The presence of more oxytocin oxygen to, and remove waste from, receptors in the uterus leads to weak, irregular contractions known as the embryonic blood by the ________ ________. week of pregnancy.

Correct Answer: C

Rationale: The correct answer is C: Braxton Hicks contractions. These contractions are weak, irregular contractions that occur in the uterus during pregnancy. They are often referred to as "practice contractions" as the body prepares for labor. The presence of more oxygen and removal of waste from the uterus can trigger Braxton Hicks contractions. Choice A, dystocia, refers to difficult or prolonged labor, not weak contractions. Choice B, first week, is not relevant to the question as Braxton Hicks contractions typically occur later in pregnancy. Choice D, second week, is also not correct as Braxton Hicks contractions occur later in pregnancy, typically in the third trimester.

Correct Answer: D

Rationale: The correct answer is D because the first polar body is formed during the first meiotic division of the primary oocyte before birth. The primary oocyte undergoes meiosis I to form the secondary oocyte and the first polar body. This process occurs during fetal development, not after birth. Choice A is incorrect because the primary oocyte completes meiosis I to form the secondary oocyte and the first polar body before ovulation. Choice B is incorrect because the primary oocyte forms the first polar body before birth, not after birth. Choice C is incorrect because the first polar body is formed during meiosis I of the primary oocyte, not after fertilization.

Correct Answer: C

Rationale: The correct answer is C: Vulva. The vulva is the fleshy outer part of the female reproductive system that includes the labia majora, labia minora, clitoris, vaginal opening, and urethral opening. It is where the opening to the vagina is located. The uterus (A) is a hollow, muscular organ where the fetus develops during pregnancy. The ovary (B) is the female reproductive organ that produces eggs and hormones. Vaginitis (D) is inflammation or infection of the vagina, not the outer part of the reproductive system. Therefore, the correct answer is C as it accurately describes the external female genitalia where the vaginal opening is situated.

Correct Answer: B

Rationale: Step-by-step rationale: 1. FSH stimulates development of follicles in ovaries. 2. Follicle cells release estrogen. 3. Estrogen levels increase as follicles develop. 4. Estrogen plays key role in menstrual cycle regulation. Therefore, the correct answer is B (estrogen). Other choices are incorrect: A (hormones are broad, not specific), C (progesterone is released after ovulation), D (implantation occurs in the uterus, not ovaries).

Correct Answer: C

Rationale: Step 1: The epididymis is a structure where sperm mature and are stored. Step 2: The deferent duct (vas deferens) carries sperm from the epididymis to the urethra. Step 3: Since the deferent duct crosses the epididymis, choice C is correct. Summary: Choices A, B, and D are incorrect because they do not accurately describe the anatomical relationship between the epididymis and the deferent duct.