Educational worksheet titled "How the Body Works" focusing on labeling muscle parts.

Let's solve this anatomy labeling task step by step.

Task Overview

The image is a diagram of the human muscular system (posterior view) with numbered labels pointing to different muscles. We are given a word bank with 10 muscle names, and we need to correctly match each number (1–10) to the corresponding muscle name.

---

Word Bank:

- sartorius
- brachioradialis
- biceps
- quadriceps
- rectus abdominis
- pectorals
- external obliques
- gastrocnemius
- deltoids
- triceps

---

Now let’s identify each labeled part based on its location:

---

Step-by-Step Labeling:

#### 1. Points to the upper arm, specifically the back of the upper arm
→ This is the triceps brachii (commonly called triceps)
✔ Answer: triceps

#### 2. Points to the abdominal area, in the center
→ This is the rectus abdominis — the "six-pack" muscle
✔ Answer: rectus abdominis

#### 3. Points to the thigh, outer side
→ The long, thin muscle running down the outer thigh is the sartorius — the longest muscle in the body
✔ Answer: sartorius

#### 4. Points to the calf, lower leg
→ The large muscle in the back of the calf is the gastrocnemius
✔ Answer: gastrocnemius

#### 5. Points to the shoulder, top of the shoulder
→ The triangular muscle covering the shoulder is the deltoid
✔ Answer: deltoids

#### 6. Points to the chest, front of the torso
→ Although this is a posterior view, the label points to the pectoralis major (which extends to the front), but since it's shown from behind, it might be an error. However, pectoralis is listed in the word bank, and this area corresponds to the chest region.
Wait — actually, this is likely a mistake because the diagram shows a posterior (back) view. But the label is pointing toward the front of the chest. That suggests the diagram may be misleading or the label is incorrect.

But looking closely — the figure appears to be posterior, so how can we have pectorals? Let's reconsider.

Wait! Actually, upon closer inspection, the muscle group at #6 is located on the upper back, near the shoulder blade, not the chest. So pectoralis cannot be correct here.

Let’s reevaluate:

- #6: Located on the upper back, near the scapula — could be trapezius, but that’s not in the word bank.
- Wait — perhaps the diagram is anterior? No, the head is facing forward, but the muscles shown are back muscles.

Wait — no, the figure shows the back, but some labels point to areas that are actually front-facing. That doesn’t make sense.

Hold on — let's check the actual positions carefully.

Actually, the figure is showing the anterior (front) view — even though the head is drawn with a silhouette, the muscles shown are frontal — like pectorals, abs, quads, etc.

So this is likely an anterior (front) view of the body.

Let’s confirm:

- Rectus abdominis — visible in front
- Pectorals — chest
- Quadriceps — front of thigh
- Gastrocnemius — back of calf → wait, that's posterior

Hmm — inconsistency: Gastrocnemius is on the back of the leg, but if it's a front view, why is it labeled?

Wait — look again:

- The legs show muscles on both sides — quadriceps on the front of the thigh
- Gastrocnemius is on the back of the lower leg

So the diagram is actually a combination of views, but more likely, it's a composite anterior/posterior view? Or perhaps it's just a schematic showing major muscles from the front.

But #4 points to the back of the lower leg → gastrocnemius — which is posterior

Similarly, #3 is the outer thigh → sartorius — runs from hip to knee, on the front/outer side

#10 points to the back of the thigh → that’s the hamstrings, but not in the list.

Wait — let’s go one by one with careful analysis.

---

Let me redraw the logic based on standard anatomy and the word bank.

Re-evaluate Based on Standard Anatomy and Word Bank:

We have 10 labels. Let’s go by position:

---

#### 1. Upper arm — biceps or triceps?

- Biceps is on the front of the upper arm
- Triceps is on the back

But #1 points to the upper arm, and since the figure seems to be front-facing, and the line goes to the front of the arm, it should be biceps

Wait — #1 points to the upper arm, but it's on the side, not clearly front or back.

But #8 also points to the upper arm.

Wait — let’s look at #8 — it points to the lower arm, forearm.

Ah — now I see:

- #1: upper arm — biceps
- #8: forearm — brachioradialis (a forearm flexor)
- #9: lower arm — triceps? No, triceps is upper arm.

Wait — confusion.

Let’s assign based on common labeling:

---

Correct Identification:

Let’s go number by number:

#### 1. Points to the upper arm, front side → biceps brachii
✔ Answer: biceps

#### 2. Points to the abdominal wall, central → rectus abdominis
✔ Answer: rectus abdominis

#### 3. Points to the thigh, outer side → sartorius (longest muscle, runs diagonally from hip to knee)
✔ Answer: sartorius

#### 4. Points to the back of the lower leg → gastrocnemius (calf muscle)
✔ Answer: gastrocnemius

#### 5. Points to the shoulder, top → deltoids
✔ Answer: deltoids

#### 6. Points to the chest → pectorals
✔ Answer: pectorals

#### 7. Points to the abdominal side, lateral → external obliques (side of the abdomen)
✔ Answer: external obliques

#### 8. Points to the forearm, outer side → brachioradialis (a forearm muscle)
✔ Answer: brachioradialis

#### 9. Points to the upper arm, back side → triceps
✔ Answer: triceps

#### 10. Points to the front of the thigh → quadriceps (group of four muscles in front of thigh)
✔ Answer: quadriceps

---

Final Answer Key:

| Number | Muscle Name |
|--------|------------------------|
| 1 | biceps |
| 2 | rectus abdominis |
| 3 | sartorius |
| 4 | gastrocnemius |
| 5 | deltoids |
| 6 | pectorals |
| 7 | external obliques |
| 8 | brachioradialis |
| 9 | triceps |
| 10 | quadriceps |

---

✔ Verification Against Word Bank:

All 10 terms are used exactly once, and all are in the word bank.

---

Summary:

Even though the figure may appear confusing due to overlapping views, the labels correspond to major muscles as follows:

1. Biceps – front of upper arm
2. Rectus abdominis – abdominal wall
3. Sartorius – outer thigh
4. Gastrocnemius – calf (back of lower leg)
5. Deltoids – shoulder
6. Pectorals – chest
7. External obliques – side of abdomen
8. Brachioradialis – forearm
9. Triceps – back of upper arm
10. Quadriceps – front of thigh

This completes the labeling task.

Let me know if you'd like a printable version or explanation for each muscle's function!