Bladder Capacity and 'Back Up' to the Kidneys

We have had recent discussion and posts on the forum about bladder function and how there is a risk of 'back up' to the kidneys.

Spinal Cord Injury can often cause us to have a neurogenic bladder which means our bladder does not function as normal because the muscles within the bladder rely on signal from the spinal cord and the injury may have caused nerves to become damaged so the function become impaired.

We always therefore have to consider the risks of this and then how to reduce these risks. Effective voiding of the bladder at regular periods is needed....and for many of us catheterizing becomes an essential routine  to enable effective emptying.

The bladder can can hold up to 600ml of urine but this varies with each person...for some the capacity is less...The bladder is a muscle and will stretch to allow more volume. The danger for us is caused by the inability to feel the normal urge to naturally void which occurs at a much lower capacity at approximately 200ml.

In a 'normal' functioning bladder, as it becomes full, the muscles within the bladder squeeze and send the urine out through the urethra. None of the urine should flow back into the ureter when the bladder is squeezing.

Each ureter has a one-way valve where it enters the bladder that prevents urine from flowing back up ..BUT for us this function cannot be relied upon so the best policy is to self void through catheterizing.

I think we have all had occasions when we have left it too long between emptying, especially overnight and the capacity has been significantly over the limit...but we really should consider the risks associated with this as permanent kidney damage can be caused by this 'back up'.
Maybe we have just been 'lucky' when these occasions have occurred?


The diagram above shows:
1. Human urinary system
2. Kidney
3. Renal pelvis
4. Ureter
5. Urinary bladder
6. Urethra. (Left side with frontal section)
7. Adrenal gland

Vessels:
8. Renal artery and vein
9. Inferior vena cava
10. Abdominal aorta
11. Common iliac artery and vein

With transparency
12. Liver
13. Large intestine
14. Pelvis

Always consider your bladder health and adopt a catheterizing routine that is strict and effective in avoiding a potentially serious health risk. Catheterizing can be very annoying to have to carry out especially when it interferes with sleep patterns or other activities but it is very important to keep the bladder capacity to a healthy limit.

Sources of information:here, here and here.