Muscle actions Flashcards
Facial muscles: Describe the actions of the frontalis, occipitalis, and orbicularis oculi muscles
Frontalis: wrinkles the forehead; lifts the eyebrows
Occipitalis: antagonist to frontalis
Orbicularis oculi: squinting and winking
Facial muscles: Describe the actions of the zygomaticus, risorius, and orbicularis oris
Zygomaticus: smiling (pulls the corners of the mouth up)
Risorius: pulls angle of the mouth laterally; synergist to the zygomaticus
Orbicularis oris: puckers the lips (kissing, whistling)
Facial muscles: Describe the actions of the mentalis, levator labii superioris, depressor labii inferioris, and genioglossus
Mentalis: protrudes lower lip as in pouting; wrinkles the chin.
Levator labii superioris: elevates the upper lip.
Depressor labii inferioris: pulls the lower lip down as in pouting.
Genioglossus: protrudes the tongue; moves tongue side to side.
Name and describe the actions of the muscles from lab lists used for chewing and swallowing.
1) Buccinator: compresses the cheeks; sucking (nursing infants); assists in chewing by directing the food between molars.
2) Temporalis and masseter: elevates the mandible (chewing)
Name and describe the actions of the neck muscles from lab lists that move the head. (2)
1) Sternocleidomastoid: flexes the head and neck
2) Trapezius: extension of the head and neck
Name and locate the muscles of respiration (from lab) (3)
1) Diaphragm: internal muscle that’s the prime mover for inhalation
2) External intercostals: muscle that elevates (lifts) the ribs that assist inhalation; increase size of thoracic cavity
3) Internal intercostals: muscles depress and retract the ribs for forced expiration; decreases size of thoracic cavity.
Name and locate the muscles from lab lists of the abdominal wall and back. (4)
1) Rectus abdominis: flexes the waist as in sit-ups; compresses abdominal viscera for urination, defecation, childbirth, and vomiting.
2) External oblique: most superficial muscle located on lateral abdomen; produces twisting at the waist and compresses abdominal viscera
3) Internal oblique: middle muscle layer on the lateral abdomen; produces twisting at the waist and compresses the abdominal viscera
4) Transverse abdominis: deepest muscle layer on the lateral abdomen; compresses abdominal viscera.
Name the origin and insertion of pectoralis major
Origin (medial): clavicle, cartilage of ribs 1-6, sternum
Insertion (lateral): intertubercular groove, sulcus of the humerus
Name the origin and insertion of the deltoid
Origin (proximal): clavicle and acromion process of the scapula
Insertion (distal): deltoid tuberosity of the humerus
Name the origin and insertion of the latissimus dorsi
Origin (medial): spinous processes of T6-L5, iliac crest, and ribs 9-12
Insertion (lateral): intertubercular groove of the humerus
Name the origin and insertion of biceps brachii
Origin (proximal): coracoid process and glenoid cavity of the scapula
Insertion (distal): radial tuberosity
Name the origin and insertion of triceps brachii
Origin (proximal): posterior humerus and glenoid cavity of the scapula
Insertion (distal): olecranon process of the ulna
Describe the action of the deltoid
Abduction of the arm (prime mover); anterior fibers flex the arm, posterior fibers extend the arm
Describe the action of pectoralis major
Flexion and adduction of the arm (prime mover)
Describe the action of latissmus dorsi
Extension and adduction of the arm (prime mover)
Describe the action of teres major
Synergist to latissimus dorsi
Name the 4 rotator cuff muscles and describe their action
As a whole, stabilizes shoulder joint and rotates the humerus. Supraspinatus Infraspinatus Teres minor Subscapularis
Describe the action of serratus anterior and pectoralis minor
Protracts and laterally pulls scapulae forward
Describe the action of trapezius and levator scapulae
Elevates scapulae
Describe the action of trapezius and latissimus dorsi
Retracts scapulae
Describe the action of biceps brachii
Flexion and supination of the forearm
Describe the action of brachialis and brachioradialis
Flexion of the forearm
Describe the action of the pronator teres
Pronation of the forearm
Describe the action of triceps brachii
Extension of the forearm
Describe the action of the supinator
Supination of the forearm
The flexors of the wrist are located _______, whereas the extensors of the wrist are located ______.
anteriorly; posteriorly
Describe the action of the iliopsoas
Flexion of the hip (prime mover)
Describe the action of the rectus femoris
Flexion of the hip (synergist)
Describe the action of the sartorius
Flexion, abduction, and lateral rotation of the hip; flexion of the knee
Describe the action of the tensor fasciae latae
Abduction of the hip
Describe the action of the gluteus medius
Abduction of the hip (prime mover)
Describe the action of the gluteus maximus
Extension of the hip (prime mover)
Describe the actions of the hamstrings and name the muscles involved
Extension of the hip and flexion of the knee Biceps femoris (lateral) Semitendonosis (superficial) Semimembranosus (deep) Located on posterior thigh
Describe the action of the gracilis, abductor longus, and abductor magnus
Adduction of the hip
Describe the action of the quadriceps and name the muscles involved
Extension of the knee (all prime movers) Rectors femoris (front of thigh) Vastus lateralis (lateral) Vastus medialis (medial) Vastus intermedius (deep to rectus femoris)
Describe the action of the gastrocnemius
Flexion of the knee
Walking on your tiptoes is called _______
plantar flexion
Describe the action of the tibialis anterior
Dorsiflexion (prime mover)
Describe the action of the gastrocnemius and soleus
Plantar flexion (prime movers)
Describe the action of the tibialis posterior
Inversion of the foot (prime mover)
Describe the action of the fibularis longus
Eversion of the foot
Name the origin and insertion of the gastrocnemius
Origin: medial and lateral condyles of the femur
Insertion: calcaneus
