Endocrine System

Question 1

1) describe how hormones are transported, how they act on cells and how hormone secretion is controlled

Answer 1

The endocrine system is a collection of glands located throughout the body
Hormones are chemical signals produced in endocrine glands or tissues that travel in the bloodstream to cause an effect on other tissues

Question 2

2) understand common conditions related to the endocrine system (1): Cushing’s syndrome

Answer 2

Caused by chronic excessive exposure to cortisol, either due to prescribed glucocorticoids (more common) or endogenous causes (less common).

Endogenous:
benign pituitary adenoma (cushing’s disease)
Excess cortisol produced by adrenal tumour (adrenal cushing’s)
Non pituitary-adrenal tumours producing ACTH e.g. small cell lung cancer

Signs and symptoms:
Plethoras moon-shaped face
Hump on the back of the neck
Abdominal obesity
Purple striae
Actuate weight gain
Hyperglycaemia
Hypertension

Question 3

2) understand common conditions related to the endocrine system- Addison’s disease (2)

Answer 3

Caused by chronic adrenal insufficiency
Previously main cause was a complication of tuberculosis, now most common cause is destructive atrophy from autoimmune response
Affected more women than men

Signs and symptoms:
Postural hypotension
Lethargy
Weight loss
Anorexia
Increased skin pigmentation
Hypoglycaemia

Question 4

2) understand common conditions related to the endocrine system- disorders of the thyroid glands (3)

Answer 4

Hypothyroidism (under active thyroid): not enough T4 is produced for the body’s needs.

Signs/ symptoms:
Dry hair
Puffy face
Goiter (enlargement of the thyroid gland)
Slow heartbeat
Weight gain
Constipation
Possible infertility

Hyperthyroidism (overactive thyroid): too much T4 is produced for the body’s needs.

Signs/symptoms:
Hair loss
Bulging eyes
Goiter
Rapid heartbeat
Weight loss
Diarrhoea
Irregular menstrual periods

Question 5

2) understands common conditions related to the endocrine system: Hashimoto’s disease (4)

Answer 5

Autoimmune disease resulting in destruction of thyroid follicles. Leads to hypothyroidism,
Most common disease of the thyroid gland
5 times more common in women than in men
Goitre might be present

Plasma: low T3, low T4, elevated TSH

Treatment : oral thyroid hormone

Question 6

2) understand common conditions related to the endocrine system: grave’s disease (5)

Answer 6

Autoimmune disease resulting in hyperthyroidism
Caused by production of thyroid stimulating immunoglobulin (TSI)
TSI continuously stimulates thyroid hormone secretion
Outside of normal negative feedback control

Signs/symptoms:
Increase in BMR
Excessive sweating
Decrease in body weight
Muscle weakness
Heart palpitations
Some may have bulging eyes