Chapter 10 - The Muscular System Flashcards
Origins, Insertions and Actions
A. Origin – orginates from, usually a fixed or immovable point of attachment for muscle
B. Insertion – where it inserts, usually on a moveable bone
C. Action – defines the effect that’s exhibited through contraction
Functional Classification of Muscles (AASF)
A. Agonists – prime mover, leaders of muscle or muscle group that has a specific movement
B. Antagonists – against the leaders, they oppose or reverse a particular movement
C. Synergists – help prime movers, they add extra force to the same movement, they reduce unnecessary movement as the prime movers contract
D. Fixators – prime stabilizers of a joint and they exhibit their action when other muscles
Arrangement of Muscle Fascicles (CCPFUBM)
A. Circular – the fascicles are arranged in concentric rings B. Convergent – muscle has a broad origin and its fascicles will converge with to a single tendon of insertion C. Parallel – long axis of fascicles runs parallel to the long axis of the muscle D. Fusiform – separate class of spindle shaped muscle, falls under a parallel class – biceps E. Unipennate – fascicles are short and they attach obliquely to a central tendon which runs the length of the muscle which runs the entire length of the muscle, the fascicles insert only in ONE side of the tendon F. Bipennate – fascicles insert into the tendon from opposite sides (looks like a feather) G. Multipennate – this looks like many feathers situated side by side with their quills into ONE tendon
Naming Muscles
A. Location – bone or body region which the muscle is associated
B. Shape – named according to their dominate shape
C. Relative size – maximus, minimus, longeus and brevious
D. Direction of fascicles – some names reveals the direction of the fibers
E. Number of origins – biceps, triceps, and quadriceps
F. Location of origin and insertion – sternoclidomastiod – sternal and mastoid
G. Action – flex or extendsor or adductor, abduction
Facial Expressions: Epicranius
Epicranius – occipital and frontal belly
O: frontal – galea aponeurotica; occipital – occipital and temporal bones
I: frontal – skin of eyebrows and root of nose; occipital – galea aponeurotica
A: frontal – raises eyebrows, wrinkles forehead; occipital – fixes aponeuroses and pulls scalp posterioly
Facial Expressions: Orbicularis Oculi
Around the eyes
O: frontal and maxillary bones and ligaments around orbit
I: tissue of eyelid
A: protects eyes from intense light and injury, blinking
Facial Expressions: Orbicularis Oris
Around the lips/ helps forms lips
O: arises indirectly from maxilla and mandible; fibers blended with fibers of other facial muscles associated with the lips
I: encircles mouth; inserts into muscle and skin at angles of mouth
A: closes lips, purses lips, etc.
Mastication (Chewing): Masseter
Zygomatic and mandible
O: Zygomatic arch and maxilla
I: angle and ramus of mandible
A: prime mover of jaw closure, elevates mandible
Mastication (Chewing): Temporalis
Temporal bone
O: temporal fossa
I: coronoid process of mandible
A: Closes jaw
Mastication (Chewing): Buccinator
Pursing lips
O: molar region of maxilla and mandible
I: orbicularis oris
A: draws corner of mouth laterally, holds food between teeth during chewing
Muscles of the Anterior Neck and Throat: Suprahyoid - Digastric
O: lower margin of mandible and mastoid process of the temporal bone
I: by a connective tissue loop to hyoid bone
A: elevate hyoid bone and steady it during swallowing and speech
Muscles of the Anterior Neck and Throat: Suprahyoid - Mylohyoid
O: medial surface of mandible
I: hyoid bone and median raphe
A: elevates hyoid bone and floor of mouth
Muscles of the Anterior Neck and Throat: Infrahyoid - Stemohyoid
O: manubrium and medial end of clavicle
I: lower margin of hyoid bone
A: depresses larynx and hyoid bone if mandible is fixed
Muscles of the Anterior Neck and Throat: Infrahyoid - Stemothyroid
O: posterior surface of manbrum of sternum
I: thyroid cartilage
A: pulls thyroid cartilage
Muscles of the Anterior Neck and Throat: Infrahyoid - Thyohyoid
O: thyroid cartilage
I: hyoid bone
A: depresses hypoid bone and elevates larynx