4. List of muscles you need to know
Serratus Anterior
Biceps Brachii
Rectus Abdominis
External Abdominal Oblique
Deltoid
Pectoralis Major
Brachialis
Brachioradialis
Trapezius
Triceps Brachii
Latissimus Dorsi
Quadricep
Hamstring
Gastrocnemius
Achilles Tendon

6. Muscles can only contract
Since muscles can only contract, you need at least two muscles or a group of muscles to move a body part
While one muscle contracts, the opposite muscle relaxes and vice versa for movement in the opposite direction

7. I feel like the illustrations of muscles in the textbook are a bit inadequate so here are some additional illustrations to help you visualize the muscles

8. Serratus Anterior – Brings Scapula Forward

9. Flexing the Elbow
Biceps Brachii
Brachialis
Brachioradialis

13. Flexing the Spine
Rectus Abdominis
External Abdominal Oblique

15. Deltoid