Five Quarts_ A Personal and Natural History of Blood - Bill Hayes [104]
You must be brought to it. It must be reached. And in order to be fully felt and appreciated, an orgasm depends on the hot, twisting passageways of the bloodstream. In the build to climax, the hormone oxytocin is launched into the blood in a double volley from the brain and either ovaries or testes. The surge peaks at orgasm, reaching up to five times the normal concentration. By causing heart rate and blood pressure in the typical person to double, oxytocin accelerates its own speedy travels through the body. Most pleasingly, it helps trigger the pelvic shudders that women experience during orgasm and possibly the muscular contractions in men.
Love poets have long rhapsodized how souls touch during lovemaking, and oxytocin may well be the biochemical basis for this claim. The hormone, known to be vital in forging the adamantine bond between a mother and her child (and also that between father and child, probably), may perform a similar function in sexual partners, researchers believe. Oxytocin-spiked blood stirs immediate feelings of connectedness to the person with whom you are intimate, which may either lay the foundation for long-lasting ties or, if you’re already well acquainted, strengthen existing ones. In a remarkable sense, then, oxytocin is part of the blood’s formula for building familial bonds with those who aren’t blood kin.
But blood at orgasm is not just relationship-minded, so to speak. At the same time it helps curl your toes, oxytocin signals other chemicals to gush forth, such as potent opiates aimed more at dulling sensation than amping it. These are of the same family as the endorphins released during exercise and have, for example, the effect of temporarily numbing raw nerve endings in people with migraine, arthritis, or peripheral neuropathy. Furthermore, oxytocin activates mechanisms that help heal wounds and raises blood levels of immunoglobulin, a microbe-fighting antibody. So significant are these and other benefits that, experts agree, not only is sex good for you, but it may also lead to your living longer.
Of course, those same experts are not saying, when you’re sick, have lots of sex. The heat of passion and the heat of illness do not usually overlap. And for good reason. When you’re sick, the blood is rigged to make you drowsy. Hypnos, the god of sleep, almost always thwarts Eros. You need only have a cold to appreciate this. Or, for the sake of illustration, say you’ve got a flu bug—nothing too serious, but enough to confine you to bed. While you rest, white blood cells directly attack the infection and, launching a broader assault, the body changes its internal environment to make itself less accommodating to invaders. Cellular messengers called pyrogens—“fire starters,” roughly translated—are sent through the blood to the body’s thermostat, the anterior hypothalamus in the brain, which turns up the heat. At the same time, blood vessels in the skin narrow, reducing sweating, which is a major way body heat escapes. Now producing more heat than it can lose, the body runs a fever. (By the way, for most people, what’s widely considered the normal body temperature, 98.6 degrees Fahrenheit, actually isn’t. An enduring math error from the 1800s is the cause of this misconception. The true average is 98.2.) Fever, which helps kill whatever virus or bacterium swims within, may be “a lovely way to burn,” as Peggy Lee crooned, but, truth be told, it’s lousy for lovemaking.
Even if there weren’t such sound immunological explanations for the lost carnal itch, common sense should tell you plenty: You could be contagious. You shouldn’t overexert yourself. You look like the unfed undead. And naturally, your sex appeal