When the micturation reflex is initiated, the brain responds by action potentials (aps) in somatic motor neurons, resulting in the relaxation of the urinary sphincter so urine can be voided.

1. Reducing

2. External

Explanation:

The external urinary sphincter, also called as external urethral sphincter consists of skeletal muscles. During micturition reflex, the micturition center present in the brain serves to inhibit the somatic motor neurons by reducing their action potential. These somatic motor neurons innervate in the external urinary sphincter.  

Inhibition of somatic motor neurons of the external urinary sphincter results in relaxation of the sphincter to facilitate the act of urination.

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.

the correct answer in apex is tissue development, i know because i just had this question