關於陰莖你不知道的事情

Use it or lose it

You need regular erections to keep your penis in shape. It must be intrinsically exercised.

To maintain healthy tone, the smooth muscles of the penis must be regularly replenished with oxygen through blood flow, engorging the penis with blood and allowing it to become erect.

If a man is physically capable of erections but never gets one during the day—and perhaps finds himself in very unsexy situations for long periods of time—there is no need to worry. The brain has automatic penis maintenance built into it.

Impulses from the brain can cause an erection during the dreaming stage of sleep, known as the rapid eye movement stage. Whether you're having sexy sex dreams or zombie apocalypse nightmares, your penis gets hard during this time in your sleep cycle.

But some men are physically unable to achieve an erection, such as those who have suffered trauma to their nerves or damage to nerves or blood vessels caused by diabetes.

If nothing is done to maintain a normal erection, the penis will shorten. Without a normal erection, the penile tissue becomes less elastic and shrinks, making the penis shorter by 1-2 cm.

Devices like a vacuum pump, which forces the penis to swell with blood, can help men with erection problems maintain a healthy penis.

There is no consistent relationship between the size of a flaccid penis and its fully erect length

In a study of 80 men, researchers found that the increase in length from flaccid to erect was substantial, from less than a quarter of an inch to 3.5 inches longer.

Whatever the clinical significance of these data, the implications in the locker room are considerable. You can't assume that a guy with a big, soft penis will get even bigger when erect. People with seemingly small penises may develop surprisingly large erections.

An analysis of more than a thousand measurements shows that shorter flaccid penises tend to be twice as long as longer flaccid penises.

Data suggests that most penises are not extreme show-offs or growers. About 12 percent of penises increase in length by one-third or less when erect, and about 7 percent double in length when erect.

Happy Zone

Many men believe that the underside of the glans penis (head) and the underside of the penile shaft are most sensitive to sexual pleasure.

Researchers asked 81 healthy men to rate the sexual sensitivity of different parts of their bodies, including not just the penis but also the scrotum, anus, nipples and neck.

For most men, sensitivity is highest on the underside of the glans penis and under the body of the penis, followed by the upper side of the glans penis, the left and right sides of the glans penis, both sides of the penis, the upper side of the shaft of the penis, and the foreskin (for the uncircumcised minority) of men). The findings were reported in the British Journal of Urology International in 2009.

Sensitivity decreases with age

Research shows that as men age, they gradually lose sensitivity in their penis, although it's difficult to say exactly how much. This is because different researchers use different methods to stimulate the penis and measure sensitivity.

Generally speaking, penile sensitivity is measured by the minimum amount of stimulation a man can feel. This is the so-called "sensory threshold".

Although there are differences between studies, the data show clear trends when taken together. Starting at age 25, sensitivity begins to decline. The greatest decrease in sensitivity occurs between the ages of 65 and 75.

Vibrators also work on the penis

Vibrators aren’t just for women. They also work on the penis. In fact, vibrations are so effective on the penis that men with spinal cord injuries can often ejaculate with the help of special medical vibrators. For this treatment, the vibrator is usually placed against the underside of the glans penis.

Most men don't need a medical vibrator to induce orgasm. When patients come to him about delayed ejaculation (difficulty reaching orgasm), he recommends they try a store-bought vibrating personal massager.

Although vibrators can often help men with ejaculation problems, no medical condition is required to use one. You can do this just for fun.

There's more to your penis than meets the eye

Most men would be proud to know that their penis is twice as long as they thought it was.

That's because half the length of your penis is inside you. Just like you can't see all of a large oak tree above ground, you can't see the base of your penis hidden within your pelvis and attached to your pubic bone.

As you can see from the MRI photo, the erect penis is shaped like a boomerang.

Your penis is a habitat

The skin of the penis is home to a diverse bacterial community.

Research shows that a total of 42 unique species of bacteria live on the skin of the penis.

The human body is essentially an ecosystem.

Research shows that uncircumcised and circumcised penises have different types and amounts of bacteria. The researchers first analyzed penis samples from 12 men scheduled to undergo circumcision. After the men were circumcised, samples were collected again and analyzed.

After circumcision, men have fewer types of bacteria on their penis. Many bacteria that are less common or absent after circumcision are anaerobic, meaning they don't need oxygen to grow.

The inner folds of the foreskin are mucous membranes, just like the inside of a human eyelid. Certain anaerobic bacteria thrive in this environment, but not on dry skin.

The types of bacteria found in men in other parts of the world vary.

Research may help explain why circumcision is associated with a lower risk of HIV infection. One theory is that anaerobic bacteria may prompt an immune system response that makes cells more susceptible to HIV infection.

Most men are not circumcised

Globally, approximately 37% to 39% of males aged 15 and older have been circumcised, according to a 2016 report by Population Health Metrics.

The report noted that costs vary widely based on religion and nationality. Nearly all Jewish and Muslim men in the world are circumcised, and together they account for almost 70% of all circumcised men worldwide.

Some studies suggest that circumcision may have health benefits. For example, circumcised men are less likely to transmit sexually transmitted diseases to their female partners or to develop penile cancer.

A 2012 policy statement from the American Academy of Pediatrics (AAP) affirms that “an evaluation of the available evidence indicates that the health benefits of neonatal male circumcision outweigh the risks and that the benefits of the procedure justify families who choose the procedure.” The procedure. Specific benefits identified include prevention of urinary tract infections, penile cancer, and the spread of certain sexually transmitted infections, including HIV." This claim is also endorsed by the American College of Obstetricians and Gynecologists.

In recent years, several studies have shown that circumcised men are less likely to contract HIV. The World Health Organization and the United Nations Program on AIDS now recommend male circumcision as an HIV prevention measure. The World Health Organization states that "there is compelling evidence that male circumcision reduces the risk of HIV infection in heterosexual men by approximately 60%."

Review

All comments are moderated before being published

HealthyPIG Magazine

View all
小朋友叫唔應?可能唔係無禮貌,而係科學:專注時真係聽唔到你

小朋友叫唔應?可能唔係無禮貌,而係科學:專注時真係聽唔到你

小朋友一睇YouTube、打機、畫畫,突然叫佢,佢完全聽唔到。係咪扮聾?係咪發展遲緩?抑或專注力問題? 研究顯示,大部分情況完全正常,與腦部的「選擇性注意力(Selective Attention)」同「過度專注(Hyperfocus)」有關,不代表有疾病。 什麼是「選擇性注意力」?(Sele...
高血壓|隱形殺手的成因、統計數據與科學研究

高血壓|隱形殺手的成因、統計數據與科學研究

  高血壓|隱形殺手的成因、統計數據與科學研究 快速導讀 高血壓係全球最普遍、但最容易被忽視嘅慢性病之一。 超過一半患者完全無症狀,但長期會破壞血管、增加中風同心臟病風險。 主要成因包括:高鹽、肥胖、缺乏運動、低鉀、飲酒、睡眠窒息症、壓力、吸煙、腎病等。 全球研究顯示:高鹽攝取加上肥胖...
為何肺癌早期大多沒有症狀?科學原理、風險因素與早期發現方法全解析

為何肺癌早期大多沒有症狀?科學原理、風險因素與早期發現方法全解析

肺癌一直是全球最常見、死亡率最高的癌症之一。令人憂心的是,大部分肺癌患者在早期(第一、二期)都沒有明顯症狀,往往直到腫瘤擴散、壓迫周邊結構或影響呼吸功能後才被發現。本文以科學角度深入講解:為何肺癌早期「靜悄悄」、身體不察覺?身體內部究竟發生了甚麼? 亦會加入實際的自我檢查策略與醫學建議。 一...
黑眼圈成因全解析:從生理、生活習慣到醫學對策

黑眼圈成因全解析:從生理、生活習慣到醫學對策

前言:為何黑眼圈總是揮之不去? 「黑眼圈」係現代人嘅常見問題之一。無論係通宵工作、壓力過大、過敏,甚至遺傳因素,都可能令眼底皮膚變黑或出現陰影。雖然多數情況屬於美容問題,但有時亦可能反映身體狀況,例如貧血、睡眠質素差、血液循環不良等 [1]。  一、黑眼圈的主要類型與成因 色素型黑眼圈(Pi...
智慧手錶 vs 專用 O₂Ring 血氧儀:血氧監測能力的科學比較

智慧手錶 vs 專用 O₂Ring 血氧儀:血氧監測能力的科學比較

1. 前言 血氧飽和度(SpO₂)是評估呼吸、循環系統狀態的重要指標。近年來,市面上兩大類可穿戴設備用於血氧監測: 智慧手錶(如 Samsung Watch、Apple Watch) 專用血氧監測設備(如 O₂Ring、指夾式脈搏血氧儀) 兩種設備的設計目的、測量方式、準確性、監測...
血氧飽和度、氧氣下降與「警戒線」的科學探討

血氧飽和度、氧氣下降與「警戒線」的科學探討

1. 前言 血氧飽和度(SpO₂)即血液中氧合血紅蛋白佔總血紅蛋白的百分比,是臨床及居家監測呼吸、循環功能的重要指標。當血氧飽和度下降,可能反映體內氧的供應或運送出現問題(低氧血症、hypoxemia)或更廣泛的組織缺氧(hypoxia)[1][2]。本文旨在探討: 血氧飽和度正常範圍與變...
冰敷(Cold Therapy)真正作用全面解析:止痛、減腫,還是幫助修復?|科學視角 + 實證文獻

冰敷(Cold Therapy)真正作用全面解析:止痛、減腫,還是幫助修復?|科學視角 + 實證文獻

冰敷(Ice Pack / Cold Therapy / Cryotherapy)係好多運動、急性受傷(如扭傷、撞擊、肌肉拉傷)時的第一時間處理方法。但不少人會疑惑: 「冰敷純粹止痛,定係真係會幫助組織修復?」「冰敷幾耐?冰敷幾多日?會唔會影響身體自然修復?」 本文從科學、醫學、運動治療角度,...
長時間保持同一姿勢後關節痛、僵硬、郁唔到:成因、科學解釋與改善方法

長時間保持同一姿勢後關節痛、僵硬、郁唔到:成因、科學解釋與改善方法

前言:為何「坐耐、蹲耐、跪耐」之後會痛? 無論係坐喺電腦前、跪低執嘢、長時間翹腳、側睡又唔郁——好多人體驗過一樣情況: 「一動就痛、一企起身腳軟、膝蓋直唔到、關節卡卡聲,又或者要行幾步先鬆返。」 其實呢種情況係非常普遍,而且通常並非關節已經壞死,而係 和關節生理、滑液循環、血液供應、肌肉張力 ...
魚醒味的科學:成因、風險與處理方法全面解析

魚醒味的科學:成因、風險與處理方法全面解析

「魚醒味」是華人烹飪文化中常見的說法,用以描述魚類在 解凍、切片或加熱後所突然出現的腥味、血水味或脂肪味。此現象並不代表食材變壞,但背後牽涉到蛋白質變化、脂肪氧化與揮發性化合物釋放等多種科學機制。本文將以科學角度剖析魚醒味的成因,並提供實證方法降低這種味道,同時探討其安全性。 🧪 什麼是「魚...