Skip to content

Course home

Sign up

3.2 Coordination and control – the endocrine system

EasyMediumHard
123456
Question 4

Doctors can diagnose subclinical hyperthyroidism by measuring the level of Thyroid Stimulating Hormone (TSH) in a patient's blood.

  • If the TSH level is strictly below 0.40 mU/L0.40\text{ mU/L}0.40 mU/L, this suggests the patient may have hyperthyroidism.
  • A patient has her TSH levels monitored monthly over an eight-month period as shown in the table below:
MonthTSH level (mU/L\text{mU/L}mU/L)
January0.35
February0.42
March0.38
April0.40
May0.31
June0.45
July0.28
August0.39
a.

Calculate the percentage of the monthly readings that are strictly below the threshold of 0.40 mU/L0.40\text{ mU/L}0.40 mU/L.

[2]
b.

Suggest two further steps or laboratory investigations the doctor should take to confirm whether the patient has permanent hyperthyroidism.

[2]
c.

The doctor discusses a treatment option called carbimazole (an antithyroid medication) with the patient, providing her with the following information:

Information about Carbimazole treatment:

  • Benefits: Reduces the synthesis of thyroid hormones to relieve symptoms such as anxiety, palpitations, tremors, and heat intolerance. Reduces long-term risks of heart failure and osteoporosis.
  • Risks/Considerations:
    • Can cause bone marrow suppression (agranulocytosis), which is a life-threatening reduction in white blood cells. Patients must immediately report infections, fevers, or sore throats.
    • Can cause drug-induced liver injury (hepatotoxicity), particularly in individuals with compromised liver function.
    • Associated with an increased risk of congenital malformations (birth defects) if taken during early pregnancy.
    • Requires long-term periodic blood tests to monitor hormone levels, liver function, and full blood counts.

The patient is a 28-year-old female with moderate anxiety and hand tremors who is planning to start a family in the next year. She has a history of mild hepatic impairment from a previous viral infection.

Discuss the factors this specific patient should consider when making her decision about whether to start carbimazole treatment.

[4]
Markscheme

3.2 Coordination and control – the endocrine system Questions

  1. GCSE
  2. /Biology
  3. /3.2 Coordination and control – the endocrine system

23 exam-style questions on OCR GCSE Biology 3.2 Coordination and control – the endocrine system, covering 3.2.1 Principles of hormonal coordination and control, 3.2.2 Roles of thyroxine and adrenaline, 3.2.3 Hormones in human reproduction, 3.2.4 Interactions of reproductive hormones, 3.2.5 Hormones in contraception, 3.2.6 Hormones in reproductive technologies, 3.2.7 Plant hormones in growth and coordination, 3.2.8 Effects of plant hormones, and 3.2.9 Uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank