Muscular System Flashcards
Prime mover (agonist)
major responsibility for producing specific movement
antagonist
opposes or reverses movement
prime mover and antagonist are located on opposite sides of joint across which they act
synergist
helps prime movers
adds extra force to same movement
reduces undesirable or unnecessary movement
fixator
synergist that immobilizes bone or muscle’s origin
gives prime mover stable base on which to act
coronal plane
anterior and posterior
sagittal plane
medial and lateral
transverse plane
superior and inferior
proximal
near to the approximate centre of mass
some reference point further from the centre of mass
distal
distant from the approximate centre of mass
a muscle that crosses on the anterior side of a joint produces…
flexion
a muscle that crosses on the posterior side of a joint produces…
extension
a muscle that crosses on the lateral side of a joint produces….
abduction (moving up and away)
a muscle that crosses on the medial side of a joint produces…
adduction
protraction vs retraction
protraction - forward motion, jaw juts forward
retraction - backward motion, jaw juts backward
dorsiflexion vs plantar flexion
dorsiflexion - foot arches upward
plantar flexion - foot arches downward
inversion vs eversion
inversion - inside of the foot sticking up
eversion - outside of the foot sticking up
circular fascicle arrangement
fascicles arranged in concentrate rings
convergent fascicle arrangement
broad origin; fascicles converge toward single tendon insertion
fusiform fascicle arrangement
spindle-shaped muscles with parallel fibers
parallel fascicle arrangements
fascicles parallel to long axis of strap-like muscles
pennate fascicle arrangement
short fascicles attach obliquely to central tendon running length of muscle
unipennate
bipennate
multipennate
unipennate: fascicles attach only to one side of tendon
bipennate: fascicles insert on opposite sides of tendon
multipennate: appears as feathers inserting into one tendon
components of a lever system:
lever
effort
load
lever - bone that moves on a fixed point (joint)
effort - force applied to move the load
load - the resistance moved by the effort (the weight of the object)
power versus speed
levers allow given effort to move heavier load or to move load farther or faster
mechanical advantage (power level): load is close to fulcrum, with effort fair from fulcrum - small effort can move large load
mechanical disadvantage (speed lever): load is far from fulcrum, with effort close to fulcrum - load moved rapidly over large distance
what is the equation for the lever systems
effort x length of effort arm = load x length of load arm
force x distance = resistance x distance
first class lever system
fulcrum is between load and effort
seesaw, scissors
second class lever
load is between fulcrum and effort
(wheelbarrow, standing on toes)
Load is in the middle
third class lever
effort is applied between fulcrum and load
(tweezers, most skeletal muscles)
effort in the middle
epicranius
main muscle for facial expression
has frontal belly (frontalis) and occipital belly
connected by the epicranial aponeurosis
allows us to raise eyebrows
corrugator supercilli
o: arch of frontal bone
i: skin of eyebrow
a: draws eyebrows medially and inferiorly
* *angry eyebrows
orbicularis oculi
o: frontal and maxillary bone
i: eyelid
a: closes eye
* *blinking
zygomaticus:
has major and minor
o: zygomatic bone
i: mouth
a: raises lateral corners of mouth
* *smile
risorius
o: masseter muscle
i: mouth
a: draws corner of lips laterally
* *laughter
levator labii superioris
o: zygomatic bone and maxilla
i: upper lip
a: opens lip
depressor labii inferioris
o: mandible
i: lower lip
a: draws lower lip inferiorly
depressor anguli oris
o: mandible
i: mouth
a: draws corners of mouth down and laterally
orbicularis oris
o: maxilla and mandible
i: mouth
a: closes lips
* *pucker
mentalis
o: mandible
i: chin
a: wrinkles chin (pout)
buccinator
o: maxilla and mandible
i: orbicularis oris
a: compresses cheek
platysma
o: chest
i: mandible and mouth
a: tenses skin of neck
happy facial expression muscles
levetator labii superioris
zygomaticus minor and major
risorius
sad facial expression muscles
mentalis
depressor labii inferioris
depressor anguli oris
what are the muscles of mastication?
*all invervated by cranial nerve V
temporalis and masseter: prime movers of jaw closure
Pterygoids: grinding movements
buccinator: chewing role
what are the muscles promoting tongue movements?
genioglossues
hypoglossus
styloglossus
masseter
o: zygomatic bone
i: mandible
a: jaw closure
temporalis
o: temporal fossa
i: mandible
a: closes jaw
medial pterygoid
o: spheniod bone, maxilla
i: mandible
a: protract the mandible and promote side-to-side movement
lateral pterygoid
o: sphenoid bone
i: mandible
a: forward sliding and side-to-side grinding movements, protracts mandible
genioglossus
o: mandible
i: hyoid bone
a: protracts tongue
hypoglossus
o: hyoid bone
i: tongue
a: depresses tongue
styloglossus
o: temporal bone
i: tongue
a: retracts and elevates tongue
suprahyoid muscles
form floor of oral cavity
anchor tongue
elevate hyoid bone
move larynx during swallowing
infrahyoid muscles
depress hyoid bone and larynx during swallowing and speaking
epiglottis
closes over larynx while muscles in walls of pharynx propel food forward to stomach
digastric
o: mandible and temporal bone
i: hyoid bone
a: open mouth and depress mandible
stylohyoid
o: temporal bone
i: hyoid bone
a: elevates and retracts hyoid
mylohyoid
o: mandible
i: hyoid bone
a: elevate hyoid bone and floor of mouth
geniohyoid
o: mandibular
i: hyoid bone
a: pulls hyoid bone superiorly and anteriorly
sternohyoid
o: manubrium and clavicle
i: hyoid bone
a: depresses larynx and hyoid bone if mandible is fixed
sternothyroid
o: manubrium
i: thyroid cartilage
a: depresses larynx and hyoid bone
omohyoid
o: scapula
i: hyoid bone
a: depresses and retracts hyoid bone
thyrohyoid
o: thyroid cartilage
i: hyoid bone
a: depresses hyoid bone or elevates larynx if hyoid is fixed
superior, middle, inferior pharyngeal constrictor muscles
o: mandible, hyoid bone, laryngeal
i: pharynx
a: contract pharynx during swallowing
suprahyoid bone vs infrahyoid bones
Suprahyoid bones (GSDM)
- Geniohyoid
- Digastric
- Stylohyoid
- Mylohyoid
Infrahyoid (TOSS)
- Thyrohyoid
- Omohyoid (superior)
- Omohyoid (inferior)
- Sternyhyoid
- Sternothyroid
what are the 2 functional groups of the head and neck?
anterolateral neck muscles: move head
intrinsic muscles: extend trunk and maintain posture
sternocleidomastoid
- two headed muscle
o: manubrium and clavicle
i: temporal bone and occipital bone
a: flexes and laterally rotates the head
scalenes
o: cervical vertebrae
i: first 2 ribs
a: elevate first 2 ribs
splenius
consists of capitis and cervicis
o: ligamentum nuchae, vertebrae C7-T6
i: temporal and occipital bone (capitis)
C2-C4 vertebrae (Cervicis)
a: extend head
ligamentum nuchae
ligament extending from occipital bone to cervical vertebrae
inhibits excessive head and neck flexion
erector spinae muscles
iliocostalis
longissimus
spinalis
- prime mover of back extension
- full flexion if relaxes
- extension is initiated by hamstring muscles of thighs and gluteus maximus muscles
iliocostalis
consists of lumborum, thoracis, cervicis
*lateral
o: iliac crest (lumborum), ribs (thoracis), ribs (cervicis)
i: ribs (lumborum and thoracis), cervical vertebrae (cervicis)
a: extend and laterally flex the vertebral column
longissimus
consists of thoracis, cervicis, and capitis parts
*intermediate
o: lumbar to cervical vertebrae
i: thoracic or cervical vertebrae and ribs
capitis inserts into the temporal bone
a: extend adn laterally flex vertebral column, extends head and turns face
spinalis
consists of thoracis and cervicis *medial
o: lumbar and thoracic vertebrae
i: thoracic and cervical
a: extends vertebral column
semispinalis
consists of thoracis, cervicis, capitis
O: C2-T12
I: occipital bone (capitis), cervical (cervicis), thoracic vertebrae (thoracis)
a: extends vertebral column and head and rotates them to opposite sides
quadratus lumborum
o: iliac crest
i: lumbar vertebrae
a: forced inspiration
transversospinalis muscles
rotatores
- in and around transverse process
- insert 1 full vertebrae up
- full length of the spine
- stabilization of the spine
multidifidus
- o: transverse process of vertebrae
- i: spinous process of vertebrae
runs the entire length of vertebrae
external intercostals
o: inferior ribs
i: superior ribs
a: pulls ribs toward one another to elevate rib cage
(fibers going down)
internal intercostals
o: superior rib
i: inferior rib
a: draws ribs together and depress rib cage
(fibers going up)
diaphragm
o: rib cage, sternum, costal cartilages
i: central tendon
a: prime mover of inspriation
rectus abdominus
o: pubic crest
i: xiphoid process and ribs
a: flex and rotate lumbar region of vertebral column
external oblique
forms inguinal ligament
o: ribs
i: linea alba and iliac crest
a: flex vertebral column and compress abdominal wall, rotates trunk and flex laterally
internal oblique
o: lumbar and iliac crest
i: linea alba, pubic crest, ribs
a: same as external oblique
transversus abdominus
o: lumbar
i: linea alba, pubic crest
a: compresses abdominal contents
functions of the pelvic diaphragm
seals inferior outlet of pelvis
supports pelvic organs
lifts pelvic floor to release feces
resists increased intra-abdominal pressure
levator ani
pubococcygeus, puborectalis, iliococcygeus
o: inside pelvis
i: coccyx
a: supports and maintains pelvic organs
coccgeus
small triangular muscle
o: spine of ischium
i: sacrum and coccyx
a: supports pelvic organs
actions of the superficial muscles of anterior and posterior thorax
elevation, depression, rotation, lateral and medial movements, protraction, retraction
act in combination to fix shoulder girdle
pectoralis minor
o: ribs 3-5
i: scapula
a: with ribs fixed, draws scapula forward and downward
serratus anterior
o: ribs 1-8
i: scapula
a: rotates scapula
subclavius
o: costal cartilage of rib 1
i: clavicle
a: stabilize and depress pectoral girdle
trapezius
o: occipital bone, C7, thoracic vertebrae
i: scapula and clavicle
a: stabilizes, elevates, retracts and rotates scapula
levator scapulae
o: C1-C4
i: scapula
a: elevator and adduct scapula
rhomboids
consists of major and minor
o: C7 and T1 (minor), and T2-T5 (major)
i: scapula
a: stabilize scapula
what are the 3 prime movers of arm?
pectoralis major
latissimus dorsi
deltoid
rotator cuff muscles
supraspinatus
infraspinatus
teres minor
subscapularis
pectoralis major
o: clavicle, sternum, ribs 1-6, external oblique
i: humerus
a: clavicular part, sternal part
deltoid
o: clavicle and scapula
i: humerus
a: prime mover of arm
- anterior fibers active: flex and rotate arm medially
- posterior fibers active: lateral rotation of arm
latissimus dorsi
o: thoracic vertebrae, lumbar vertebrae, ribs 3-4, iliac crest, scapula
i: humerus
a: prime mover of arm extension
subscapularis
o: scapula
i: humerus
a: medial rotator of arm
supraspinatus
o: scapula
i: humerus
a: initiates abduction of arm
infraspinatus
o: scapula
i: humerus
a: rotate arm laterally
teres minor
o: scapula
i: humerus
a: same as infraspinatus
teres major
o: scapula
i: humerus
a: extends, medially, rotates and adducts arm
coracoid brachialis
o: scapula
i: humerus
a: flexes and adducts arm
triceps brachii
o: long head: scapula, lateral head: humerus, medial head: humerus
i: ulna
a: prime mover is medial head, long and lateral head extend the forearm
aconeus
o: humerus
i: ulna
a: may control ulnar abduction during forearm pronation
biceps brachii
has 2 heads
o: scapula
i: radial tuberosity
a: flexes and supinates arm
brachialis
o: humerus
i: ulna
a: major forearm flexor
brachioradialis
o: humerus
i: radius
a: flexing forearm
anterior and posterior muscle characteristics of the wrist, hand, fingers
anterior muscles are flexors and insert via flexor retinaculum
posterior muscles are extensors, insert via extensor retinaculum
actions of the muscles of the forearm
movement of wrist, fingers, thumb, pronation and supination of forearm
pronator teres
o: humus and ulna
i: radius
a: pronates forearm
flexor carpi radialis
o: humerus
i: metacarpals
a: flexor and abductor of hand
palmaris longus
o: humerus
i: palmar aponeurosis
a: tenses skin and fascia of palm
flexor carpi ulnaris
o: humerus and ulna
i: metacarpal
a: powerful flexor and adductor
flexor digitorum superficialis
o: humerus, ulna, radius
i: second to fifth fingers
a: flexes wrist and middle phalanges of second to fifth fingers
flexor pollicis longus
o: radius
i: thumb
a: flexes distal phalanx of thumb
flexor digitorum profundus
o: ulna
i: second to fifth fingers
a: flexes distal interphalangeal joints
pronator quadratus
o: ulna
i: radius
a: pronation
extensor carpi radialis longnus
o: humerus
i: metacarpals
a: extends hands
extensor carpi radialis brevis
o: humerus
i: metacarpals
a: extends hand
extensor digitorum
also called extensor digiti minimi
o: humerus
i: second to fifth fingers
a: prime mover of finger extension
extensor carpi ulnaris
o: humerus and ulna
i: metacarpal
a: extends hands and adducts
supinator
o: humerus and ulna
i: proximal end of radius
a: assist biceps brachii to forcibly supinate forarm
abducor pollicis longus
o: radius and ulna
i: first metacarpal
a: abducts and extends thumb
extensor pollicis brevis and longus
o: radius and ulna
i: thumb
a: extends thumb
extensor indicis
o: ulna
i: index finger
a: extends index finger
iliopsoas - iliacus
o: iliac fossa and crest
i: femur
a: flexing thigh
iliopsoas - psoas major
o: lumbar vertebrae and T12
i: femur
a: flexes vertebral column, flex thigh
sartorius
longest muscle in the body
o: iliac spine
i: tibia
a: flexes, abducts, laterally rotates thigh
gluteus maximus
o: dorsal ilium, sacrum, coccyx
i: femur, iliotibial tract
a: extensor of thigh, most effective when thigh is flexed
gluteus medius
for intramuscular injections
o: ilium
i: femur
a: abducts and medially rotates thigh, walking, holding pelvis in
gluteus minimus
deepest gluteal muscle
o: ilium
i: femur
a: same as medius
piriformis
o: sacrum
i: femur
a: rotates thigh laterally, help abduct
obturator externus
o: margins of obturator foramen
i: femur
a: same as piriformis
obturator internus
o: obturator foramen
i: greater trochanter
a: piriformis
gemellus
has superior and inferior
o: ischial spine
i: femur
quadratus femoris
o: ischial tuberosity
i: femur
a: rotates thigh laterally
quadriceps femoris
common insertion tendon - quadriceps tendon which inserts into patella and then patellar ligament
rectus femoris
o: iliac spine
i: patella and tibial tuberosity
a: extends leg and flexes thigh at hip
vastus lateralis
o: linea aspera (femur)
i: patella and tibial tuberosity
a: extends and stabilizes leg
vastus medialis
o: linea aspera (femur)
i: patella and tibial tuberosity
a: extends leg
vastus intermedius
o: femur shaft
i: patella and tibial tuberosity
a: extends leg
tensor fascia lata
o: femur shaft
i: patella and tibial tuberosity
a: steadies the leg and trunk on thigh by making iliotibial tract
hamstrings
cross both the hip and knee joints
thigh extension and knee flexion
biceps femori
o: ischial tuberosity (long head) and femur (short head)
i: fibula and tibia
a: extends thigh and flexes leg
semitendinosous
largely tendinous
o: ischial tuberosity
i: tibia
a: extends thigh and flexes leg
semimembranosous
deep to semitendinosous
o: ischial tuberosity
i: tibia
a: extends thigh and flexes leg
adductor
three muscles
- adductor magnus
- adductor longus
- adductor brevis
adductor magnus
o: ischial and pubic rami
i: femur
a: adducts and medially rotates and flexes thigh
adductor longus
o: pubis
i: linea aspera (femur)
a: adducts, flexes and medially rotates thigh
adductor brevis
o: pubic ramus
i: linea aspera (femur)
a: adducts, flexes, medially rotates thigh
pectineus
o: pubis
i: femur
a: adducts, flexes, medially rotates thigh
gracilis
o: pubis
i: tibia
a: adducts thigh, flexes and medially rotates leg
anterior lower leg muscles
primary toe extensors and ankle dorsiflexions
tibialis anterior
o: tibia
i: first metatarsal bone
a: dorsiflexion, inverts foot
extnesor digitorum longus
o: tibia and fibula
i: second to fifth toes
a: toe extension and dorsiflexion
fibularis tertius
o: fibula
i: fifth metatarsal
a: dorsiflexes and everts foot
extensor hallucis longus
o: fibula
i: great toe
a: extends great toe, dorsiflexes foot
fibularis longus
o: fibula
i: first metatarsal
a: plantar flexes and everts foot
fibularis brevis
deep to longus
o: fibula
i: fifth metatarsal
a: plantar flexes and everts foot
triceps surae
refers to both gastrocnemius and soleus
inserts via a common tendon of the calcaneous or achilles tendon
gastrocnemius
two prominent bellies
o: 2 heads of femur
i: calcaneus
a: plantar flexes foot, flexes knee
soleus
o: tibia and fibula
i: gastrocnemius
a: plantar flexes foot, walking, running, dancing
plantaris
o: femur
i: calcaneus
a: flex leg, plantar flex foot
popliteus
o: femur
i: tibia
a: flexes and rotates leg medially
flexor digitorum longus
o: tibia
i: second to fifth toes
a: plantar flexes and inverts foot, flexes toe
flexor hallucis longus
o: fibula
i: great toe
a: plantar flexes, inverts, flexes great toe
