Final answer:
The upper and middle vagina receive pain innervation from visceral afferents, which are part of the autonomic nervous system and can cause referred pain. Somatic afferents, pudendal nerve, and solely autonomic nerves are not the correct answers.
Step-by-step explanation:
The pain innervation of the upper and middle vagina is primarily provided by visceral afferents. This type of nerve fiber is responsible for transmitting pain, stretch, and temperature sensations from the viscera (internal organs). Unlike somatic afferents, which innervate skin, muscles, and joints, visceral afferents conduct sensations from internal organs and are a part of the autonomic nervous system. The upper part of the vagina receives its nerve supply from the uterovaginal plexus (also known as the Frankenhäuser plexus), which contains fibers from the hypogastric plexus. These fibers do not provide a clear localized pain sensation, which is why vaginal pain may not always be sharply localized and might be experienced as a diffuse discomfort rather than a specific point of pain, a phenomenon known as referred pain.