Muscles Flashcards
Occipitofrontalis (frontal belly)
Action: Raise the eyebrows, wrinkles the forehead and protract the scalp
Occipitofrontalis (occipital belly)
Action: retracts the scalp slightly
Galea aponeurotica
Location: tendinous sheath in superior skull
Orbicularis oris
Action: puckers the lips, used to kiss and suck on a straw
Buccinator
Action: Compresses cheeks, holds food between cheeks, aids in sucking and blowing. “trumpeter”
Temporalis
Mastication muscle
Action: elevates and retracts the mandible
Origin: Superior and inferior portion of temporal bone
Insertion: Coronoid process of mandible
Masseter
Mastication muscle
Action: Prime mover of jaw closure; elevates and protracts mandible. “chewer”
Origin: zygomatic arch
Insertion: lateral surfaces of angle of mandible and coronoid process
Medial and Lateral Pterygoid
Action: Elevates and protracts mandible, moves mandible laterally. “grinder”
Platysma
Action: Pulls lower lip inferiorly, tenses skin of neck, depresses mandible. “grimace”
Sternocleidomastoid
Action: Both contracted - flexion pulls head forward and down. One contracted - rotation of the atlantoaxial joint; lateral flexion turns head to the opposite side
Origin: Manubrium and sternal ends of clavicle
Insertion: mastoid process of temporal bone
Splenius Capitis/Semispinalis Capitis
Action: Both contracted - extends and hyperextends head/neck. Unilateral contractions turn head and neck to the same side.
Synergistic to Trapezius
Muscles of facial expression
- Occipitofrontalis (frontal and occipital belly)
- Orbicularis oris
- Buccinator
- Platysma
Erector Spinae / Transversospinalis
Action: Both contracted - extends vertebral column.
One side contracted - flexes vertebral column laterally toward that same side.
Rectus sheath
Tendinous sheath over the abdominal muscles
Rectus Abdominis
Action: Flexes vertebral column, and compresses the abdominal wall
Origin: Superior surface of pubis near symphysis
Insertion: Xiphoid process, inferior surface of middle ribs
External/Internal Obliques
Both contracted - compresses abdomen, and flexes the vertebral column. One side contracted - lateral trunk flexion and/or trunk rotation occurs.
Transverse abdominis
Compresses abdomen. Supports spine while lifting.
“the body’s natural back brace”
Linea Alba
Fibrous tissue running down the center if the rectus abdominis
Linea semilunaris
Fibrous tissues running along the lateral edges of the rectus abdominis
Inguinal Ligament
connects the oblique muscles of the abdomen to the pelvis, deep in the groin
Pectoralis Major
Action: Prime mover of arm flexion; adducts and medially rotates arm at glenohumeral joint
Origin: Body of sternum, medial clavicle, and costal cartilage of upper ribs.
Insertion: Lateral part of intertubercular groove of humerus
Pectoralis Minor
Action: Protracts and depresses scapula
Synergistic muscles for scapular protraction
Antagonistic rhomboid major/minor
Serratus Anterior
Action: Prime mover in scapular protraction; stabilizes and superiorly rotates scapula
Synergistic muscles for scapular protraction
Antagonistic rhomboid major/minor
Deltoid
Action: Anterior fibers: flexes and medially rotates. Middle fibers: prime abductor. Posterior fibers: extend and laterally rotates
Origin: Acromial end of clavicle, acromion, and spine of scapula
Insertion: Deltoid tuberosity of humerus
Coracobrachialis (action only)
Action: Adducts and flexes at the glenohumeral joint
Synergistic to the Pectoralis major
Biceps Brachii (Long Head)
Action: Flexes cubitus, powerful supinator of antebrachium at cubitus; weakly flexes the glenohumeral joint
Origin: Supraglenoid tubercle of scapula
Insertion: Radial tuberosity and bicipital aponeurosis
Biceps Brachii (short head)
Action: Flexes cubitus, powerful supinator of antebrachium at cubitus
Origin: Coracoid process of scapula
Insertion: Radial tuberosity and bicipital aponeurosis
Trapezius
Action: Adducts and elevates the scapula; extends neck
Origin: Occipital bone, Ligamentum nuchae, and spinous processes of C7-T12
Insertion: Clavicle, acromion process, and spine of scapula
Rhomboid Minor/Major
Action: Adducts and elevates scapula; inferiorly rotates scapula
Antagonist to pectoralis minor and serratus anterior
Rotator Cuff Muscles
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres minor
Subscapularis
Action: Medially rotates the brachium
Antagonist to infraspinatus and teres minor
Supraspinatus
Action: Abducts brachium at glenohumeral joint
Infraspinatus
Action: Adducts and laterally rotates at glenohumeral joint
Synergistic to teres minor
Teres minor
Action: Adducts and laterally rotates at glenohumeral joint
Synergistic to Infraspinatus
Teres major
Brachium extension, adducts humerus inferiorly and posteriorly while rotating it medially
Synergistic to latissimus dorsi
Latissimus dorsi
Action: Prime mover of arm extension; adducts humerus inferiorly and posteriorly while rotating medially. “swimmers”
Origin: Spinous processes of T7-T12, lower ribs, thoracolumbar fascia, iliac crest
Insertion: Intertubercular groove of humerus
Triceps brachii (long head)
Action: Prime extensor of cubitus; also extends the glenohumeral joint
O: Infraglenoid tubercle of scapula
I: Olecranon of ulna
Triceps brachii (lateral head)
Action: prime extensor of cubitus
O: Posterior humerus above radial groove
I: Olecranon of ulna
Triceps brachii (medial head)
Action: prime extensor of cubitus
O: Posterior humerus below radial groove
I: Olecranon of ulna
Tensor fascia latae
Action: Abducts and medially rotates femoral region at acetabulofemoral joint.
O: Iliac crest and lateral surface of anterior superior iliac spine
I: Iliotibial tract
Sartorius
Action: Flexes acetabulofemoral joint and laterally rotates femoral region. Flexes tibiofemoral joint and medially rotates crural region.
O: Anterior superior iliac spine
I: Medial side of tibial tuberosity (Pes Anserine)
Muscles of Quadricep
- Rectus Femoris
- Vastus Lateralis
- Vastus intermedius
- Vastus medialis
Rectus femoris
Action: Extends leg at tibiofemoral joint; also flexes femoral region
O: Anterior inferior iliac spine
I: Quadriceps tendon to patella then patellar ligament to tibial tuberosity
Vastus lateralis
Action: Extends leg at tibiofemoral joint
O: Greater trochanter and linea aspera of femur
I: Quadriceps tendon to patella then patellar ligament to tibial tuberosity
Vastus intermedius
Action: Extends leg at tibiofemoral joint
O: Anterior and lateral surface of femur
I: Quadriceps tendon to patella then patellar ligament to tibial tuberosity
Vastus medialis
Action: Extends leg at tibiofemoral joint
O: Intertrochanteric line and linea aspera of femur
I: Quadriceps tendon to patella then patellar ligament to tibial tuberosity
Gracilis (only insertion)
Action: Adducts and flexes femoral region at acetabulofemoral joint, flexes crural region at tibiofemoral joint
I: Pes Anserine
Tibialis anterior
Action: Primary dorsiflexor of foot; inverts
Peroneus (fibularis) longus
Action: Plantar flexes and everts foot at talocrural region
Gluteus Maximus
Action: Chief extensor of femoral region; extends and laterally rotates femoral region
O: Iliac crest, sacrum, and coccyx
I: Iliotibial tract, linea aspera of femur, and gluteal tuberosity of femur
Piriformis
Action: rotates the femur during the hip extension and abducts the femur during flexion of the hip
Deep to the gluteus maximus
3 Hamstring Muscles
- Biceps femoris (long/short head)
- Semitendinosus
- Semimembranosus
Biceps femoris
Action: Extends femoral region and flexes crural at tibiofemoral joint (long head). Biceps femoris laterally rotates crural
O: Ischial tuberosity
I: Head of fibula
Semitendinosus
Action: Semitendinosus and semimembranosus medially rotate crural
O: Ischial tuberosity
I: Medial side of tibial tuberosity (Pes Anserine)
Semimembranosus
Action: Semitendinosus and semimembranosus medially rotate crural
O: Ischial tuberosity
I: Posterior surface of medial condyle of tibia
2 Tricep surae muscles
Gastrocnemius has 2 heads
Soleus
Gastrocnemius
Action: Plantar flexes foot and flexes tibiofemoral joint
O: Superior posterior lateral and medial condyles of femur
I: Calcaneus via the calcaneal (Achilles) tendon
Soleus
Action: Plantar flexes foot at talocrural region
Deep to the gastrocnemius
Muscles of respiration
Diaphragm
External intercostals
Internal intercostals
Diaphragm
Inhalation - contracts and flattens diaphragm to pull lung interior and compress abdominopelvic cavity
External intercostals
Restful breathing - elevates ribs up and out
Exhalation - muscles relax allowing the elastic recoil of lung tissue
Internal intercostals
Forceful exhalation - depresses ribs. Used in coughing and sneezing.
Pes Anserine insertion muscles
Sartorius
Gracilis
Semitendinosus
3 muscles originating on axial skeleton
Pectoralis major
Trapezius
Latissimus dorsi
IM Injection Muscles
Deltoid
Gluteus maximus
Vastus lateralis
Deltoid and Pectoralis major are synergistic to what muscles?
latissimus dorsi/supraspinatus
