Transcript Lymphatic System

Begin
© Craig Weston, 2008
The Lymphatic System
Yeah, this is a
weird one. Let’s
take it slowly.
For now, just
know that the
Lymphatic System
is found all
throughout your
body.
Review!
Homeostasis = balance in the body
Functions = jobs
Stimulus:Response = how your
body reacts to something
Structures = the parts
Disorders = when the
system is diseased or
works poorly
#1 Lymphatic System Overview
To understand what this strange body system does, you have to
remember a lot about your circulatory system. Think about your
capillaries, in particular:
Any living cell in
your body has a
capillary running
pretty close, but
likely not directly
against it.
The blood in the capillary will provide these cells with oxygen and
nutrients, but not by directly handing those things over to the cells…
#2 Lymphatic Sys. Overview,
contd.
…your capillaries have such thin walls that they can purposefully leak
out a lot of the blood plasma. This liquid contains the nutrients and O2
that your body cells need. The leaked out fluid bathes and coats your
cells so that they can absorb what they need from it.
The body cell is the large,
gray blob. It gets its oxygen
and nutrients from the fluid
that surrounds it, which
leaked out of the capillary.
#3 Lymphatic Sys. Overview,
contd.
And that takes us to where the Lymphatic System comes in.
Imagine if that leaked-out fluid just sat around, building up. In just a
few days, your hands and feet would swell up from this fluid settling
down thanks to gravity. You’d get squishy and likely dehydrated,
and probably end up looking something like:
We’ll see how your Lymphatic System makes
sure that you don’t end up Mickey-ized.
The Lymphatic System is a network of tubes
and organs alongside your blood vessels
#4 FUNCTIONS of the
Lymphatic System
1. soaks up leaked fluids from around your cells; returned to blood
2. produces White Blood Cells
3. destroys old blood cells & germs
Hm…
seems
important!
#5 STRUCTURES of the
Lymphatic System
Fill in the structures on the back as we go!
1. lymph – clear fluid surrounding cells, mostly leaked from blood
This is blood plasma and other fluids that surround and bathe your
cells. Nutrients and oxygen leave the capillaries and float through
this fluid (called interstitial fluid in this diagram) to feed your body
cells.
(no need to label anything on
your notes-diagram from this
slide)
Oh yeah, label box #2 on your diagram “lymphatic vessels”
#6 Structures, contd.
2. lymphatic vessels – tiny tubes that soak up lymph, take it to lymph
nodes, then to veins. They’re like soda straws, drawing in liquid.
Study these different diagrams…notice what they have in common—the
lymphatic vessels weave amongst the capillaries, soaking up the lymph.
#7 Structures, contd.
Hmm…if the lymphatic vessels act a lot like your blood vessels, then
there must be a “heart” or some sort of pump that moves the lymph to
the big veins of the body where it’s dumped back into the blood, right?
No, not really. There is no “heart” or “pump” of the lymph system.
Instead, your body relies on your skeletal muscles flexing during the
day to squeeze the lymph vessels like toothpaste, making it flow
through the body.
Uh…which of these characters is
helping his lymphatic vessels get
the lymph back into his veins???
#8 Structures, contd.
3. lymph nodes – small swellings in lymph vessels all over body
that filter lymph & kill germs
Lymph nodes are found all over, but mainly in your neck, armpits,
chest, and groin. When you are fighting an infection, they can swell or
become sore.
(label your ppr)
#9 Structures, contd.
4. tonsils – First of all, it is NOT the uvula (the dangling thing in the
back of your mouth). The tonsils are lymphatic tissues that store
WBCs for fighting infections.
The tonsils are ready to take on any germ challenge, but sometimes they
get so enlarged and tender when fighting infections that they either
deteriorate into uselessness or obstruct breathing & swallowing. In that
case, the tonsils will be removed (and yes, this somewhat decreases a
person’s ability to fight diseases).
(eww)
#10 Structures, contd.
5. thymus – organ in chest that produces WBCs. How your body fights
germs is a complicated matter, but needless to say, the WBCs made in
the thymus are important to the lymphatic system’s overall efforts not
just in killing germs, but remembering what they’re like for future
reference. These particular WBCs are efficient killers.
#11 Structures, contd.
6. spleen – lymph organ that recycles RBCs, stores blood, and holds
WBCs for germ-killing.
The spleen is one of those organs that people have heard of but often
have no clue what it does. It’s very important to the maintenance of
your blood and also helps you fight off diseases. If it ruptures, people
have been known to bleed to death!
A swollen or ruptured spleen
can be life-threatening
#12 DISORDERS of the
Lymphatic System
So, the lymphatic system soaks up all this lymph that oozes around in
your body. But what if it doesn’t do that? Or maybe it just does a bad
job of it? Well, that puts the person at a high risk of developing a
lymphedema.
1. lymphedema – swelling of a body part due to lymph not being soaked up
#13 Disorders, contd.
Remember a few slides back when we talked about the Thymus making
a bunch of special WBCs? These are called T-lymphocytes. Well, one
very Very VERY nasty disease makes a habit of killing these T-cells.
2. AIDS – H.I.V. (virus) kills T-WBCs, making you vulnerable to any
other diseases.
You would normally kill these other diseases
with little effort, but the HIV virus kills your
soldiers, making your body like a town with no
police.
The huge green blob is a dying T-cell. The little red
spheres are HIV viruses leaving the T-cell, each
ready to go invade other T-cells. Infected T-cells
are forced to make new HIV viruses before they die.
What a mean, horrible disease.
#14 Disorders, contd.
People don’t die from AIDS itself…rather, they die from what are
called “AIDS-related complications.” In other words, they die of some
other disease that takes advantage of their weakened bodies. We
should all have compassion for these people.
Magic Johnson is HIV+, but
he doesn’t have AIDS
This person is suffering from fullblown AIDS, and is fighting several
diseases.
#15 REVIEW
Could you live without the lymphatic system? Let’s see.
1. Soaking up leaked fluids from around your cells; returned to blood
Yep, Joe would suffer from lymphedemas
which might not ever kill him, but would
lower his quality of life greatly.
Dang
…this
is no
fun
2. Produces White Blood Cells
If you can’t fight germs, they will win.
3. Destroys old blood cells & germs
Your blood would still work, but not as well as you’re
used to, and you’ve GOT to kill germs, or else!
#16 Review, contd.
The lymphatic system soaks up excess
fluids from around your cells, returning
your fluid level to a proper balance.
Die, germ, die!
Infection : Make more WBCs to fight, fight, fight!
#17 And That’s…
Well, it was nice being your guinea pig
for all this body system stuff. Hopefully
seeing me turned into an 80 year old
woman, having a heart attack, kicking the
smoking habit, and being chased by a
dinosaur helped you see how our bodies
work. See ya…I’ve gotta remember how
to get my TV up on my dresser…
Bye, Joe. May you live in interesting times…
#18 And That’s…