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Reproductive & Endocrine Systems — Step 1 practice questions
286 questions in this area, with an explanation for every answer choice.
Three samples below, free and without an account.
How this shows up on Step 1
Endocrine questions are built on feedback loops. A hormone panel with one value out of place is the standard format, and the work is deciding whether the lesion is primary, secondary or tertiary. Reproductive questions blend embryology with pathology, and menstrual-cycle physiology underlies far more of them than the vignettes let on.
Sample questions
Sample question 1
A 22-year-old woman has goiter, tachycardia, and elevated free T4 and T3, but her TSH is INAPPROPRIATELY normal rather than suppressed. There is no evidence of a pituitary mass and her father has similar laboratory findings. Which of the following best explains these results?
Explanations
A. Graves disease with thyroid-stimulating immunoglobulins
Graves disease suppresses TSH profoundly.
B. Iodine-induced hyperthyroidism
Iodine-induced hyperthyroidism (Jod-Basedow) likewise suppresses TSH.
C. Subacute thyroiditis with hormone leak
Thyroiditis suppresses TSH and shows low radioiodine uptake with a painful gland.
D. Factitious thyroid hormone ingestion
Exogenous hormone also suppresses TSH, and causes a SMALL thyroid with low thyroglobulin.
E. A mutation in the thyroid hormone receptor beta gene causing tissue resistance to thyroid hormone · correct
Resistance to thyroid hormone (usually a dominant THRB mutation) blunts negative feedback at the pituitary, so TSH is not suppressed despite high free hormone levels. Tissues expressing predominantly TR-beta (pituitary, liver) are resistant, while TR-alpha-rich tissues (heart) may show thyrotoxic features — producing the mixed picture of goiter and tachycardia with a "non-suppressed TSH." The family history supports an inherited defect; a TSH-secreting pituitary adenoma is the main differential.
Sample question 2
A researcher compares the time course of action of different hormones. Which of the following best explains why thyroid and steroid hormones act more slowly than peptide hormones?
Explanations
A. All hormones act through identical mechanisms with similar time courses
Mechanisms and time courses differ fundamentally by hormone class.
B. Thyroid hormone acts within seconds through cyclic AMP
Thyroid hormone acts genomically over hours.
C. Steroid hormones act through cell surface G protein-coupled receptors
Steroids act through intracellular nuclear receptors.
D. Peptide hormones bind intracellular receptors
Peptides cannot cross the membrane and bind surface receptors.
E. Steroid and thyroid hormones bind intracellular receptors and alter gene transcription, requiring hours, whereas peptide hormones act on surface receptors through second messengers within seconds to minutes · correct
Hormone class determines mechanism and therefore speed. LIPOPHILIC hormones — steroids, thyroid hormone, and vitamin D — cross the plasma membrane, bind INTRACELLULAR receptors, and act as transcription factors, so their effects require transcription and translation and unfold over HOURS to days while persisting after the hormone is gone. They also circulate bound to carrier proteins with long half-lives. HYDROPHILIC peptide and catecholamine hormones bind SURFACE receptors and act through second messengers such as cAMP, IP3, and calcium, producing effects within seconds to minutes.
Sample question 3
Which of the following clinical uses reflects anti-Müllerian hormone's modern application beyond its classic embryologic role?
Explanations
A. Assessing ovarian reserve in fertility evaluations · correct
Beyond its classic embryologic role in male sexual differentiation (causing Müllerian duct regression), AMH (produced by ovarian granulosa cells) is used clinically as a marker of ovarian reserve in fertility evaluations, since it correlates with the remaining follicle pool.
B. Diagnosing pneumonia
AMH is not used for pneumonia diagnosis.
C. Diagnosing acute myocardial infarction
AMH is not used for cardiac diagnosis.
D. Screening for colorectal cancer
AMH is not used for colorectal cancer screening.
E. Monitoring diabetes control
AMH is not used for diabetes monitoring.
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