前立腺とは

前立腺について、それが何であるか、どのように機能し、どこにあるかを知れば知るほど、前立腺の状態と前立腺の処置が現在および進行中の健康にどのように影響するかをよりよく理解できます。

このページは、前立腺、一般的な状態、および治療オプションを理解するのに役立つ資料として、健康をより適切に管理し、自分に適した決定を下すことができるようにしています。

ひと目でわかる前立腺

前立腺は腺である
前立腺は骨盤底にある
前立腺は神経に囲まれている
前立腺は尿道を取り囲んでいる

前立腺の解剖学

Prostate-Anatomy-Function_Labels-01-scaled-e1655938233283.jpg

前立腺は、膀胱と陰茎の間にあるクルミ大の腺で、男性にのみ見られます。

前立腺は直腸のすぐ前にあります。

尿道は膀胱から陰茎まで前立腺の中心を通り、尿を体外に排出します¹。

前立腺の機能

前立腺は、男性生殖器系の重要な部分です。

前立腺は射精時に収縮し、尿道に液体を噴出します。この液体は前立腺液として知られています。

prostate-model

前立腺は外分泌腺です。外分泌腺は管を通って体外に分泌されます。

前立腺は、前立腺液と呼ばれる乳白色の液体を生成します。前立腺液は、精巣からの精子、および精嚢からの液体と結合して精液を形成します。前立腺液は、射精液のおよそ30%を占めています。前立腺液は精子に栄養素を提供し、精子を保護して長生きさせることで精子の送達を助けます¹。

The prostate also produces a protein called Prostate Specific Antigen (PSA).

PSA is released with the ejaculatory fluid and can also be traced in the bloodstream. After ejaculation, PSA makes thickened semen runnier, which helps sperm travel through it more easily¹

The amount of PSA that is found in the blood increases with the size of the prostate gland, age and prostate conditions such as BPH, cancer and prostatitis (infection of the prostate)1. There is more information on why this is useful in the following section.

The prostate surrounds the urethra as it passes from the bladder towards the penis and is adjacent to sphincters, which plays a role in controlling urine flow.

The prostate may become enlarged and cause urethral compression which can make urination difficult².

The prostate and bladder neck also contract during ejaculation, closing the opening between the bladder and urethra, making it impossible to urinate and ejaculate at the same time¹.

Tom, Canada

72 years old

“TULSA is the perfect choice for someone young and active like me. I was treated like a king the day of the treatment, and I had so little pain all I needed was a single Tylenol the next day. I was back to my job and taking meetings within a couple of days!”

患者の声

Why is prostate specific antigen (PSA) testing useful?

PSA, a protein produced in the ducts of the prostate, is absorbed into the bloodstream. PSA is produced by both normal and malignant prostate cells.

A PSA blood test measures the amount of PSA found in the blood. PSA levels in the blood can also increase with prostate diseases such as BPH, prostate cancer and prostatitis (infection of the prostate). The PSA test, combined with the digital rectal exam is the most accurate guide to early cancer detection.

The PSA level that is considered normal for an average man increases with age and can range from 0 to 4 nanograms per milliliter (ng/ml)¹.

参考文献

1.National Cancer Institute.（国立がん機関）（2011年8月）。前立腺の変化を理解する。取得元: http://www.cancer.gov/types/prostate/understanding-prostate-changes/prostate-booklet.pdf.

2. Nakajima, C., Iimura, Y., & Yamanishi, T. (2001). The reason why prostatic hyperplasia causes lower urinary tract symptoms. A Journal of Medical Sciences of Japan and Other Asian Countries, 44(2), 91-96.