The urinary bladder in mammals opens into the urethra. Here is a detailed explanation:
Introduction:
In mammals, the urinary bladder is an organ that stores urine produced by the kidneys before it is excreted out of the body. The bladder is connected to various other organs through different openings.
Answer:
The correct answer is B: Urethra.
Explanation:
The urinary bladder opens into the urethra, which is the tube responsible for carrying urine from the bladder to the outside of the body. The urethra serves as a passage for urine to exit the body during the process of urination.
Other options:
To provide further clarity, let's briefly explain the other options:
A: Uterus: The uterus is a female reproductive organ and is not directly related to the urinary system. In females, the urethra and the vagina have separate openings.
C: Vestibule: The vestibule is a part of the female reproductive system and is not directly associated with the urinary bladder.
D: Ureter: The ureter is a tube that carries urine from the kidneys to the urinary bladder. It does not connect directly to the bladder itself but rather to the upper part of the bladder.
In conclusion, the urinary bladder in mammals opens into the urethra, which serves as the pathway for urine to leave the body.