Muscles of form and expression Flashcards
- Bones
- Muscles
- Fascia & glands
- Integument (skin)
Relationship with surface
Superficial muscles will affect this.
Surface Form
This will leave signs.
- Contracting muscles draw skin with them.
- Results in some surface formations (4)
Constant repetition of a muscular action
- Prominences
- Hollows
- Folds
- Furrows
Resulting surface formations (from contracting muscles drawing skin with them).
Facial markings are more definite on ___1___ because they usually have less ____2_____.
- Males
- Adipose Tissue
- Sagging of tissues.
- An effect on the form of the head and features
- Gravitational pull
Loss of muscular tone results in these.
- When standing the pull is inferior.
- When laying horizontal the pull is lateral and posterior.
- There may be complaints of the old looking too young.
Gravitational pull
The gravitational pull when standing.
Inferior
The gravitational pull when lying horizontal.
Lateral And Posterior
- For every muscle pulling in one direction, another is there to return it to its position.
- Points of attachment
- Furrows (wrinkles)
Movement of muscles
- Origin
- Insertion
Points of attachment
End of the muscle, attached to a fixed point (bone, cartilage).
Origin
Moveable part or skin.
Insertion
Cross the direction of muscles at right angles. (aka sulci)
Furrows (Wrinkles)
Muscles whose fibers are long and few in number.
Have little strength
Muscles whose fibers are short and many in number.
Are powerful
- Quadrilateral
- Sphincter
- Fan Shaped
- Double-bellied
Examples of muscle types
Fibers are parallel and run directly from origin to insertion.
Quadrilateral
Surrounds a natural orifice.
Sphincter
Fibers which converge to a narrow insertion (temporalis)
Fan Shaped
Consists of two fleshy portions which are separated by a tendon or on an aproneurosis.
Double-Bellied
Flattened, ribbon-shaped tendon.
Aproneurosis
- Covers the top and side of the skull, from occipital to the eyebrows.
- Composed of two broad bellies
- The inferior furrows of the forehead are usually deeper.
- Muscle of the cranium
- Draws the scalp posteriorly and aneriorly, causing eyebrows to raise and wrinkles to form on the forehead.
Occipitofrontalis (1)- epicranius
- Occipital Belly
- Frontal Belly
- Continuous with the procerus muscle.
Two broad bellies of the occipitofrontalis (epicranius)
- Temporalis (2)
- Masseter (2)
Muscles of Mastication
- Broad fan-shaped muscle
- Strongest of the chewing muscles
- Arises in the temporal cavity and inserts into the mandible.
- Closes the mandible and assists in side to side movement of the mandible.
Temporalis
- It’s name means- to chew
- It raises the lower jaw (closes the mandible)
- Thick quadrilateral muscle
- Arises in the zygomatic arch and inserts into the mandible.
Masseter (2)
- Cutaneous muscles (affecting the skin).
- They lie in layers of superficial fascia.
- Are shorter and thinner (more active and responsive).
Muscles of the Face (general description)
- Obicularis oculi (2)
- Corrugator (2)
- Levator palpebrae superioris
Muscles of the Eyelids
- Sphincter muscle
- Surrounds the eye socket
- Closes the eyelid and compresses the lacrimal sac.
- Crows feet (optic facial sulci)
Obicularis oculi
A pyramid-shaped muscle of facial expression. Lies beneath the fontalis and orbicularis oculi.
- Known as the Frowning muscle
- Draws the eyebrows downward and medial. (as in frowning)
Corrugator (2)
A muscle of facial expression that runs from the inside of the eye socket to the superior tarsal plate of the eyelid.
- Raises the upper eyelid.
- May cut when unable to close eyelid.
Levator palpebrae superioris
Lower muscles affect nostrils.
- Procerus (1)
Muscles of the nose
- Fibers merge with the frontalis muscle.
- Covers the bridge of the nose
- Draws the medial ends of the eyebrows down.
- Draws the skin of the forehead inferiorly, causing transverse and vertical wrinkles in the forehead.
Procerus (1)
- Obicularis oris
- Quadratus Labii Superioris
- Levator Labii Suprioris Alaeque Nasi (2)
- Levator Labii Superoris (2)
- Zygomaticus Minor (2)
- Levator Anguli Oris (2)
- Zygomaticus Major (2)
- Buccinator (2)
- Risorius (2)
- Depressor Angulus Oris (Triangularis) (2)
- Depressor Labii Inferioris (Quadratus) (2)
- Mentalis (1)
Muscles of the Mouth
- A flat band of muscles in the upper and lower red lips and integumentary lips (updated definition)
- This large sphincter muscle encircles the mouth. (old definition)
- 10 pairs of muscles intsert into the spincter.
- Closes the lips, compresses lips against the teeth and shapes the lips during speech.
Obicularis Oris (1)
- Quadrilateral muscle
- Originates along the entire lower margin of the eyesocket.
- Runs downward to the upper lip.
- Composed of three heads:
- Levator labii superioris alaeque nasi
- levator labii superioralis
- zygomaticus minor
Quadratus Labii Superioris (Mouth Muscle)
“Common elevator” of the upper lip and wing of the nose.
- A muscle of facial expression
- Elevates and extends the upper lip
Levator Labii Superioris Alaeque Nasi (2)
Raises the upper lip.
- A muscle of facial expression
- Elevates and extends the upper lip.
Levator Labii Superioris (2)
From the anterior part of the zygomatic bone (cheekbone) it moves obliquely downward and medialward inserting in the upper lip at the angle of the mouth.
- Muscle of the face
- Draws the upper lip superiorly and laterally.
Zygomaticus Minor (2)
Contraction of th quadratus labii superioris together with the levator anguli oris lends to the increasing development of the fold of skin at the anterior margin of the cheek known as the __________.
Nasolabial Fold
A small muscle at the angle of the mouth.
- Elevator of the angle of the mouth.
- Located in the region of the canine tooth
- Originates from the canine fossa and inserts into the angle of the mouth.
- Contributes to the formation of:
- Nasolabial fold
- Angulus Oris Eminence (natural facial marking).
Levator Anguli Oris (2)
- Descends obliquely from the posterior portion of the cheekbone to the angle of the mouth.
- “Laughing muscle”- draws the angle of the mouth backward and upward. (posterior, superior, and laterally as in smiling or laughing).
- Helps to create the prominence of the nasolabial fold.
- Point of insertion contributes to the fullness of the Angulus Oris Eminence.
- Change of planes from the front to the side of the face.
Zygomaticus Major (2)
- Originates in the skin over the molar teeth and inserts into the skin at the anguli oris (corners of the mouth).
- “Trumpter’s” muscle
- Thin quadrilateral muscle
- principal cheek muscle
- Creates the lateral wall of the mouth
- Makes up part of the angulus oris eminences
- Compresses the cheek, and it pulls the anguli oris posteriorly. It produces the action of sucking.
Buccinator (2)
- Narrow superficial muscle
- Origin is the fascia over the masseter muscle
- Runs along the cheek area entering the skin at the angle of the mouth. (inserts in anguli oris)
- Contraction:
- Retracts the angle of the mouth (draws the corners of the mouth posteriorly)
- Action is atagonistic to that of the buccinator
Risorius (2)
(False Smile Muscle)
- Three sided muscle
- Approaches mouth from below
- Originates on oblique line of the mandible
- Muscle narrows to a small fasiculus and inserts at the angle of the mouth. (anguli oris)
- Contributes to the prominence of the angulus oris eminence.
- Depresses the angle of the mouth.
Depressor Angulus Oris (Triangularis) (2)
Slender bundle of fiber.
Fasciculus
- Small quadrilateral muscle
- Approaches lower lip from below
- Originates on oblique line of mandible
- Moves upward and medialward inserting into the skin of the lower lip.
- Contraction:
- Pulls upper lip down and slightly to the side
- Will change the form of the line of closure of the mouth
- Gives the angulus oris sulcus an oblique form.
Depressor Labii Inferioris (Quadratus)
- Wrinkles the chin
- Raises and protrudes the lower lip
- Does not insert into the lower lip
- Originates at the incisive fossa of the mandible while moving downward to insert into the skin of the chin. (located on the tip of the chin)
- May drop fibers into the skin holding it down to form a dimple.
Mentalis
- Platysma (2)
- Sternocleidomastoideus (2)
- Digastricus (2)
Muscles of the neck
- Softens the contour of the neck.
- Lowers the angle of the mouth.
- Is responsible for the transverse wrinkles of the neck.
- Wrinkles the skin of the neck and chest. Also depresses the mandible and anguli oris, as in pouting.
Platysma (2)
- Together, they are used to measure the widest part of the neck.
- Arise from two points:
- Sternum
- Clavicle
- Insert into the lateral surface of the mastoid process.
- Rotates and depresses the head
Sternoclediomastoideus (2)
(SCM)
- Double-bellied
- One form of cords on aged persons.
- Attaches to the mastoid process and the mandible.
Digastricus (2)
