b. Papillae. Some taste buds are located in elevated connective tissue on the
tongue. This tissue is called papillae. Papillae cause the upper surface of the tongue to
look rough. Circumvallate papillae are the largest papillae; they form an inverted V-
shaped row at the back of the tongue. Fungiform (mushroom-shaped) papillae are
located primarily on the tip and sides of the tongue. There are taste buds in all
circumvallate and most fungiform papillae. The front two thirds of the tongue are
covered with pointed, thread-like structures called filiform papillae.
1-14. PHYSIOLOGY OF GUSTATION
To create the sensation of taste, a substance must be in a solution of saliva so
that the substance can enter the taste pores. The taste substance makes contact in the
pores with plasma membranes of the gustatory hairs; this causes the taste receptors to
be stimulated. There are two sensory pathways for taste. Pathway one contains the
facial nerve which carries taste sensations from the front two-thirds of the tongue.
Pathway two, the glosso-pharyngeal nerve, carries taste sensations from the back one
third of the tongue. These sensations are transmitted to the brain where the information
is interpreted as the sensation of taste.
A thorough understanding of the sensory system is essential in your ability to
provide basic emergency and primary medical care for today's soldier. For example,
laser injuries affect eyesight; artillery blasts affect hearing. Your knowledge of the
anatomy and physiology of the senses is necessary for you to recognize the effects of
modern weaponry and treat the soldier accordingly.