Anatomy
Fact-checked

At TheHealthBoard, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Endosteum?

Constance Simmons
Constance Simmons

Endosteum is a soft, thin connective tissue that lines the inner cavity of long bones. It plays an important role in the healing of fractures by creating new cells necessary for the bone to fuse. This connective tissue also has hematopoietic potencies, which means that it contains haematopoietic stem cells (HSCs). HSCs are significant because they can create any type of blood cell.

There are a couple of medical terms used to describe the area of bone that contains endosteum. These include medullary cavity and medullary membrane. This membrane is found in the diaphysis, or shaft, of long bones. The walls of this cavity are made of cancellous bone, also called spongy bone. This is responsible for only 20-percent of the skeleton’s weight. The medullary cavity contains red and yellow bone marrow.

There are three different types of endosteum. They are cortical, osteonal, and trabecular. The name of each type refers to the area of the inner bone where it is located.

Periosteum, the equivalent to endosteum on the outside of the bone, is important in the healing of fractures.
Periosteum, the equivalent to endosteum on the outside of the bone, is important in the healing of fractures.

The cortical endosteum lines the cortical bone. It also forms the boundaries of the marrow cavity. This cavity contains yellow bone marrow, which stores fat cells for the body. In cases of extreme malnutrition these cells are used by the body to fuel itself.

The trabecular endosteum covers the inner surface of trabeculae, which covers the spongy bone at the shaft. Trabeculae are bony bars that help the bone absorb contact without damage. They also contain red marrow, which contains HSCs and is responsible for creating new blood cells for the body.

Osteonal endosteum forms the lining of osteonal canals. These are found in compact bone and are home to the bone’s blood and nerve supplies. They are also known as Haversian Canals, after the physician who discovered them.

A diagram of the anatomy of a bone, showing the endosteum.
A diagram of the anatomy of a bone, showing the endosteum.

When an individual is malnourished, this tissue is reabsorbed by the body. Since it is part of the inner bone, a decrease results in less bone thickness and density. This thereby reduces the cortical thickness of the bone, which is devastating to the body because cortical bone is responsible for many bodily functions, including storing and releasing calcium. It can also reduce weight because cortical bone makes up about 80 percent of the human skeleton’s weight.

Periosteum is the equivalent to endosteum on the outside of the bone. It is durable and firm. Periosteum is also important in the healing of fractures because it produces cells needed to rebuild the bone.

Chronic malnutrition can lead to a condition in which the body uses fat cells that are stored in yellow bone marrow to fuel itself.
Chronic malnutrition can lead to a condition in which the body uses fat cells that are stored in yellow bone marrow to fuel itself.

Taking care of your body’s exterior is simple when you can rely on visible results of your progress. It’s harder, though, to care for the parts of your body that can’t be seen — parts such as your heart, lungs, and bones. The latter of these — your bones — are particularly important to keeping your body in good shape. That’s one reason why everybody should be familiar with the endosteum and its function. If you’re wondering what the endosteum is, or why it’s important, read on for more information about this vital part of your bones.

Where Is the Endosteum Located?

Casting is effective for most broken bones because it provides stability while the endosteum creates new cells to fuse the bone parts.
Casting is effective for most broken bones because it provides stability while the endosteum creates new cells to fuse the bone parts.

The endosteum is not a single part of your body, but rather it refers to the connective tissue within your bones’ inner cavities. More specifically, it lines the medullary cavity that is found in every bone in your body. The endosteum tissue is thin, soft, and haematopoietically potent. This potency means that it can be used to produce stem cells, which can then be used to create blood cells of any type. Because of its location inside the inner surface of bones, the endosteum is important to facilitating healing after an injury.

Understanding Endosteum Function

The endosteum is found in the femur and other skeletal long bones.
The endosteum is found in the femur and other skeletal long bones.

The endosteum offers several different functions in the body. Its primary function is to help your bones grow adequately throughout childhood and adolescence. Its job isn’t over once you reach adulthood, though. The endosteum continues to work even after you’ve matured and helps your bones to repair themselves. This is a vital function that prevents minor injuries from causing major trauma to the body. In addition to repairing bones, the endosteum lining helps to remodel your bones. Remodeling is your body’s process of replacing bone tissue that’s old and brittle with newer, stronger bone tissue. This is supported by the proteins contained in the endosteal lining.

How Does the Endosteum Get Injured?

Unfortunately, like any other part of the body, the endosteum in your bones can become injured. Inflammation can cause this, but it is most commonly the result of a severe injury. An injury that causes extensive damage to the bones may compromise or even halt endosteal circulation. This can cause necrosis from within the bone, which effectively kills the endosteum lining. Treatment of such a severe injury would require the insertion of an arterial supply and a venous drainage system in order to restore circulation to the endosteum.

Effects of Osteoporosis on Endosteum

A more common cause of endosteum deterioration is the bone disease osteoporosis. It’s estimated that 44 million Americans suffer from this affliction. Osteoporosis causes gradual loss of bone density, which affects the density of the endosteum lining, too. The disease is particularly damaging because it dysregulates the bones’ natural remodeling process and inhibits the regenerative power of the endosteum. The result is a dangerous loss of bone density and thinning out of the protective endosteal lining.

Effects of Malnutrition on Endosteum

Osteoporosis isn’t the only affliction that can damage the endosteal lining. Unfortunately, malnutrition is another culprit in the damage and dysfunction of the endosteum. This is because the endosteum relies on proteins and other nutrients found in your diet to continuously build and repair bone tissue. When the endosteum is not supplied with the nutrients it needs, it cannot perform its necessary functions. Malnutrition is particularly detrimental to the endosteal lining, though, because it causes the endosteal surface to resorb. This leads to a thinner cortical lining within the bones and a damaged endosteum.

Recovering From an Endosteum Injury

If you’ve suffered from a bone injury, malnutrition, or osteoporosis, it’s likely that your endosteum has been damaged — but how can you recover and restore it to its full strength? You can benefit from the following tips:

  • Consult with a medical professional as soon as possible
  • Ensure that you are consuming sufficient nutrients and protein
  • Follow any physical therapy or rehabilitation that’s prescribed
  • Wear any casts, braces, or splints that you are instructed to wear

These tips can help you recover from a bone injury, including injuries that have damaged your endosteum.

Nurturing Endosteum Health

Prevention is the best medicine, and if you want to ensure that you aren’t dealing with any injuries in the future, you can be proactive about your endosteum health. Taking care of your endosteum can be accomplished simply by caring for your general bone health. To keep bones healthy, you should eat lots of vegetables and protein, exercise on a regular basis, and incorporate collagen into your diet, too, for optimal bone density.

Discussion Comments

KoiwiGal

It wasn't until I took a biology class on the structure of the skeletal system that I realized how complex our bones really are. They aren't just supports for our muscles and organs, they are living tissue just like every other part of the body.

One thing I found interesting was when our professor told us that the weight of the skeleton can vary over time depending on how much force it's subject to. So, if you are a heavy person, you'll end up with heavy bones as well (so that old saying "she's got big bones" has a kind of truth to it!).

He didn't go into it in depth, but it must be this part of the bone that increases, as it says in the article, it makes up most of the weight.

bythewell

@pleonasm - I'm sure they are working toward being able to do this. I know they are with ordinary stem cells at least.

And I've heard there is some progress. From what I remember they are pretty good at getting the stem cells to turn into the cells that they want, although I don't know if that applies to HSCs particularly.

It would be fantastic for research too, you see. If you had what amounts to an infinite supply of blood cells you'd be able to test different medications on them without needing to worry.

Unfortunately, I don't think they have a foolproof way of making cells live in the lab, or they would have already eliminated the stem cell debate by simply making their own supply.

pleonasm

If the endosteum contains haematopoietic stem cells, I wonder if it can be used to create blood for people. If they could make a sample of endosteum grow in a lab indefinitely, they could create as many of the HSCs as they wanted for each person.

And in turn they could stimulate those HSCs to become different kinds of blood cells.

It would eliminate the need for blood donors, and the very careful screening that needs to be done when people donate blood, in order to make sure they are disease free and that their blood type will match the person receiving the donation.

This would be invaluable, especially to people with rare blood types who might otherwise have difficulty finding donor blood.

And I assume it can also make marrow cells, which would be even more useful, because marrow extraction is so much worse than blood donation.

Post your comments
Login:
Forgot password?
Register:
    • Periosteum, the equivalent to endosteum on the outside of the bone, is important in the healing of fractures.
      By: kmiragaya
      Periosteum, the equivalent to endosteum on the outside of the bone, is important in the healing of fractures.
    • A diagram of the anatomy of a bone, showing the endosteum.
      By: Alila
      A diagram of the anatomy of a bone, showing the endosteum.
    • Chronic malnutrition can lead to a condition in which the body uses fat cells that are stored in yellow bone marrow to fuel itself.
      By: poco_bw
      Chronic malnutrition can lead to a condition in which the body uses fat cells that are stored in yellow bone marrow to fuel itself.
    • Casting is effective for most broken bones because it provides stability while the endosteum creates new cells to fuse the bone parts.
      By: Fotoluminate LLC
      Casting is effective for most broken bones because it provides stability while the endosteum creates new cells to fuse the bone parts.
    • The endosteum is found in the femur and other skeletal long bones.
      By: AlienCat
      The endosteum is found in the femur and other skeletal long bones.