It begins with a bit of discomfort and soon becomes a pressing sensation that's impossible to ignore. Finally, it's all you can think about, and out of sheer desperation, you go on a hunt for a bathroom until "ahh." Humans should urinate at least four to six times a day, but occasionally, the pressures of modern life forces us to clench and hold it in. How bad is this habit, and how long can our bodies withstand it? The answers lie in the workings of the bladder, an oval pouch that sits inside the pelvis. Surrounding this structure are several other organs that together make up the whole urinary system. Two kidneys, two ureters, two urethral sphincters, and a urethra. Constantly trickling down from the kidneys is the yellowish liquid known as urine. The kidneys make urine from a mix of water and the body's waste products, funneling the unwanted fluid into two muscular tubes called ureters. These carry it downward into the hollow organ known as the bladder. This organ's muscular wall is made of tissue called detrusor muscle which relaxes as the bladder fills allowing it to inflate like a balloon. As the bladder gets full, the detrusor contracts. The internal urethral sphincter automatically and involuntarily opens, and the urine is released. Whooshing downwards, the fluid enters the urethra and stops short at the external urethral sphincter. This works like a tap. When you want to delay urinating, you keep the sphincter closed. When you want to release it, you can voluntarily open the flood gates. But how do you sense your bladder's fullness so you know when to pee? Inside the layers of detrusor muscles are millions of stretch receptors that get triggered as the bladder fills. They send signals along your nerves to the sacral region in your spinal cord. A reflex signal travels back to your bladder, making the detrusor muscle contract slightly and increasing the bladder's pressure so you're aware that it's filling up. Simultaneously, the internal urethral sphincter opens. This is called the micturition reflex. The brain can counter it if it's not a good time to urinate by sending another signal to contract the external urethral sphincter. With about 150 to 200 milliliters of urine inside of it, the bladder's muscular wall is stretched enough for you to sense that there's urine within. At about 400 to 500 milliliters, the pressure becomes uncomfortable. The bladder can go on stretching, but only to a point. Above 1,000 milliliters, it may burst. Most people would lose bladder control before this happens, but in very rare cases, such as when as a person can't sense the need to urinate, the pouch can rupture painfully requiring surgery to fix. 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. The external urethral sphincter is one of the muscles of the pelvic floor, and it provides support to the urethra and bladder neck. It's lucky we have these pelvic floor muscles because placing pressure on the system by coughing, sneezing, laughing, or jumping could cause bladder leakage. Instead, the pelvic floor muscles keep the region sealed until you're ready to go. But holding it in for too long, forcing out your urine too fast, or urinating without proper physical support may over time weaken or overwork that muscular sling. That can lead to an overactive pelvic floor, bladder pain, urgency, or urinary incontinence. So in the interest of long-term health, it's not a great habit to hold your pee. But in the short term, at least, your body and brain have got you covered, so you can conveniently choose your moment of sweet release.
Ia bermula dengan sedikit ketidakselesaan dan tidak lama lagi menjadi sensasi mendesak yang mustahil untuk diabaikan. Akhirnya, itu anda boleh fikirkan, dan kerana terdesak , anda pergi ke bilik air sehingga “ahh.” Manusia harus buang air kecil 4 ke 6 kali sehari tetapi, tekanan kehidupan moden memaksa untuk menahannya. Betapa buruknya tabiat ini, dan berapa lama badan kita boleh menahannya? Jawapannya terletak pada tugas pundi kencing, kantung bujur yang terletak di dalam pelvis. Di sekeliling struktur ini, ada beberapa organ lain yang bersama-sama membentuk keseluruhan sistem kencing. Dua ginjal, dua ureter, dua sfinkter uretra, dan uretra. Selalu menitis dari buah pinggang ialah cecair kekuningan iaitu air kencing. Ginjal membuat air kencing daripada air dan bahan buangan badan, menyalurkan cecair yang tidak diingini ke dalam dua tiub iaitu ureter. Ia dibawa turun ke bawah ke dalam organ berongga iaitu pundi kencing. Dinding otot organ ini diperbuat dari tisu otot detrusor dimana ia mengendur apabila pundi kencing terisi kembang seperti belon. Apabila pundi kencing penuh, detrusor mengecut Sfinkter uretra dalaman automatik terbuka dan secara tidak sengaja dan air kencing dikeluarkan. Berdengung ke bawah, cecair memasuki uretra dan berhenti sebentar di sfinkter uretra luar Ia berfungsi seperti paip Apabila anda melambatkan buang air kecil, anda menutup sfinkter. Apabila anda mahu melepaskannya, anda boleh membukanya. Tetapi bagaimana anda rasa pundi kencing penuh supaya tahu bila hendak kencing? Dalam lapisan otot detrusor ada berjuta-juta reseptor regangan yang tercetus apabila pundi kencing terisi Ia menghantar isyarat sepanjang saraf ke sakral dalam saraf tunjang Isyarat refleks kembali ke pundi kencing menjadikan otot detrusor mengecut sedikit dan meningkatkan tekanan pundi kencing supaya sedar ia berisi. Pada masa sama, sfinkter uretra dalaman terbuka Ia dipanggil refleks miksi. Otak boleh melawan jika ia bukan masa sesuai untuk kencing dengan menghantar isyarat lain untuk mengecutkan sfinkter uretra luar. Kira-kira 150-200 mililiter air kencing di dalamnya, dinding otot pundi kencing diregangkan untuk merasakan ada air kencing dalamnya. Kira-kira 400-500 mililiter, tekanan menjadi tidak selesa Pundi kencing boleh meregang tetapi hanya ke satu titik. Lebih 1,000 mililiter, ia mungkin pecah Banyak orang akan kehilangan kawalan pundi kencing, tetapi kes jarang berlaku, seperti seseorang tidak merasa untuk kencing kantung boleh pecah dengan menyakitkan dan memerlukan pembedahan untuk dibaiki. Tetapi dalam keadaan biasa, keputusan buang air kecil hentikan isyarat otak kepada sfinkter uretra luar, menyebabkannya berehat dan pundi kencing kosong. Sfinkter luar ialah salah satu otot lapisan pelvis, dan ia berikan sokongan kepada uretra dan leher pundi kencing Nasib baik kita ada otot pelvis kerana meletakkan tekanan seperti batuk,bersin,ketawa atau melompat menyebabkan kekurangan pundi kencing. Sebaliknya, otot pelvis memastikan kawasan itu tertutup sehingga bersedia untuk pergi. Tetapi menahannya masa yang lama, memaksa air kencing keluar dengan pantas, atau buang air kecil tanpa sokongan fizikal mungkin melemahkan otot kerana terlebih bekerja. Menyebabkan pelvis aktif, sakit pundi kencing atau intontinensia kencing. Jadi untuk kesihatan jangka panjang, menahan kencing bukan tabiat yang baik. Tetapi dalam jangka pendek, badan dan otak telah dilindungi jadi anda boleh memilih saat pelepasan dengan mudah.