Related Experiment Video
Updated: Jul 16, 2025
12:09
Stimulating the Lip Motor Cortex with Transcranial Magnetic Stimulation
Published on: June 14, 2014
19.1K
Proprioceptive innervation of the human lips
José Martín-Cruces1, Patricia Cuendias1, Yolanda García-Mesa1
1Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain.
Anatomical Record (Hoboken, N.J. : 2007)
|September 15, 2023
Summary
Human lips lack muscle spindles but have dense sensory nerve formations, including Ruffini-like and Pacinian corpuscles. These nerve endings, expressing PIEZO2, likely enable lip proprioception.
Area of Science:
- Neuroscience
- Anatomy
- Sensory Biology
Background:
- Facial muscles, particularly the orbicularis oris, are traditionally considered devoid of typical proprioceptors like muscle spindles.
- Recent research has questioned the absence of proprioceptors in facial muscles, necessitating further investigation.
Purpose of the Study:
- To investigate the proprioceptive innervation of human lips, focusing on the orbicularis oris muscle.
- To determine the presence or absence of muscle spindles and characterize other sensory nerve formations in the lips.
Main Methods:
- Human lip tissues (n=5) from frozen cadavers were utilized.
- Immunohistochemistry was performed to detect S100 protein (nerves), myosin heavy chain (muscle fibers), and PIEZO2 (mechanosensitive channel).
Main Results:
- No typical muscle spindles were identified in the human lip muscles.
- A high density of morphologically diverse sensory nerve formations was observed.
- These formations exhibited characteristics of Ruffini-like and Pacinian corpuscles.
- Axons of these sensory formations showed PIEZO2 immunoreactivity.
Conclusions:
- Human lip muscles do not possess typical muscle spindles.
- Lips are equipped with a rich sensory innervation, likely responsible for proprioception.
- The identified sensory nerve formations, expressing PIEZO2, play a crucial role in lip sensory feedback.
More Related Videos
Related Concept Videos
01:22Cranial Nerves: Types Part II
2.5K
Cranial nerves are responsible for transmitting motor and sensory information between the brain and various parts of the body. There are twelve pairs of cranial nerves. While the first six innervate the head and neck, the latter six nerves innervate the head and neck, as well as organs and tissues in the thoracic and abdominal cavities. They facilitate communication, expression, and autonomic control within the human body.
Facial Nerve (Cranial Nerve VII)
Cranial nerve VII, or the facial nerve,...
Facial Nerve (Cranial Nerve VII)
Cranial nerve VII, or the facial nerve,...
2.5K
01:19Cranial Nerves: Overview and Anatomy
1.9K
The cranial nerves are an important part of the complex network of nerves in the human body. These nerves emerge directly from the brain and are responsible for transmitting essential information between the brain and various parts of the head and neck. There are 12 pairs of cranial nerves, systematically numbered using Roman numerals from I to XII, beginning from the anterior and moving to the posterior of the brain. Each cranial nerve is uniquely identified by names that reflect its function...
1.9K
01:14Cranial Nerves: Types Part I
2.7K
Cranial nerves are responsible for transmitting motor and sensory information between the brain and various parts of the body. There are twelve pairs of cranial nerves, with the first six being essential in sensory perception, motor control, and autonomic functions related to the head and neck.
Olfactory Nerve (Cranial Nerve I)
The olfactory nerve, or cranial nerve I, is unique as it is purely sensory and dedicated to the sense of smell. This nerve originates in the olfactory epithelium of the...
Olfactory Nerve (Cranial Nerve I)
The olfactory nerve, or cranial nerve I, is unique as it is purely sensory and dedicated to the sense of smell. This nerve originates in the olfactory epithelium of the...
2.7K
01:16Sensory Functions of the Skin
5.1K
The skin is the largest organ of the human body and plays a crucial role in our sensory perception. It contains a vast network of sensory receptors that contribute to the skin's protective function by perceiving physical, biological, and environmental cues and generating relevant responses.
There are two main categories of receptors on the skin: capsulated and non-capsulated. The non-capsulated ones are mainly the pain receptors. The capsulated ones can be further categorized based on the...
There are two main categories of receptors on the skin: capsulated and non-capsulated. The non-capsulated ones are mainly the pain receptors. The capsulated ones can be further categorized based on the...
5.1K
01:33Somatosensation
36.7K
The somatosensory system relays sensory information from the skin, mucous membranes, limbs, and joints. Somatosensation is more familiarly known as the sense of touch. A typical somatosensory pathway includes three types of long neurons: primary, secondary, and tertiary. Primary neurons have cell bodies located near the spinal cord in groups of neurons called dorsal root ganglia. The sensory neurons of ganglia innervate designated areas of skin called dermatomes.
36.7K
01:28Major Somatic Sensory Pathways
1.0K
Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the...
1.0K