All Human Anatomy and Physiology Resources
Example Question #1 : Help With Gustatory And Olfactory Physiology
Which of the following senses uses chemoreceptors in order to send signals to the brain?
Chemoreceptors are used to sense taste and smell. Receptors in the nose and the mouth bind to chemicals that enter these regions. Once bound, the receptors send action potentials to the brain in order to stimulate the sensation of smell and taste. Depending on the type of receptor being bound, different sensations can arise.
Vision, hearing, and touch result from photoreceptors and mechanoreceptors. Photoreceptors in the eyes (namely rods and cones) generate electrical signals in response to light. Mechanoreceptors in the cochlea generate action potentials based on the vibrations of sound waves. Mechanoreceptors in the skin respond to pressure and other external stimuli to produce the sensation of touch.
Example Question #2 : Help With Gustatory And Olfactory Physiology
Which nerve allows for special sensory taste fibers for the anterior two-thirds of the tongue?
The chorda tympani branch of the facial nerve (cranial nerve VII), which is carried by the lingual branch (of the trigeminal nerve), allow for special sensory taste fibers for the anterior two-thirds of the tongue. The general sensory innervation for the anterior two=thirds of the tongue is provided by the lingual branch of the mandibular nerve from the trigeminal nerve (cranial nerve V).
The glossopharyngeal nerve (cranial nerve IX) provides sensory and taste to the posterior one-third of the tongue. Hypoglossal nerve (cranial nerve XII) provides motor innervation for all the muscles of the tongue (except for palatoglossus which is innervated by the pharyngeal branch of the vagus nerve (cranial nerve X).