1.
The optimal temperature (in degrees Fahrenheit) for producing sperm is:
Correct Answer
A. 93.0
Explanation
The optimal temperature is 5.6 degrees below body temperature, according to Dr. Beisel's lecture. 98.6 - 5.6 = 93.0
2.
A developing sperm is in the rete testis. If the sperm is on the way out of the testis, where did it just come from, and where will it go next?
Correct Answer
E. Seminiferous tubule, efferent ductules
Explanation
The correct path out of a testis is seminiferous tubule, rete testis, efferent ductules, epididymis, vas deferens. The only answer that follows this path is E.
3.
Luteinizing hormone is inhibited primarily by a product of ________, and follicle stimulating hormone is inhibited primarily by a product of _________.
Correct Answer
C. Leydig cells, Sertoli cells
Explanation
Sertoli cells make inhibin, which inhibits FSH. Leydig cells make testosterone which inhibits LH. Testosterone also inhibits GnRH, which is produced in the hypothalamus to promote production of the three glycoproteins LH, FSH, and TSH in the anterior pituitary
4.
Testosterone is not involved in which of the following?
Correct Answer
F. Actually, all of the above are related to testosterone
Explanation
Testosterone is involved in all of the processes mentioned. It plays a crucial role in the initiation of spermatogenesis, inhibits the release of GnRH (gonadotropin-releasing hormone) which in turn inhibits the production of LH (luteinizing hormone), it also contributes to bone growth, and stimulates the secretion of erythropoietin, a hormone that promotes the production of red blood cells. Therefore, all of the given options are related to testosterone.
5.
Epispadias differ from hypospadius in that
Correct Answer
C. Epispadias occur earlier in development and are unrelated to the cause of hypospadius
Explanation
Hypospadius are related to deficiencies in testosterone. Epispadias occur earlier in development and are unrelated to hypospadius. Epispadias are associated with extrophy of the bladder, and hypospadius is not.
6.
The earliest that the sex of a fetus can be determined by ultrasound is approximately:
Correct Answer
B. 12th week
Explanation
Dr. Nichols said that a good guess can be made by the 9 week. However, 8 weeks is clearly too early, so A is incorrect. 12 weeks is the number given in his PowerPoint.
7.
Which of the following conditions would most be most likely to result in infertility?
Correct Answer
D. Atresia of the cervix
Explanation
Only D would completely prevent pregnancy from happening. All other answers would likely result in fertility issues but would still allow pregnancy to occur.
8.
The first polar body:
Correct Answer
A. Is produced only in oogenesis after meiosis I
Explanation
Only oogenesis produces polar bodies. After completion of meiosis I, one polar body is produced. After meiosis II, either two or three polar bodies have been produced, depending on whether the first polar body replicated
9.
A deficiency in 5-alpha reductase would most likely result in:
Correct Answer
C. A male pseudo-hermapHrodite from decreased DHT levels
Explanation
Testosterone is converted into dihydrotestosterone (DHT) by 5-alpha reductase. DHT is crucial for proper male development. Failure to produce enough testosterone and/or DHT may result in male pseudohermaphrodism (male genotype with feminized phenotype).
10.
A patient complains of painful erections. He admits to an upward bend in the shaft of his penis. The most likely cause for this abnormality is:
Correct Answer
B. Excessive fibrosis following trauma
Explanation
Peyronie's disease is a disorder of inappropriate fibrosis of the penis. This typically results in an upward bend of the erect penis, and may result in painful erections. Hypospadius also may cause a bend in the penis, but will typically cause a downward bend. Moreover, hypospadius would likely have been addressed soon after birth. None of the other conditions are likely to result in a bent shaft.
11.
Which of the following is a common feature of benign prostatic hypertrophy and prostate cancer?
Correct Answer
D. Indistinguishable median sulcus
Explanation
The features of benign hypertrophy include symmetrical enlargement, protusion into the rectal lumen, smooth, no nodules, as well as elastic or rubbery consistency. Prostate cancer is largely the opposite of this, including features such as hard consistency, asymmetry, and nodules. Both may have an unidentifiable median sulcus.
12.
The location and size (from side to side) of a normal prostate observed by a digital rectal exam is:
Correct Answer
A. Anterior to rectal wall, 2.5 cm
Explanation
The correct answer is anterior to rectal wall, 2.5 cm. During a digital rectal exam, the prostate gland can be felt by inserting a finger into the rectum. The normal position of the prostate is in front of the rectal wall, which is why it is described as "anterior." The size of a normal prostate, when measured from side to side, is typically around 2.5 cm.
13.
HPV, or Human Papilloma Virus, is a cause of genital warts. Which of the following types of HPV is most likely to cause benign disease? Which are associated with malignant disease? (There are two best answers to each question)
Correct Answer
B. HPV- 6
Explanation
Answer: B,D HPV 6 and 11 are the most common cause of condyloma acuminatum, or benign genital warts, accounting for ~90% of all cases. Answer F,G HPV 16 and 18 are associated with carcinoma of the penis. The role of HPV in malignancy is unclear.
14.
A 55 year old patient presents with numerous wart-like lesions on his penis that have not healed over the past year. Some areas are bleeding and appear infected. Biopsy reveals hyperchromic, dysplastic epithelial cells that have broken through the basement membrane. After treatment of the primary lesions, what is the next appropriate step?
Correct Answer
B. Inguinal and iliac lympH node biopsy
Explanation
Squamous cell carcinoma of the penis accounts for less than 1% of male cancer in the US. However, it is up to 20x more common in many other parts of the world. Risk factors include an uncircumcised penis, poor hygiene, HPV-16 and HPV-18, and cigarette smoking. Inguinal and iliac lymph nodes are highly susceptible to metastasis. Therefore, the next best step is to biopsy these lymph nodes.
15.
A baby boy with microcephaly and rocker-bottom feet is born 4 weeks early. He is breathing on his own, but has difficulty eating. Additionally, his left testicle remains in the inguinal canal. Which of the following is best accounts for his condition?
Correct Answer
A. Trisomy 13
Explanation
The testicles typically descent around the 7th or 8th month. It would not be uncommon to see undescended testes (aka cryptorchidism) at this stage. However, microcephaly and foot deformity should alert you to a more severe problem. Descent of the testes occurs in two distinct stages. First, the trans-abdominal stage depends on mullerian inhibiting substance, produced by Sertoli cells. The second stage, or trans-inguinal stage, is controlled by androgens. However, according to 7th Edition Robbins pg. 1038, cryptorchidism is only "rarely associated with hormonal disorders". Chromosomal disorders are more likely. Common features of trisomy 13 include microcephaly, cleft lip, heart defects, and rocker-bottom feet.
16.
Circumcision does not significantly reduce the likelihood of which of the following
Correct Answer
D. Benign prostatic hyperplasia (BpH)
Explanation
There has been clear evidence to suggest that circumcision reduces the likelihood of HIV and UTIs, as well as squamous cell carcinoma. No such evidence exists for BPH.
17.
Which of the following experimental approaches would be most likely to prevent benign prostatic hyperplasia (BpH)?
Correct Answer
A. 5-alpHa reductase inhibitor targeted to stromal cells of the prostate
Explanation
The proposed mechanism for BPH is that testosterone is converted to DHT by 5-alpha reductase in the stromal cells of the prostate. DHT then binds to androgen receptors in both stromal cells and epithelial cells, resulting in production of growth factors which produce hyperplasia. Other factors are likely important, since experiments with 5-alpha reductase inhibitors did not benefit all patients who took it. (Robbins 7th Ed, pg 1049). 5-alpha reductase is a better target than testosterone since DHT is 10x more potent at activating androgen receptors. Other appropriate targets for therapy may include the androgen receptors and growth factor receptors.
18.
Which of the following is not a common feature of eunuchoidism?
Correct Answer
F. Gynecomastia (male breasts)
Explanation
Eunuchoidism is the failure of puberty to begin and proceed. There should be no hormonal increase that would result in gynecomastia. A less obvious feature is that these individuals tend to have long legs and therefore a sitting height less than half of their standing height. Anosmia is commonly seen in eunuchoids because there is often a problem in the pituitary which may affect the nearby olfactory system.
19.
A 7 year old boy presents with Turner stage 4 genital and pubic hair development (significant enlargement of penis and scrotum, darkening of scrotal skin, and adult type pubic hair). Which of the following would you most likely find in a patient with adrenogenital syndrome?
Correct Answer
C. Increased urinary 17-ketosteroids
Explanation
Precocious sexual development can be the result of 21-beta-hydroxylase deficiency. This deficiency will reduce the output of both mineralocorticoids (from the zona glomerulosa) and glucocorticoids (zona fasciculata). The anterior pituitary responds by increasing ACTH. As a result, there is overproduction of androgens (zona reticularis), which can lead to early sexual development. The increase in androgens will be broken down into excretory metabolites such as 17-ketosteroids, leading to increased urinary levels. Hyperglycemia is more likely to be seen in cortisol excess, and anosmia is associated with eunuchoidism (failure to enter puberty).
20.
Which of the following features is common to both 21-beta-hydroxylase deficiency and 17-alpha hydroxylase deficiency?
Correct Answer
E. Increased ACTH
Explanation
Both deficiencies result in a decrease in cortisol levels which results in an increase in ACTH. 21-beta-hydroxylase causes adrenogenital syndrome, where only androgens are increased. 17-alpha-hydroxylase deficiency results in decrease in all except mineralocorticoids. Here's a visual:
----------------------------21-β-hydroxylase deficiency .............17-α-hydroxylase deficiency
zona granulosa - aldosterone + aldosterone
zona fasciculata - cortisol - cortisol
zona reticularis + androgens - androgens