Muscular System Flashcards
Origin
Attachment of tendon to stationary bone
Insertion
Attachment of tendon to moveable bone
Is origin proximal or distal?
Proximal
Belly
Fleshy part of muscles between tendons
Reverse Muscle Action
Some muscles are capable of reversing the direction of action. Origin and insertion are reversed
Lever System
Move around a fixed point called a fulcrum
What are two forces involved in a lever
Effort
Load
Effort
Force exerted by muscle contraction
Load
Opposes movement
Mechanical Advantage
Load is closer to fulcrum so small effort is needed to move a large load for a short distance
Mechanical Disadvantage
Effort is closer to load so large effort is needed to move a small load for a long distance
First class lever
Fulcrum is between load and effort
Does a first class lever have mechanical advantage or disadvantage?
Both
Second class lever
Load is between fulcrum and effort
Does a second class lever have mechanical advantage or disadvantage?
Advantage
What type of lever produces the most force?
Second class
Third class lever
Effort is between fulcrum and load
Does a third class lever have mechanical advantage or disadvantage?
Disadvantage
Which type of lever favours speed over force?
Third class
Fascicle
Bundles of skeletal muscle fibers
What does fascicle arrangement effect?
Power and range of motion
What are the 7 fascicle arrangements
Fusiform Parallel Triangular Circular Unipennate Bipennate Multipennate
What fiber factor effects range of motion?
The longer the fiber the greater the range of motion
What fiber factor effects power?
Cross- sectional area
Prime Mover (Agonist)
Contracts to cause a movement
Antagonist
Stretches and yields to the effect of the prime mover
Synergist
Contract and stabalize the intermediate joints to prevent unwanted movement
Fixators
Stabalize origin of prime mover so it can contract more efficiently
Direction of muscle
Orientation of muscle fascicles relative to body’s midline
Rectus
Parallel to midline
Transverse
Perpindicular to midline
Oblique
Diagonal to midline
Maximus
Largest
Minimus
Smallest
Longus
Long
Brevis
Short
Latissimus
Widest
Longissimus
Longest
Magnus
Large
Major
Larger
Minor
Smaller
Vastus
Huge
Deltoid
Triangular
Trapezius
Trapezoid
Serratus
Saw- Toothed
Rhomboid
Diamond shaped
Orbicularis
Circular
Pectinate
Comb- like
Piriformis
Pear shaped
Platys
Flat
Quadratus
Square shaped
Gracilis
Slender
Flexor
Decreases joint angle
Extensor
Increases joint angle
Abductor
Moves bone away from midline
Adductor
Moves bone closer to midline
Sphincter
Decreases size of opening
Biceps
Two origins
Triceps
Three origins
Quadriceps
Four origins
Orbicularis Oculi
Circle around eye that closes eyes
O: medial wall of orbit
I: circular path around orbit
Two parts of occipitofrontalis
Frontal Belly
Occipital Belly
Frontal belly
Forehead. Raises eyebrows
O: Epicranial aponeurosis
I: Skin above supraorbital margin
Occipital Belly
Back of head. Draws scalp posteriorly
O: Occipital bone and mastoid process
I: Epicranial aponeurosis
Epicranial Aponeurosis
Covers superior and lateral sides of the head
Buccinator
Sucks cheeks in and draws corner of mouth laterally.
O: Alveolar processes of maxilla and mandible
I: Fibers of orbicularis oris
Zygomaticus Major
Inferior to minor. Smiling
O: Zygomatic
I: Skin at angle of mouth
Zygomaticus Minor
Superior to major. Raise upper lip
O: Zygomatic
I: Upper lip
Levator Labii Superioris
Right beside nose. Raises upper lip
O: Maxilla
I: Skin at angle of mouth
Depressor Anguli Oris
Chin. Opens mouth
O:Mandible
I: Angle of mouth
Corrugator Supercili
Angle up across eyebrow. Eyebrows down
O: Frontal bone
I: Skin of eyebrow
Nasalis
Bridge of nose
Masseter
Elevates mandible.
O: Maxilla and zygomatic arch
I: Angle of mandible
Risorius
Draws angle of mouth laterally
O: Fascia over partoid gland
I: Skin at angle of the mouth
Platysma
Pouting
O: Fascia over deltoid muscles
I: Mandible
Extrinsic Eye Muscles
Muscles that move the eyeballs
Where do extrinsic eye muscles insert and originate?
Originate on the orbit and insert on the sclera
Sclera
White of the eye
3 pairs of extrinsic muscles controlling eye movement?
Superior and inferior recti
Lateral and medial recti
Superior and inferior obliques
Where do the 4 recti eye muscles originate?
Tendinous ring in posterior orbit
Superior and Inferior Recti movements
Move the eyeball superiorly and inferiorly
Lateral and medial recti movements
Move the eyeball laterally and medially
Superior oblique eye muscle
Originates posteriorly. Ends in a round tendon that passes through trochlea. Inserts on on side of eyeball.
Moves eye inferiorly and laterally
Trochlea
Pulley like loop on the top of the orbit
Inferior oblique eye muscle
O: Maxilla
I: Lateral part of eyeball inferior to superior oblique
Moves eye superiorly and laterally
Levator palpebrae superioris
Cut off the top of superior oblique. Raises upper eyelid
What is the antagonist to orbicularis occuli?
Levator palpebrae superioris
Muscles of mastication
Muscle moving the mandible at TMJ used in chewing
How many pairs of muscles are used in mastication?
4
What are the three muscles used to close the jaw?
Masseter
Temposralis
Medial pterygoid
Medial Pterygoid
Side of jaw inferior to lateral pterygoid.
O: Pterygoid process
I: Angle of ramus of mandible
Which muscle moves the jaw side to side
Medial and lateral Pterygoid
Lateral Pterygoid
Side of jaw superior to medial pterygoid
O: Pterygoid process
I: Condyle of mandible
Temporalis
Elevates and retracts mandible. Side of temple
O: Temporal bone
I: Coronoid process of mandible
Deglutition
Swallowing
3 places the tongue attaches to
Mandible
Styloid process
Hyoid bone
Where does the fibrous septum of the tongue attach inferiorly?
Hyoid bone
Extrinsic Tongue muscles
Originate outside the tongue and insert into it
Intrinsic Tongue muscles
Originate and insert within the tongue
What muscles alter the shape of the tongue rather than moving it?
Intrinsic tongue muscles
Genioglossus
Protraction of tongue
O: Mandible
I: Under tongue and hyoid bone
Styloglossus
Retraction of the tongue
O: Styloid process
I: Side and under tongue
Hyoglossus
Depresses tongue and draws down sides
O: Hyoid bone
I: Side of tongue
Palatoglossus
Elevates tongue
O: Soft palate
I: Side of tongue
2 groups of muscles that stablize hyoid bone
Suprahyoid muscles
Infrahyoid bones
What nerve innervates facial muscles?
Facial nerve VII
2 components of the digastric muscle?
Posterior and anterior bellies
Digastric
Elevates hyoid
O: Mandible and temporal bone
I: Body of hyoid
Stylohyoid
Elevates hyoid bone
O: Styloid process
I: Hyoid bone
Mylohyoid
Elevates hyoid bone
O: Mandible
I: Hyoid
Gleniohyoid
O: Mandible
I: Hyoid
What are the four suprahyoid muscles?
Digastric
Stylohyoid
Mylohyoid
Gleniohyoid
What are the four infrahyoid muscles?
Omohyoid
Sternohyoid
Sternothyroid
Thyrohyoid
Which 2 hyoid muscles have two bellies connected by an intermediate tendon?
Digastric
Omohyoid
What are the 3 components of the omohyoid?
Superior and inferior bellies
Intermediate tendon
Which 3 muscles depress the hyoid bone?
Omohyoid
Sternohyoid
Thyrohyoid
Which muscle depresses the thyroid cartilage (adams apple)?
Sternothyroid
Omohyoid
O:Scapula and superior transverse ligament
I: Hyoid
Sternohyoid
O: Clavicle and manubrium
I: Hyoid
Sternothyroid
O: Manubrium
I: Thyroid cartilage of larynx
Thyrohyoid
O: Thyroid cartilage of larynx
I: Hyoid
Extrinsic muscles of the larynx
Infrahyoid muscles
2 muscles that regulate tension of the vocal cords
Cricothyroid
Thyroarytenoid
What 2 muscles adjust space between vocal cords?
Lateral cricoarytenoid
Posterior cricoarytenoid
Cricothyroid
O: Cricoid cartilage
I: Thyroid cartilage