The resting ureteric pressure in mm –
**Core Concept**
The resting ureteric pressure, also known as the basal pressure, is the normal pressure within the ureters when the individual is at rest. This pressure is crucial for the proper functioning of the urinary system, as it helps to prevent the backflow of urine from the ureters into the kidneys.
**Why the Correct Answer is Right**
The resting ureteric pressure is approximately 5-10 mmHg, which is a critical range to maintain proper urine flow and prevent ureteral reflux. This pressure is regulated by the smooth muscle tone in the ureteral wall and is influenced by the autonomic nervous system, particularly the sympathetic and parasympathetic branches. The sympathetic nervous system helps to increase ureteric pressure by stimulating alpha-adrenergic receptors, while the parasympathetic nervous system has a relaxing effect on the ureteral smooth muscle.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely too high, as pressures above 10 mmHg can lead to ureteral damage and increased risk of stone formation. Elevated pressures can also cause ureteral spasms and pain.
* **Option B:** This option is too low, as pressures below 5 mmHg may not be sufficient to prevent ureteral reflux and can lead to urinary incontinence.
* **Option C:** This option is not a valid measurement unit for ureteric pressure, which is typically expressed in millimeters of mercury (mmHg).
**Clinical Pearl / High-Yield Fact**
It's essential to remember that ureteric pressure can be affected by various factors, including age, gender, and underlying medical conditions. For example, women are more prone to ureteral damage due to their narrower ureteral diameter and increased risk of pelvic organ prolapse.
**Correct Answer:** C. 5-10