Filiform papillae, the most numerous of the lingual papillae, is the only type that does not contain taste buds. Rather, they serve to move food toward the esophagus, cleanse the interior of the mouth, and spread saliva onto food and mucus membranes.

The sensation of taste is carried to the brainstem by three cranial nerves: the facial nerve (CN VII), the glossopharyngeal nerve (CN IX), and the vagus nerve (CN X). The facial and glossopharyngeal nerves both communicate sensation from the tongue, while the vagus nerve transmits sensory information from the epiglottis. The trigeminal nerve (CN V) is not directly involved in the sensation of taste, though there is evidence that it is involved in the senses of "heat" and "coolness" experienced while eating spicy or minty foods.

In addition to the taste receptors in the mouth and pharynx, taste receptors are located in many other areas of the body. These including the lung (which has taste receptors for bitter flavors, possibly as a mechanism to protect against airborne toxins), the pancreas, the small intestine, the stomach, the brain, and the testis. While the function of taste receptors in the testes is not well known, some research indicates that testicular taste receptors may play an important role in male fertility.  

Sweet, umami, and bitter taste are all correlated with receptors for guanine nucleotide-binding proteins, also known as G proteins. Taste bud receptors that transmit information about saltiness are triggered by sodium ion channels in the cell wall. 

The four types of lingual papillae are fungiform (mushroom-shaped), filiform ("thread-like"), circumvallate, and foliate.

Filiform papillae are the most numerous, covering the majority of the anterior two-thirds of the tongue. Fungiform papillae are scattered along the surface of the tongue, but are more concentrated on the tip and sides of the tongue. Foliate papillae are located on the sides and back of the tongue, and circumvallate papillae are the large, round papillae visible in a row on the posterior aspect of the tongue, just anterior to the foramen cecum and sulcus terminalis.  

Sour flavor taste bud receptors are triggered in the presence of hydrogen ions (thus acidic foods often have a sour taste). Sodium triggers receptors for salty flavor, while glutamate and gustducin (a guanine nucleotide-binding protein, or G protein), are associated with umami, sweet, and bitter flavors.

The most superior vertebra of the spine is the atlas, or C1. This bone sits on the axis, or C2, over a bony process called the dens. The coccyx, or "tailbone," is part of the sacrum.

There are 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae. The mnemonic for this is "breakfast at 7, lunch at 12, dinner at 5."

The occiput is the inferior and posterior bone of the skull. It wraps under the bottom of the skull and forms the base on which the head articulates with the spine. The ethmoid bone and sphenoid bone are housed primarily within the skull, and the maxilla forms the upper jaw and part of the orbit.

The bony protuberance(s) at which the occipital bone articulates with the atlas (C1) are the occipital condyles. The external occipital protuberance, external occipital crest, and inion are all part of the occipital bone and serve as the attachment points for various muscles and ligaments.