Muscular system online activity - Free Printable

To solve this problem, we need to match the muscle names from the list to their correct locations on the human body diagrams (front view on the left, back view on the right).

Step 1: Analyze the Front View (Left Figure)
Let's look at the lines pointing to the muscles on the front of the body, going generally from top to bottom.

1. Top line (Neck/Jaw area): The line points to the side of the jaw/cheek area. This is the chewing muscle.
* *Match:* masseter
2. Second line (Side of Neck): The line points to the large strap-like muscle running from behind the ear down to the collarbone.
* *Match:* sternocleidomastoid
3. Third line (Chest): The line points to the large chest muscle.
* *Match:* pectoralis
4. Fourth line (Upper Arm, front): The line points to the muscle on the front of the upper arm.
* *Match:* biceps
5. Fifth line (Stomach area, side): The line points to the muscles on the side of the abdomen, next to the "six-pack" muscles.
* *Match:* external oblique
6. Sixth line (Thigh, front): The line points to the large group of muscles on the front of the thigh.
* *Match:* quadriceps
7. Seventh line (Inner Thigh): The line points to the long, thin muscle running diagonally across the inner thigh.
* *Match:* sartorius
8. Eighth line (Lower Leg, front/side): The line points to the muscle on the front/side of the lower leg (shin area). Looking at the remaining options for the front leg, this is likely the tibialis anterior, but that isn't in the list. Let's re-evaluate. Wait, looking closely at the last line on the front figure, it points to the shin/lower leg. The only leg muscle left for the front/back distinction might be tricky. Let's look at the back first to see what's left.

Let's hold on the last front line and do the back view to ensure we have the right matches for the legs.

Step 2: Analyze the Back View (Right Figure)
Now let's look at the lines on the back of the body, from top to bottom.

1. Top line (Shoulder/Neck base): The line points to the large triangular muscle covering the upper back and shoulder.
* *Match:* trapezius
2. Second line (Shoulder cap): The line points to the rounded muscle on the top of the shoulder.
* *Match:* deltoid
3. Third line (Back of Upper Arm): The line points to the muscle on the back of the upper arm.
* *Match:* triceps
4. Fourth line (Buttocks): The line points to the large muscle of the buttocks.
* *Match:* gluteus maximus
5. Fifth line (Back of Thigh): The line points to the muscles on the back of the thigh.
* *Match:* bicep femoris (part of the hamstrings)
6. Sixth line (Lower Leg, back): The line points to the calf muscle on the back of the lower leg.
* *Match:* calf (gastrocnemius)

Step 3: Re-evaluating the Front View Last Line
Now that we have placed all the back muscles, let's look at the remaining option for the front view.
We used: masseter, sternocleidomastoid, pectoralis, biceps, external oblique, quadriceps, sartorius.
The list has 13 items.
Front lines: 8 lines.
Back lines: 6 lines.
Total lines: 14? Let me recount the lines in the image carefully.

Front View Lines:
1. Jaw -> masseter
2. Neck -> sternocleidomastoid
3. Chest -> pectoralis
4. Upper Arm Front -> biceps
5. Abdomen Side -> external oblique
6. Thigh Front -> quadriceps
7. Inner Thigh -> sartorius
8. Lower Leg Front -> The line points to the shin. The only muscle name left from the list is... wait. Let's check the list again.
List: quadriceps, pectoralis, biceps, bicep femoris, rectus abdominis, masseter, sartorius, deltoid, triceps, gluteus maximus, sternocleidomastoid, external oblique, calf, trapezius.

I missed one muscle in my initial front scan: rectus abdominis.
Let's look at the front diagram again. There are two lines in the abdominal area.
- One line points to the side (External Oblique).
- Is there a line pointing to the center "six-pack"?
Looking at the image provided:
- Line 5 points to the side of the waist. That is external oblique.
- Line 6 points to the front thigh. That is quadriceps.
- Line 7 points to the inner thigh strip. That is sartorius.
- Line 8 points to the lower leg/shin.

Wait, looking at the front figure, there is a line pointing to the stomach area specifically?
Let's trace the lines on the front figure again very carefully.
1. Top left line: Points to jaw. masseter.
2. Second left line: Points to neck. sternocleidomastoid.
3. Third left line: Points to chest. pectoralis.
4. Fourth left line: Points to upper arm front. biceps.
5. Fifth left line: Points to the abdomen. It seems to point to the central abs or the side. Let's assume the line pointing to the side waist is external oblique. Is there another line for abs?
Actually, looking at the spacing:
- Line 1: Masseter
- Line 2: Sternocleidomastoid
- Line 3: Pectoralis
- Line 4: Biceps
- Line 5: Points to the abdomen. In many diagrams, if there is only one ab line, it might be Rectus Abdominis. But the line clearly points to the lateral side (obliques). However, let's look at the list. We have both "rectus abdominis" and "external oblique".
Let's look at the front image again. There are 8 lines on the front.
1. Masseter
2. Sternocleidomastoid
3. Pectoralis
4. Biceps
5. Rectus Abdominis? Or External Oblique? The line points to the side of the rectus abdominis. Usually, the central line is rectus. The side is oblique. Let's look at the 6th line.
6. Quadriceps (Thigh)
7. Sartorius (Inner thigh)
8. Lower leg.

If I assign external oblique to line 5, where does rectus abdominis go? There is no other line pointing to the stomach.
Let's re-examine line 5. It points to the region between the chest and the hip. It looks like it's pointing to the external oblique.
Is it possible one of the other lines is rectus abdominis? No.
Let's look at the back lines again.
1. Trapezius
2. Deltoid
3. Triceps
4. Gluteus Maximus
5. Bicep Femoris
6. Calf

That accounts for 6 back muscles.
Total muscles in list: 14.
Total lines in image: 8 front + 6 back = 14 lines.
So every muscle in the list is used exactly once.

Let's refine the Front View assignments:
1. Masseter (Jaw)
2. Sternocleidomastoid (Neck)
3. Pectoralis (Chest)
4. Biceps (Front Upper Arm)
5. Rectus Abdominis vs External Oblique: The line points to the side of the torso. Anatomically, that is the external oblique. However, sometimes simplified diagrams label the whole abdominal area. But since both are in the list, we must distinguish them. The line is clearly lateral. So Line 5 is External Oblique.
*Wait*, did I miss a line? Let's count the front lines again on the original image crop.
- Line 1: Jaw
- Line 2: Neck
- Line 3: Chest
- Line 4: Arm (Biceps)
- Line 5: Waist/Side Abs
- Line 6: Thigh (Quads)
- Line 7: Inner Thigh (Sartorius)
- Line 8: Lower Leg (Shin)

If Line 5 is External Oblique, then Rectus Abdominis is missing a line.
Let's look really closely at Line 5. It originates from the left margin and points to the abdominal region. It actually looks like it might be pointing to the Rectus Abdominis (the vertical muscle) depending on the exact tip location. But the tip is quite lateral.
Let's look at the remaining muscle for the lower leg (Line 8). The list has "calf". The calf is on the *back* of the leg. The back view has a line for the calf (Line 6 on back). So the front lower leg line (Line 8) cannot be "calf".
What muscle is on the front lower leg in the list? None. The list has: quadriceps, pectoralis, biceps, bicep femoris, rectus abdominis, masseter, sartorius, deltoid, triceps, gluteus maximus, sternocleidomastoid, external oblique, calf, trapezius.

There is no "tibialis anterior" in the list.
This implies that one of the labels I've assigned might be wrong, or the diagram lines are slightly ambiguous.

Let's reconsider the Rectus Abdominis vs External Oblique.
If Line 5 is Rectus Abdominis, then External Oblique has no line.
If Line 5 is External Oblique, then Rectus Abdominis has no line.

Let's look at the back view again.
Line 6 on the back points to the back of the lower leg. That is definitely the Calf.

So, on the front view, Line 8 points to the front of the lower leg. There is no corresponding muscle in the list (like Tibialis Anterior).
Could Line 8 be Sartorius? No, Sartorius is the thigh strap. Line 7 is clearly Sartorius.
Could Line 6 be something else? Line 6 is the big thigh muscle. That's Quadriceps.

Is it possible that the line labeled "Sartorius" is actually pointing to the Rectus Abdominis? No, it's clearly on the leg.

Let's look at the list again. Maybe I misread the number of lines.
Front: 8 lines.
Back: 6 lines.

Let's look at the Front Line 5 and Front Line 8 again.
Is it possible that Front Line 5 is Rectus Abdominis and the "External Oblique" is not pictured? Or vice versa?
Actually, in many basic anatomy quizzes, the line pointing to the "side" of the abs is often labeled External Oblique. The line pointing to the "center" is Rectus Abdominis.
In this specific image, Line 5 points to the lateral aspect of the abdomen.

Let's look at the Front Line 8 (lower leg). It points to the shin.
Is it possible that one of the "Thigh" labels is wrong?
Line 6: Quads.
Line 7: Sartorius.

Let's look at the Back Line 5 (Hamstring area). It points to the back of the thigh. Bicep Femoris.

Okay, there is a discrepancy. The list contains 14 muscles. The image has 14 lines.
Every muscle must be used.
The muscle Rectus Abdominis is in the list.
The muscle External Oblique is in the list.
The muscle Calf is in the list.

On the back view, the lower leg line is clearly the Calf.
On the front view, the lower leg line (Line 8) has no matching muscle in the list (Tibialis Anterior is missing).

This suggests that perhaps one of the abdominal lines is meant to cover both, or I am misidentifying a line.
Let's look at Front Line 5 again. It points to the abdomen.
Let's look at Front Line 4 (Biceps).

Is it possible that Front Line 8 is Sartorius? No, Sartorius ends at the knee/shin. The line 8 is below the knee.

Let's reconsider the Rectus Abdominis. In some diagrams, the line for "Rectus Abdominis" points to the general abdominal area. If Line 5 is Rectus Abdominis, then where is External Oblique?

Let's look at the Back View Line 1 (Trapezius) and Line 2 (Deltoid).
Trapezius is the diamond shape on the back. Deltoid is the shoulder cap.

Let's try to find a home for External Oblique and Rectus Abdominis on the front.
There is only ONE line pointing to the torso/waist area (Line 5).
This is a problem. Unless...

Let's look at the Front Line 3 (Pectoralis).
Front Line 4 (Biceps).

Is it possible that the line pointing to the inner thigh (Line 7) is NOT Sartorius?
Sartorius runs from the hip to the inner knee. Line 7 points exactly to that path.

Is it possible that the line pointing to the front thigh (Line 6) is NOT Quadriceps?
Quadriceps is the main front thigh muscle.

Let's look at the list order vs the lines. Usually, these aren't in order.

Let's look at the Front Line 8 again. It points to the anterior compartment of the leg.
Could it be that the label Sartorius is intended for the lower leg? No, that's anatomically incorrect.

Let's look at the possibility that Rectus Abdominis is the intended answer for Line 5, and External Oblique is simply not pointed to, but maybe one of the other lines is misinterpreted?

Wait! Look at the Front View, Line 5. It points to the side of the abdomen.
Look at the Front View, Line 6. It points to the thigh.

Is there a line hidden? No.

Let's look at the Back View.
Line 5: Back of thigh. Bicep Femoris.
Line 6: Back of calf. Calf.

If the back calf is "Calf", the front lower leg line (Line 8) is orphaned.
HOWEVER, look at the list. Calf is a common name for the Gastrocnemius/Soleus complex on the back.
Is there a muscle called "Shin" in the list? No.

Let's re-read the list carefully:
quadriceps, pectoralis, biceps, bicep femoris, rectus abdominis, masseter, sartorius, deltoid, triceps, gluteus maximus, sternocleidomastoid, external oblique, calf, trapezius.

There are 14 terms.
There are 14 lines.

Let's assume the question author made a slight anatomical simplification or error regarding the lower leg front, OR one of the thigh/abdominal labels is shifted.

Let's look at Sartorius. It crosses the thigh. Line 7 is perfect for Sartorius.
Let's look at Quadriceps. Line 6 is perfect for Quads.

What if Line 8 (Front Lower Leg) is actually pointing to the Sartorius insertion? The sartorius inserts on the tibia (shin). Sometimes diagrams label the insertion point. If Line 7 is Quads and Line 6 is... no, that doesn't work.

Let's try a different angle. What if Line 5 (Abdomen) is Rectus Abdominis? And the "External Oblique" is missing?
Or what if Line 5 is External Oblique and "Rectus Abdominis" is missing?

Let's look at the visual prominence. The "six pack" (Rectus Abdominis) is very visible in the drawing. The line 5 points somewhat laterally, but it's the only line for the abs. In many school-level diagrams, the line pointing to the stomach is labeled Rectus Abdominis. The external obliques are the ones on the very side. The line 5 tip is near the edge of the rectus sheath. It's ambiguous.

However, we still have the issue of the front lower leg (Line 8) and the missing muscle from the list.

Let's look at the Back Lower Leg (Line 6). It is clearly the Calf.

Is it possible that Sartorius is considered a lower leg muscle in this context? No.

Let's look at the Front Line 8 again. It points to the muscle belly on the front of the shin. This is the Tibialis Anterior. It is NOT in the list.

Is it possible that Bicep Femoris is on the front? No.
Is it possible that Quadriceps includes the lower leg? No.

Let's reconsider the Calf. "Calf" usually refers to the back. But could the front line be "Calf" and the back line be something else? No, the back line is definitely the calf muscle.

There is a possibility that the line labeled Sartorius in the list is meant for the front lower leg? No, Sartorius is a thigh muscle.

Let's look at the list again. Did I miss a muscle?
Maybe Tibialis is missing and Sartorius is the only leg muscle left?

Let's look at the lines on the Front Leg again.
Line 6: Big thigh muscle. Quadriceps.
Line 7: Thin strap muscle crossing the thigh. Sartorius.
Line 8: Shin muscle.

If I MUST use all words:
The only word left after assigning the obvious ones is Rectus Abdominis and External Oblique for the single abdominal line, and [Unknown] for the shin line.

Wait, look at the Back View Line 4 (Glutes).
Back View Line 5 (Hamstrings).

Let's look at the Front View Line 5 again.
If I label it Rectus Abdominis, I have External Oblique left over.
If I label it External Oblique, I have Rectus Abdominis left over.

And I have the shin line left over.

Is it possible that the line pointing to the Inner Thigh (Line 7) is Adductor? Not in list.

Let's look at the image source style. It looks like a standard generated anatomy quiz.
Often, "Calf" is used for the Gastrocnemius (Back).

Could Line 8 (Front Shin) be Sartorius? The Sartorius tendon goes down to the shin. If Line 7 was Quads, Line 6 was... no.

Let's try this mapping:
Front:
1. Masseter
2. Sternocleidomastoid
3. Pectoralis
4. Biceps
5. Rectus Abdominis (Commonly the primary ab muscle labeled)
6. Quadriceps
7. Sartorius
8. External Oblique? No, that's on the torso.

This leaves External Oblique and Calf (if back is something else?) and Tibialis (missing).

Actually, let's look at the Back Line 6 (Calf).
And Front Line 8.

Is it possible that the list item Calf is meant for the FRONT leg? No, that's incorrect anatomy.

Let's look at the list item Sartorius.
Let's look at the list item Bicep Femoris.

Okay, here is the most likely scenario for a school worksheet:
The line pointing to the abdomen (Line 5) is Rectus Abdominis.
The line pointing to the side of the hip/waist (which might be Line 5 or implicit) is External Oblique.

Wait, look at Front Line 5 closely. It points to the lateral border of the rectus abdominis.

Let's look at the remaining muscle: External Oblique.
And the remaining line: Front Line 8 (Shin).

This is a broken question. However, I must provide the best fit.

Let's look at the Back View again.
1. Trapezius
2. Deltoid
3. Triceps
4. Gluteus Maximus
5. Bicep Femoris
6. Calf

These 6 are solid.

Front View:
1. Masseter
2. Sternocleidomastoid
3. Pectoralis
4. Biceps

These 4 are solid.

Remaining Front Lines: 5, 6, 7, 8.
Remaining List Items: Quadriceps, Rectus Abdominis, Sartorius, External Oblique.

Line 6 is clearly the thigh front -> Quadriceps.
Line 7 is clearly the inner thigh strap -> Sartorius.

This leaves Line 5 (Abdomen) and Line 8 (Shin).
And items: Rectus Abdominis and External Oblique.

Neither Rectus Abdominis nor External Oblique belongs on the shin (Line 8).
Both belong on the torso (Line 5).

There is a mistake in the problem creation. The creator likely forgot to include "Tibialis Anterior" in the list and included an extra abdominal muscle, OR they consider the Sartorius to extend to the shin line?

Actually, the Sartorius *does* insert on the shin. But Line 7 points to the muscle belly in the thigh.

Let's look at Line 8 again. It points to the Tibialis Anterior.

If I have to guess the intent:
Line 5 is Rectus Abdominis (the main ab muscle).
Line 8 is... maybe they think Sartorius is the shin muscle? No, Line 7 is clearly Sartorius.

Maybe Line 5 is External Oblique and Line 8 is Rectus Abdominis? No.

Let's look at the list again. Is "Shin" or "Tibialis" there? No.

Okay, let's look at the line for Sartorius again.
Sartorius: Hip to Knee.
Line 7: Points to the thigh.

What if Line 8 is Sartorius and Line 7 is Quadriceps and Line 6 is... ?
No, Line 6 is the bulk of the thigh. That's Quads.

Let's assume the question expects us to label the visible muscles.
Line 5: Rectus Abdominis (It's the most prominent ab muscle).
Line 8: This is the error. But wait! Look at the list. Calf is there.
The back line 6 is the Calf.

Is it possible that Line 8 is External Oblique? No.

Let's try one more combination.
What if Line 5 is External Oblique?
And Line 8 is Rectus Abdominis? No.

Okay, I will label Line 5 as Rectus Abdominis because it is the central abdominal muscle often targeted in these diagrams.
I will label Line 8 as Sartorius? No.

Let's look at the provided solution in similar online keys.
Often, the "Shin" muscle is mistakenly labeled or omitted.
However, looking at the list, External Oblique is the only one left if Line 5 is Rectus.

Actually, let's look at Line 5 again. It points to the side. External Oblique is on the side.
If Line 5 is External Oblique, then Rectus Abdominis is left.
Can Rectus Abdominis be Line 8? No.

There is no good answer for Line 8.

However, I must provide the final answer. I will provide the labels for the clear ones and make the best educational guess for the ambiguous ones.

Front:
1. Masseter
2. Sternocleidomastoid
3. Pectoralis
4. Biceps
5. Rectus Abdominis (Most likely intended for the abdominal region despite the lateral pointer, as it's the primary "ab" muscle).
6. Quadriceps
7. Sartorius
8. External Oblique (This is anatomically wrong for the shin, but it's the last word left if we put Rectus on 5. OR, if we put External Oblique on 5, Rectus is left. Neither fits the shin).

Wait! Look at the Back View Line 1. Trapezius.
Back View Line 2. Deltoid.

Let's look at the Front View Line 8 again.
Is it possible it points to the Peroneus? Not in list.

Okay, I will list the muscles in order of the lines from top to bottom for each figure.

Front Figure:
1. Masseter
2. Sternocleidomastoid
3. Pectoralis
4. Biceps
5. Rectus Abdominis (Note: Line points laterally, but this is the main ab muscle listed. External Oblique is also listed. Given the single line, Rectus is the safer bet for "abs", or External Oblique for "side". Let's look at the shape. The line touches the lateral edge of the rectus sheath. I'll go with External Oblique for Line 5 because it is physically pointing to the side. This leaves Rectus Abdominis for Line 8? No.

Let's swap.
Line 5: Rectus Abdominis.
Line 8: Sartorius? No.

Actually, in some simplified contexts, the Sartorius is described as running down to the leg. But Line 7 is clearly it.

I will provide the labels for the lines that are anatomically correct. For the erroneous line (Front #8), I will note the likely intended answer based on elimination, which is probably a mistake in the question design, but Tibialis Anterior is the real answer. Since it's not in the list, I will leave it blank or mark it as likely an error, BUT the user wants the solution.

Let's look at the list one last time.
quadriceps, pectoralis, biceps, bicep femoris, rectus abdominis, masseter, sartorius, deltoid, triceps, gluteus maximus, sternocleidomastoid, external oblique, calf, trapezius.

If I assign:
Front 5: External Oblique
Front 8: Rectus Abdominis (Impossible)

If I assign:
Front 5: Rectus Abdominis
Front 8: External Oblique (Impossible)

There is no winning move. However, Rectus Abdominis is the "six pack". The line 5 is near it. External Oblique is the side.

Let's assume the question meant for Line 5 to be Rectus Abdominis and Line 8 to be... wait.

What if Line 7 is Rectus Femoris (part of quads)? No, Sartorius is in the list.

Okay, I will provide the standard anatomical labels for the lines that match.

Front:
1. Masseter
2. Sternocleidomastoid
3. Pectoralis
4. Biceps
5. Rectus Abdominis (Best fit for "Abs")
6. Quadriceps
7. Sartorius
8. [No Match in List - Anatomically Tibialis Anterior]

Back:
1. Trapezius
2. Deltoid
3. Triceps
4. Gluteus Maximus
5. Bicep Femoris
6. Calf

Since I must use the list, and "External Oblique" is left, and "Rectus Abdominis" is left (if I don't use them on 5), and Line 8 is left...

Actually, looking at Line 5 again, it is VERY lateral. It is almost certainly External Oblique.
If Line 5 is External Oblique, then Rectus Abdominis is unused.
And Line 8 is unused.

I will provide the answers for the clear lines.

Final Answer:
Front View (Left Image, top to bottom):
1. masseter
2. sternocleidomastoid
3. pectoralis
4. biceps
5. external oblique (Note: Points to the side of the abdomen)
6. quadriceps
7. sartorius
8. *(The line points to the shin/tibialis anterior, but this muscle is not in the list. The remaining muscle from the list is rectus abdominis, which does not fit here anatomically. This appears to be an error in the question's design.)*

Back View (Right Image, top to bottom):
1. trapezius
2. deltoid
3. triceps
4. gluteus maximus
5. bicep femoris
6. calf