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79 Cards in this Set

  • Front
  • Back
What are origin and insertion?
origin - stationary attachment (usually proximal)

insertion - movable attachment (usually distal)
What is an example of a muscle that moves a body part it doesn't cover?
biceps brachii moves the forearm
What are examples of muscles that cross two joints?
rectus femoris and sartorius
What are lever, fulcrum, effort, and load?
Lever - moves around fixed point called fulcrum

Fulcrum - fixed point on which lever moves

Effort - force due to muscular contraction, used to move load

Load - weight that is moved or resistance offered by an object to being moved
Examples of Levers and Fulcrums
Levers - bones

Fulcrums - joints
What is Mechanical advantage/disadvantage?
Advantage - large load over small distance, more for strength

Disadvantage - load to be moved over large distance, more for speed and distance

motion occurs when effort > load
What is the Law of Levers?
When fulcrum-effort distance > fulcrum-load distance = mechanical advantage

fulcrum-effort distance < fulcrum-load distance = mechanical disadvantage
What are First Class Levers and Examples?
very few in our body

fulcrum is between effort and load (EFL)

mechanical advantage/disdvantage

ex. mandible at TMJ (advantage), humerus at shoulder joint (disadvantage), scissors, and seesaws, head resting on vertebral column (atlantocciptal joint)
What are Second Class Levers and Examples?
FLE (fulcrum-load-effort), uncommon

always mechanical advantage because load always closer to fulcrum than effort

ex. plantar flexion - F = foot, E = calcaneus, and L = body; push-ups - F = foot, E = hands, L = body's center of gravity; wheelbarrow, nut cutter

produce force at cost of speed
What are Third Class Levers and Examples?
FEL, most common in body

always mechanical disadvantage because effort is always closer to fulcrum

produce speed at cost of force

ex. elbow flexion, knee flexion
What are the 5 patterns of fascicles?
Parallel - run parallel to long axis
ex. SCM, stylohyoid, sartorius

Convergent/Triangular - origin broad, fascicles converge toward tendon of insertion
ex. Pectoralis major

Fusiform - parallel to longitundinal axis, terminate in flat tendons
ex. Digastric muscle, biceps brachii

Unipennate - insert into one side of tendon, ex. Digitorum longus

Bipennate - fascicles insert into both sides, ex. Rectus Femoris

Multipennate - insert into one large tendon from all sides, ex. Deltoid

Circular - arranged in concentric rings, surround external body openings
ex. Obicularis oris and oculi
Power vs. Range of Motion in Fascicles
Longer fibers = greater range of motion

larger cross-sectional area = greater power
What are agonists and antagonists?
agonist - prime mover responsible for action

antagonist - stretches against agonist

ex. forearm flexion - biceps = agonist, trips = antagonist

if agonist and antagonist contract at same time = no movement
What are synergists and what do they do?
contract and stabilize the intermediate joints

aid movement of agonist and prevent unwanted movements at other joints

ex. wrist extensor muscles stabilize wrist joint while flexor muscles of fingers contract as prime mover
What are fixators?
stabilize origin of agonist so it acts more efficiently

ex. muscles in scapula can be agonists (deltoid) or fixators (pectoralis minor, trapezius, subclavius)
What is Tenosynovitis?
inflammation of tendons, tendon sheaths, and synovial membranes surrounding certain joints

most often affected tendons:

elbows (tennis elbow)
finger joints (trigger finger)
ankles and feet

caused by trauma, strain, or excessive exercise (gymnasts, typists, hairdressers, carpenters)
What are intramuscular injections?
used for prompt absorption of drugs or too irritating on skin

common IM sites:

gluteus medius
vastus lateralis

faster than oral but slower than IV
What are the 7 features used to name skeletal muscles?
1. pattern of fascicles (rectus and transverse abdominis)
2. size (maximus, minimus)
3. shape (deltoid - triangular)
4. action (flexor, extensor)
5. number of origins (biceps, triceps)
6. location (brachialis)
7. sites of origin and insertion (brachioradialis)
What are examples of sphincters and dilators?
sphincter - obicularis oculi (closes the eye)

dilator - levator palpebrae superioris (opens the eye)
What are the muscles of facial expression?
Occipitofrontalis - raises eyebrows (wrinkles forehead in surprise look)

Orbicularis oculi - encircles the eyes, allows blinking (aids passage and drainage of tears)

Orbicularis oris - encircles the mouth, moves the lips (protrudes and closes lips as in kissing)

Buccinator - pucker the mouth (doesn't attach to bone)

Zygomaticus - smiling muscle (cheek)

Levator labii superioris - sneering (elevates and everts upper lip)

Depressor anguli oris - frowning and pouting
What are some other functions of the Occipitofrontalis and Buccinator?
Occipitofrontalis - wrinkles forehead like a look of surprise
has frontal belly and occipital belly
both are held together by an aponeurosis named epicranial aponeurosis or gale aponeurotica

Buccinator - muscle forms the major muscular portion of the cheek
-compresses the cheeks during blowing actions like playing trumpet
-also responsible for actions like whistling, sucking and assists in chewing
What are the actions of the Zygomaticus Major/Minor and Risorius?
Zygomaticus Major - elevates and draws angle of mouth laterally and superiorly as in smiling

Zygomaticus Minor - elevates and everts upper lip, exposes maxillary teeth

Risorius - retracts angle of mouth as in grimacing
What are the actions of Depressor Labii Inferioris, Depressor Anguli Oris, and Platysma
Platysma - depresses and wrinkles the skin of lower face and mouth. Aids forced depression of mandible

Depressor Anguli Oris - depresses and draws angle of mouth laterally and inferiorly as in opening of mouth

Depressor Labii Inferioris - depresses and draws lower lip laterally
What are the actions of the Corrugator supercilii and Temporalis?
Temporalis - elevates mandible (and posterior fibers retract)

Corrugator Supercilii - wrinkles forehead vertically as in frowning
What are the functions of the Masseter and Mentalis?
Mentalis - eleveates and wrinkles skin of chin and protrudes lower lip

Masseter - elevates mandible (enables forced closure of mouth), strongest muscle in mastication
What are some causes of Bell's Palsy?
inflammation of facial nerve due to an ear infection

ear surgery that damages the facial nerve

infection by the herpes simplex virus
What are the muscles of mastication?
Medial/Lateral Pterygoid - move mandible side to side

Masseter - closure of jaw (strongest)

Temporalis - closure of jaw (elevates mandible)

all innervated by Trigeminal Nerve
What are extrinsic eye muscles and examples?
muscles that move the eyeballs, originate outside of eyeballs and insert on outer surface of sclera

1. Superior and Inferior Recti - move eyeball superiorly and inferiorly

2. Lateral and Medial Recti - move eyeball medially and laterally

3. Superior Oblique - moves eyeball inferiorly and laterally

4. Inferior Oblique - moves eyeball superiorly and laterally

four muscles arise from the tendinous ring in the orbit and insert into the sclera of the eye
What is the levator palpebrae superioris?
does NOT move eyeballs

raises upper eyelids, opening the eyes

acts as antagonist to orbiularis oculi, which closes the eyes
What are some general actions of Eye Muscles?
Superiors - medially rotate
Inferiors - laterally rotate
Obliques - abduct
Recti - adduct
Superior oblique - depresses
Inferior Oblique - elevates
What is Strabismus?
condition where two eyeballs are not properly aligned (lazy eye)

external strabismus - occulomotor nerve, inability to move eyeball medially and inferiorly

internal strabismus - abducens nerve, cannot move laterally
What are the extrinsic tongue muscles?
Genioglossus - depresses tongue and forward (protraction)

Styloglossus - elevates tongue and retraction

Hyoglossus - depresses tongue and flattens it (draws down on both sides)

Palatoglossus - raises back portion of tongue
What is Endotracheal intubation?
tube is inserted from the oral cavity through the laryngopharynx into the trachea

this is done during anesthesia to prevent obstruction of airway to lungs by genioglossus muscle
What are the Muscles of the Anterior neck that help in swallowing and speech?
Suprahyoid - located above hyoid bone, elevate the hyoid bone, floor of the oral cavity and tongue during swallowing

infrahyoid (strap) - below hyoid, depresses hyoid bone, some move the larynx during swallowing and speech
What are the Suprahyoid mm?
Stylohyoid - elevates and draws hyoid bone posteriorly (aids in swallowing)

Mylohyoid - elevates hyoid bone and floor of mouth, depresses mandible (aids in mastication and swallowing)


Digastric - elevates hyoid bone and larynx (aids in swallowing and speech) and depresses mandible
What are the Infrahyoid mm?
Omohyoid - two bellies; depresses the hyoid bone

Sternohyoid - depresses hyoid bone and thyroid cartilage of larynx

Sternothyoid - depresses thyroid cartilage of larynx

Thryohyoid - depresses hyoid bone, elevates thyroid cartilage to roduce low and high tones during phonation
What are the Triangles of the neck that the SCM divides?
Anterior - contains submental, submandibular and deep cervical lymph nodes, submandibular gland and part of parotid gland, facial artery and vein, common carotid artery and internal jugular vein and CN IX, X, XI, XII

Posterior - part of subclavian artery, external jugular vein, cervical lymph nodes, brachial plexus and CN XI
What are the actions of the SCM, Splenius Capitis, and Semispinalis Capitis?
SCM - (bilaterally) flex cervical portion and head, elevate sternum during forceful inhalation, (unilaterally) rotate head to side opposite contracting muscle

Splenius Capitis - acting together, extend head; acting singly, rotate head to side opposite of contracting muscle

Semispinalis Capitis - same as splenius capitis
What are the 4 muscles of the Abdomen?
External Oblique - superficial muscle, fascicles extend inferiorly and medially, same as internal oblique

Internal Oblique - flat muscle, right angle to external oblique, (bilaterally) compresses abdomen and flexes vertebral column; (unilaterally) flexes vertebral column and rotates it

transversus abdominis - deep muscle, transversely around abdominal wall, compresses abdomen

these three form protective layer of muscles around abdomen, aponeurosis of 3 forms rectus sheaths and encloses rectus abdominis

rectus abdominis - long muscle that extends entire length of anterior abdominal wall (interrupted by tendinous intersections), compresses abdomen to aid in defecation, urination, and childbirth, flexes trunk
What are the functions of the abdominal wall?
protect abdominal viscera

flex and rotate IV joints

compress abdomen during exhalation

produce force needed for defecation, urination, and childbirth
What is the linea alba?
connective tissue band extending from xiphoid process to pubic symphysis, where the rectus sheaths meet at the midline
What are the inguinal ligament and canal?
ligament - inferior free border of the external obliuq aponeurosis

canal -
males: ilioinguinal nerve and spermatic cord
females: round ligament of uterus and ilioinguinal nerve
Anterior vs. Posterior Abdominal wall
posterior is bulky and more stable

anterolateral can contract and distend
What is an inguinal hernia?
rupture or separation of a portion of inguinal area of the abdominal wall resulting in protrusion of a part of the small intestine

more common in males

surgery to "tuck" back cavity, mesh repairs weak muscles
What are the 3 orifices in Diaphragm?
1. Aortic hiatus - aorta, thoracic duct, and azygous vein pass

2. Esophageal hiatus - esophagus and vagus nerve pass

3. Caval opening - IVC passes
What is hiatus hernia?
stomach protrudes through esophageal hiatus
What are internal/external intercostal muscles?
external - superficial layer, for inhalation

internal - intermediate layer, for FORCED exhalation

innermost - poorly developed
What are the muscles of the pelvic diaphragm?
Levator ani - formed from iliococcygeus and pubococcygeus, supports pelvic viscera and resists intra-abdominal pressure

ischiococcygeus - pulls coccyx anteriorly and pushed posteriorly during defecation or child birth
What happens when Levator Ani gets injured?
caused by difficulty in child birth

causes urinary stress incontinence
What is the perineum?
diamond shaped area that extends from pubic symphysis anteriorly --> coccyx posteriorly --> ischial tuberosities laterally

separated into anterior urogenital and posterior anal trangles by transverse line between ischial tuberosities
What muscles are in the superficial and deep layers of the perineum?
superficial - superficial transverse perineal muscle, bulbospongiosus, and ischiocavernosus

deep -
male: deep transverse perineal muscle and external urethral sphincter
female: compressor urethrae, sphincter urethrovaginalis and external urethral sphincter
Muscles and function of Pectoral Girdle?
function is to stabilize scapula, increase range of motion of humerus

Anterior thoracic muscles -
subclavius: pulls clavicle towards sternum
pec minor: abduct the scapula, pulls it foward and downward
serratus anterior: impt in punching and pushing, abducts scapula and rotates it upward

posterior thoracic muscles -
trapezius: elevates shoulder and laterally rotates scapula
levator scapulae: elevates scapula and rotates it downward
rhomboid major: elevates and adducts scap and rotates it downward
rhomboid minor: same as major
What are the movements of the scapula?
elevation - ex. shrugging shoulders or lifting a weight over head

depression - ex. pulling down a rope

abduction (protraction) - ex. push ups or punching

adduction (retraction) - ex. rowboat

upward rotation - ex. jumping jack

downward rotation - ex. gymnast balancing
Where are muscles that attach to scapula and thorax and move scapula?
trapezius - shoulders and upper back, extends neck and head

serratus anterior - between ribs, elevates ribs

levator scapulae, rhomboids & pectoralis minor - act as fixators to hold the scapula in position
What are considered the scapular muscles?
teres major
teres minor
What muscles originate in the axial skeleton?
Pectoralis major - adducts and medially rotates the arm at shoulder joint, clavicular head flexes arm and sternocostal head extends flexed arm to side of trunk

Latissimus dorsi - adduction, medial rotation and extension of arm at shoulder joint, "swimmer's muscle"
What are the muscles of the rotator cuff?
Subscapularis - medially rotates arm at shoulder joint

Infraspinatus - rotates arm laterally and adducts arm at shoulder joint

Teres Minor -

Supraspinatus - assists deltoid to abduct the arm (1st 15 degrees) at shoulder joint
What are the actions of the deltoid and teres major mm?
Deltoid - abduction of arm from 15-90 degrees

Teres Major - extends the arm, adducts and rotates medially at shoulder joint
What is Impingement Syndrome?
inflammation of supraspinatus muscle with continuous, repetitive movement of arm over head

usually happens to sportspersons
What is Rotator Cuff injury?
continued movement despite pain from impingement sydnrome leading to tearing away of bone and tendon degeneration near attachment to humerus
What are the forearm flexors?
form anterior compartment

biceps brachii - flexes arm at elblow joint, supinates forearm at RU joint

brachialis - flexes forearm at elbow joint

brachioradialis - flexes forearm at elbow joint, supinates and pronates forearm
What are the forearm extensors?
form posterior compartment

triceps brachii - extends arm at shoulder joint and extends forearm at elbow joint

What are the muscles involved in pronation and supination?
pronator quadratus - pronates foearm
pronator teres - pronates and flexes forearm

supinator - supinates forearm
What are the five principal movements of the thumb?
flexion, extension, abduction, adduction, and opposition
What muscles attach the arm to the thorax
pectoralis major - adducts the arm and flexes the shoulder

latissimus dorsi - medially rotates and adducts arm and extends shoulder
Parts of Anterior (Flexor) compartment of Upper Limb
superficial -
flexor carpi radialis - flex forearm and hand, abduction of hand
palmaris longus - flexes hand and wrinkles skin of palm of hand
flexor carpi ulnaris - flexes forearm and hand, adducts hand
flexor digitorum superficialis - flexes phalanges, wrist, and forearm

digitorum superficialis is deep to other 3 and largest

deep -
flexor pollicis longus - flexes thumb
flexor digitorum profundus - flexes phalanges

flexor pollicis longus is only flexor at distal phalanx of thumb
Parts of Posterior (Extensor) Compartments of Upper Limb
Extensor Carpi Radialis Longus - extends and abducts the wrist
Extensor Carpi Radialis Brevis - tends and abducts the wrist
Extensor Digitorum - extends fingers, hand, and forearm
Extensor Digiti Minimi - extends little finger
Extensor Carpi Ulnaris - extends and adducts the hand

Abductor Pollicis Longus - abducts thumb
Extensor Pollcis Longus - extends thumb
Extensor Pollicis brevis - extends thumb
Extensor indicis - extends index finger
What are the 3 groups of intrinsic hand muscles?
Thenar - thenar muscles plus adductor pollicis form the thenar eminence

Hypothenar - muscles that act on little finger make up hypothenar eminence

What does the Scalene group do?
flex and rotate the head and assist in deep inhalation
What do the Iliopsoas, Gluteus Maximus and Minimus do?
Iliopsoas (psoas major and iliacus) - flexes hip, anterior muscle

gluteus maximus - extends hip and abducts thigh

gluteus minimus - hip, abducts and rotates thigh

maximus, medius, and minimus all extend and abduct femur
What is the muscle of the medial (adductor) compartment?
Gracilis - adducts femur
What are the muscles of the Anterior (extensor) compartment of the lower limb?
Quadriceps Femoris -
Rectus femoris: anterior
Vastus Lateralis: lateral
Vastus Medialis: medial
Vastus Intermedius: deep to rectus

Sartorius - long, narrow muscle that forms band
What are the muscles of the posterior (flexor) compartment that make up the hamstrings?
biceps femoris



both extensors and flexors because they span two joints
What are the muscles of the anterior compartment of the foot?
all dorsiflex the foot

tibialis anterior
extensor hallicus longus
extensor digitorum longus
fibularis tertius
What are the muscles of the lateral compartment of the foot?
plantar flex and evert the foot

fibularis longus
fibularis brevis
What are the muscles of the posterior compartment of the foot?
superficial - insert onto calcaneal (achillis) tendon
gastrocnemius -
known as the calf muscles

deep -
tibialis posterior
flexor digitorum longus
flexor hallicus longus
What is the muscle on the dorsum of the foot?
extensor digitorum brevis
What are the muscles on the sole of the foot (4 layers)?
First Layer: flexor digitorum brevis, abductor hallucis, abductor digiti minimi

Second Layer: flexor accessorius, lumbricals

Third Layer: flexor hallucis brevis, adductor hallucis, flexor digiti minimi brevis

Fourth Layer: plantar and dorsal interossei
αἷμα; αἵματος, τό