Question

When testing a client's ability to identify odors, the nurse is assessing the function of which cranial nerve? a. Facial b. Trigeminal c. Olfactory d. Spinal accessory

Short answer

c. Olfactory

Step-by-step solution

- Identify Cranial Nerves Related to Senses

Cranial nerves can be associated with various functions like motor, sensory, or a combination of both. To find the correct answer, we need to identify which cranial nerve is responsible for the sense of smell.

- Review the Functions of Given Cranial Nerves

We need to understand what each of the given cranial nerves controls:- The Facial nerve (VII) mainly controls facial expressions and taste sensations from the anterior two-thirds of the tongue.- The Trigeminal nerve (V) is responsible for sensations in the face and motor functions such as biting and chewing.- The Olfactory nerve (I) is responsible for the sense of smell.- The Spinal accessory nerve (XI) controls certain shoulder and neck muscles.

- Determine the Correct Answer

Since the client’s ability to identify odors relates to the sense of smell, the cranial nerve responsible for this function is the Olfactory nerve (I).

Key concepts

Olfactory Nerve

The olfactory nerve, also known as Cranial Nerve I, is primarily responsible for the sense of smell. It is a sensory nerve that transmits smell information from the nose to the brain. The olfactory nerve starts in the upper part of the nasal cavity where specialized receptors pick up odor signals. These signals are then sent to the olfactory bulb, and ultimately, to various regions of the brain for interpretation. If there is any damage to this nerve, it can lead to loss of smell, a condition known as anosmia.
To assess the olfactory nerve, doctors or nurses often conduct a smell identification test. This involves the client being asked to identify familiar scents, such as vanilla or coffee, while one nostril is occluded. Proper function of the olfactory nerve is crucial as it not only affects smell but can also influence taste sensations.

Sensory Function

Sensory function pertains to the ability of the nervous system to perceive and relay information about the external and internal environment. Cranial nerves may have sensory, motor, or mixed functions. Sensory nerves, such as the olfactory nerve, are responsible for transmitting sensory data to the brain.
Other examples of sensory nerves include the optic nerve (Cranial Nerve II) for vision and the vestibulocochlear nerve (Cranial Nerve VIII) for hearing and balance. Sensory assessments typically involve evaluating the client’s perception of light touch, pain, temperature, and special senses like vision and hearing. Any abnormalities in sensory function can give important clues about the underlying neurological condition.

Smell Identification

Smell Identification is a key method used to assess the function of the olfactory nerve. It's a simple yet effective test that involves asking clients to identify specific odors. This test helps healthcare providers identify any impairments in the sense of smell.
During the test, familiar and non-irritating substances, such as lemon, coffee, or mint, are used. A specific scent is presented to the client, who is asked to identify it while one nostril is closed. This test not only confirms the proper working of the olfactory nerve but also assists in detecting early signs of neurological disorders.
Regular smell identification tests are important, especially for elderly patients or those with neurological conditions, as early detection of abnormalities can lead to prompt treatment and better outcomes.