Mean bladder capacity in male adults varies around 400 500 + is pain caused by tension in the wall, leading to the urgent desire to void. pain is referred to the cutaneous areas supplied by spinal segments supplying the bladder
Micturition,the act of emptying the bladder . it consist of storage phase and voiding phase.
- Storage phase -as the bladder fills with urine, distention of the bladder wall initiates storage reflexes . Afferent impulses from stretch receptors in the bladder are sent to the spinal cord resulting in the following.
- activation of sympathetics: To detrusor muscle and internal urethral sphincter
2. Activation of somatic efferents: via duodenal nerve to external urethral sphincter.
3. additionally, activation of somatic efferents is further stimulated by the storage center
within the pons , thus providing conscious control.
- Micturition Reflex- the micturition reflex is initiated either by further bladdera distension more than 500 , which increases afferent impulses to the pontine micturition center, or by the input from higher brain center initiating voluntary micturition.1. afferent impulses from stretch receptors in the bladder are sent to the pons.
2. The pontine micturition cente
r is activated and results in the following
a. Activation of parasympathetics,(to detrusor muscle and internal urethral sphincter)
b. inhibition of sympathetics
inhibition of somatic efferents .(Relaxes External urethral sphincter).