This study unit will teach you how to:
- Identify the structures that receive taste sensations.
- Name nerves that transmit the taste sensations to the brain.
- Describe the parts of the brain involved in processing and interpreting taste sensations.
The taste pathway is an ascending sensory pathway that carries gustatory information. It is provided by the special visceral afferent (SVA) fibers of the facial (CN VII), glossopharyngeal (IX) and vagus nerve (CN X). Special visceral afferent fibers by definition convey information about special senses (in this case taste) from the visceral organs.
The main structure involved in taste sensation is the tongue, with its anterior 2/3 being innervated by the facial nerve, and its posterior 1/3 by the glossopharyngeal nerve. Additional structures that receive taste sensations are the inferior surface of the soft palate, supplied by the facial nerve, and the epiglottis, supplied by the vagus nerve.
The taste sensations are carried by these nerves to the nucleus of solitary tract in the medulla oblongata. From here, the majority of the impulses are transmitted to the thalamus which, in turn, projects the taste information to the primary gustatory cortex found in the insula. In addition, some of the fibers from the nucleus tractus solitary are projected to the hypothalamus and amygdala, which are involved in certain unconscious mechanisms related to taste.
Learn more about the components, course and function of the taste pathway by watching the following video!
Take a quiz
Now that you've watched our video about the taste pathway, you might want to test what you just learned! We've created an interesting and smart quiz with all the structures that are involved in the taste pathway. Try it and see how much you know!
Take a closer look at the components of the taste pathway in the gallery below.
|Facial nerve||Anterior 2/3 of tongue → Chorda tympani
Soft palate → Greater petrosal nerve
→ Geniculate ganglion → Rostral solitary nucleus
|Glossopharyngeal nerve||Posterior 1/3 of tongue → Lingual nerve → Inferior ganglion of glossopharyngeal nerve → Rostral solitary nucleus|
|Vagus nerve||Epiglottis → Superior laryngeal nerve → Inferior ganglion of vagus nerve → Rostral solitary nucleus|
Taste sensation: Rostral solitary nucleus → Ventral posteromedial nucleus of thalamus → Insula
Appetite/satiety response: Rostral solitary nucleus → Pontine taste area → Lateral hypothalamic area
Emotional/memory formation: Rostral solitary nucleus → Pontine taste area → Amygdaloid body