Whooshing downwards, the fluid enters the urethra and stops short at the external urethral sphincter.

液体飞速的向下流进尿道，从膀胱经尿道排出体外。

The internal urethral sphincter automatically and involuntarily opens, and the urine is released.

尿道内括约肌自然而然的张开，尿就排出来了。

Simultaneously, the internal urethral sphincter opens. This is called the micturition reflex.

同时，括约肌内壁开始打开。叫做排尿反射。

In men and women, around the internal urethral orifice, the detrusor muscle thickens to form the internal sphincter.

无论男性女性，尿道内口的逼尿肌增厚，形成尿道内括约肌。

The urethra is a thin muscular tube that drains urine from the bladder, starting from the internal urethral orifice to the external opening.

尿道是细的肌性管道，从膀胱引流尿液；起于尿道内口，终于尿道外口。

The external urethral sphincter is one of the muscles of the pelvic floor, and it provides support to the urethra and bladder neck.

尿道外括约肌是一种盆底肌，它向尿道和膀胱颈提供支撑。

The urethral sphincter is a collective name for the muscles used to control the flow of urine from the urinary bladder.

尿道括约肌是用来控制尿液从膀胱流出的肌肉的总称。

The brain can counter it if it's not a good time to urinate by sending another signal to contract the external urethral sphincter.

通过发射另一个信号来控制尿道外括约肌大脑会判断现在是不是排尿的合适时机。

But under normal circumstances, your decision to urinate stops the brain's signal to the external urethral sphincter, causing it to relax and the bladder to empty.

但是在正常情况下，你要排尿的决定阻止了大脑向尿道外括约肌发出信号使得它开始放松，膀胱排空。

The floor of the bladder has a smooth triangular region called the trigone region - with two corners at the ureterovesical junctions and the third corner being the internal urethral orifice, where the bladder meets the urethra.

膀胱的底部有一个光滑的三角形区域，称为膀胱三角；其中两角顶端为输尿管-膀胱连接处，第三角定点为尿道内口；膀胱与尿道通过尿道内口相通。