Human muscular system diagram highlighting key muscle groups.

You're looking at an anterior (front) view of the human muscular system with several key muscles labeled by lines pointing to them. Since the labels are blank, your task is to identify each muscle based on its anatomical location.

Here’s a step-by-step solution identifying each labeled muscle, starting from top to bottom and left to right:

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✔ Top Label (Head/Face):
➡️ Frontalis
- This is the broad, flat muscle of the forehead. It’s part of the occipitofrontalis muscle and helps raise the eyebrows and wrinkle the forehead.

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✔ Left Side Labels (from top to bottom):

1. Deltoid
- The rounded, triangular muscle covering the shoulder joint. It abducts the arm and gives the shoulder its contour.

2. Pectoralis Major
- Large, fan-shaped chest muscle. It adducts, medially rotates, and flexes the humerus.

3. Biceps Brachii
- Two-headed muscle on the front of the upper arm. Primary function: elbow flexion and supination of the forearm.

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✔ Right Side Labels (from top to bottom):

1. Rectus Abdominis
- The “six-pack” muscle running vertically on the front of the abdomen. It flexes the trunk.

2. External Oblique
- Outermost abdominal muscle, running diagonally downward and inward. Helps rotate and flex the trunk.

3. Flexor Digitorum Superficialis (or Hand Muscles)
- *Note:* The line points to the forearm/hand area. While not perfectly clear, it likely indicates forearm flexor muscles or specifically the flexor digitorum superficialis, which flex the fingers. In some simplified diagrams, this may be labeled as “Hand Muscles” or “Forearm Flexors.”
➡️ For educational purposes, we’ll label it: Forearm Flexor Muscles (commonly including flexor digitorum superficialis/profundus).

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✔ Bottom Left Label (Leg):

➡️ Tibialis Anterior
- Located on the front of the lower leg. It dorsiflexes and inverts the foot. It’s clearly visible as the prominent muscle along the shin.

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✔ Final Labeled Answers (in order as they appear on diagram):

1. Frontalis *(top head)*
2. Deltoid *(left shoulder)*
3. Pectoralis Major *(left chest)*
4. Biceps Brachii *(left upper arm)*
5. Rectus Abdominis *(right abdomen, vertical)*
6. External Oblique *(right side of abdomen, diagonal)*
7. Forearm Flexor Muscles *(right hand/forearm area — most accurate general term)*
8. Tibialis Anterior *(lower left leg/shin)*

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📌 Note: If this is for a specific curriculum or textbook, the exact terminology might vary slightly (e.g., “biceps” instead of “biceps brachii,” or “abdominal muscles” instead of rectus abdominis). But the above labels are anatomically precise and widely accepted.

Let me know if you’d like a version formatted for printing or labeling!