A viral photo claiming that a bite from a Brazilian spider causes an erection lasting up to four hours is misleading.
The photo, widely shared in WhatsApp groups, encouraged those with an erection disorder to try the spider to up their performance.
This came up following an online publication claiming that the species contains a possible breakthrough for erectile dysfunction.
“Most people who find a spider in their bedroom quickly try to get rid of it. But new research shows that one arachnid might actually be best kept by your bedside. A single bite from the Brazilian wandering spider has been shown to have side effects including a four-hour-long erection,” read part of the article.
But Urologist Dr. Peter Mungai said an erection occurs when a man becomes sexually aroused allowing hormones, muscles, nerves, and blood vessels to work together.
Mungai said penile erection involves neuron stimulation and production of hormones which has nothing to do with a spider bite.
“This is just a good joke because a spider cannot produce the hormones or neurons needed to stimulate a penile erection,” he said.
“If it is true that such information is doing rounds then it could be by some sadists who do not understand the mechanism of erection,” he added.
The neurons in these hypothalamic nuclei contain peptidergic neurotransmitters, including oxytocin and vasopressin, which may be involved in penile erection.
Several brain stem and medullary centres are also involved in sexual function.
For an erection to occur, nerve signals sent from the brain to the penis stimulate muscles to relax in turn, allowing blood to flow to the tissue in the penis.
Once the blood fills the penis and an erection is achieved, the blood vessels to the penis close off so that the erection is maintained.
Following sexual arousal, the blood vessels to the penis open up again, allowing the blood to leave.
However several studies here indicate that the Brazilian wandering spiders' venom is a complex cocktail of toxins, proteins and peptides which affects ion channels and chemical receptors in victims' neuromuscular systems.
The wandering spiders, also called armed spiders or banana spiders, belong to the genus Phoneutria, which means "murderess" in Greek. And it's no wonder why — it's one of the most venomous spiders on Earth.
After a human is bitten by one of these spiders, he or she may experience initial symptoms such as severe burning pain at the site of the bite, sweating and goosebumps.
Within 30 minutes, symptoms become systemic and include high or low blood pressure, fast or a slow heartbeat, nausea, abdominal cramping, hypothermia, vertigo, blurred vision, convulsions and excessive sweating associated with shock.
In addition to intense pain and possible medical complications, the bite of a Brazilian wandering spider can deliver a long, painful erection to human males because the venom boosts nitric oxide, a chemical that increases blood flow.
People who are bitten by a Brazilian wandering spider should seek medical attention immediately.
Several studies are looking at incorporating the venom into drugs for erectile dysfunction.
However, these bites are rare, and envenomations are usually mild.
The Star’s fact check concludes that while it is true a bite from this spider may cause an erection, it is a painful erection which is a disorder due to the venom.
The information is thus misleading.