New muscle views in the 2nd edition include:

29 new head muscles including Buccinator, Corrugator Supercilii, Depressor Anguli Oris and Levator Anguli Oris.
8 new Larynx/pharynx muscles including Thyrohyoid, Stylohyoid, Geniohyoid and Mylohyoid.
17 new pelvic floor muscles including Obturator Internus, Bulboapongiosus and Perineal Body
7 new respiration muscles including Diaphragm, Serratus Posterior Inferior and Intercostal Externus and Internus.
3 new abdominal muscles views: Internal Oblique, External Oblique and Transversus Abdominis.
A total of over 70 muscle function animations 27 are new for the 2nd Edition including:

-Lateral flexion of the trunk
-Rotation of the trunk
-Respiration
-Opening/Closure of the lips
-Retraction of the angles of the mouth
-Elevation/Depression of the eyebrows
-Elevation/Depression of the TMJ
-Elevation/Depression of the hyoid bone
-Contraction of the pelvic floor
-Flexion/extension of the IP joints of the hand
-PLUS new gross motor animations.
-In addition to walking, standing from sitting, sit up and push up, new of the 2nd Edition include:

Walking upstairs
-Running
-Jumping forward
-Jumping on the spot

Benefits
-Many new anatomy views.
-All muscle function animations can be exported as video clips