Final answer:
The region between the anus and the vagina is known as the perineum, which is part of the urogenital triangle in females.
Step-by-step explanation:
The region between the anus and the vagina is known as the perineum. In females, the perineum is part of the urogenital triangle, which includes the external genitals, and is the area that lies below the pelvic diaphragm.
The perineum contains muscles such as the compressor urethrae and sphincter urethrovaginalis, which help to close the vagina, and is also adjacent to structures like the Bartholin's glands that keep the vestibular area moist.