Question

The outline of principal events of urination is given below in a random manner.
a. Stretch receptors on the wall of the urinary bladder send signals to the CNS.
b. The bladder fills with urine and becomes distended.
c. Micturition.
d. CNS passes on motor messages to initiate the contraction of smooth muscles of the bladder and simultaneous relaxation of the urethral sphincter.
A) a, b, c, d.
B) d, c, b, a.
C) b, a, d, c.
D) c, b, a, d.

Answer 1

Hint:The process of urination begins by the filling of the bladder. The bladder is a bag-like structure that holds urine. Until it gets full, it keeps on receiving urine.

Complete answer: The urinary bladder is a muscular structure. The urinary bladder functions like a storage vessel for urine to decrease the frequency of urination. It is one of the most elastic organs of the human body and can increase its volume greatly to accommodate nearly 800 mL to 1.5 L of urine at maximum capacity in adults.
Urine enters the bladder, it gets fully distended. Then, the stretch receptors on the wall of the urinary bladder send a signal to the CNS. The CNS then passes on the signal to motor neurons in order to initiate smooth muscle contraction. This results in micturition.

So, the answer is option C.

Additional information:
During urination, the bladder muscles squeeze, and the external two sphincters (valves) relax to allow urine to flow out. Urine exits the bladder and enters the urethra, which carries urine out of the body. The urethra of females is around 1.5 inches long. As it passes through the penis in males, its length is longer. The average male urethra is nearly 8 inches long.

Note: The process of release of urine from the urinary bladder is known as micturition. This process occurs almost 5 to 6 times a day. The frequency may increase or decrease based on environmental conditions.