Dominic Stone
The orbicularis oris muscle is a complex, multi-layered muscle that surrounds the mouth and forms the majority of the lips. It is responsible for pulling the lip tissue centrally, allowing for actions such as eating, drinking, whistling, and kissing. The muscle is also used in playing brass and some woodwind instruments. It is composed of four independent quadrants that interlace, giving the appearance of circularity. The orbicularis oris muscle is part of a large group of muscles of facial expression called the buccolabial group.
| Characteristics | Values |
|---|---|
| Description | A complex, multi-layered muscle that surrounds the orifice of the mouth and forms the majority of the lips |
| Alternative names | Musculus orbicularis oris, orbicular muscle of the mouth |
| Function | Controls the shape and movements of the lips, including closing, protruding, compressing, and puckering |
| Facial expressions | Enables various facial expressions, such as anger and sadness |
| Speech | Facilitates speech |
| Music | Used in playing brass and some woodwind instruments |
| Parts | Consists of two parts: a larger peripheral part and a smaller marginal part |
| Peripheral portion | Also called the extrinsic portion, it originates from the modiolus and arises from the fibers of five buccolabial muscles: levator anguli oris, depressor anguli oris, buccinator, risorius, and zygomaticus major |
| Superior peripheral portion | Blends with levator labii superioris, zygomaticus major, zygomaticus minor, and levator anguli oris |
| Inferior peripheral portion | Blends with depressor labii inferioris, depressor anguli oris, mentalis, and platysma |
| Innervation | Buccal and mandibular branches of the facial nerve (CN VII) |
| Arterial blood supply | Superior and inferior labial branches of the facial artery, mental and infraorbital branches of the maxillary artery |
| Fibers | Consists of four quadrants (upper, lower, right, and left) with fibers running in different directions |
| Actions | Pulls the lip tissue centrally, enabling actions such as eating, drinking, whistling, and kissing |
Explore related products
What You'll Learn
Anatomy and function
The orbicularis oris muscle is a complex, multi-layered muscle that encircles the mouth and forms the majority of the lips. It is composed of four independent quadrants (upper, lower, right, and left) that interlace, giving the appearance of circularity. The muscle consists of two parts: a larger peripheral part and a smaller marginal part. The peripheral portion, also called the extrinsic portion, arises from the modiolus, a dense fibromuscular nodule at the angle of the mouth, and is formed by fibres from five buccolabial muscles: the levator anguli oris, depressor anguli oris, buccinator, risorius, and zygomaticus major. The superior peripheral portion blends with the levator labii superioris, zygomaticus major, zygomaticus minor, and levator anguli oris, while the inferior peripheral portion blends with the depressor labii inferioris, depressor anguli oris, mentalis, and platysma.
The orbicularis oris muscle is unique in that it has neither a bony nor a tendinous origin. Instead, it attaches through a thin, superficial musculoaponeurotic system to the dermis of the upper and lower lips. It is covered externally by skin and internally by mucosa, with the junction between the two forming the vermilion border of the lips. The muscle receives its arterial blood supply primarily from the superior and inferior labial branches of the facial artery, as well as the mental and infraorbital branches of the maxillary artery.
Functionally, the orbicularis oris muscle is responsible for controlling the shape and movements of the lips. It closes, protrudes, and compresses the lips, facilitating actions such as eating, drinking, whistling, kissing, and speaking. It also aids in producing various facial expressions, such as those associated with anger and sadness. The muscle may act independently or in conjunction with other facial muscles, such as the mimetic muscles that elevate and depress the lips.
The orbicularis oris muscle is also involved in playing certain musical instruments, particularly brass and some woodwind instruments. Its contraction decreases the size of the mouth opening, resulting in a pursing or puckering of the lips, which is essential for producing sound on these instruments.
The Longest Muscle in the Human Body
You may want to see also
Explore related products
Facial expression
The orbicularis oris muscle is a complex muscle that surrounds the orifice of the mouth and forms the majority of the lips. It is responsible for controlling the shape and movements of the lips, including closing, protruding, and compressing them. This muscle is part of a larger group of muscles called the buccolabial group, which also includes the levator anguli oris, levator labii superioris, and zygomaticus major, among others. These muscles work together to facilitate speech and produce various facial expressions, such as those associated with anger or sadness.
The orbicularis oris muscle is composed of two parts: a larger peripheral part and a smaller marginal part. The peripheral portion, also known as the extrinsic portion, arises from the modiolus and is made up of fibres from five buccolabial muscles: the levator anguli oris, depressor anguli oris, buccinator, risorius, and zygomaticus major. The superior peripheral portion blends with muscles like the levator labii superioris and zygomaticus major, while the inferior peripheral portion blends with muscles such as the depressor labii inferioris and depressor anguli oris.
The orbicularis oris muscle is a powerful muscle with a thin layer of fat covering it. It pulls the lip tissue centrally, enabling essential functions such as eating, drinking, whistling, and kissing. The muscle is also involved in playing brass and some woodwind instruments, as it is responsible for puckering the lips and closing the mouth.
The upper and lower lips are formed by this muscle, which is covered externally by skin and internally by mucosa. The junction between the mucous membrane and the skin is known as the vermillion border, and it contributes to the overall form and shape of the lips. The position and movement of the lips are influenced by mimetic muscles that elevate and depress them, attaching to the connective tissue at the oral commissures, known as the modiolus.
The orbicularis oris muscle is innervated by the buccal and mandibular branches of the facial nerve (CN VII), and its arterial blood supply comes primarily from the superior and inferior labial branches of the facial artery. This muscle demonstrates the presence of fibres with unique staining characteristics, indicating a functional subdivision within the muscle.
Muscle Injections: Why This Route?
You may want to see also
Explore related products
Speech and facial expressions
The orbicularis oris muscle is a complex, multi-layered muscle that encircles the mouth and forms the majority of the lips. It is responsible for controlling the shape and movements of the lips, including closing, protruding, and compressing them. This muscle is part of a large group of muscles called the buccolabial group, which are responsible for facial expressions.
The orbicularis oris muscle plays a crucial role in speech and facial expressions. Its primary function as a sphincter of the mouth is to close the lips and narrow the oral opening. This action is essential for speech production, as it helps to articulate words and form different sounds. For example, when we pronounce words with certain consonants, such as "p," "b," or "m," the orbicularis oris muscle contracts, pursing the lips together. This contraction also helps to prevent drooling, an important function during speech and in everyday life.
Additionally, the orbicularis oris muscle contributes to a range of facial expressions. By manipulating the shape and position of the lips, it helps convey emotions such as anger, sadness, and others. For instance, when we feel angry, the muscle may compress the lips into a thin line, whereas sadness might be expressed with a downturned mouth. The muscle's ability to protrude the lips is also essential for various facial expressions, such as puckering up for a kiss or blowing a kiss to a loved one.
The orbicularis oris muscle is also involved in other oral functions beyond speech and facial expressions. It assists in eating, drinking, and even whistling. When we eat or drink, this muscle helps to pull the lip tissue centrally, ensuring that food and liquid enter the mouth without spillage. Whistling, too, requires a precise manipulation of the lips and oral cavity, with the orbicularis oris muscle contracting to create the necessary airflow for the production of sound.
In summary, the orbicularis oris muscle is integral to speech and facial expressions. Its ability to control the shape and movement of the lips allows for the articulation of words, the expression of emotions, and the performance of various oral functions. This muscle is a key component of human communication and expression, working in conjunction with other facial muscles to facilitate our interactions with the world.
Treating Muscle Adhesions: Effective Strategies for Quick Recovery
You may want to see also
Explore related products
Composition and structure
The orbicularis oris muscle is a complex muscle that surrounds the mouth and forms the lips. It is composed of two parts: a larger peripheral part and a smaller marginal part. The peripheral portion, also known as the extrinsic portion, originates from the modiolus, a dense fibromuscular nodule at the angle of the mouth where most of the buccolabial muscles attach. The marginal portion, or intrinsic portion, consists of a single or double band of muscle fibres that stem from the modiolus toward the midline, passing through the connective tissue of the lips.
The orbicularis oris muscle is derived from the second branchial arch and is composed of intrinsic and extrinsic muscles of the lip. It is not a true sphincter but is made up of four independent quadrants that interlace to give the appearance of circularity. It is composed of numerous strata of muscular fibres surrounding the mouth, with different directions and sources. Some fibres are derived from other facial muscles inserted into the lips, while others are specific to the lips. A significant number of fibres are derived from the buccinator muscle, which forms the deeper stratum of the orbicularis.
The marginal part of the orbicularis oris muscle arises from the labial sides of the modiolus of angulus oris. The inner labial part of the muscle arises from the vermillion line, with fibres extending into the submucosa of the lips and laterally to the base of the modiolus of angulus oris. The fibres from the marginal part course into their respective upper and lower labial areas, attaching to the surfaces of the maxilla and mandible, as well as to the labial part at the vermillion line.
The superior peripheral portion of the orbicularis oris blends with the levator labii superioris, zygomaticus major, zygomaticus minor, and levator anguli oris. The inferior peripheral portion blends with the depressor labii inferioris, depressor anguli oris, mentalis, and platysma. The orbicularis oris muscle is innervated by the buccal and mandibular branches of the facial nerve (CN VII). Its arterial blood supply is derived primarily from the superior and inferior labial branches of the facial artery.
The Secret to Unlocking Your IPC Muscle's Full Potential
You may want to see also
Explore related products
Surrounding facial muscles
The orbicularis oris muscle is a complex, multi-layered muscle that encircles the mouth and forms the majority of the lips. It is responsible for pulling the lip tissue centrally, allowing for actions such as eating, drinking, whistling, and kissing. This muscle is not a true sphincter, but it does close the mouth and pucker the lips when contracted.
The orbicularis oris muscle is part of a large group of muscles of facial expression called the buccolabial group. The buccolabial group includes the levator anguli oris, levator labii superioris alaeque nasi, levator labii superioris, zygomaticus major, zygomaticus minor, risorius, depressor labii inferioris, depressor anguli oris, mentalis, incisivus superior and inferior, and buccinator muscles. These muscles work together to control the shape and movements of the lips, facilitating speech and various facial expressions.
The orbicularis oris muscle itself is composed of two parts: a larger peripheral part and a smaller marginal part. The peripheral portion, also called the extrinsic portion, arises from the modiolus, a dense fibromuscular nodule at the angle of the mouth. The modiolus is also where most of the buccolabial muscles attach. The superior peripheral portion of the orbicularis oris blends with the levator labii superioris, zygomaticus major, zygomaticus minor, and levator anguli oris. The inferior peripheral portion blends with the depressor labii inferioris, depressor anguli oris, mentalis, and platysma.
Deep to the orbicularis oris lie the inferior and superior labial arteries, while it is externally covered by the skin of the periorbital area. The muscle is innervated by the buccal and mandibular branches of the facial nerve (CN VII). The arterial blood supply is derived from the superior and inferior labial branches of the facial artery, mental and infraorbital branches of the maxillary artery.
The orbicularis oris muscle is also connected to other facial muscles and structures. For example, the medial band m. nasolabialis connects the upper lip to the back of the septum of the nose. Fibers from the quadratus labii superioris, the zygomaticus, and the quadratus labii inferioris intermingle with the transverse fibers of the orbicularis oris. Additionally, the muscle is connected with the maxilla and the septum of the nose above and the mandible below.
Relieving Muscle Soreness: Effective Strategies for Quick Recovery
You may want to see also
Frequently asked questions
The Orbicularis Oris muscle is a complex, multi-layered muscle that surrounds the mouth and forms the lips. It is responsible for pulling the lip tissue centrally, allowing for actions such as eating, drinking, whistling, and kissing.
The Orbicularis Oris muscle is made up of its own fibres and those lent from the dilator muscles of the mouth, mainly the buccinator muscle. It is divided into four quadrants (upper, lower, right, and left), each with a major peripheral portion and a smaller marginal portion.
The function of the Orbicularis Oris muscle is to control the shape and movement of the lips. It closes, protrudes, and compresses the lips, facilitating speech and various facial expressions.
