Flashcards in Normal physio/disorders of male sexual fxn: Nace Deck (14)
Outline the key steps in penile erection.
Centrally-perceived sensual stimuli are relayed to
a spinal cord center SNS fibers at levels T-10 to L2, and to another involving the PSNS at levels S2-S4. Tonic SNS activity is responsible for flaccidity via *a-adrenergics*. Stimulation of the parasympathetic sacral segments produces erection by stimulating activity of nitric oxide synthase ---> NO---> guanylyl cyclase ---> cGMP---> cavernous SM relaxation---> vasodilation---> cavernosa engorge /w blood---> block off draining veins---> erection.
::Erection fades as cGMP ---> GMP by PDE5 (target for PDE5 inhibitors that tx ED)
What are the absolute prerequisites for erection?
Good arterial supply to penis (deep artery of penis), and adequate nitric oxide synthase activity.
Which is not a cause of decreased libido?
Meds (SSRIs, antiandrogens, 5-alpha reductase inhibitors, and opioids)
Describe the difference between global and contextual loss of interest in sex (loss of libido).
Global loss of interest is more suggestive of systemic causes, whereas contextual loss of interest is more suggestive of psychological and/or relational causes.
How are CVD and ED related?
The same RFs for CVD can cause ED (T2DM, obesity, HTN, dyslipidemia, smoking, etc). So, ED could be an early indicator for CVD and given the RFs, may prompt investigation into the pt's CV health.
T/F: the H&P has a high sensitivity for ED and low specificity as to the cause of ED.
What are the most common causes of ED that deserve special attention in the diagnostic evaluation?
Psychogenic factors and medications
Complaints of ED accompanied by other times of normal erections (e.g., nocturnal or early morning erections or satisfactory erections with masturbation) is suggestive of _____________ causes.
Complete loss of nocturnal erections is seen in men with __________ or __________.
neurologic or vascular causes
What lab tests could help you evaluate cause of ED?
Glucose and lipid profiles.
Total testosterone and free testosterone.
The focused physical exam for evaluation of cause of ED should include evaluation for:
CV and neurological status
What is priapism?
persistent and painful erection. Could be an AE of drug tx for ED.
Describe retrograde ejaculation.
Normally, the *internal bladder neck sphincter* contracts during ejaculation, ensuring the semen is propelled into the urethra. Retrograde ejaculation of semen into the bladder can instead occur if the bladder neck is damaged during prostate surgery or if there is *interruption of the α-adrenergic impulses* normally responsible for constriction of the bladder neck sphincter. The result may be described by patients as a “dry ejaculate”. Such men may present for evaluation of infertility. Retrograde ejaculation is suggested by low-volume ejaculates with low sperm counts, but the presence of ample sperm in post-ejaculatory urine specimens. Not surprisingly, retrograde ejaculation may be caused by α-adrenergic blockers.