Final answer:
The floor of the bladder has three openings within the triangular area called the trigone: two ureteral openings for urine to enter from the kidneys and one urethral opening for urine to be excreted from the body.
Step-by-step explanation:
The internal floor of the bladder contains three openings: two ureteral openings and one urethral opening. These three openings are positioned in a triangular-shaped area known as the trigone, with the ureters located posterior-laterally and the urethra in the anterior aspect. The bladder itself is a hollow, muscular, and distensible organ that holds urine from the kidneys before it is excreted from the body. It is lined with transitional epithelium, which allows it to handle volume fluctuations as it fills and empties. In males, the anatomy of the bladder also includes the prostate gland located just below it.
Learn more about Bladder Floor Openings