27 Questions
Which laboratory measure would be expected to decrease in both primary and secondary hyperthyroidism?
TSH
What is the primary cause of secondary hypothyroidism?
Pituitary disorders
Which of the following is an example of primary hyperthyroidism?
Toxic Multinodular Goitre
What would be expected to increase in primary hypothyroidism?
TSH
Which of the following would be expected to decrease in tertiary hypothyroidism?
TRH
What is the laboratory measure that would differentiate between primary and secondary hyperthyroidism?
TSH
Which of the following is a characteristic of primary hypothyroidism?
Increased TSH
What would be expected to increase in hyperthyroidism?
T3 and T4
Which of the following is an example of secondary hyperthyroidism?
TSH-Secreting Pituitary Adenoma
What is the common characteristic of TSH levels in secondary and tertiary hypothyroidism?
Decreased
What is the effect of decreased LDL receptor expression in hypothyroidism?
Increased LDL levels
Which of the following is NOT an example of primary hyperthyroidism?
TSH-Secreting Pituitary Adenoma
What is the effect of increased T3 and T4 on TSH levels in primary hyperthyroidism?
Inhibition of TSH production
What is the characteristic of T3 and T4 levels in hypothyroidism?
Decreased
What is the cause of secondary hyperthyroidism?
Pituitary gland disorders
What is the effect of hyperthyroidism on cholesterol levels?
Increased total cholesterol levels
What is the characteristic of thyrotropin-releasing hormone (TRH) levels in tertiary hypothyroidism?
Decreased
What is the common characteristic of primary and tertiary hypothyroidism?
Decreased T3 and T4 levels
Which of the following is a characteristic of both primary and secondary hypothyroidism?
Decreased T3 and T4 levels
What would be expected to decrease in response to increased T3 and T4 levels in primary hyperthyroidism?
Thyroid stimulating hormone (TSH) levels
A patient presents with decreased T3 and T4 levels, and increased TSH levels. What is the most likely diagnosis?
Primary hypothyroidism
Which of the following is a characteristic of tertiary hypothyroidism?
Decreased thyrotropin-releasing hormone (TRH) levels
A patient presents with increased T3 and T4 levels, and decreased TSH levels. What is the most likely underlying mechanism?
Feedback mechanism in response to increased T3 and T4 levels
Which of the following would be expected to increase in response to decreased LDL receptor expression?
LDL levels
A patient presents with decreased TSH levels, and increased T3 and T4 levels. What is the most likely diagnosis?
Secondary hyperthyroidism
Which of the following is a characteristic of secondary hypothyroidism?
Decreased TSH levels
What is the most likely underlying cause of secondary hyperthyroidism?
Overstimulation of the pituitary gland by ectopic sources
Study Notes
Hypothyroidism
- Primary hypothyroidism: most common, caused by thyroid disorders, characterized by decreased T3/T4 production and increased thyroid-stimulating hormone (TSH) as a compensatory response.
- Secondary hypothyroidism: caused by pituitary disorders, characterized by decreased T3/T4 and decreased TSH.
- Tertiary hypothyroidism: caused by hypothalamic disorders, characterized by decreased T3/T4, decreased thyrotropin-releasing hormone (TRH), and decreased TSH.
Hypothyroidism Laboratory Measures
- Thyroid-stimulating hormone (TSH): increased in primary hypothyroidism, decreased in secondary and tertiary hypothyroidism.
- T3 and T4: decreased in all types of hypothyroidism.
- Cholesterol: increased LDL (due to decreased LDL receptor expression) in hypothyroidism.
Hyperthyroidism
- Primary hyperthyroidism: condition where the thyroid gland itself produces too much thyroid hormone, examples include toxic multinodular goiter, postpartum thyroiditis, and Graves' disease.
- Secondary hyperthyroidism: condition where excess thyroid hormone production is due to overstimulation by the pituitary gland by ectopic sources, examples include TSH-secreting pituitary adenoma, thyrotropin-releasing hormone (TRH)-producing hypothalamic tumors, and Jod-Basedow phenomenon.
Hyperthyroidism Laboratory Measures
- Thyroid-stimulating hormone (TSH): decreased due to feedback mechanism in response to increased T3 and T4.
- T3 and T4: increased in all types of hyperthyroidism.
- Cholesterol: increased LDL, HDL, and total cholesterol in hyperthyroidism.
Hypothyroidism
- Primary hypothyroidism: most common, caused by thyroid disorders, characterized by decreased T3/T4 production and increased thyroid-stimulating hormone (TSH) as a compensatory response.
- Secondary hypothyroidism: caused by pituitary disorders, characterized by decreased T3/T4 and decreased TSH.
- Tertiary hypothyroidism: caused by hypothalamic disorders, characterized by decreased T3/T4, decreased thyrotropin-releasing hormone (TRH), and decreased TSH.
Hypothyroidism Laboratory Measures
- Thyroid-stimulating hormone (TSH): increased in primary hypothyroidism, decreased in secondary and tertiary hypothyroidism.
- T3 and T4: decreased in all types of hypothyroidism.
- Cholesterol: increased LDL (due to decreased LDL receptor expression) in hypothyroidism.
Hyperthyroidism
- Primary hyperthyroidism: condition where the thyroid gland itself produces too much thyroid hormone, examples include toxic multinodular goiter, postpartum thyroiditis, and Graves' disease.
- Secondary hyperthyroidism: condition where excess thyroid hormone production is due to overstimulation by the pituitary gland by ectopic sources, examples include TSH-secreting pituitary adenoma, thyrotropin-releasing hormone (TRH)-producing hypothalamic tumors, and Jod-Basedow phenomenon.
Hyperthyroidism Laboratory Measures
- Thyroid-stimulating hormone (TSH): decreased due to feedback mechanism in response to increased T3 and T4.
- T3 and T4: increased in all types of hyperthyroidism.
- Cholesterol: increased LDL, HDL, and total cholesterol in hyperthyroidism.
Hypothyroidism
- Primary hypothyroidism: most common, caused by thyroid disorders, characterized by decreased T3/T4 production and increased thyroid-stimulating hormone (TSH) as a compensatory response.
- Secondary hypothyroidism: caused by pituitary disorders, characterized by decreased T3/T4 and decreased TSH.
- Tertiary hypothyroidism: caused by hypothalamic disorders, characterized by decreased T3/T4, decreased thyrotropin-releasing hormone (TRH), and decreased TSH.
Hypothyroidism Laboratory Measures
- Thyroid-stimulating hormone (TSH): increased in primary hypothyroidism, decreased in secondary and tertiary hypothyroidism.
- T3 and T4: decreased in all types of hypothyroidism.
- Cholesterol: increased LDL (due to decreased LDL receptor expression) in hypothyroidism.
Hyperthyroidism
- Primary hyperthyroidism: condition where the thyroid gland itself produces too much thyroid hormone, examples include toxic multinodular goiter, postpartum thyroiditis, and Graves' disease.
- Secondary hyperthyroidism: condition where excess thyroid hormone production is due to overstimulation by the pituitary gland by ectopic sources, examples include TSH-secreting pituitary adenoma, thyrotropin-releasing hormone (TRH)-producing hypothalamic tumors, and Jod-Basedow phenomenon.
Hyperthyroidism Laboratory Measures
- Thyroid-stimulating hormone (TSH): decreased due to feedback mechanism in response to increased T3 and T4.
- T3 and T4: increased in all types of hyperthyroidism.
- Cholesterol: increased LDL, HDL, and total cholesterol in hyperthyroidism.
Understand the differences between primary, secondary, and tertiary hypothyroidism, including their causes and characteristics. Learn about the role of T3, T4, TSH, and TRH in these conditions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
