Liberal Arts Blog — Don’t Take Bones for Granted!
By: John Muresianu
Tags: Health, Biology, Anatomy, Bones, Liberal Arts Blog

Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day

Today’s Topic: Don’t Take Bones for Granted! Bones are amazing! Miraculous, really, and very, very busy!

Bones appear inert but are very much alive. Did you know that they churn out one trillion red blood cells per day and that red blood cells in total represent 80% of all the cells in your body? Did you know that a complete new skeleton is generated every seven to ten years? that in outer space, astronauts lose 1–2% of their bones every month such that after a year in outer space, it will take years for their bones to recover? Experts — please chime in. Correct, elaborate, elucidate.

FIVE BIG JOBS — support, protection, storage, production, movement

1. Support: light and strong. Think the Eiffel Tower — a network of light weight trusses. Not quite triangular, the internal matrix of spongy bone is however very much analogous to the basic structure of the Parisian icon. Bone is very strong in compression (oriented vertically) but relatively weak in tension). Another analogue is a tree with the deposition of successive layers of concentric rings. The basic unit of compact bone is the osteon which consists of concentric rings of tissue called lamellae around a central canal (the Haversian canal).

2, Protection: note that there are only a few inches between the bottom of your rib cage and the top of your pelvic bone giving remarkable protection to your internal organs. The skull is especially well shaped to protect the real you — your brain.

3. Storage: not just blood cells (red and white), but also fat, and minerals such as calcium and phosphorus.

NB: Production and movement: not just red blood cells but white and platelets, too. And for movement well there are even more joints than there are bones (about 300 versus 250). Also about 4000 tendons connecting them to muscles and about 900 ligaments which connect bone to bone.

THE YIN AND THE YANG OF OSTEOCLASTS AND OSTEOBLASTS

1. Nature is all about balance. Applies to physics. Applies to biology. The Yin and the Yang. Homeostasis. Positive and negative feedback loops.

2. Well the yin of bone are osteoblasts which make new bone. They are the mini-creators. The osteoclasts are the destroyers. The mini-Shivas. The diagram above is of an osteoclast. Frightening, no? Pac-man like?

3. The scientific euphemism for destruction is “resorption.”

NB: The first step of “resorption” is the dissolution of the mineral components by the injection of acid (that is hydrogen ions). Step Two is the injection of two enzymes (collagenase and gelatinase) which degrade and digest the collagen and other organic components remaining in the decalcified bone. Worthy of a Sci Fi drama!

FROM THE TINY STAPES TO THE MIGHTY FEMUR

1. A size and shape for every purpose under heaven.

2. The stapes (“stirrup”), the smallest bone in the human body, is one of the three bones in the middle ear and gets its name from its horse-shoe shape. It is 3 by 5 millimeters in size. The stapes works with two other little bones (“ossicles”), namely, the malleus (“the hammer”), and the incus (“the anvil”) to make possible the miracle of Beethoven, Bach, and the Beatles.

3. The femur is the largest, longest, and strongest bone in the body and represents on average 27% of the human body length. Breaking your femur is a very bad idea. Most common cause; motor vehicle collisions. Especially bad idea in the elderly.

FINAL WORD: The Pain of a Broken Leg in 1967

1. I broke my tibia and fibulla in four places when I was fourteen (playing soccer during lunch period at St. Anselm’s Abbey School in DC). It really, really hurt.

2. I recently learned that the acute pain did no emanate from the inside of the bone as I imagined at the time, but from the tearing of the outer layer — the periosteum.

3. Knowing that at the time would probably not have made any difference.

Bone

Osteoclast

Osteoblast

Types of Bones Anatomy

Stapes

Femur

Much Like the Rings of a Tree, Bones Reveal Biological Age in Humans | Hinda and Arthur Marcus Institute for Aging Research

https://en.wikipedia.org/wiki/Osteon#Structure

Periosteum

Periosteum | anatomy

General Information about Pain After A Fracture | Osteoporosis Canada

A LINK TO THE LAST THREE YEARS OF POSTS ORGANIZED BY THEME:

PDF with headlines — Google Drive

YOUR TURN

Please share the coolest thing you learned this week related to science, engineering, or technology. Or, even better, the coolest or most important thing you learned in your life related to science and engineering.

This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.