Lecture Exam 3: Muscles Flashcards
Masseter (strongest jaw muscle)
Action: closes jaw/moves the mandible
Origin: zygomatic arch
Insertion: angle and ramus of mandible
Sternocleidomastoid
Action: flexion of neck forward and rotation to the shoulder of opposite side
Origin: manubrium of sternum and the clavicle
Insertion: mastoid process of temporal bone
Orbicularis Oris
“Kissing Muscle”
Action: closes mouth, protrudes lips
Origin: maxillary bone and mandible
Insertion: skin and muscle around mouth
Diaphragm
Action: flattens to increase the volume of the thoracic cavity (inspiration)
Origin: inferior border of rib and sternum, costal cartilage of last 6 ribs and lumbar vertebrae
Insertion: central tendon
Supraspinatus
Action: abduction at the shoulder
Origin: supraspinous fossa of scapula
Insertion: greater tubercle of humerus
Gracilis
Action: flexion at knee, medial rotation and adduction at hip
Origin: inferior ramus and body of pubis
Insertion: medial side of distal tibia
Gastrocnemius
Action: plantar flexion at ankle, inversion of foot, flexion at knee
Origin: medial and lateral condyles of femur via two heads
Insertion: calcaneus via calcaneal tendon
Sartorius
Action: flexion at knee, flexion and lateral rotation at hip
Origin: anterior superior iliac spine
Insertion: medial side of proximal tibia
Genioglossus
Action: depresses and protrudes the tongue
Origin: chin
Insertion: hyoid bone and the dorsum of the tongue