Question

Place the following in order of the micturition reflex starting with the first event that occurs?

1) Relaxation of the external urethral sphincter
2) Detrusor muscle contraction
3) Activation of stretch receptors in the bladder wall
4) Inhibition of the pontine micturition center

Answer 1

The micturition reflex involves several events, including the activation of stretch receptors in the bladder wall, inhibition of the pontine micturition center, detrusor muscle contraction, and relaxation of the external urethral sphincter.

Step-by-step explanation:

The micturition reflex is a complex process that involves several events. Here is the correct order of these events:

1. Activation of stretch receptors in the bladder wall
2. Inhibition of the pontine micturition center
3. Detrusor muscle contraction
4. Relaxation of the external urethral sphincter

The micturition reflex starts with the activation of stretch receptors in the bladder wall when it becomes distended. This leads to the inhibition of the pontine micturition center, which helps to overcome the voluntary control of urination. Then, the detrusor muscle contracts, causing the bladder to expel urine. Finally, the external urethral sphincter relaxes, allowing urine to flow out of the body.