The fungiform papilla is a small organ on the surface of the human tongue and is named for its broad flat upper surface and long narrow lower structure, which makes it resemble a mushroom. It's one of the four types of pappillae found scattered across the tongue, and is particularly concentrated on the tip and along the sides. On the upper, or epithelial, surface of each fungiform papilla sits a taste-bud that can distinguish between five different taste sensations: sour, sweet, bitter, salty, and umami, which is a Japanese word that refers to savoriness or deliciousness. Fungiform papilla are part of the gustatory system, which is the sensory system related to the sense of taste.
The core of the fungiform papilla is made of connective tissue, which is a strong fibrous type of tissue found throughout the body. There are four different types of the connective tissue in the human body: epithelial, muscular, skeletal, and nervous connective tissue. The seventh cranial nerve, which is also called the facial nerve, innervates the fungiform papilla and allows sensory information collected in the mouth to travel to the brain.
The facial nerve erupts from the brain stem, which is the lower rear portion of the brain that attaches to the spinal cord. The brain stem consists of the pons, the mid brain and the medulla oblongata. The seventh cranial nerve originates from between the medulla oblongata and the pons and controls the muscles of facial expression. The facial nerve is one of twelve paired cranial nerves that serve to innervate the head and neck, allowing motor movement and the transference of sensory information, usually in the form of taste, to travel to the brain for processing.
The human tongue has four types of papillae: fungiform, conical, vallate, and filiform. The vallate papillae, which are also known as the circumvallate papillae, are arched structures that are sometimes described as being dome-shaped. They vary in number from eight to twelve, are arranged in rows, and are located in the back of the mouth just in front of the tongue's root.
The filiform papillae are elongated, narrow, v-shaped structures that do not have taste-buds and are not part of the gustatory system. They are the most common of the four types of lingual papillae and the fungiform papillae are found distributed among them. The conical papillae, which resemble the filiform papillae, but are smaller, are projections found along the back of the tongue.