Exam 3 Muscles Flashcards
fulcrum
fixed point on which a level moves
resistance
the load to be overcome in a lever system
effort
the force exerted to overcome the resistance in a lever system
first class lever
EFR extension of head: effort= contraction of the posterior neck muscles fulcrum= alanto-occipital joint resistance= weight of the head ex. seesaw
second class lever
FRE
standing on toes:
fulcrum= distal epiphyses of the metatarsals
resistance= weight of body
effort= contraction of gastrocnemius and posterior leg muscles
ex. wheelbarrow
third class lever
REF
lifting a weight with one arm (flexion at the elbow):
resistance= weight of arm + weight you are trying to lift
effort= contraction of biceps brachii
fulcrum= elbow joint
*most muscles
power of a muscle contraction depends on:
the total cross-sectional area of the muscle
agonist
- prime mover
- when contracts, a desired action occurs
antagonist
-opposing muscle which must relax to allow the agonist to work
synergist
-the muscles which contract and stabilize the intermediate joints
stabilizer
-these muscles stabilize the origin of the prime mover so that it can act more efficiently
compartment
- muscles which have a common function
- associated with vessels and nerves
flexion
movement that decreases the angle between two bones
“flexor”
extension
an increase in the angle between two bones
“extensor”
abduction
movement away from the midline
“abductor”
adduction
movement towards the midline
“adductor”
elevation
movement of the body superiorly
“levator”
depression
movement of the body inferiorly
“depressor”
supination
turning the palm anteriorly
“supinator”
sphincter
ring of muscle
tensor
muscle that tightens or stretches a part of the body
muscles of facial expression
O= fascia or bone of face I= skin N= Facial Nerve (C-VII) orbicularis oris orbicularis oculi buccinator platysma frontalis occipitalis zygomaticus
masseter
O= maxilla and zygomatic arch I= angle and ramus of mandible N= trigeminal (C-V) A= elevates mandible (closes mouth)
temporalis
O= temporal bone I= coronoid process and ramus of mandible N= trigeminal (C-V) A= elevates and retracts mandible
medial pterygoid
O= maxilla I= mandible N= trigeminal (C-V) A= elevates mandible
lateral pterygoid
N= trigeminal (C-V) A= only muscle that opens the mouth
superior rectus
O= common tendinous ring I= superior central eyeball N= oculomotor (C-III) A= elevation of the eye (look up)
inferior rectus
O= common tendinous ring I= inferior central eyeball N= oculomotor (C-III) A= depression of eye (look down)
lateral rectus
O= common tendinous ring I= lateral eyeball N= abducens (C-VI) A= abduct the eye
medial rectus
O= common tendinous ring I= lateral eyeball N= oculomotor (C-III) A= adduct the eye
superior oblique
O= common tendinous ring I= between SR and LR, through trochlea N= trochlear (C-IV) A= rotate eye medially
inferior oblique
O= maxilla in floor of orbit I= between IR and LR N= oculomotor (C-III) A= rotate eye laterally
levator palpebrae superioris
elevates eyelids
extrinsic muscles of tongue
-glossus
N= hypoglossal (C-XII)
digastric
O= mandible, temporal bone I= hyoid bone N= facial & trigeminal (C-V & C-VII) A= elevates hyoid bone
suprahyoid muscles
-elevate hyoid bone digastric stylohyoid mylohyoid geniogyoid
infrahyoid muscles
-depress hyoid bone ("strap muscles")
omohyoid
sternohyoid
sternothyroid
thyrohyoidsternocleidomastoid
O= sternum, clavicle I= mastoid process N= cervical spinal nerves A= both flex the neck (if one side contracts, the head is rotated to opposite side)
muscles of neck that move the head
sternocleidomastoid
semispinalis capitis
splenius capitis
longissimis capitis
external oblique
O= ribs 5-12 I= linea alba
internal oblique
O= iliac crest, thoracolumbar fascia I= linea alba
transverse abdominis
O= ribs and cartilages 5-12, iliac crest I= linea alba
rectus abdominis
O= pubic crest, pubic symphysis I= xiphoid process, rib cartilages 5-7
abdominal muscles
- work together to compress and protect abdominal contents
- innervated by segmental spinal nerves
diaphragm
O= sternum, costal cartilages, lumbar vertebrae I= central tendon of the diaphragm N= phrenic nerve (C3-C5) A= dome flattens during inhalation/contraction
muscles of pelvic floor
-act as sphincters
-assist in resisting increased intra-abdominal pressure
-innervated by the sacral spinal nerves
levator ani & ischiococcygeus
levator ani
elevates anus
two parts:
pubococcygeus
iliococcygeus
muscles of the perineum
anterior border= pubic symphysis lateral border= ischial tuberosities posterior border= coccyx anterior triangle= urethra and external genitalia posterior triangle: anus innervated by pudendal nerve
superficial perineal muscles
superficial transverse perineal
bulbospongiosus
ischiocavernosus
deep perineal muscles
deep transverse perineal muscle
external urethral sphincter
external anal sphincter
muscles that move the pectoral girdle anteriorly
subclavius
pectoralis minor
serratus anterior
pectoralis minor
O= ribs 3-5 I= coracoid process N= pectoral nerves A= abducts scapula, elevates ribs when scapula is fixed
serratus anterior
O= ribs 1-8
I= vertebral border and inferior angle of scapula
N= long thoracic
A= abducts scapula, elevates ribs when scapula is fixed
-important in horizontal arm movements like punching and pushing & stabilizes scapula
muscles that move pectoral girdle posteriorly
trapezius levator scapulae (deep to sternomastoid & trapezius) rhomboid major and minor (deep to trapezius, used when forcibly lowering the raised upper limbs- like using sledgehammer)
trapezius
O= occipital bone, nuchal line, C7-C12 vertebrae I= clavicle, acromion, spine of scapula N= XI & C3-C4 A= elevates clavicle, adducts scapula, elevates/depresses/extends head
pectoralis major
O= clavicle, sternum, ribs 2-6 I= greater tubercle of the humerus N= medial/lateral pectoral nerves A= adducts and medially rotates arm, flexes arm
latissimus dorsi
O= spines of lower 6 thoracic vertebrae, lumbar vertebrae, sacrum, ilium, lower 4 ribs I= intertubercular sulcus of humerus N= thoracodorsal nerve A= extends, adducts, and medially rotates arm at shoulder, draws arm inferiorly and posteriorly (swimmer's muscle)
deltoid
O= clavicle, acromion, scapular spine I= lateral surface of humerus N= axillary nerve A= abducts arm
muscles of the rotator cuff
subscapularis
supraspinatus
infraspinatus
teres minor
subscapularis
O= subscapular fossa I= lesser tubercle of humerus N= subscapular nerves A= medially rotates arm
supraspinatus
O= supraspinous fossa I= grater tubercle of humerus N= suprascapular nerve A= assists deltoid in abduction
infraspinatus
O= infraspinous fossa I= greater tubercle of humerus N= axillary nerve A= lateral rotation of arm, adduction of arm
teres major
moves humerus and originates on scapula
coracobrachialis
moves humerus and originates on scapula
forearm flexors
biceps brachii
brachialis
brachioradialis
biceps brachii
O= coracoid process (short head), supraglenoid tubercle (long head) I= radial tuberosity and bicipital aponeurosis N= musculocutaneous A= flexion, supination
triceps brachii
O= infraglenoid tubercle (long head), posterior lateral humerus (lateral head), posterior humerus (medial head) I= olecranon of ulna N= radial A= extension of forearm at elbow, extension of arm at shoulder
muscles that move the wrist, hand, thumb, and fingers
anterior group= flexors of the wrist/fingers & pronators
posterior group= extensors of wrist/fingers & supinators
-flexors originate at medial epicondyle
-extensors originate at lateral epicondyle
muscles of anterior compartment (forearm)
flexor carpi radialis (median nerve)
flexor carpi ulnaris (ulnar nerve)
palmaris longus (outside of carpal tunnel, median nerve)
flexor digitorum superficialis (median nerve, splits)
flexor pollicis longus (deep, median nerve)
flexor digitorum profundus (deep, median nerve, goes through split)
muscles of the posterior compartment (forearm)
extensor carpi radialis longus extensor carpi radialis brevis extensor digitorum extensor digiti minimi extensor carpi ulnaris abductor pollicis longus (deep) extensor pollicis brevis (deep) extensor indicis (deep) -all innervated by radial nerve
thenar eminence
abductor pollicis brevis (median)
opponens pollicis (median)
flexor pollicis brevis (median and ulnar)
adductor pollicis (ulnar)
hypothenar eminence
abductor digiti minimi (ulnar)
flexor digiti minimi brevis (ulnar)
opponens digiti minimi (ulnar)
interosseous muscles of the hand
4 dorsal interossei =abductors of fingers II, III, IV
3 palmar interossei= adductin of fingers II, IV, V
ulnar nerve
muscles that move the vertebral column
splenius capitis & cervicis erector spinae complex iliocostalis (most lateral) longissimus (middle) spinalis (most medial) scalenes
iliopsoas
O= lumbar vertebrae, iliac fossa I= lesser trochanter of femur N= L2-L3, femoral nerve A= flexes thigh and vertebral column, laterally rotates thigh -anterior to spine
gluteus maximus
O= iliac crest, sacrum, coccyx, aponeurosis of erector spinae I= gluteal tuberosity of femur, iliotibial tract N= inferior gluteal nerve A= extension of thigh, lateral rotation of thigh
gluteus medius & minimus
O= ilium I= greater trochanter N= superior gluteal nerve A= abducts and medially rotates femur, maintains axis of pelvis when stepping w/ opposite foot
tensor fascia lata
O= iliac crest I= tibia via iliotibial tract N= superior gluteal nerve A= flexion and abduction of thigh
muscles of posterior thigh
-hamstrings
-cross at the hip and knee
-flex knee and extend thigh
-tibial nerve
biceps femoris (lateral)
semitendinosus (medial group)
semimembranosus (medial group)
biceps femoris
O= ischial tuberosity, femur I= fibular head, lateral condyle of tibia N= tibial nerve
semimembranosus
O= ischial tuberosity I= medial condyle, surface of the tibia N= tibial nerve
muscles of the anterior thigh
iliopsoas
quadriceps femoris complex
sartorius
tensor fascia lata
quadriceps femoris complex
rectus femoris
vastus lateralis, medialis, intermedius
rectus femoris
O= ilium I= upper border of patella N= femoral nerve A= flexes thigh, extends knee
vastus lateralis, medialis, intermedius
O= anterior and lateral femur I= patellar tendon into tibial tuberosity N= femoral nerve A= extends knee
sartorius
O= anterior superior iliac spine I= surface of tibia N= femoral nerve A= flexes leg at knee, flexes thigh and rotates it laterally (cross legs)
muscles of the medial thigh
-all adductors
adductor group
pectineus (small adductor, most superior)
gracilis
adductor magnus, longus, brevis (adductor group)
O= pubis, ischium I= linea aspera of femur A= adducts, rotates, and flexes
gracilis
O= pubic symphysis and arch I= medial surface of tibia A= adducts thigh and flexes knee
gastrocnemius/soleus (posterior leg)
O= lateral and medial condyles of femur, knee capsule I= calcaneus via achilles tendon N= tibial nerve A= flexes knee, plantar flexes foot
tibialis anterior (anterior leg)
O= tibia I= anterior tarsal bones A= dorsiflexes/inverts foot
anterior compartment of leg
tibialis anterior
extensor hallucis longus
extensor digitorum longus
tibialis anterior
O= lateral condule and body of tibia I= 1st metatarsal and 1st cuneiform N= deep fibular nerve A= dorsiflexes foot at ankle and inverts foot
lateral compartment of leg
fibularis longus and brevis
posterior compartment of leg (superficial)
gastrocnemius
soleus
plantaris
posterior compartment of leg (deep)
popliteus
tibialis posterior
flexor hallucis longus
flexor digitorum longus
tibialis posterior
O= tibia, fibula I= metatarsals 2,3,4 & some tarsals N= tibial nerve A= plantar flexes foot and inverts foot
extensor digitorum & extensor hallucis brevis
only muscle located on dorsum of food
lateral plantar muscles
abductor digiti minimi
flexor digiti minimi brevis
medial plantar muscles
abductor hallucis
flexor hallucis brevis
adductor hallucis
