Hypothyroidism — Flashcards

Flashcard 1: Which thyroid imbalance presents with weight gain and decreased appetite?_____

Answer: hypothyroidism

Flashcard 2: In which disorder (hyper- or hypothyroidism) may a patient present with a goiter? _____

Answer: Both!

Flashcard 3: _____ is an autoimmune disorder that initially causes a hyperthyroidism that then becomes a hypothyroidism.

Answer: Hashimoto's Thyroiditis

Flashcard 4: Which thyroid imbalance presents with increased TSH (if 1*) and decreased free T3 / T4?_____

Answer: Hypothyroidism

Flashcard 5: A _____ multinodular goiter occurs when a multinodular goiter has hyperfunctioning follicular cells that work independently of TSH, causing increased release of T3 and T4

Answer: toxic

Flashcard 6: Kallmann syndrome

Answer: defective migration of GnRH cells

Extra: anosmia, lack of secondary sex characteristicsdecreased: GnRH, FSH, LH, testosterone, sperm count

Flashcard 7: Hormone profile in Hypogonadotropic Hypogonadism (LH/FSH and Sex Steroids)

Answer: Decreased LH/FSH and decreased Testosterone/Estrogen

Extra: Hypogonadotropic hypogonadism (secondary hypogonadism) is characterized by low gonadotropins (LH, FSH) which leads to low sex steroid production. Contrast with Hypergonadotropic hypogonadism (primary): High LH/FSH, low sex steroids.

Flashcard 8: Hormonal profile in primary hypogonadism:

Answer: Increased LH, Decreased Testosterone

Extra: In primary hypogonadism (hypergonadotropic hypogonadism), the problem is at the level of the testes. Loss of negative feedback from testosterone leads to a compensatory rise in LH (and FSH).

Flashcard 9: What is the basic defect in Androgen Insensitivity Syndrome?

Answer: Defect in androgen receptor

Extra: • Genotype: 46, XY (Normal male) • Phenotype: Female external genitalia, rudimentary/blind-pouch vagina, absent uterus/tubes (due to MIF). • Gonads: Internal testes (often in labia/inguinal canal). • Labs: Increased Testosterone, LH, and Estrogen. • Clinical: Scant sexual hair (distinguishes from Mullerian agenesis).

Flashcard 10: What is the fundamental defect in 5α-reductase deficiency?

Answer: Inability to convert testosterone to DHT (Dihydrotestosterone)

Extra: - Presentation: Male internal genitalia, ambiguous external genitalia until puberty (when increased testosterone leads to virilization). - Lab findings: Normal testosterone and estrogen; LH normal or slightly increased. - Inheritance: Autosomal Recessive (AR).