevated BP, HR 
Restless, excitable, mood swings
Hyper-defaecation
Limited energy, experience fatigue
Polyphagia, but weight loss due to increased metabolic activity
Stare and protruding eyes (exophthalmos) – muppet eyeballs

Question 13

What is Graves Disease

Answer 13

Most common form of hyperthyroidism

1 in 100 women, 1 in 500 men

Often recognised by exophthalmos

Look like Muppets

Treatment – drug Tx, radioactive iodine, surgery to remove thyroid (but then develop hypothyroidism as no thyroid gland making thyroid hormones, so have to take levothyroxine)