GD: Bones 2

An osteon is found in compact bone, which is also called cortical bone. Compact bone is the bone that is really dense. The osteons in the bone are like little rods–or logs–as the article calls them. Each osteon is several millimeters long. If dogs get a piece of osteon-built compact bone from a cow leg (pic is below), they won’t be able to crush it with their teeth because it so hard.

Osteons are like logs in that they have concentric rings. The log-like osteons grow side-by-side each other and are held tightly together by horizontal tubes and other means.

Giant Sequoia trees may have a thousand rings or more, but the maximum amount of rings that an osteon has is about 200.

The tube ( C is pointing to one layer of it ) that has concentric circles which are protruding out from the rest of the tubes is:

A full-sized osteon is about as wide as a cat’s whisker. They are made of rings of bone material arranged in concentric circles. Concentric circles are circles inside of circles like the circles in a bullseye. The concentric circles of osteons are called lamellae.

One lamellae layer of bone is 7-8 millimeters wide which is about as wide as a red blood cell. This is just a little thinner than a capillary which is the smallest blood “pipe”.

Lamellae means “thin layer”. A tree ring has what can be called lamellae and so does an alligator’s foot. The dark “lamellae rings” of wood are the summer growth of the wood.

Mushroom “gills” are where spores are made. They are also called lamellae

A mushroom spore has all the mushroom DNA to make a new mushroom fungus. b. A spore is a little like a seed without much “seed food” in it. c. Fern spores grow into a different little plant. These plants breed and they make a fern.

Mushroom lamellae increase the surface area to make spores for the fungus. b. Spores on the top of fern leaves grow in clusters rather than lamellae. c. This is because there are so many leaves on a fern that lamellae aren’t needed to increase surface area.

Fish gill lamellae (secondary) stand upright. The blood flow in them runs the opposite direction to the water flow coming in through the gills. This is makes countercurrent exchange of oxygen and heat possible.

A two-pound tuna fish has 5 million secondary lamellae. Tuna can weigh up to 1500 pounds! These large tuna have an unbelievable amount of secondary lamellae.

What covers the gills to protect them is the popacitum.

A nudibranch has very unusual gills. The are located in the slime-secreting “foot” that it slides on. As the mucus covers the ocean floor that they slide over, the mucus acts like an oxygen transfer site. Oxygen molecules diffuse into the mucus and the nudibranch can then uptake them through special cells on their slime “foot”.

Between the osteon rings, there are living osteoclasts which are encased in bone in compartments called lacunae. These osteoclasts have undergone metamorphosis. They started as the bone-laying osteoblasts.

The central hollow tube of the osteon is the Haversian Canal. This is a larger bone cave than the canaliculi. In this hollow tube there are blood vessels, lymph “pipes” and nerves.

The trabeculae bone in this picture are also called:

The pinpoint openings in the trabeculae above are very strange. They are openings leading to the “bone caves” called canaliculi.

The gentle Clydesdale horse’s massive 2000-pound body is supported by their bones because of something that is happening in every BB-sized amount of bone. (BTW, the gentle disposition of the Clydesdale horse is not wired into the brain by the animal’s DNA. It is purely the environment that the animal is raised in that determines its “personality”.)

The blood flowing through the canaliculi “bone caves” gives the osteocytes that are encased in the bone food and oxygen. They need this supply of food and oxygen because they are encased in bone lacunae “prisons” for years.

Osteoblasts, the bone building cells, get buried in bone. As they are buried, they go through a type of metamorphosis which makes them into osteocytes. This metamorphosis prepares them for the new job they have to do. (Think!)

Canaliculi are found in the super-dense, super-hard compact bone. They play a critical part in keeping imprisoned osteocytes alive. These osteocytes need to be kept alive because they are critical for the lives of all boned animals and humans. Why? For one reason, it’s because these osteocytes play an important role in stopping micro-fractures.

There are 1 million osteon logs laying side-by-side in a cubic inch of compact bone.

An osteon is about the exact size of an upper eyelash. b. There are maybe about 10 osteocytes per lamellae. c. There are about 50 canicili bone tunnels per osteocyte. d. There are maybe 150 “floors of osteocytes per osteon.

About ten living “osteoblast-metamorpohsized” osteocytes are buried in each 8-10 micron thick lamellae layer of an osteon. (It’s obviously going to be less the closer you move to the Haversian Canal in the center of the osteon, but this gives an estimate.)

This amazing picture (below) shows lamellae as snake-like caves which interconnect with each other. These not only connect the osteocytes to one another, but they also provide them with food and oxygen.

The dark spots in the picture above are living buried osteocytes which are living in “bone compartments” called lacunae”. We likened these lacunae to the Japanese capsule hotels.

The dark circle in the center of the osteon above is the centriole.

There are living osteoblasts and osteoclasts on the outside and the inside of each of the rings of each osteon.

The life of a tiger is dependent on the nano and molecular structure of its bones being correct. If things weren’t correct in both “places”, the bones of the tiger would break and the tiger would die. An example of moleculat things being correct is that collagen molecules must be formed correctly. And example of nano-construction is that the osteons must be correctly “fastened” to one another.

In a BB-sized amount of compact bone there are tens of thousands of buried living osteocytes with one billion interconnected bone tunnels.

This is an accurate computer-generated image of a dust-sized amount of a mouse’s brain. It took a lab at Harvard 5 years to put this image together. The colored sections are different neurons. (Look it up if you need to.)

As we said above, the colored parts of the image above are the neurons in the mouse’s brain. At the researcher’s speed of getting this image, it would take them 1.5 billion more years to complete the project of mapping a mouse brain.

The image below is an actual picture of compact bone taken by an electron microscope. It’s difficult to count the rings, but some of the osteons have at least 10 lamellae. Others seemed to have as little as 7 lamellae. The picture also shows the bone material between the log-shaped osteons. The bone material between the osteons appears to be made of the same material that the osteons are made of.

The compact bone that the image above is part of will grow wider because the dark dots in the center of the concentric circles grow wider.

Each of the concentric ring layers in the picture above is a lamellae layer.

The big dot in the center of each osteon above is the blood vessel-nerve-and-lymph vessel containing Haversian Canal. This canal is really a bone cave.

The sand-like spots around each concentric circle are the buried-alive osteoclasts.

The larger osteons in the picture above are 200 millimeters across. The bone grows by each of these adding new lamellae rings.

The two “canals” (caves) in bone are called the canaliculi and the Haversian Canals.

The Haversian Canals in the bones must allow the blood to leave the bone once the blood has given up its oxygen. This is essential for the red blood cells in the blood to return to the lungs to get fresh supplies of oxygen. This makes the blood piping in bones very complex.

Compact bone and cortical bone are different kinds of bone. Compact bone is the bone on the outside edge of dense bone and cortical bone is the scientific name for the bone closer to the center of the bone where it transitions into trabecular bone.

If the blood piping was plumbed incorrectly in bones, all vertebrate life with bones would die out instantly. Think!

High-speed soccer players, gymnasts and basketball players are continually damaging their bones. Their bones have to be able to repair themselves.

If the blood didn’t flow correctly in the bones, the osteocytes would do fine. The bone cells that would die are the osteoblasts and the osteoclasts.

The picture below shows that the blood vessels in the Haversian Canals are inter-connected. (Bonus question for discussion: Why or why not would it be good if they were interconnected?)

The maze-like bone on the far left of the picture above is trabecular bone.

As a children grow older, their bones grow longer and wider. When they grow wider, all the thousands of osteons across the bone add rings. Based on what you know about the total number of lamellae rings bone osteons can have, is the bone in this illustration above an illustration of a young person’s bones or someone who is middle-aged or older?
(Discussion question: Why did you come to your conclusion?)

Michael Jordan’s bones would look like the bones below.

When a tiger leaps 30 feet, there are huge stresses both from the muscles that pull on anchoring bones and from the impact of the jump. Even in tiny animals like hummingbirds, there are fantastic stresses on their tiny bones due to their 60-plus-wing-beats a second! Imprisoned osteocytes which help in maintaining bones like their bones. These amazing cells can live to be a whopping 25-years old!

List 5 summaries of the devotional parts in this article and give a different personal application to each.