First 10 Muscles

Question 1

Temporalis

Answer 1

Location: Cranium, Temporal bone above cheek
Origin: Temporal bone
Insertion: Mandible
Action: Elevates & retracts mandible, involved in lateral excursion

Question 2

Masseter

Answer 2

Location: Side of cheek
Origin: Zygomatic Bone
Insertion: Mandible
Action: Elevation of the mandible (protraction, retraction and lateral and medial excursion)

Question 3

Sternohyoid

Answer 3

Location: Anterior neck
Origin: Manubrium of sternum
Insertion: Hyoid bone
Action: Depresses the hyoid bone

Question 4

Trapezius

Answer 4

Location: Upper shoulders to midback
Origin: Occipital bone
Insertion: Scapula
Action: Extends and laterally flexes neck, elevates scapula

Question 5

Sternochleidomastoid

Answer 5

Location: Muscular ridge in the anterolateral neck
Origin: Manubrium (sternum)
Insertion: Mastoid process (temporal bone)
Action: Roates and flexes atlantooccipital joing, one contracting alone: laterally flexes head and neck to same side, Both contract: flex neck

Question 6

Rectus Abdominus

Answer 6

Location: Medial ventral surface from ribs to pubis
Origin: Pubic symphysis
Insertion: Xiphoid process
Action: Flexes lumbar spine, compresses abdomen, unilaterally flexes trunk ipsilaterally (same side)

Question 7

Deltoid

Answer 7

Location: Rounded upper surface of shoulder
Origin:Scapula
Insertion: Deltoid tuberosity of humerus
Action: Abduction of the arm at the shoulder joint

Question 8

Teres Minor

Answer 8

Location: no external appearance
Origin: Lateral border of scapula
Insertion: Greater tubercle of humerus
Action: Stabilizes GHJ, external rotation, horizontal abduction, extension of GHJ

Question 9

Pectoralis Major

Answer 9

Location: Upper half of chest and anterior margin of axilla
Origin: Clavicle and sternum
Insertion: Greater tubercle of humerus
Action: Adducts (frontal place); flexes shoulder (sagittal plane); horizontally adducts (transverse plane); medially rotates arm

Question 10

Latissimus Dorsi

Answer 10

Location: Lower half of back, posterior margin of axilla
Origin: Spinous processes of T7-L5; sacrum and iliac crest
Insertion: Intertubercular groove (humerus)
Action: Adducts (frontal), extends shoulder (sagittal), horizontally abducts (transverse) and medially rotates arm