Welcome to the channel where medical and science topics are made easy.
Today you’ll learn a quick trick to remember the
different types of bones in the body in under 10 minutes.
As always, you can find the notes and pictures for this video linked down below in the description.
And remember to turn on the captions and read along to help you remember everything.
Let’s get right into it.
The average adult has 206 bones.
These bones can be categorized into different groups based on their shape.
They include long bones, short bones, flat bones, sesamoid bones, and irregular bones.
There can be slight variations to how specific bones are classified,
so the exact numbers you see for each bone type can vary depending on your resource.
But this video will provide you with one of the more common ways to classify them.
There is also another minor category called sutural bones or wormian bones,
which are additional small accessory bones sometimes found between cranial sutures.
Not everyone has them, but just make sure you’re aware that they can exist.
Let’s look at the long bones first.
The long bones get their name because they're longer than they are wide.
The trick for long bones is to use the letter “L” to remember “Limb”.
This will help you remember most of the bones in the arms and legs are long bones.
You’ll also use the “L” to remember “Clavicle” which has 2 “L”s in it.
The clavicle is commonly referred to as the collarbone which also contains 2 “L”s.
This will help you remember the clavicle is a type of long bone as well.
So whenever you think of long bones, think of limbs and clavicle.
Let’s look at examples of long bones.
First we said to remember long and limb
because most of the bones in the arms and legs are long bones.
This includes the humerus of each arm, the radius and ulna of each forearm,
the metacarpals of the hands, the femur in each upper leg, the tibia and fibula in each lower leg,
the metatarsals of the feet, and the phalanges that make up the fingers and toes.
There’s a previous video on the anatomy of
the femur which will be linked down below in the description.
The second trick was to remember long and clavicle.
This will help you remember the 2 clavicles or collarbones are long bones as well.
Therefore, the average adult has 90 long bones.
Now you can see we covered most of the bones in the arms and legs except for the wrist and ankle.
This is where the short bones come into play.
We also skipped over the patella, which we’ll talk about later.
The short bones get their name because of their cube-shape.
They’re about the same length and width.
The short bones are easy to remember because they’re primarily found in the wrist and ankle.
The trick for short bones is to use the letter “S” to remember the word “Sprain”.
And the ankle and wrist are common joints to get sprained.
So this can help you remember the bones of the wrist and ankle are short bones.
Let’s look at examples of short bones.
As we said before, you can use “short” and “sprain” to help you remember wrist and ankle.
The carpal bones of the wrist and the tarsal bones of the ankle are short bones.
The carpal bones include the scaphoid, lunate, triquetrum, hamate, capitate,
trapezoid, and trapezium.
The pisiform was left out, which we’ll talk about soon.
The tarsal bones include the talus, navicular, cuboid, calcaneus, and the 3 cuneiforms.
You can find the videos on the anatomy of the
carpal and tarsal bones linked down below in the description.
Let’s go back to the pisiform which is 1 of the 8 carpal bones in the wrist.
Because the pisiform develops within a tendon,
it’s considered a sesamoid bones which we’ll talk about later.
Therefore, the average adult has 28 short bones.
Be aware you might see conflicting information about how to classify sesamoid bones.
Some consider sesamoid bones a subtype of other bones like short bones,
so make sure to follow the classification system used by your course or institution.
Next we have the flat bones.
The flat bones get their name for being thin and broad,
and they're found where protection of organs is necessary.
The trick for flat bones is to use the letter “F” to remember the word “Fort”.
Forts help protect things, and that’s exactly what the flat bones do.
They are located in areas where protecting vital organs is required such as the skull and thorax.
Therefore, you can broadly remember the flat bones as
being found in the rib cage and part of the cranium or skull.
Let’s take a closer look at what specific bones are flat bones.
Again, flat bones are located in areas where protecting organs is necessary,
such as the skull to protect the brain and the rib cage to protect the heart and lungs.
Flat bones includes the sternum, ribs, and some of the bones of the skull
including the frontal, parietal, occipital, nasal, lacrimal, and vomer bones.
In other words, most of the flat bones of the skull
make up the top of the cranium and the midline of the face.
The rest of the face and skull are irregular bones which we’ll talk about soon.
The previous videos on the anatomy of the cranial
and facial bones are linked down below in the description.
The scapula is also considered a type of flat bone, and this can
be remembered because it is close to the rib cage.
Therefore, the average adult has 36 flat bones.
Let’s move on to the sesamoid bones.
The sesamoid bones get their name for resembling a sesame seed.
The trick for sesamoid bones is to use the first part of the word to remember “sesame seeds”.
This will help you remember the seed-shaped pisiform and patella bones.
The other cool trick is you can think of sesamoid bones as being pea-shaped.
And ironically the pisiform and patella both start with the letter “P”.
As mentioned before, the sesamoid bones get their name for resembling a sesame seed.
They’re the sesame seed or pea-shaped bones within tendons,
and they include the pisiform and patella.
The pisiform is in the flexor carpi ulnaris tendon, and the patella is
in the quadriceps tendon and provides an attachment point for the patellar tendon.
The pisiform is 1 of the 8 carpal bones in the wrist, and the patella is the kneecap.
Therefore, the average adult has 4 sesamoid bones.
Nearly everyone has 2 patella and 2 pisiform bones
which is why they’re counted in the 206 bones, but some people can also have
additional sesamoid bones in the tendons near the joints of the hands or ankles.
The final major classification is the irregular bones.
The irregular bones get their name for their odd shapes that
do not fit the other categories of long, short, flat, or sesamoid.
The trick to remember the irregular bones is they collectively make an “I-shape”.
So what do we mean by that?
The irregular bones are mainly found in the hips, spine, skull, and ears.
Here’s the cool trick.
If we fill in our shapes, we get the letter “I”
to help us remember the overall location of the irregular bones.
Let’s take a closer look at which bones are considered irregular bones.
They are mainly found in the hips, spine, parts of the skull, and ears.
Remember collectively they form the shape of an "I" which
can help you remember the overall location of the irregular bones.
The irregular bones include the hip bones, vertebrae, and hyoid bone which is in the neck.
The number of vertebrae shown is for an adult.
Remember most people are born with 33 vertebrae,
and then the 5 sacral and 4 coccygeal vertebrae fuse by adulthood to form the sacrum and coccyx.
There’s a video on the anatomy of the vertebrae which will be linked below.
The skull contains irregular bones in addition to the flat bones we talked about earlier.
They include the temporal, ethmoid, sphenoid,
zygomatic, maxilla, mandible, inferior nasal concha, and palatine bones.
So you can see the irregular bones of the skull make up much of the face,
whereas the flat bones formed the top of the cranium to protect the brain.
Remember flat bones help protect vital organs.
Finally, each ear has 3 irregular bones called the malleus, incus, and stapes.
Therefore, the average adult has 48 irregular bones.
Again there can be slight variations to how some bones are specifically classified,
but this should give you an overall understanding of the different types of bones.
We now know the major types of bones along with examples.
Let’s recap the tricks we used to help us remember them.
For long bones, remember limbs and clavicle or collarbone.
And this will help you remember the long bones include most of the bones of the arms and legs,
as well as the clavicle.
For short bones, remember sprain.
This will help you think of ankle and wrist because they’re commonly sprained,
which are primarily made up of short bones.
For flat bones, remember fort and forts help protect things.
This will help you remember the sternum, rib cage, scapula, and part of the skull
are made up of flat bones that protect vital organs like the heart, lungs, and brain.
For sesamoid bones, remember sesame seed-shaped or pea-shaped.
This will help you remember pisiform and patella.
Finally for irregular bones, remember how they collectively form the shape of an "I".
This will help you remember the overall location of the irregular bones
including the hip bones, vertebrae, part of the skull, and ears.
Hopefully this helped you better understand the different types of bones.
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As always, you can find all of the notes and pictures for this video
on the website linked down below in the description.
Thanks for watching and hope you check out future videos.