Synarthosis vs. Synovia: Blame a Swiss Physician

Every once in a while, I get to dig into anatomy and physiology. While I'm not super great at remembering specifics, I have always been a "word nerd," relying on my knowledge of prefixes, word roots, and suffixes to work out what a strange word means. Usually, this works really well.

And then I got to the words "synarthrosis" and "synovial" and my usual strategies flew out the window:

Synarthrosis, noun: "an immovable articulation in which the bones are united by intervening fibrous connective tissues."

Synovial fluid, noun: "a transparent viscid lubricating fluid secreted by a membrane of an articulation, bursa, or tendon sheath;" synovia, noun: "a lubricating fluid resembling the white of an egg."

A synarthrosis or synarthrotic joint, which is held together by fibrous connective tissues and is relatively immovable, does not have a membrane that secretes synovial fluid. However, synovial joints, which do have synovial fluid and are freely movable, are considered diarthrotic.

In my frustration, I reached out to a college friend of mine ("L.B.," below) who teaches Latin, by essentially asking, "Why are these words like this???"

L.B.: "Why are they so similar?"

B.I.: "Yeah, so, in anatomy and physiology, we have synovial joints -- a synovial cavity and membrane that secrete synovial fluid, right? But we can also classify joints by how movable they are. Synarthrotic joints have little to no movement, amphiarthrotic have some movement, diarthrotic are fully movable."

L.B.: "It's what happens when a random Swiss dude [arbitrarily] makes up words by mashing Latin and Greek together (synovial)."

B.I.: *laugh-emoji-with-tears*

L.B.: "Synarthrotic is Greek. Syn means 'with,' the artho part is 'joint.' Syn is a Greek prefix but scientists don't care about that so it's also new Latin to mean 'with' and ova is 'eggs' and it's egg-like in color.

"But I was only partially joking... 'Mid 18th century: from modern Latin synovia, probably formed arbitrarily by Paracelsus.' Whereas the other is from the 1500s as a [first] use and developed in the anatomy community naturally."

B.I.: "gdi, Paracelsus."

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"Paracelsus (c. 1493 – 24 September 1541), born Theophrastus von Hohenheim (full name Philippus Aureolus Theophrastus Bombastus von Hohenheim), was a Swiss physician, alchemist, lay theologian, and philosopher of the German Renaissance.

He was a pioneer in several aspects of the 'medical revolution' of the Renaissance, emphasizing the value of observation in combination with received wisdom. He is credited as the 'father of toxicology'." -- Wikipedia, accessed 4/18/2025.

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So, just to recap:

• Synarthrotic Joints -- Typically immovable & fibrous, such as the sutures between cranial bones.
• Amphiarthrotic Joints -- Slightly movable & cartilaginous, such as the pubic symphysis and the joints between vertebral bodies.
• Diarthrotic Joints -- Freely movable within a synovial capsule filled with synovial fluid, such as your shoulder, knee, and hip joints.

... gdi, Paracelsus.

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Frequently Asked Project Questions

Actual video footage of my students, probably:

"Am I overthinking this?"

Yeah, probably.

"How do I get started?"

The same way that you eat an elephant: one bite at a time.

"What book is this in? When is this due? Who do I send this to?"

Double-check the syllabus and/or the first email you received about the class.

"I don't remember going over this in class."

1. I may have actually forgotten to mention that, in which case, thank you for the reminder.
2. We did go over that, but you might have been late/absent/dissociated. 
3. I didn't explain it very well. Thank you for your patience and for giving me the opportunity to try again.

"Can I have an exception because of XYZ?"

It's always worth asking, but please be mentally and emotionally prepared in case the answer is, "No." I try to say yes to a lot of things. If I do say "No," there is likely a reason -- sometimes that reason is, "someone else ruined it for the rest of you" or "I already asked someone else in charge and they said 'no.'"

"OH MY GAWD, WHY ARE YOU FREAKING OUT ABOUT ZYX?"

I do my best to be patient and professional. If you perceive that I am "freaking out" about something, I have likely hit my limit. It may or may not have anything to do with you. Please send feedback through the appropriate channels. (Related: public chats/forums/social media accounts are not the appropriate channels.)

"Why do I have to do this?"

It builds character. It's an opportunity for you to push the edges of your comfort zone to try something new or different. This way, if you encounter this again in the future, it will feel a little more familiar and a little less daunting.

"AAAAAAAAAAAAA?!"

Yes, I agree and I empathize. Your feelings are valid; however, some of your behaviors may not be appropriate. Again, please direct your feedback to the appropriate persons through the appropriate channels.

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