Hypothalamus-pituitary gland system and disorder

Question 1

The hypothalamus is the …. gland and regulates the ….

Answer 1

the hypothalamus is the master gland and regulates the pituitary

Question 2

Thyroid gland structure

Answer 2

consists of an inner thyroid follicle surrounded by follicular cells and parafollicular cells

Question 3

Regulation of thyroid hormone release

What is the process involved in the release of Thyroid hormone

Answer 3

1) Hypothalamus releases Thyrotropin releasing hormone (tri-peptide) which acts on the anterior pituitary
2) This then releases Thyroid stimulating hormone which acts on the thyroid
3) the thyroid then releases T3 and T4 (thyroid hormone)

Question 4

What are the effects of thyroid hormone?

Answer 4

It is calorigenic (heat producing)
Increases BMR

Increases heart rate and force of contraction

Growth and maturation (essential)

• embryo development
• CNS development
• linear growth (promotes effect of growth hormone)

Question 5

What is a symptom from excessive TSH stimulation of thyroid gland in iodine-deficiency?

Answer 5

Large goitre

Question 6

Hypothyroidism symptoms in adults

Answer 6

weight gain, cold intolerance, lethargy, depression, puffiness of skin and muscle (myxoedema) sluggish reflexes, muscular weakness, reduced cardiac output

Question 7

Hypothyroidism symptoms in fetus and/or child

Answer 7

Cretinism, foetal brain damage (may be irreversible), shortness, obesity, mental retardation

routine neonatal screening

Question 8

What is hashimoto’s thyroiditis?

Symptoms

what is it treated with?

Answer 8

autoimmune damage to gland

Very short stature
delayed skeletal development

Treated with T4 replacement

Question 9

Causes of hypothyroidism?

Answer 9

Primary failure of thyroid gland (e.g autoimmune damage)

Secondary due to hypothalamic or anterior pituitary failure

Secondary due to dietary iodine

Question 10

Treatment of hypothyroidism?

Answer 10

Lifelong replacement therapy of T4 (adult ~150ug/day)