Nokea
Which of the following is produced by the trophoblast cells during the first 3 weeks of pregnancy?
- A. Estrogen
- B. Luteinizing hormone
- C. Oxytocin
- D. Human chorionic gonadotropin
Correct Answer: D
Rationale: The correct answer is D: Human chorionic gonadotropin (hCG). During the first 3 weeks of pregnancy, trophoblast cells produce hCG, which is crucial for maintaining the corpus luteum and ensuring the production of progesterone to support the early pregnancy. hCG is also the hormone detected in pregnancy tests.
Rationale:
A: Estrogen is mainly produced by the ovaries, not trophoblast cells in the early stages of pregnancy.
B: Luteinizing hormone is produced by the pituitary gland to trigger ovulation, not by trophoblast cells.
C: Oxytocin is produced by the hypothalamus and released by the pituitary gland during labor and breastfeeding, not by trophoblast cells in the early stages of pregnancy.
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Which hormone is secreted by the corpus luteum after ovulation?
- A. Progesterone
- B. Relaxin
- C. LH
- D. FSH
Correct Answer: A
Rationale: The correct answer is A: Progesterone. After ovulation, the corpus luteum forms from the ruptured follicle and secretes progesterone to prepare the uterus for implantation. Progesterone helps maintain the endometrial lining for potential pregnancy. Choice B, Relaxin, is secreted by the corpus luteum, but its main function is to soften the cervix and pubic symphysis. Choices C and D, LH and FSH respectively, are pituitary hormones involved in the menstrual cycle regulation, not directly secreted by the corpus luteum.
The primary oocyte completes its first meiotic division
- A. during fetal development
- B. just after ovulation
- C. just before ovulation
- D. just before fertilization
Correct Answer: D
Rationale: The correct answer is D because the primary oocyte completes its first meiotic division just before fertilization. This occurs when the oocyte is released from the ovary during ovulation. The meiotic division is completed when the sperm penetrates the oocyte, forming a zygote. Choices A, B, and C are incorrect because the primary oocyte does not complete its first meiotic division during fetal development, just after ovulation, or just before ovulation.
The epididymal duct:
- A. is an intratesticular spermatic duct;
- B. continues with the deferent duct;
- C. continues with the testicular efferent ducts (vas efferens);
- D. part of the extratesticular spermatic ducts.
Correct Answer: B
Rationale: Step 1: The epididymal duct is a coiled tube located on the posterior surface of the testis.
Step 2: It continues as the deferent duct (vas deferens) which is responsible for transporting sperm from the epididymis to the ejaculatory duct.
Step 3: Therefore, choice B is correct as the epididymal duct indeed continues as the deferent duct.
Summary:
A: Incorrect - The epididymal duct is not located within the testis.
C: Incorrect - The testicular efferent ducts are separate from the epididymal duct.
D: Incorrect - The epididymal duct is considered part of the male reproductive system within the scrotum, not outside it.
Floating ribs of the thoracic cage are
- A. 1-7 ribs
- B. 8-10 ribs
- C. 11, 12 ribs
- D. None of the above
Correct Answer: C
Rationale: The correct answer is C: 11, 12 ribs. Floating ribs are ribs that do not have a direct attachment to the sternum. Ribs 11 and 12 are considered floating ribs because they do not attach to the sternum or cartilage of other ribs, only to the vertebrae in the back. Choices A and B are incorrect because ribs 1-10 are not considered floating ribs. Choice D is incorrect because ribs 11 and 12 are indeed the floating ribs of the thoracic cage.
The process by which a secondary oocyte is ejected from the ovary is called ________.
- A. emission
- B. menses
- C. fertilization
- D. ovulation
Correct Answer: D
Rationale: The correct answer is D: ovulation. This process involves the release of a mature egg (secondary oocyte) from the ovarian follicle. During ovulation, the egg is released into the fallopian tube, where it can potentially be fertilized by sperm.
A: emission - Incorrect. This term typically refers to the discharge of semen from the male reproductive system.
B: menses - Incorrect. Menses refers to the shedding of the uterine lining during menstruation, not the release of an egg from the ovary.
C: fertilization - Incorrect. Fertilization is the process of the sperm uniting with the egg, which occurs in the fallopian tube after ovulation.