Saturday, December 13, 2008


I don't know about you, but I never learned about the lymphatic system when I was in school. We learned about skeletons and hearts and stomachs and brains. But not lymph. So now I am supposedly teaching my own children. Oops. Jay Wile's section on biology (in the general science book) has intrigued Andrew. He's telling me all this cool stuff he reads and learns. Some of it I knew. And to some of it I say, "HUH?"

Lymph is what I just do not understand. So in addition to what Andrew taught me from his science book, I checked me out a kiddie-book from the library. Best I could find was a book on the cardiovascular system and the lymphatic system. As I read, I discovered that the authors didn't have too much to say about lymph. I guess that's why the lymphatic system didn't warrant its own book, eh? I suppose I could get a grown-up's book on the subject, but deciphering that would leave me no time for onion-chopping and laundry-folding and snow-shoveling. So I delved into the kiddie-version.

Well, here's what I learned.

The lymphatic system is made up of vessels (like the veins and arteries) all over the body, almost like a frontage road following along the highway of the cardiovascular system. The tubey-guys are bigger than capillaries but smaller than the smallest veins and arteries. And the tubey-guys in the lymphatic system have valves that go only one way; they take lymph AWAY FROM the body's cells.

Interstitial fluid is the liquid in the body that allows movement of molecules. That is, the slippery slidey lubrication, in my super-advanced way of categorizing things. This excess fluid flows into the lymphatic system, and then it is called {ta da!} lymph. Lymph looks a lot like plasma and has much the same composition.

Lymph flows through the lymphatic vessels. Scattered all along this frontage road (the lymphatic system) are lymph nodes. These guys I understand. They are places where the germies meet up with the germ-fighters. That's why lymph nodes swell when you're sick, because you have extra germ-fighters. Lymph nodes are the part of the lymphatic system that is so important to a person's immune system. I did not know, though, that tonsils are a big ol' collection of lymphatic tissue.

After the lymph makes its circuit around the body, there are two bigger tubes in the chest where the lymph gets dumped into the blood. I guess that's where the white blood cells fight off the rest of the germies that made it past the lymph nodes??

So here's what I want to know. When you get a teeny-tiny cut or a cold sore, and you get that yellow crusty stuff instead of a scab, is that lymph and not plasma?


  1. Matt says:
    Lymph and plasma are basically the same thing. It's hard to tell if you've cut open a lymphatic tube, because they're small and not showy like blood vessels- but if it's really clear, then it's a good chance that it's lymphatic fluid.

  2. As I was reading my 3rd-grade book the other day, it crossed my mind that I could just ask Matt. But there'd be one huge barrier to that: I'd have to remember to ask him when I saw him...

    Thank you for checking with him! It helps to know that lymph and plasma are pretty much the same.

  3. In John's gospel. he says when they pierced Jesus' side after he was dead, blood and water poured out. Does this water fit anywhere into this discussion? I've always wondered what the water meant.

  4. Biologically, I'm not sure what the water was. Maybe it was plasma and/or lymph?

    But theologically, I know where the water fits in. Baptism. Blood and water poured out. These show us that the sacraments (baptism and the Supper) flow from Jesus' side to create His bride the Church. Eve came from Adam's side. Jesus is the New Man, the second Adam. On the cross He left His mother ("a man shall leave his father and mother and be joined to his wife...") and gave her over to the care of John, so that He could be joined to His bride.

    Lest you think I'm getting whacko, look at 1 John 5. Remember, this is the same writer who made such a big deal about swearing on oath that blood and water came from Jesus' side when He was pierced after His death. In his epistle, John says that Jesus came by the Spirit, the water, and the blood. And he's still talking here in the epistle about "testifying" like he was in the 19th chapter of his gospel.

    Although the water and blood was a historical, biological fact, and although it did surely indicate that death had already taken place, that wasn't why John made such a big deal about it. The water is important because of baptism, and that Jesus comes by the work of the Spirit in preaching, baptism, and the Lord's Supper.

  5. This doesn't weigh in so much with the lymph conversation, but the water/blood one...

    Ever notice that prior to the blood flowing out of Jesus' side, they gave him sour wine? He drinks the wine, and from his side flows the blood, and is the water and blood that creates the church.

    I hadn't noticed until a Dr. Scaer class...

  6. About 3 years ago I read a book about heating healthy fats and such. I think the book was something with peri-menopausal in the title, but anyway, she talked about the lymph system. She encouraged that one do jumping jacks every day because the bouncing plus the arms raising above the head helps to get the lymphs moving and that is another help in losing weight. I always wondered how true that was. Hmm, now I'm gonna have to refind that title and reborrow the book from the library to see exactly what it said.

  7. I was told once that when under EXTREME stress (like, stressed enough to sweat blood), it can happen that fluid will build up around the heart. I was told, also, that it is water, though a quick Google search did not confirm that. Most people crucified died of suffocation, but Jesus died so much more quickly that they were surprised. The blood and water confirms that Jesus died not as the typical crucified person, but literally from a broken heart, stopped from the pressure of the fluid on it.

    I can't do any more research to confirm any of the medical facts of this because I've about reached the limits of my internal-organ-phobia.

    But I think it's a beautiful and terrible side to a beautiful and terrible story...

  8. I know I'm a bit late, but hopefully better late than never.

    Your question about the scab has to do with the coagulation system, the bodies regulation in stopping bleeding where needed, but not too much so the blood can flow throughout the body.

    When you have an injury to tissue, there is a chemical released from the damaged cells (whether from a cut or damage on the inside of blood vessels) that triggers the coagulation cascade. First to respond are the platelets that form a plug at the injury site. Sometimes the sticky platelets can stick to fat or other tissue and cause a blood clot to form in a vessel causing a heart attack, stroke or Pulmonary Embolism (PE).

    After the platelets form the plug (usually what you see with a scab), the cascade continues and various proteins form a glue that holds the plug in place until your tissue can heal. Maybe you have cut yourself shaving and if you put pressure on the wound, you get the pletelet plug, but if you wipe the blood off with water sometimes you can dislodge this weaker plug and start bleeding again until the stronger proteins are formed to hold it in place for longer term healing.

    For your question, the yellow crusty stuff may be your coagulation proteins especially if you haven't bled. Another thing it can be with a cold sore or a pimple or other bacterial infection is it is more likely to be a collection of white blood cells (WBCs) that rush to the scene and fight the infection. That is usually what makes up pus. So you may have some WBCs contribuing to what you see.

    Hoe this helps. Let me know if you need other resources. checkl out to learn about all the tests doctors can order and what they measure and the effects on disease on your system. It's informative and laboratory professionals can answer your specific questions.

    -luvable lutheran

  9. Cool, L.L. Thanks!
    Now that I read this, I'm realizing that I don't know what you were studying in school, but I just know what your Lutheran extra-curriculars were. Were you in medicine or pharmacology or something like that?