Muscles and Their Functions.

42. The triceps, a notable large muscle, functions significantly for various other muscles by turning the leg inward. See illustration A. B.

43. Rectus. Positioned alongside three other muscles - Vastus Internus, Vastus Externus, and Cruceus - surrounds the knee joint as depicted in illustration A.

44. Vastus Externus; Located externally, it assists the Vastus Internus in straightening the leg and, together with the aforementioned Rectus, encompasses the kneecap. See the illustrations A. B.

45. Vastus Internus. This is located internally, functioning similarly to the previous muscle. Illustrated in A. B. The Cruceus mentioned earlier is not externally visible.

46. Rotula, the kneecap, described further in the explanation of bones. See the number 43.

47. Major. This is the largest muscle, which alongside Medius and Minimus forms the buttocks. They align the thigh bone (Femur) or ensure it stands straight. The Major, the largest, is visible prominently, sprouting from the upper hip bone (34) and the ischium (35). It descends in a gentle arc a palm's width below the Trochanter Major (39). See illustrations B. and C.

48. Medius is the second contributing to the buttocks, aiding the thigh bone (Femur) in standing straight. Named Medius due to its placement and moderate size compared to others, it extends from the front of the hip bone (34) onto the upper surface of the Trochanter Major (39). See the illustrations B. and C.

Translation Notes:

Triceps: In the context of the illustration, it refers to a particular reference rather than a sole muscle.

Illustrations: The text refers to depictions labeled as A, B, C, which are presumably diagrams.