Health Information Online

Emission Phase

The anatomical structures involved in emission include the epididymis, vas deferens, seminal vesicles, prostate gland, prostatic portion of the urethra, and bladder neck. These structures have both sympathetic and parasympathetic innervation with nerve fibers that arise predominately from the pelvic plexus. These nerve fibers are located in the retroperitoneum, traveling alongside the rectum and also lying posterolateral to the seminal vesicles. Pelvic plexus nerve fibers come superiorly from the hypogastric and pelvic nerves, and inferiorly from the caudal paravertebral sympathetic chain.

Emission is initiated when afferent stimulatory input, primarily arising from sensory fibers within the glans penis, is integrated at the level of the spinal cord. Sympathetic nerves (T10-L2) mediate the release of several neurotransmitters, including norepinephrine, causing epithelial cell secretion and smooth muscle cell contraction throughout the excurrent ductal system. As a result, accessory gland secretions  are admixed with spermatozoa and ejected into the posterior urethra.

www.hqcanadianpharmacy.com – online viagra and sildenafil shop in Canada – click here.

Expulsion Phase

The anatomical structures involved in seminal expulsion include the bladder neck, urethra, and striated pelvic muscles. Expulsion is a spinal cord reflex triggered once inevitability, or “the point of no return” is reached during sexual activity. During expulsion, the bladder neck smooth muscle fibers, under sympathetic fiber stimulation, forcibly contact to prevent retro-grade ejaculation. Next, the striated pelvic floor muscles, in particular the ischiocavernosus and bulbocavernosus muscles, contract in an intermittent, rhythmic fashion, and the external ure-thral sphincter relaxes.

While these muscles are innervated solely by the somatic nervous system (S2–4), the expulsion phase of ejaculation Viagra Australia does not appear to have any component of volitional control. In the setting of tight bladder neck con-traction, the series of striated pelvic muscular contractions leads to antegrade propulsion of semen through the prostatic, bulbar, and penile urethra and out the urethral meatus. To date, the specific trigger for the expulsion phase has not been clearly elucidated. Early work in a rat model suggested that the presence of semen in the bulbous urethra is the predominant factor that triggers seminal expulsion. Subsequent manuscripts describe the presence of a spinal ejaculatory generator that leads to the expulsion of seminal fluid once a critical level of spinal activation has been achieved.

The spinal ejaculatory center is believed to integrate stimuli from peripheral and central sites, with efferent output through both parasympathetic and somatic pathways. In 2002, Truitt and Coolen reported that neurons having a role in generating ejaculation are located within lamina X and the medial portion of lamina VII of lumbar segments 3 and 4. These neurons receive descending input from the nucleus paragigantocellularis, the medial preoptic area, and the paraventricular nucleus of the hypothalamus, each providing supraspinal modulatory effects on the spinal ejaculatory generator. While descending cortical input may influence ejaculation, it is not essential for ejaculation to occur.

Men with complete spinal cord transection superior to the tenth thoracic segmental level (superior to the location of the spinal ejaculatory generator) exemplify this point; in these men, the ejaculatory reflex is typically still feasible. Penile vibratory stimulation is routinely used in such patients to induce the ejaculatory response for reproductive purposes, in order to collect sperm for assisted reproductive techniques, such as intrauterine insemination or in vitro fertilization. The intact function of the spinal ejaculatory generator neurons is essential for normal ejaculatory function, as their ablation leads to the complete loss of ejaculatory function.

Fact: Men Have a Wide Range of Sexual Concerns

Every man (and woman) has concerns about what is sexually normal. There is a wide range of concerns about what is normal physically (like penis size); how your sexual body functions (erections, ejaculation – generic viagra New Zealand); what thoughts or fantasies are normal (e.g., being sexually aggressive, group sex, attracted to a coworker, sex with animals); how to make love (how to “turn a woman on”); and what are appropriate sexual feelings (e.g., “horny”), sexual interest (e.g., “Am I addicted to strip bars?”), or behaviors (“Is my use of porn okay?”). We hear real men say things like:

• “Am I normal?”
• “Is my partner normal?”
• “I love sex; it’s great. But I am not like men in the movies or TV. Is there something wrong with me?”
• “My testicles hang differently. Is there something wrong with me?”
• “I don’t want to get older, 55 or 75, because sex surely must decline and end.”
• “I’m embarrassed that I don’t know how to be a super lover.”
• “I had really great sex with her, but is that all there is?”
• “I feel so dumb! Nobody talked to me about what healthy sex is. I don’t trust all the braggadocio I hear from male friends in the locker room or sports bar.”
• “Sex with a long-term partner gets boring.”
• “I use pornography regularly because it is my guarantee for variety. It ensures that I can get aroused and erect. Is that healthy?”
• “I feel inadequate; I doubt my ability to perform and satisfy my partner.”
• “Penis size seems so important to women. I worry, am I big enough?”
• “Sex is supposed to be natural, but I have difficulty letting go.”
• “My sexuality as a man seems more complex than what other men say, TV or movies show, or what the Internet says. Am I peculiar or inadequate?”
• “There are times that I feel very ashamed of my honest sexual desires, that they are ‘bad.’”
• “I often doubt my ability to perform, to sexually satisfy my partner.”
• “Are my fantasies, my body, my lovemaking style normal?”
• “I’m afraid she’s judging me, my sexual skills and performance; this makes me anxious.”
• “I have some weird thoughts and desires. How do I know if I’m deviant?”

These and other thoughts and feelings represent common concerns men have about their masculinity and sexual performance. If you are a man who wants to be honest with yourself and not live in the world of beer commercials, simplistic promises of Viagra ads, and sexual hype, you’ll find yourself in this book. You can learn to feel proud of your masculinity and sexuality – viagra professional online. This is a book for honest, strong, thoughtful men. We will explore common anxieties that many of us experience. Most men have little opportunity to learn from other men about healthy sexuality. We will confront common barriers to growing and developing an adult, healthy, and satisfying male sexuality.

This book takes men’s sexuality seriously. Rather than trivializing men and sex, we consider complexity. This is a book for real men, not politically correct men. We will give you essential facts and discuss how sexual health can confirm your masculinity and promote life satisfaction.