Repro USMLE step 1 9-6 (12) Flashcards
This patient underwent a radiographic examination that demonstrated a leak from the dorsal vein to the saphenous vein. Cavernosography is the radiographic technique used to identify the location of?
venous leakage in the penis.
In cavernosography, vasodilators and contrast medium are injected into the penile tissue, causing an erection. Images are taken to evaluate for leakage. In a normal patient, there is little or no contrast seen outside the veins. In patients with erectile dysfunction, leakage may be visualized at one or multiple sites
A leak into the dorsal (shown in the image) and saphenous (not shown in the image) veins, which demonstrates a venous outflow abnormality, is typically due to?
nsufficient relaxation of the smooth muscle, resulting from excessive adrenergic tone or damaged parasympathetic innervation. In a normal erection, blood flow accelerates, increasing the pressure within the intracavernous spaces and blocking penile venous outflow. Contraction of the bulbocavernosus and ischiocavernosus muscles also helps with this process. Abnormalities in venous outflow, such as the leak from the dorsal vein to the external pudendal veins, a tributary of the great saphenous vein, in this patient can result in failure to acquire or maintain a firm erection.
Penile cancer, urinary incontinence, and urinary retention are not associated with abnormal penile blood flow. Priapism is associated with an inability to return to flaccid state rather than an inability to acquire or maintain an erection and would not be caused by?
a leak from the dorsal vein to the saphenous vein.
A penile venous outflow abnormality (such as a leak from the dorsal to the saphenous vein) can result in ?
erectile dysfunction, with a failure to acquire or maintain a firm erection. Cavernosography can be used to detect leaks in the veins in a patient with erectile dysfunction.
This patient presents with a bulge in his groin and undergoes an inguinal hernia repair. During the procedure, the surgeon cuts through a structure that lies on the superior surface of the spermatic cord. The spermatic cord itself is a thick cord containing structures that run to and from the testes. It is covered by three layers: external spermatic fascia derived from the external oblique muscle, cremasteric muscle and fascia derived from?
the internal oblique muscle, and internal spermatic fascia derived from the transversalis fascia. The surgeon has likely cut through the ilioinguinal nerve, which passes through the inguinal ligament on top of the spermatic cord.
The ilioinguinal nerve arises from L1 and supplies cutaneous sensation to the scrotum (labia in females) and medial aspect of the thigh. Thus, this patient would be expected to have loss of sensation or numbness of ?
The scrotum and medial thigh. The ilioinguinal nerve is not a part of the spermatic cord and must be isolated separately from the cord during hernia surgeries.
The damage sustained during this patient’s surgery would not cause any of the following symptoms or conditions:
Dissection of the ductus deferens could lead to infertility.
Dissection of the genitofemoral nerve within the spermatic cord would result in ?
loss of the cremasteric reflex.
Damage to the pampiniform plexus (found within the spermatic cord), would cause testicular edema
Damage to the testicular artery would cause testicular ischemia.
Twisting of the spermatic cord would result in testicular pain.
The ilioinguinal nerve arises from L1, passes through the inguinal ligament, and lies on top of the spermatic cord. It supplies cutaneous sensation to?
the scrotum/labia and medial aspect of the thigh.
A young couple is trying to conceive their first child. A friend tells the woman that she should take her temperature daily to determine when she ovulates. The woman asks her physician if this is true, and her physician explains that changes in the concentration of a particular hormone during ovulation lead to temperature changes.
The action of which of the following hormones is responsible for this change in body temperature?
It is possible to assess when ovulation has occurred by checking one’s basal body temperature on a daily basis. Progesterone is produced by the corpus luteum shortly after ovulation. One of its locations of action is the hypothalamic thermoregulatory center, leading to a slightly elevated basal body temperature (up to 1°F).
Normally estrogens lower core body temperature. In hypoestrogenic states such as menopause, core body temperature increases, but this effect would not be seen in a young woman. Follicular stimulating hormone promotes the growth of developing follicles but does not affect body temperature. Luteinizing hormone promotes ?
ovulation and progesterone secretion but does not affect thermoregulation. Human chorionic gonadotropin likewise does not affect body temperature, and is measurable once the woman is pregnant.
A woman’s basal body temperature changes throughout the menstrual cycle and is notably higher during the luteal phase. This is due to the action of ?
progesterone on the hypothalamic thermoregulatory center.
A Giemsa stain showing intracytoplasmic inclusions in the context of a urethral discharge, potentially due to a sexually transmitted infection, is indicative of Chlamydia trachomatis. Cytoplasmic inclusions can be seen on Giemsa- or fluorescent antibody–stained urethral or cervical smear, but diagnosis of Chlamydia can also be made from a urine sample using nucleic acid amplification techniques. Although it is frequently asymptomatic, C. trachomatis infection can cause urethritis, cervicitis, and pelvic inflammatory disease (PID) in women, as well as conjunctivitis and reactive arthritis (Reiter syndrome). Treatment of Chlamydia infection requires a course of either doxycycline or azithromycin. Chlamydia is infectious when it reaches the developmental stage described as an ?
extracellular elementary body, as this form can attach and enter host cells.
The cytoplasmic inclusions (arrows in image above) are non-infectious as are the intracellular elementary bodies. Similarly, independent reticulate bodies and reticulate bodies that are in the process of multiplying are both intracellular, and therefore are not infectious. The stages of Chlamydia development and relationship to infectivity are explained by the figure and table below.
Chlamydia trachomatis, which can cause urethritis, cervicitis, and pelvic inflammatory disease in women, is infectious when it is as an elementary body that can enter host cells from the extracellular domain. While all of the intracellular forms of C. trachomatis are necessary for the reproduction of ?
the organism, only the extracellular form is considered infectious.
This male infant is found to have a urethral opening on the ventral shaft of his penis. This is consistent with hypospadias, which results from improper fusion of the urogenital folds during fetal development. The urogenital folds form the ventral shaft of the penis and penile urethra in the male. Hypospadias is characterized by?
a urethral opening located abnormally on the ventral shaft of the penis, anywhere from the glans to the perineum. Hypospadias is one of the most common fetal anomalies and is believed (though not confirmed) to result from disruption of in utero androgenic stimulation.
The genital tubercle develops into the glans penis and corpus spongiosum in the male. The mesonephric duct gives rise to the seminal vesicles, epididymis, ejaculatory duct, and vas deferens in males. The paramesonephric duct leads to?
the development of the Müllerian system, whose derivatives are not typically present in male infants. The urogenital sinus produces the bladder, prostate, and prostatic urethra. This infant has a problem with the development of the shaft of the penis, which is not derived from any of these.
