Muscle Naming - Online Tutor, Practice Problems & Exam Prep

Muscle naming is influenced by various factors, including body region, shape, size, action, fiber direction, attachment locations, and the number of heads. For instance, "biceps" indicates two heads, while "maximus" and "minimus" denote size differences. Understanding these naming conventions aids in identifying muscles like the "adductor longus," which adducts the thigh. Recognizing these patterns enhances memory retention and comprehension of muscle functions, crucial for mastering anatomy and physiology.

Muscle Naming

As you start to learn the muscles of the body, you may start to get the feeling this is a lot of long complicated Latin names that you need to remember, and it is. But understanding that those Latin names have meanings can make the whole process a lot easier. So, we're just going to start out by saying that there are many factors that influence muscle naming, and recognizing them can help you both identify and remember muscles. So, we're going to go through these factors now. First off, muscles can be named after the body region in which they're found. So, for example, you have 2 muscles called the biceps in your body. Now, you're probably familiar with the biceps brachii. Brachii refers to the brachial region in your arm, but you also have a muscle called the biceps femoris. Femoris refers to the femoral region, your thigh. That's a muscle of your hamstring.

Another thing muscles can be named after is their shape. So, for example, in your back, you have the trapezius. That's roughly the shape of a trapezoid. In your shoulder, you have the deltoid. That's named after the Greek letter delta, which is the shape of a triangle. Next, muscles could be named after their size. A lot of times we'll have muscles with the same name, but then one will be the maximus and one the minimus. Well, if you remember that one name, then you remember there's a big one and a small one. Or one might be the longest and the other one's the brevis. Longus means it's long. Brevis is Latin for short. It's the same root as the word brief.

Now, muscles could also be named after the muscle action. So, for example, the adductor longus. Well, adduction means to bring a body part in line with the body, closer to the midline of the body. So now you know what the adductor longus does. That one is attached to your thigh. It adducts the leg. Next, we have the direction of the muscle fibers. Now, a good example of this is you have a whole bunch of different abdominal muscles. You have the obliques. Those go at an angle. You have the transverse abdominis. Those run crosswise. You have the rectus abdominis. Rectus is a word that means straight. Those run straight up and down.

Next, you have the location of attachments. Now, when it's a location of attachments, it will just tell you the origin and the insertion in that order. A good example of this is the sternocleidomastoid, this muscle right here. sternocleido. It has origins on the sternum, and cleido refers to the clavicle. And then, its insertion is the mastoid, the mastoid process right here. Just knowing that, I know everything I need to know about the muscle.

And finally, we have the number of heads, and heads is another term for origins. So, sometimes muscles split at the ends, and they have an origin; they have more than one origin. So, for example, I bet you know how many heads the biceps brachii has, and how many heads the triceps brachii has? 2 and 3. Alright. So, just for some more examples of these here, we have the gluteus maximus. Well, they recognize gluteus as a body region. That's your rear end. And maximus, that's big. Well, so that tells me that's the big old muscle of your butt, and there it is. We have the rhomboid major. Well, rhomboid refers to a rhombus, which is a diamond shape. And if I look here, look at this muscle is about a diamond shape. And major means that it's big, or at least that it's bigger than another rhomboid muscle. So, I already know there's going to be a rhomboid minor, and sure enough there is. It's a smaller muscle just above it. You have the extensor digitorum muscle. Well, extensor, that's an action. It's going to straighten something. What is it going to straighten? Well, it's going to give us a body region, the digits. It's going to extend the fingers. And so, if I think about what's going to make my fingers extend, that's going to be a muscle on the back of my forearm. And lookie loo, there it is.

This information up here is less likely to be tested on directly. You are very likely to be tested on the names for those muscles though. So again, understanding where the muscles are, what they do by looking at their names can be incredibly helpful. It could just help you remember it, or it could even help you figure out a muscle if you don't remember it when you're sitting there on a test.

Alright. With that, I think it's time for you to go learn your muscles.

Muscle Naming Example 1

To practice our muscle naming, we're going to fill out this table here, and it says that the table below lists several muscles. Put a check in the box if the muscle's name involves a particular naming convention. Our naming conventions are if it's named after the body region, the shape, the size, the muscle action, the direction of fibers, the location of attachments, or the number of heads. Let's take a look at our muscles.

First up, we have the biceps femoris muscle. Looking at the word "biceps", what do you see? I see "bi". "Bi" means 2. So I'm going to put a check in the number of heads box because "biceps" indicates it has 2 origins or 2 heads. And then we have "femoris". What does that tell you? Well, it tells me it's a body region. "Femoris", referring to the femoral region, is in your thigh. That's a muscle with 2 origins in your thigh, part of your hamstring.

Next, we have the brachioradialis. What do you think that's named after? You might be tempted to say you see "brachio" there, indicating a body region, your upper arm. So let me go ahead and put a small check there. But, another component "radialis" indicates a listing of two body regions. It has "brachio", which is the upper arm, and "radialis", one of the bones in your forearm. This tells us it's the origin and the insertion of this muscle; the origins are in the brachial region on the humerus and the insertion is on the radius. This means I am going to put a check in the location of attachments box. When you have a muscle named directly after the location of the attachments, it always lists the origin before the insertion.

Next, we have the transverse abdominis. What do you see in the name "transverse"? "Transverse" is a directional term indicating it’s running crossways, which will be the direction of the fibers. Then "abdominis" clearly refers to the muscle's location, being in the abdominal area – a body region.

Then there's the serratus anterior muscle. What do you see in the word "serratus"? It’s slightly tricky. It’s derived from "serrated". The serratus anterior muscle extends from the scapula around your back, and its insertions are along the ribs. Because it inserts along many ribs, the edge of the muscle is somewhat jagged, looking serrated. When you contract this muscle, it pulls your shoulders forward. The term "serratus" is telling you about the shape of that muscle. Additionally, "anterior" indicates a body region or location that’s towards the front. It pulls around to the front. So, we'll add a check for body region.

Finally, we have the flexor hallucis brevis muscle. We have three important words here. "Flexor" implies the action to flex, which is a muscle action of bending at a joint. So, I'll put a check in muscle action. "Hallucis" refers to a body region; your hallux is your big toe. So what is it going to flex? It’s going to flex your big toe, indicating the body region. Lastly, "brevis" means "short", indicating the size of the muscle. It's essential to learn this as it often appears in muscle names.

Although it’s unlikely you will need to break down muscle names as we just did all the time, remembering this information about the muscles as you learn them helps you understand what the muscles are, what they do, and their size. As always, there are 4 practice problems to follow. Give them a try.

Based on the name, how does the fibularis brevis compare to the fibularis longus?

• A. The fibularis brevis muscle is relatively short while the fibularis longus is relatively long.
• B. The fibularis brevis muscle is flat while the fibularis longus is triangular.
• C. The fibularis brevis muscle is relatively slender while the fibularis longus is relatively wide.
• D. The fibularis brevis muscle has a pennate fascicle arrangement while the fibularis longus has a parallel fascicle arrangement.

Based on the name, how would you expect the orbicularis oris muscle to be shaped?

• A. Triangular.
• B. Comb-like.
• C. Circular.
• D. Serrated.

Which of the following muscle names does NOT provide information about the muscle's actions?

• A. Flexor pollicis brevis.
• B. Abductor digiti minimi.
• C. Transverse abdominis.
• D. Extensor carpi radialis longus.

Here’s what students ask on this topic:

What are the main factors that influence muscle naming?

Muscle naming is influenced by several factors, which can help in identifying and remembering them. These factors include:

• Body Region: Muscles are often named after the region they are located in, such as the biceps brachii (arm) and biceps femoris (thigh).
• Shape: The shape of the muscle can influence its name, like the trapezius (trapezoid shape) and deltoid (triangle shape).
• Size: Terms like maximus (large) and minimus (small) indicate the size of the muscle.
• Action: The function of the muscle, such as the adductor longus (adducts the thigh).
• Fiber Direction: The orientation of muscle fibers, like the rectus abdominis (straight fibers).
• Attachment Locations: The origin and insertion points, such as the sternocleidomastoid (sternum, clavicle, and mastoid process).
• Number of Heads: The number of origins, like the biceps (two heads) and triceps (three heads).

How does understanding Latin roots help in learning muscle names?

Understanding Latin roots can significantly aid in learning muscle names because many anatomical terms are derived from Latin. For example, 'biceps' means 'two heads,' indicating the muscle has two origins. 'Maximus' means 'largest,' helping to identify the largest muscle in a group. Recognizing these roots can make it easier to remember the muscle's location, function, and characteristics, thereby enhancing your ability to recall and understand muscle names during exams and practical applications.

What is the significance of the term 'rectus' in muscle naming?

The term 'rectus' in muscle naming signifies that the muscle fibers run straight. For instance, the rectus abdominis muscle has fibers that run vertically along the abdomen. Understanding this term helps in identifying the orientation of the muscle fibers, which can be crucial for understanding the muscle's function and location. This knowledge is particularly useful in anatomy and physiology studies, as it aids in visualizing and remembering muscle structures.

Can you explain the naming of the sternocleidomastoid muscle?

The sternocleidomastoid muscle is named based on its attachment points. 'Sterno' refers to the sternum, 'cleido' refers to the clavicle, and 'mastoid' refers to the mastoid process of the temporal bone. This muscle originates from the sternum and clavicle and inserts into the mastoid process. Understanding this naming convention helps in identifying the muscle's location and its role in movements such as rotating and flexing the head.

What does the term 'adductor' indicate about a muscle's function?

The term 'adductor' indicates that the muscle's function is to bring a body part closer to the midline of the body, a movement known as adduction. For example, the adductor longus muscle in the thigh adducts the leg, moving it toward the body's midline. Recognizing this term helps in understanding the muscle's action and its role in various movements, which is essential for mastering anatomy and physiology.