Exam 3: Muscular System Flashcards
Masseter
Origin: zygomatic arch
Insertion: angle and ramus of the mandible
Action: raises of the mandible
Sternocleidomastoid
Origin: manubrium of sternum and medial portion of the clavicle
Insertion: mastoid process of the temporal bone
Action: flexes the cervical vertebral column
Trapezius
Origin: occipital bone and ligamentum nuchae
Insertion: clavicle; acromion and spine of scapula
Action: rotates, adducts, and stabilizes the scapula
Levator scapulae
Origin: transverse processes of upper cervical vertebrae
Insertion: vertebral border of the scapula
Action: elevates the scapula
Pectoralis major
Origin: medial half of the clavicle and the sternum
Insertion: intertubercular groove of humerus
Action: flexes, adducts, and medially rotates the arm
Latissimus dorsi
Origin: spinous process of lower thoracic vertebrae
Insertion: intertubercular groove of humerus
Action: extends, adducts, and medially rotates the arm
Deltoid
Origin: clavicle; acromion and spine of scapula
Insertion: deltoid tuberosity of humerus
Action: abducts the arm
Supraspinatus
Origin: supraspinous fossa of the scapula
Insertion: greater tubercle of the humerus
Action: abducts the arm
Infraspinatus
Origin: infraspinous fossa of the scapula
Insertion: greater tubercle of the humerus
Action: rotates the arm laterally
Subscapularis
Origin: subscapular fossa of the scapula
Insertion: lesser tubercle of the humerus
Action: rotates the arm medially
Biceps brachii (long head and short head)
Origin: coracoid process of the scapula
Insertion: radial tuberosity of the radius
Action: flexes the forearm and arm; supination of forearm
Triceps brachii (long, lateral, and medial heads)
Origin: infraglenoid tubercle of the scapula and posterior surface of the humerus
Insertion: olecranon process of the ulna
Action: extends the forearm
Flexor carpi radialis
Origin: medial epicondyle of the humerus
Insertion: 2nd and 3rd metacarpals
Action: flexes the hand
Flexor carpi ulnaris
Origin: medial epicondyle of the humerus
Insertion: 5th metacarpal
Action: flexes the hand
Extensor carpi ulnaris
Origin: lateral epicondyle of the humerus
Insertion: 5th metacarpal
Action: extends the hand
Extensor carpi radialis longus
Origin: supracondylar ridge of the humerus
Insertion: 2nd metacarpal
Action: extends the hand
Gluteus maximus
Origin: gluteal line of the ilium
Insertion: gluteal tuberosity of the femur
Action: extends and laterally rotates the thigh
Iliacus
Part of iliopsoas
Origin: iliac crest of the ilium
Insertion: lesser trochanter of the femur
Action: flexes the thigh
Psoas major
Part of the iliopsoas
Origin: transverse processes of the lumbar vertebrae
Insertion: lesser trochanter of the femur
Action: flexes the thigh
Adductor magnus
Origin: inferior ramus of the pubis and ischium
Insertion: linea aspera of the femur
Action: adducts the thigh
Gracilis
Origin: pubic symphysis
Insertion: medial surface of the tibia
Action: adducts the thigh
Sartorius
Origin: anterior superior iliac spine
Insertion: medial surface of the tibia
Action: flexes the thigh and leg
Rectus femoris
Part of the quadriceps femoris
Origin: anterior inferior iliac spine
Insertion: tibial tuberosity of the tibia
Action: flexes the thigh and extends the leg
Vastus lateralis
Part of the quadriceps femoris
Origin: greater trochanter of the femur
Insertion: tibial tuberosity of the tibia
Action: extends the leg
Biceps femoris (long and short head)
Part of the hamstring
Origin: ischial tuberosity and linea aspera of the femur
Insertion: head of the fibula and lateral condyle of the tibia
Action: flexes the leg and extends the thigh
Semimembranosis
Part of the hamstring
Origin: ischial tuberosity
Insertion: proximal end of the tibia
Action: flexes the leg and extends the thigh
Tibialis anterior
Origin: lateral condyle of the tibia
Insertion: 1st metatarsal
Action: dorsiflexes and extends the foot
Gastrocnemius (lateral and medial heads)
Origin: medial and lateral condyles of the femur
Insertion: calcaneus bone
Action: plantar flexes and inverts foot
Iliotibial tract
From iliac crest to tibia
Insertion for gluteus maximus
Ligamentum nuchae
Extends from the occipital protuberance to the spinous process of the seventh cervical vertebrae
Trapezius and splenius capitis attach to the nuchal ligament
Inguinal ligament
Runs from the anterior superior iliac spine to the pubic tubercle
Origin and insertion
First part of name indicates origin
Second part of name indicates insertion
Origin
“Fixed end”
End of muscle that doesn’t move during contraction
Proximal to insertion
Insertion
“Moving end”
End of the muscle that DOES move during contraction
Movement toward the origin
Muscle cells (fibers)
Organized in bundles (fascicles)
Four patterns of fascicles:
- parallel
- convergent
- pennate
- circular
Parallel muscles
Fibers parallel to the long axis of muscle
Ex: biceps brachii
Convergent muscles
Broad area converges on attachment site (tendon, aponeurosis)
Muscle fibers pull in different directions, depending on stimulation
Ex: pectoralis muscles
Pennate muscles
Unipennate:
- fibers on 1 side of tendon
Ex: extensor digitorum
Bipennate:
- fibers on both sides of tendons
Ex: Rectus femoris
Multipennate:
- tendon branches w/i muscle
Ex: deltoid
Circular muscles
Also called sphincter
Close and guard entrances of body
Ex: orbicularis oris, papillary constrictor muscles (eyes)
Circular muscles and their antagonists
Orbicularis oris: closes mouth
Levator labii superioris and zygomaticus: open mouth
Externus (superficialis)
Visible at body surface
Internus (profundus)
Deep muscles
Extrinsic
Muscles outside of an organ
Intrinsic
Muscles inside of an organ
Longus
Long
Longissimus
Longest
Teres
Long and round
Brevis
Short
Magnus
Large
Major
Larger
Maximus
Largest
Minor
Small
Minimus
Smallest
Temporalis
Origin: temporal bone
Insertion: coronoid process of the mandible
Action: raises the mandible
