How Do We Pee and Why Can't We Do It Any Time?

TL;DR

Understanding the process of urination and how the body controls it, along with monitoring urine color for health indicators.

Transcript

An average healthy adult responds to nature’s call anywhere between 4 and 10 times each day. The need to take a leak begins when pressure in the bladder rises, stretching the bladder wall which is made up of bands of smooth muscle (detrusor) that are filled with beta adrenergic receptors that send and receive messages between the muscle’s cells and... Read More

Key Insights

• 😟 The process of urination is controlled by a combination of the autonomic and voluntary nervous systems.
• 🥹 Holding in urine weakens control over the external urethral sphincter and intensifies the urge to urinate.
• 🧑‍⚕️ Urine color can provide insights into hydration levels and potential health issues.
• 😋 Blue or green urine is often caused by food dye or medication, but it can also be a symptom of a rare genetic condition.
• 💦 Completely clear urine can indicate excessive water intake, which can potentially be harmful.
• 😟 The parasympathetic nervous system triggers the micturition reflex and the contraction of the detrusor muscles during urination.
• 😋 The color of urine can also be affected by specific foods like beets or blueberries.

Questions & Answers

Q: Why do we feel the urge to urinate?

The need to urinate arises when pressure in the bladder increases, stretching its walls. This stretching triggers messages from the stretch receptors to the spinal cord and brain, signaling the need to urinate.

Q: How does the body control the urge to urinate?

The sympathetic nervous system sends messages to the detrusor muscles, suppresses the urge to contract, and keeps the internal urethral sphincter closed to prevent urination.

Q: What happens if we hold in urine for too long?

Holding in urine for an extended period can weaken the control of the external urethral sphincter, intensify the micturition wave, and eventually lead to a stronger urge to urinate.

Q: How does urine color indicate health?

Pale or transparent yellow urine is a sign of proper hydration, while dark yellow urine indicates the need to drink more water. Unusual colors like pink, orange, blue, or green can indicate various health issues or dietary factors.

Summary & Key Takeaways

• Urination begins when pressure in the bladder rises, stretching the bladder walls.

• The bladder initially fills through the ureters, while messages from the sympathetic nervous system suppress the urge to pee.

• As the bladder reaches a quarter to half full, stretch receptors signal the spinal cord, triggering the micturition reflex and the need to urinate.