Anatomy Chapter 18

Origin- Sternal ends of the 3rd, 4th, and 5th ribs
Insertion- Coracoid process of the scapula
Action- Pulls scapula forward and downward

Origin- External surfaces of lateral parts of ribs 1 - 8/9
Insertion- Anterior vertebral border of the scapula
Action- Pulls scapula forward and downward

Origin- Posterior tubercles of transverse process of C1-C4
Insertion- Superior part of vertebral border of scapula
Action- Elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula

Origin- Spinous process of T2-T5
Insertion- Vertebral border of the scapula from the inferior border of the rhomboideus minor to the inferior angle of the scapula
Action- Adducts scapula and rotates it to depress glenoid cavity

Origin- Medial 1/3 of superior nuchal line, external occipital protuberance, nuchal ligament, and spines of C7 and all thoracic vertebrae
Insertion- Lateral third of clavicle, acromion process, and spine of scapula
Action- Elevates, retracts, and rotates scapula; superior fibers elevate; middle fibers retracts; inferior fibers depress scapula; superior and inferior fibers work together in superior rotation of scapula

Origin- Spines of sacral, lumbar, and lower thoracic vertebrae; iliac crest and lower 4 ribs
Insertion- intertubercular groove of the humerus
Action- extends, adducts, and rotates humerus medially; retracts shoulder

Origin- Clavicular Head: anterior surface of medial half of clavicle. Sternocostal Head: anterior surface of sternum, superior six costal cartilages and aponeurosis of external abdoninal oblique
Insertion- Crest of greater tubercle
Action- Adducts and medially rotates humerus; draws shoulder joint anteriorly and inferiorly

Origin- Clavicle, acromion process, spine of the scapula
Insertion- Deltoid tuberosity of the humerus
Action- Anterior Part: Flexes and medially rotates arm. Middle Part: Abducts arm. Posterior Part: Extends and laterally rotates arm

Origin- Coracoid process of the scapula
Insertion- Middle third of medial surface of humerus
Action- Flexes and adducts arm at shoulder joint

Origin- Inferior angle and lateral border of scapula
Insertion- Crest of lesser tubercle of the humerus
Action- Medially rotates and adducts arm

Origin- Subscapular fossa
Insertion- Lesser tubercle of humerus
Action- Extends humerus, adducts and rotates arm medially

Origin- Supraspinous fossa of the scapula
Insertion- Greater tubercle of the humerus
Action- Abducts and laterally rotates humerus

Origin- Infraspinous fossa of the scapula
Insertion- Greater tubercle of the humerus
Action- Rotates arm laterally

Origin- Superior part of axillary border of scapula
Insertion- Greater tubercle of humerus
Action- Rotates arm laterally

List the four muscles that make up the rotator cuff.

What is hte main function of the rotator cuff?

What separates the limbs into compartments?

What two compartments occur in the brachium?

Origin- Short Head: Coracoid process of scapula. Long Head: Supraglenoid tubercle of scapula.
Insertion- Radial tuberosity and fascia of forearm via bicipital aponeurosis
Action- Flexes and supinates forearm

Origin-Distal half of anterior shaft of the humerus
Insertion- Coronoid process of ulna
Action- Flexes forearm

Origin-Proximal two thirds of lateral supracondylar ridge of humerus
Insertion- Lateral surface of distal end of radius
Action- Flexes forearm

Origin- Long Head: Infraglenoid tubercle of scapula. Lateral Head: Posterior surface of humerus superior to radial nerve groove. Medial Head: Posterior surface of humerus inferior to radial nerve groove
Insertion- Olecranon process of the ulna
Action- Extends forearm; Long head steadies ehad of abducted humerus

Origin- Medial epicondyle of the humerus and coronoid process of ulna
Insertion- Middle of lateral surface of the radius
Action- Pronates forearm

Origin- Distal fourth of anterior surface of ulna
Insertion- Distal fourth of anterior surface of radius
Action- Pronates hand

Origin- Lateral epicondyle of the humerus and crest of the ulna
Insertion- Lateral surface of the proximal third of radius
Action- Supinates forearm

Origin- Medial epincondyle of the humerus; anterior, proximal ulna and radius; interosseous membrane
Insertion- Carpals, metacarpals, and phalanges
Action- Flex wrist and digits

Origin- Lateral epicondyle of the humerus; posterior surfaces of the radius and ulna; interosseous membrane
Insertion- Carpals, metacaroals, and phalanges
Action- Extend wrist and digits

What is another name for the flexor retinaculum of the wrist?

The flexor retinaculum of the wrist and the arch of the carpals form what structure?

What group of muscles forms the thick, fleshy mass at the base of the thumb and work to abduct, flex or oppose the thumb?

What group of muscles forms the small fleshy mass at the base of the fifth digit of the hand and work to abduct, flex, and oppose the 5th digit?

Within the hand, what group of muslces lies between the 1st and 5th digits?

Origin- Tendons of a flexor which sends a tendon to the distal phlanx of digits 2-5
Insertion- Lateral sides of extensor expansions of digits 2-5
Action- Flex digits at metacarpophalangeal joints and extend interphalangeal joints

Origin- Adjacent sides of two metacarpal bones
Insertion- Extensor expansions and bases of proximal phalanges of digits 2-4
Action- Abducts digits 2-4

Origin- Palmar surfaces of metacarpals 2, 4, and 5
Insertion- Extensor expansions of digits and bases of proximal phalanges of digits 2, 4, and 5
Action- Adduct digits 2, 4, and 5

What muscle flexes the elbow but neither originates nor inserts on the humerus?

The tendons of what muscle group can be seen on the dorsum of the hand?

What muscle forms the anterior border of the axilla?

What muscle lies in the infraspinous fossa?

What muscle inserts on the olecranon process?