Muscles of the Head Flashcards
Definition of a muscle’s origin:
Usually the non-moving bone
Definition of a muscle’s insertion:
The part being moved by the muscle
Most muscle attachments are
indirect muscle attachments
Types of indirect muscle attachments
Tendons and aponeuroses
What is an aponeurosis?
A sheet-like membrane
What are the 4 basic fascicle arrangements?
Parallel, Circular, Convergent, Pennate
What are the 2 types of parallel fascicle arrangements?
Straplike and Fusiform
What is an example of a muscle with a straplike fascicle arrangement?
Sartorius
What is an example of a muscle with a fusiform fascicle arrangement?
Biceps Brachii
What is a fusiform fascicle arrangement?
The muscle is thicker in the middle, and the ends are more tapered
What is an example of a muscle with a circular fascicle arrangement?
Orbicularis Oris
What are the 3 types of pennate fascicle arrangement?
Unipennate, bipennate, and multipennate
What is a pennate fascicle arrangement?
Shaped like a feather
What is an example of a muscle with a unipennate fascicle arrangement?
Extensor Digitorum Longus
What is an example of a muscle with a bipennate fascicle arrangement?
Rectus Femoris
What is an example of a muscle with a mutipennate fascicle arrangement?
Deltoid
What is an example of a muscle with a convergent fascicle arrangement?
Pectoralis Major
What are the 3 functional groups of muscle?
Prime movers, synergists, and antagonists
What is the function of a prime mover?
It is the muscle mainly responsible for a specific movement
What is the function of a synergist?
Muscles that help the prime mover
What are the 2 ways in which synergists help prime movers?
A) they promote the same movement
B) they reduce undesirable movements
What is the function of an antagonist?
A) provides resistance for a specific movement
B) controls movement in the other direction
What is the epicranius?
The main muscle of the scalp
What are the 2 parts of the epicranius?
The frontal belly and the occipital belly
What is the function of the frontal belly?
Raises the eyebrows and wrinkles the forehead
What is the function of the occipital belly?
Fixes the aponeurosis and pulls the scalp posteriorly
What is the location of the orbicularis oculi?
surrounds the rim of the orbit
What is the function of the orbicularis oculi?
Protects eyes from light by producing blinking, squinting, and drawing the eyebrows down
What is the function of the zygomaticus?
Controls smiling
What is the origin of the zygomaticus?
Zygomatic bone
What is the insertion of the zygomaticus?
The mouth
What is the function of the orbicularis oris?
Closes, purses, and protrudes the lips
What is the function of the mentalis?
Protrudes the lower lip, wrinkles the chin
What is the origin of the mentalis?
The mandible
What is the insertion of the mentalis?
The chin
What is special about the mentalis?
The muscle is a v-shaped pair
Where is the buccinator located?
Deep to the masseter
What is the function of the buccinator?
whistling, sucking, holding food in place while chewing
In which case is the buccinator an extremely important muscle?
In nursing infants
What is the origin of the buccinator?
The mandible/maxilla
What is the insertion of the buccinator?
The orbicularis oris
What is the function of the platysma?
Helps depress the mandible and tense the skin of the neck
What is the origin of the platysma?
The fascia of the chest
What is the insertion of the platysma?
The mandible
What are the 3 muscles that move the tongue?
Genioglossus, styloglossus, hyoglossus
What is the function of the genioglossus?
Prime mover of tongue protrusion, anchors the tongue to prevent obstruction of respiration
What is the function of the styloglossus?
Retracts and elevates the tongue
What is the function of the hyoglossus?
Depresses the tongue, especially the lateral margins
What are the muscles involved in mastication?
Masseter, temporalis, pterygoid, buccinator
What is the function of the masseter?
It is the prime mover of jaw closure
What is the function of the temporalis?
Elevates and retracts the mandible (closes jaw) and maintains closed jaw at rest
What is the function of the pterygoid muscles?
Additional jaw movements (ex. side to side grinding)
What is the function of the buccinator during mastication?
Compresses the cheek to help keep food between grinding surfaces of teeth when chewing