santos is confused he is still unable to maintain bladder co
santo\'s is confused. he is still unable to maintain bladder control despite presence of significant volume of urine in his bladder. Which urethral spinchter is contracted and which is relaxed
Solution
Answwer:
Santo is unable to maintain bladder control despite presence of significant volume of urine in his bladder is because of the relaxation of detrusor smooth muscle and contraction of bladder neck smooth muscle and external urinary sphincter skeletal muscle.
During the bladder filling stage, the external urethral sphincter contracts due to the supraspinal centers that produce excitatory outflow through the pudendal nerve to produce this contraction. They enhance the thoracolumbar sympathetic outflow with simultaneous suppression of sacral parasympathetic outflow to the lower urinary tract. In this phase detrusor smooth muscle relaxes, bladder neck smooth muscle and external urinary sphincter skeletal muscle contracts that allow low pressure storage of urine in the bladder without leakage.
During the bladder emptying phase, the external urethral sphincter relaxes due to the supraspinal centers that produce excitatory outflow through the pudendal nerve to produce this relaxation. They reduce the thoracolumbar sympathetic outflow with simultaneous enhancement of sacral parasympathetic outflow to the lower urinary tract. In this stage, the normal bladder mechanism involves detrusor smooth muscle contraction, bladder neck smooth muscle relaxation, and external urinary sphincter skeletal muscle relaxation that allow evacuation of urine stored in the bladder.

