Corpus luteum function — MCQs

Fertilization begins when sperm binds to the corona radiata of the egg. Once the sperm enters the cytoplasm, a cortical reaction occurs which prevents other sperm from entering the oocyte. The oocyte then undergoes an important reaction. What is the next reaction that is necessary for fertilization to continue?

A 22-year-old woman comes to the physician to discuss the prescription of an oral contraceptive. She has no history of major medical illness and takes no medications. She does not smoke cigarettes. She is sexually active with her boyfriend and has been using condoms for contraception. Physical examination shows no abnormalities. She is prescribed combined levonorgestrel and ethinylestradiol tablets. Which of the following is the most important mechanism of action of this drug in the prevention of pregnancy?

A 36-year-old woman comes to the physician because she has not had her menstrual period for the past 4 months. During this period, she has had frequent headaches, difficulty sleeping, and increased sweating. She has not had any weight changes. Over the past year, menses occurred at irregular 30- to 45-day intervals with light flow. The patient underwent two successful cesarean sections at the ages of 28 and 32. She has two healthy children. She is sexually active with her husband and does not use condoms. Her vital signs are within normal limits. Physical examination shows no abnormalities. Laboratory studies show: Estradiol 8 pg/mL (mid-follicular phase: N=27–123 pg/mL) Follicle-stimulating hormone 200 mIU/mL Luteinizing hormone 180 mIU/mL Prolactin 16 ng/mL Which of the following is the most likely diagnosis?

A 31-year-old female presents to her primary care physician with mild anxiety and complaints of mood swings lasting several months. The patient reports that the mood swings affect her work and personal relationships. In addition, she complains of increased irritability, breast tenderness, bloating, fatigue, binge-eating, and difficulty concentrating for 10 days prior to her menstrual period. The patient's symptoms increase in severity with the approach of menses but resolve rapidly on the first day of menses. She states that she is very sensitive to criticism of her work by others. She also snaps at her children and her husband. She has tried yoga to unwind, but with limited improvement. She is concerned that her behavior is affecting her marriage. The patient has no past medical history, and has regular periods every 24 days. She has had two normal vaginal deliveries. She uses condoms for contraception. Her mother has major depressive disorder. The physical exam is unremarkable. What is the most appropriate next step in the treatment of this patient?

A 22-year-old female presents to her PCP after having unprotected sex with her boyfriend 2 days ago. She has been monogamous with her boyfriend but is very concerned about pregnancy. The patient requests emergency contraception to decrease her likelihood of getting pregnant. A blood hCG test returns negative. The PCP prescribes the patient ethinyl estradiol 100 mcg and levonorgestrel 0.5 mg to be taken 12 hours apart. What is the most likely mechanism of action for this combined prescription?

A 43-year-old woman, gravida 2, para 2, comes to the physician because of a 6-month history of heavy, irregular menstrual bleeding. Pelvic examination shows blood and clots in the posterior fornix and normal-appearing internal and external genitalia. An endometrial biopsy specimen shows straight uniform tubular glands lined with tall pseudostratified columnar epithelial cells with high mitotic activity embedded in an edematous stroma. Increased activity of which of the following is directly responsible for the histologic appearance of the biopsy specimen?

A 15-year-old girl is brought to the physician by her parents because she has not had menstrual bleeding for the past 2 months. Menses had previously occurred at irregular 15–45 day intervals with moderate to heavy flow. Menarche was at the age of 14 years. Eight months ago, she was diagnosed with bipolar disorder and treatment with risperidone was begun. Her parents report that she is very conscious of her weight and appearance. She is 168 cm (5 ft 5 in) tall and weighs 76 kg (168 lb); BMI is 26.9 kg/m2. Pelvic examination shows a normal vagina and cervix. Serum hormone studies show: Prolactin 14 ng/mL Follicle-stimulating hormone 5 mIU/mL Luteinizing hormone 5.2 mIU/mL Progesterone 0.9 ng/mL (follicular N <3; luteal N >3–5) Testosterone 2.7 nmol/L (N <3.5) A urine pregnancy test is negative. Which of the following is the most likely cause of her symptoms?

A 27-year-old woman with Kallmann syndrome (congenital GnRH deficiency) desires pregnancy. She has been on estrogen-progesterone replacement for bone health. Her physician plans to switch her to pulsatile GnRH therapy. After 6 weeks of treatment, labs show: LH 4 mIU/mL, FSH 5 mIU/mL, estradiol 120 pg/mL. Ultrasound shows a 16mm dominant follicle. Evaluate and synthesize the physiologic response to determine the appropriate next intervention for ovulation induction.

A 30-year-old woman at 28 weeks gestation with gestational diabetes managed with insulin presents with decreased fetal movement. Fetal monitoring shows category II tracing. Umbilical artery Doppler shows absent end-diastolic flow. Her glucose control has been suboptimal (HbA1c 7.8%). Maternal blood pressure is normal. Synthesize the pathophysiologic relationship between her metabolic condition and the Doppler findings to determine the primary mechanism.

A 42-year-old woman with previously regular 28-day cycles now reports cycles varying from 24-35 days over the past year. Day 3 labs show: FSH 18 mIU/mL (normal: 3-10), LH 10 mIU/mL, estradiol 35 pg/mL, AMH 0.4 ng/mL (normal age 40-44: 0.5-2.5). She has three children and desires no future pregnancies but wants to understand her physiology. Evaluate these findings and synthesize the underlying pathophysiologic process.