Answer
Two cranial nerves involved in the sense of taste are the facial nerve (cranial nerve VII) and the glossopharyngeal nerve (cranial nerve IX). Here's where their sensory fibers originate:
1. Facial Nerve (Cranial Nerve VII):
- The facial nerve carries taste sensations from the anterior two-thirds (front part) of the tongue.
- The sensory fibers responsible for taste originate in the taste buds located on the taste papillae of the tongue's anterior two-thirds.
- These taste signals are transmitted via the chorda tympani branch of the facial nerve.
2. Glossopharyngeal Nerve (Cranial Nerve IX):
- The glossopharyngeal nerve carries taste sensations from the posterior one-third (back part) of the tongue, as well as from the soft palate and the pharynx.
- The sensory fibers responsible for taste in the posterior one-third of the tongue originate in the taste buds located on the taste papillae of the tongue's back portion.
- Taste signals from the soft palate and pharynx also travel through the glossopharyngeal nerve.
In summary, the facial nerve is primarily responsible for taste sensations from the front two-thirds of the tongue, while the glossopharyngeal nerve carries taste signals from the back one-third of the tongue, as well as from the soft palate and pharynx. These cranial nerves play a crucial role in transmitting taste information to the brain, allowing us to perceive different flavors.
Work Step by Step
Two cranial nerves involved in the sense of taste are the facial nerve (cranial nerve VII) and the glossopharyngeal nerve (cranial nerve IX). Here's where their sensory fibers originate:
1. Facial Nerve (Cranial Nerve VII):
- The facial nerve carries taste sensations from the anterior two-thirds (front part) of the tongue.
- The sensory fibers responsible for taste originate in the taste buds located on the taste papillae of the tongue's anterior two-thirds.
- These taste signals are transmitted via the chorda tympani branch of the facial nerve.
2. Glossopharyngeal Nerve (Cranial Nerve IX):
- The glossopharyngeal nerve carries taste sensations from the posterior one-third (back part) of the tongue, as well as from the soft palate and the pharynx.
- The sensory fibers responsible for taste in the posterior one-third of the tongue originate in the taste buds located on the taste papillae of the tongue's back portion.
- Taste signals from the soft palate and pharynx also travel through the glossopharyngeal nerve.
In summary, the facial nerve is primarily responsible for taste sensations from the front two-thirds of the tongue, while the glossopharyngeal nerve carries taste signals from the back one-third of the tongue, as well as from the soft palate and pharynx. These cranial nerves play a crucial role in transmitting taste information to the brain, allowing us to perceive different flavors.