Uploaded March 2019 | Updated September 2026, 2 weeks ago
The facial nerve (cranial nerve VII) has multiple functions, but is best known for its role in controlling the muscles of facial expression. In this video, I cover all of the functions of the facial nerve, as well as describe what can happen when the nerve is damaged.
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📚Your Brain, Explained: What Neuroscience Reveals About Your Brain and its Quirks: amazon.com/Your-Brain-Explained-Neuroscience-Reveals/dp/1473696569
📚Bizarre: The Most Peculiar Cases of Human Behavior and What They Tell Us About How the Brain Works: amazon.com/Bizarre-Peculiar-Cases-Human-Behavior/dp/139980121X
TRANSCRIPT:
Welcome to 2 minute neuroscience, where I explain neuroscience topics in 2 minutes or less. In this installment I will discuss the facial nerve.
The facial nerve, also known as cranial nerve VII, is best known for its role in controlling the muscles of facial expression, as well as a number of other muscles of the face and head such as certain muscles involved with swallowing and jaw movement, muscles of the external ear, and the stapedius muscle, which is found in the middle ear and is involved with dampening loud noises. The facial nerve also receives sensory information from the outer ear and from the taste buds on the anterior two-thirds of the tongue, and it supplies most major glands in the head, including the lacrimal glands for tear production, the submandibular and sublingual salivary glands, and the mucous glands of the nose, paranasal sinuses, and palate.
The facial nerve is associated with several nuclei in the brainstem. The motor portion of the facial nerve originates in the facial motor nucleus in the pons. The portion of the nerve that supplies the glands mentioned previously originates from the superior salivatory nucleus in the pons. Taste information travels to the nucleus of the solitary tract in the medulla. And the sensory information from the outer ear travels to the spinal trigeminal nucleus in the medulla.
Facial nerve damage can cause a variety of symptoms, but the most recognizable of them is weakness and/or paralysis of the muscles of facial expression on the same side of the head that the damaged nerve supplies. The patient’s mouth on the affected side may droop, and he may be unable to close the eye on the affected side. In most cases of facial nerve palsy, the cause of the dysfunction is not known; when this is the case it is referred to as Bell’s palsy.
References:
Brackmann DE, Fetterman BL. Cranial Nerve VII: Facial Nerve. In Goetz CG, ed.
Textbook of Clinical Neurology, 3rd ed. Elsevier; 2007.
Sanders RD. The Trigeminal (V) and Facial (VII) Cranial Nerves. Head and Face Sensation and Movement. Psychiatry (Edgmont). 2010 Jan; 7(1): 13–16.
Wilson-Pauwels L, Akesson EJ, Stewart PA, Spacey SD. Cranial Nerves in Health and Disease. 2nd ed. London: BC Decker, Inc; 2002.
The facial nerve (cranial nerve VII) has multiple functions, but is best known for its role in controlling the muscles of facial expression. In this video, I cover all of the functions of the facial nerve, as well as describe what can happen when the nerve is damaged.
đź§ Take your learning further with my free, self-paced Introduction to Neuroscience course featuring my videos, articles, and hundreds of quiz questions: neuroscientificallychallenged.com/course
If you're looking for accessible and entertaining ways to learn more about the brain, check out my books:
📚Your Brain, Explained: What Neuroscience Reveals About Your Brain and its Quirks: amazon.com/Your-Brain-Explained-Neuroscience-Reveals/dp/1473696569
📚Bizarre: The Most Peculiar Cases of Human Behavior and What They Tell Us About How the Brain Works: amazon.com/Bizarre-Peculiar-Cases-Human-Behavior/dp/139980121X
TRANSCRIPT:
Welcome to 2 minute neuroscience, where I explain neuroscience topics in 2 minutes or less. In this installment I will discuss the facial nerve.
The facial nerve, also known as cranial nerve VII, is best known for its role in controlling the muscles of facial expression, as well as a number of other muscles of the face and head such as certain muscles involved with swallowing and jaw movement, muscles of the external ear, and the stapedius muscle, which is found in the middle ear and is involved with dampening loud noises. The facial nerve also receives sensory information from the outer ear and from the taste buds on the anterior two-thirds of the tongue, and it supplies most major glands in the head, including the lacrimal glands for tear production, the submandibular and sublingual salivary glands, and the mucous glands of the nose, paranasal sinuses, and palate.
The facial nerve is associated with several nuclei in the brainstem. The motor portion of the facial nerve originates in the facial motor nucleus in the pons. The portion of the nerve that supplies the glands mentioned previously originates from the superior salivatory nucleus in the pons. Taste information travels to the nucleus of the solitary tract in the medulla. And the sensory information from the outer ear travels to the spinal trigeminal nucleus in the medulla.
Facial nerve damage can cause a variety of symptoms, but the most recognizable of them is weakness and/or paralysis of the muscles of facial expression on the same side of the head that the damaged nerve supplies. The patient’s mouth on the affected side may droop, and he may be unable to close the eye on the affected side. In most cases of facial nerve palsy, the cause of the dysfunction is not known; when this is the case it is referred to as Bell’s palsy.
References:
Brackmann DE, Fetterman BL. Cranial Nerve VII: Facial Nerve. In Goetz CG, ed.
Textbook of Clinical Neurology, 3rd ed. Elsevier; 2007.
Sanders RD. The Trigeminal (V) and Facial (VII) Cranial Nerves. Head and Face Sensation and Movement. Psychiatry (Edgmont). 2010 Jan; 7(1): 13–16.
Wilson-Pauwels L, Akesson EJ, Stewart PA, Spacey SD. Cranial Nerves in Health and Disease. 2nd ed. London: BC Decker, Inc; 2002.


![2-Minute Neuroscience: Color Blindness
Color blindness is a condition in which a person has difficulty seeing or distinguishing certain colors. In this video, I explain the biological mechanisms underlying color blindness and how it is inherited.
đź§ Take your learning further with my free, self-paced Introduction to Neuroscience course featuring my videos, articles, and hundreds of quiz questions: https://neuroscientificallychallenged.com/course
If youre looking for accessible and entertaining ways to learn more about the brain, check out my books:
📚Your Brain, Explained: What Neuroscience Reveals About Your Brain and its Quirks: https://www.amazon.com/Your-Brain-Explained-Neuroscience-Reveals/dp/1473696569/
📚Bizarre: The Most Peculiar Cases of Human Behavior and What They Tell Us About How the Brain Works: https://www.amazon.com/Bizarre-Peculiar-Cases-Human-Behavior/dp/139980121X/
TRANSCRIPT
Color blindness is a condition in which a person has difficulty seeing or distinguishing certain colors. It typically does not involve a complete loss of color vision. Color blindness can be due to various causes, but the most common forms are inherited and caused by genetic differences that affect the function of cone photoreceptors in the retina. The most common type of color blindness is red-green color blindness, where individuals have difficulty distinguishing red and green hues.
Normal color vision relies on three types of cones—each sensitive to different ranges of wavelengths corresponding roughly to blue, green, and red. Some individuals have all three cones but have abnormalities in cone sensitivity that cause irregularities in color perception; this is referred to as anomalous trichromacy and is the mildest form of color blindness. When only two of the three cone cells are functional, it results in a type of color blindness known as dichromacy. The rarest and most severe form of color blindness is called monochromacy and involves a complete loss of color vision.
Red-green color blindness is much more common in males because the mutations that typically cause it are found on the x chromosome. If females possess such a mutation on one x chromosome, it is likely to be balanced out by a functional gene on the other x chromosome. Because males only have one x chromosome, a mutation is more likely to result in color blindness.
Color blindness can be diagnosed using color vision tests, and although it cannot be cured, various technologies like color-enhancing lenses can help in some situations.
REFERENCES
Breedlove SM, Watson NV. Behavioral Neuroscience. 10th ed. New York (NY): Oxford University Press; 2023.
Carroll J, Conway BR. Color vision. Handb Clin Neurol. 2021;178:131-153. doi: 10.1016/B978-0-12-821377-3.00005-2. PMID: 33832674.
Meister M, Tessier‑Lavigne M. Low‑Level Visual Processing: The Retina. In: Kandel ER, Koester JD, Mack SH, Siegelbaum SA, editors. Principles of Neural Science. 6th ed. New York (NY): McGraw‑Hill; 2021.
Naifeh N, Kaufman EJ. Color Vision. 2022 Oct 31. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan–. PMID: 29261952.
Simunovic MP. Colour vision deficiency. Eye (Lond). 2010 May;24(5):747-55. doi: 10.1038/eye.2009.251. Epub 2009 Nov 20. PMID: 19927164.
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