Unit 10 Muscular System Gross Anatomy - Axial

Unit 10 Muscular System Gross Anatomy -
Axial

agonist - -prime movers; provide most force for a given muscle action

- antagonist - -usually on opposite side of bones and joint where they
meet, have opposite action of agonist; allows for modulation and control
of agonist movement

- biceps brachii muscle - -Origin: coracoid process, supraglenoid
tubercule of scapula
Insertion: radial tuberosity
Action: supinates and flexes forearm

- brachialis muscle - -Origin: distal half of the diaphysis of anterior
humerus
Insertion: coronoid process of ulna
Action: flexes forearm (the prime mover)

- brachioradialis muscle - -Origin: distal humerus
Insertion: distal radius
Action: flexes forearm

- deltoid muscle - -Origin: lateral clavicle, acromion, spine of scapula
Insertion: deltoid tuberosity of humerus
Action: abducts arm; secondarily flexes and extends arm

- diaphragm muscle - -Origin: xiphoid process of sternum, lower ribs
and costal cartilages , lumbar vertebrae
Insertion: central tendon of diaphragm
Action: lowers floor of thoracic cavity, increasing its volume

- external intercostal muscles - -Origin: lower edge of rib superior to its
insertion
Insertion: upper edge of rib inferior to its origin
Action: elevate rib cage, spread ribs; inspiration

- external oblique muscle - -Origin: lower 8 ribs
Insertion: linea alba (fibrous CT that runs down the middle of the
abdomen)
Action: compresses abdominal cavity, flexion and rotation of vertebral
column

- fixator - -also provides stabilizing force that anchors a bone; provides
movement efficiency and protection from injury due to unnecessary
movements