Athena Vale
The human face has about 20 facial muscles on each side, which are essential for chewing and making facial expressions. These muscles are located throughout the face, including the ears, mouth, forehead, nose, and eyes. They run underneath the skin, from the scalp down to the neck, and are typically paired, with one on each side of the face. Facial muscles originate from bones or fascia and insert into the skin, manipulating the skin and soft tissues. They are the only group of muscles that insert into the skin. The facial muscles can be broadly categorized into three groups: orbital, nasal, and oral.
| Characteristics | Values |
|---|---|
| Number of facial muscles | 20-30 |
| Origin | Bones or fascia |
| Insertion | Skin or dermis |
| Function | Chewing, making facial expressions, respiration |
| Muscle groups | Orbital, nasal, oral |
| Example muscles | Occipitofrontalis, orbicularis oculi, nasalis, mentalis, zygomaticus minor |
Explore related products
What You'll Learn
Muscles involved in chewing
The human face has about 20 facial muscles on each side, which are essential for chewing and making facial expressions. These muscles are called the muscles of mastication and develop from the first pharyngeal arch. They are innervated by the mandibular division of the trigeminal nerve (CN V3).
The four main muscles of mastication are the masseter, temporalis, and medial and lateral pterygoid. They originate from the surface of the skull and attach to the rami of the mandible at the temporomandibular joint (TMJ). The masseter muscle is the most powerful muscle of mastication. It is quadrangular in shape and has two parts: deep and superficial. It lies superficial to the pterygoids and temporalis muscles. The superficial part originates from the maxillary process of the zygomatic bone, while the deep part originates from the zygomatic arch of the temporal bone. Both parts attach to the ramus of the mandible. The masseter functions to elevate the mandible and approximate the teeth.
The temporalis muscle originates from the temporal fossa of the skull and attaches to the coronoid process of the mandible. It is covered by tough fascia, which can be harvested surgically and used to repair a perforated tympanic membrane. The temporalis muscle elevates and retracts the mandible.
The medial pterygoid originates from the sphenoid bone's lateral pterygoid plate and inserts on the mandibular ramus and angle's medial aspect. It aids in jaw closure and chin protrusion. The lateral pterygoid has a similar origin but inserts on the mandibular condyle. It assists with chin protrusion, jaw opening, and articular disc/condylar stabilization.
Truncal Muscles: Core Strength and Posture Power
You may want to see also
Explore related products
Muscles that control facial expressions
The human face has about 20 to 30 facial muscles on each side, which are essential for chewing and making facial expressions. These muscles are located throughout the face, including the ears, mouth, forehead, nose, and eyes. They run underneath the skin from the scalp down to the neck and are typically paired, with one on each side of the face.
The muscles of facial expression are unique because they originate from bones and insert into the skin, manipulating the skin and soft tissues. In contrast, other skeletal muscles move the bones. Facial muscles have a higher fast-twitch fibre concentration and fewer mitochondria than other muscles. The orbicularis oculi and zygomaticus major are the fastest-moving muscles in the human body.
The facial muscles can be divided into groups based on their location and function. The orbital group includes the orbicularis oculi, which is involved in closing the eyelids and can cause crow's feet wrinkles with overuse. The nasal group includes the nasalis and procerus muscles, which are involved in creating facial expressions and respiration. The procerus pulls the eyebrows downward to produce wrinkles over the nose, while the nasalis compresses the nasal aperture and dilates the nostrils.
The oral or buccolabial group of muscles controls the shape and movements of the mouth and lips. These include the risorius, zygomaticus major, zygomaticus minor, levator labii superioris, levator labii superioris alaeque nasi, levator anguli oris, depressor labii inferioris, depressor anguli oris, mentalis, and orbicularis oris muscles. The risorius, zygomaticus major, and zygomaticus minor muscles help elevate and evert the upper lip, contributing to expressions such as smiling, frowning, or grimacing. The levator labii superioris and levator labii superioris alaeque nasi also elevate the upper lip, exposing the maxillary teeth and deepening the nasolabial lines, which are seen in expressions like smiling and grinning. The depressor anguli oris depresses the angle of the mouth, contributing to expressions of sadness or anger. The depressor labii inferioris and mentalis muscles depress and evert the lower lip, creating wrinkles on the chin associated with expressions of sadness, contempt, or doubt. The orbicularis oris closes the lips, and the buccinator compresses the cheek.
Muscle Biopsy: Is It Safe or Risky?
You may want to see also
Explore related products
Muscles around the eyes
The human face has about 20 facial muscles, which are essential for chewing and making facial expressions. Facial muscles are located throughout the face, including the ears, mouth, forehead, nose, and eyes.
The eyes, in particular, have six muscles that control which ways the eyes point, contributing to vision. These muscles are called "external" or "extrinsic" muscles because they attach to the outside of the eyeball. The six muscles work in pairs, with one muscle moving and its partner in the same eye helping to control and balance that movement.
The four rectus muscles are responsible for rotating the eyes and elevating or depressing them. The medial rectus muscle enables medial rotation around the vertical axis, while the lateral rectus muscle enables lateral rotation. The superior rectus muscle elevates the eye and contributes to adduction and intorsion. The inferior rectus muscle depresses and laterally rotates the eye, also contributing to adduction and extorsion.
The superior oblique muscle works like a pulley, starting at the upper back of the eye and extending forward, threading through a small bony opening on the upper-inner side of the eye socket called the trochlea. After passing through the trochlea, it attaches to the top of the eyeball, just behind the superior rectus. The inferior oblique muscle attaches to the lower-inner side of the eye socket, extends away from the nose, wraps around the bottom of the eye, and attaches just behind the lateral rectus on the far side.
The orbicularis oculi muscles are the main protractors (closure) of the eyelids. They are a flat, ring-like band of skeletal muscle surrounding the anterior orbit, composed of three parts: the orbital portion, the palpebral portion, and the lacrimal portion. The orbicularis oculi and zygomaticus major are the fastest-moving muscles in the human body.
Gluteus Maximus: Is Your Butt Muscle or Fat?
You may want to see also
Explore related products
Muscles around the nose
The human face has about 20 facial muscles, which are essential for chewing and making facial expressions. Facial muscles are located throughout the face, including the ears, mouth, forehead, nose, and eyes. They run underneath the skin from the scalp down to the neck.
The muscles around the nose form a distinct subgroup within the muscles of facial expression. One of the key muscles in this group is the nasalis muscle, which is a small muscle found on each side of the dorsum of the nose. The nasalis muscle is involved in creating facial expressions and contributes to respiration. It compresses the nasal aperture with its transverse part and dilates the nostrils with its alar part. These actions are important in creating facial expressions such as conveying feelings of anger and enhancing deep breathing.
The nasalis muscle is also one of the key muscles that is not formed or inserted correctly in cleft lip and cleft palate deformities. During reconstructive surgery, the head of the transverse part needs to be identified so that it can be surgically sutured to the nasal septum. Due to its superficial location, the nasalis muscle can be used to test the facial nerve, specifically the zygomatic branches.
Another muscle that is part of the nasal muscle group is the procerus muscle. This muscle is also primarily involved in creating facial expressions and contributing to respiration.
Resting Your Neck: Techniques for Muscle Relaxation and Recovery
You may want to see also
Explore related products
Muscles around the mouth
The human face has about 20 to 30 main facial muscles on each side, which are essential for chewing and making facial expressions. The muscles of facial expression are unique because they originate from bones and insert into the dermis, manipulating the skin and soft tissues.
The muscles around the mouth, or the buccolabial group of muscles, form a functional compound that controls the shape and movements of the mouth and lips. The buccolabial muscles are in and around the mouth and include the following:
- Buccinator: This thin muscle in the cheek holds it toward the teeth and fills the space between the upper and lower jaws. It is composed of three parts: superior, inferior, and posterior. It originates from the alveolar process of the maxilla, opposite the three maxillary molar teeth, and converges toward the angle of the mouth.
- Depressor Anguli Oris: This muscle is on the side of the chin and works with other muscles to produce a frown. It is part of the modiolus, a fibromuscular hub where muscle fibres insert, along with the orbicularis oris, risorius, levator anguli oris, and zygomaticus major muscles.
- Depressor Labii Inferioris: This muscle in the chin helps control movement in the lower lip.
- Levator Anguli Oris: This muscle helps you smile.
- Levator Labii Superioris: This muscle can enable you to smile or show disgust. It is a short triangular muscle that originates from the zygomatic process of the maxilla and maxillary process of the zygomatic bone. It attaches to the skin and submucosa of the upper lip, blending with other facial muscles that insert at this site.
- Levator Labii Superioris Alaeque nasi: This muscle can open your nostrils and lift your upper lip.
- Mentalis: This short conical muscle is located in the centre of the chin and helps control the lower lip. It arises from the incisive fossa of the mandible and descends to insert on the skin of the chin at the level of the mentolabial sulcus of the mandible.
- Orbicularis Oris: This circular composite muscle surrounds the mouth and forms the majority of the lips. It consists of two parts: labial and marginal. Both portions originate from the modiolus, a fibromuscular structure found on the lateral sides of the mouth. From the modiolus, the fibres of the orbicularis oris course medially to fill the peribucal area. The marginal portion passes from the modiolus on one side to the modiolus on the other side of the mouth.
- Risorius: This muscle is part of the buccolabial group.
The Role and Function of the Cremaster Muscle
You may want to see also
Frequently asked questions
The palpebral, lacrimal, and orbital parts of the orbicularis oculi muscle insert onto the skin around the margin of the orbit and the tarsal plates of the eyelid.
The mentalis is a short conical muscle located in the chin area. It originates from the incisive fossa of the mandible and inserts on the skin of the chin at the level of the mentolabial sulcus of the mandible.
The frontal belly of the occipitofrontalis muscle originates on the epicranial aponeurosis and inserts on the skin superior to the eyes and nose.
The nasalis muscle is made of two parts: a transverse part and an alar part. The transverse part originates on the maxilla on either side of the nose and inserts on an aponeurosis across the dorsum of the nose. The alar part originates on the maxilla, over the lateral incisor, and inserts on the alar cartilage.
