Muscles: Know Origin, Insertion, and Action Flashcards
Orbicularis Oris
Encircles the mouth
Orbicularis oculi
Encircles the eye
Digastric
OIA
O-Mastoid process of temporal bone
I-Mandible via pulley tendon on hyoid bone
A- Depresses mandible
Temporalis
OIA
O-Temporal bone
I-Coronoid process of mandible
A-Elevates mandible
Masseter
OOIA
O-Zygomatic bone
-Zygomatic arch
I-ramus of mandible
A-elevates mandible
Sternocleidomastoid
OOIAA
O-Manubrium -Clavicle I-Mastoid process of temporal bone A-Rotates head, if one is contracted -Flexes head, if both are contracted
Internal oblique
OOOIIAA
O-Iliac crest-ilium -Inguinal ligament -Thoracolumbar fascia I-Lower ribs -Linea alba A-Compresses abdomen -Flexes vertebral column laterally
External Oblique
OIIAA
O-ribs 5-12 I-Iliac crest of ilium -Linea alba A- Compresses abdomen -Flexes vertebral column laterally (same side as muscle) external/lateral to internal obliques fibers run as if you were to put your hands in a coat pocket rotates torso to opposite side as muscle
External intercostal
runs inferomedially
aids in inhalation
Internal intercostal
Runs inferolaterally
aids in exhalation
Diaphragm
3 structures pass through. Give names of structures and openings.
Aorta through the aortic hiatus
Esophagus through esophogeal hiatus
Inferior vena cava through caval opening
Rotator Cuff
4 muscles
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Supraspinatus
OIA
O-Supraspinous fossa of scapula- medially
I- Greater tubercle of humerus-laterally, slightly anterior
A- Abduction of arm
Infraspinatus
OIA
-crosses one joint
O-infraspinous fossa of scapula- Medial
I- Greater tubercle of humerus- Posterolateral
A- Rotates arm laterally- and I think posteromedially
Teres Minor
OIAAA
O-Lateral border of scapula- inferior, deep, dorsal
I- Greater tubercle of humerus (inferior to I of infraspinatus)
A-Adducts arm
-Extends arm
-Rotates arm laterally
Greater tubercle is lateral- anterior -> posterior. This attaches posterolaterally.
Subscapularis
OIA
crosses 1 joint
O-Subscapular fossa- Medial
I- Lesser tubercle of humerus (medial, anterior)
A- Rotates arm medially
Triceps brachii
OOOIAA
Crosses 2 joints O-Infraglenoid tubercle of scapula- Long head -Proximal 1/3 of humerus- Lateral head -Distal half of humerus- Medial head I- Olecranon process of ulna A- Extends forearm -Extends arm Medial head is very short. Only on distal half of humerus. Underneath, on lateral and medial sides.
Brachioradialis
OIA
O-Proximal to capitulum of humerus
I-Proximal to styloid process of radius
A- Flexes semi-pronated forearm
Pronator Teres
OOIAA
O-Medial epicondyle of humerus O- Coronoid process of ulna I-Mid-lateral surface of radius A-Pronates forearm A-Flexes forearm
Bicep Brachii
OOIAAA
O-Supraglenoid tubercle of Scapula O-Coracoid process of Scapula I-radial tuberosity of radius A-flexes supinated forearm A-Supinates forearm A-Flexes arm