1.
When both testes fail to develop, all of the following events occur except:
Correct Answer
C. External genitalia are the male type.
Explanation
When both testes fail to develop, it results in a condition called testicular dysgenesis. In this condition, the absence of testes leads to the absence of testosterone production, which is responsible for the development of male external genitalia. Therefore, in this scenario, the external genitalia will not develop into the male type.
2.
What is the pivotal change in the hypothalamic-pituitary-gonadal axis that defines the onset of puberty in the male?
Correct Answer
D. Increased frequency and amplitude for release of gonadotropin releasing hormone (GnRH).
Explanation
During puberty in males, there is an increase in the frequency and amplitude of release of gonadotropin-releasing hormone (GnRH). GnRH is released by the hypothalamus and stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. LH and FSH then act on the testes to stimulate the production of testosterone and sperm, leading to the development of secondary sexual characteristics and fertility. Therefore, the increased frequency and amplitude of GnRH release is the pivotal change that defines the onset of puberty in males.
3.
In male fetal development, which hormone (or absence of any hormone) is responsible for regression of the structures that would otherwise form the uterus?
Correct Answer
D. Anti-mullerian hormone
Explanation
Anti-Mullerian hormone is responsible for the regression of the structures that would otherwise form the uterus in male fetal development. This hormone inhibits the development of the Mullerian ducts, which are responsible for the formation of the uterus and other female reproductive structures. Therefore, the presence of anti-Mullerian hormone prevents the development of these structures in males.
4.
Failure to develop sinovaginal bulbs results in
Correct Answer
E. Short and atretic vagina
Explanation
Failure to develop sinovaginal bulbs results in a short and atretic vagina. The sinovaginal bulbs are embryonic structures that give rise to the lower part of the vagina. If these bulbs fail to develop properly, it can lead to a shortened and closed-off vagina, known as a short and atretic vagina. This condition can cause difficulties with sexual intercourse and may require surgical intervention to correct.
5.
The labia minora in the female and the __________ in the male are derived from the same embryonic structures.
Correct Answer
D. Penis surrounding penile urethra
Explanation
The correct answer is penis surrounding penile urethra. The labia minora in females and the penis surrounding penile urethra in males are derived from the same embryonic structures. During embryonic development, the genital tubercle forms and can differentiate into either the clitoris or the penis, depending on the presence or absence of certain hormones. The labia minora in females are homologous to the penis surrounding penile urethra in males, as they both develop from the same structure.
6.
Which of the following is the homologue of the paradidymis?
Correct Answer
D. Paroophoron
Explanation
Paroophoron is the correct answer because it is the homologue of the paradidymis. The paroophoron is a vestigial structure found in females that is equivalent to the paradidymis in males. Both structures develop from the same embryonic tissue and have similar functions. Therefore, the paroophoron is the homologue of the paradidymis.
7.
The septa within each test is that separates the different compartments of seminiferous tubules are derived from which structure?
Correct Answer
D. Tunica albuginea
Explanation
The septa within each testis that separates the different compartments of seminiferous tubules are derived from the tunica albuginea. The tunica albuginea is a dense fibrous capsule that surrounds the testis and extends inward to form septa, which divide the testis into lobules. These septa provide structural support and organization to the seminiferous tubules, where spermatogenesis takes place. The other options listed are not directly involved in the formation of the septa within the testis.
8.
Ductuli efferentes are derived from the
Correct Answer
A. Remaining excretory tubules of mesonephros
Explanation
Rete testis: --from medullary/testis cords (primitive sex cords)
Ductuli efferentes: -- from the remaining parts of excretory tubules of mesonephros
Ductus deferens& ductus epididymis: -- from the mesonephric/wollfian duct.
Vestigial structures in male:
Appendix epididymis
Paradidymis
Prostatic utricle
Appendix testis
(slide 25 Male femal repro-Yin)
9.
An infant presents with a ball-like structure on her "bottom " (see image below). The baII-Iike structure indicated by the pointer is homologous to:
Correct Answer
C. Seminal colliculus
Explanation
Hydrometrocolpos
10.
The uterus is formed from
Correct Answer
D. Caudal part of paramesonephric ducts
Explanation
The uterus is formed from the caudal part of the paramesonephric ducts. During embryonic development, the paramesonephric ducts, also known as the Müllerian ducts, give rise to the female reproductive system, including the uterus, fallopian tubes, and upper part of the vagina. The caudal part of the paramesonephric ducts specifically develops into the uterus.
11.
All of the following structures are derived from endoderm Except:
Correct Answer
C. Mesonephric duct
Explanation
Mesonephric duct is from 2nd kidney system, which is from intermediate mesoderm.