Apologia General Science, Module 15, The Human Lymphatic, Endocrine, and Urinary Systems

►Videos, etc. for M15

The kids did not find this module all that appealing.
I had no interesting games. =(
It was nearing the end of the year, and they all had spring fever.
It was about body systems that, frankly, few teenagers think about.

Some teenagers don't even know what a lymphatic system or an endocrine system is.  They knew about the urinary system, but didn't really care to absorb into their minds the vast knowledge I had to convey.  (lol, about as vast as a pea, haha)


Kidney System
As usual, I went straight to an experiment to try to get them interested, and then previewed other parts of the chapter.  (I usually do things out of order anyway, haha)
You may know that your kidneys are filters.  They clean blood and blood plasma.
But they only clean out chemicals that are not dangerous yet!  They aren't dangerous until they reach certain levels.  So their levels in the blood need to be monitored and maintained.

We did Experiment 15.2, A Model of Kidney Function
Very simple: tea bag, coffee filter, boiling water, you get the idea.

Boiled water poured over loose tea grains (no longer in the tea bag) 

Using a coffee filter in a funnel to strain out the tea grains

The first thing kidneys do to blood is filter out any large chemicals.

Folded paper towel, more filtering.

The water and tea ALL will go through the paper towel, but not all will end up in the glass.

Nephrons filter the water and chemicals in water out of the blood.  Then they put some of 

the water and chemicals back into the blood, and the rest will be sent out the ureter as urine.

Learning the path of blood and urine, etc. is a little complicated, so we spent some time discussing it and learning the terminology.  They listen pretty good since they know there will be questions later... and chocolate!
Not really a game, but they paid attention so they could get chocolatey goodness.  =)



Lymphatic System
In contrast to the kidneys (which clean blood and blood plasma), the lymph nodes clean... lymph!
You have probably had swollen lymph nodes before, but what is lymph?
(That's what the kids said.)

There is a clear fluid that is in between the body's cells, that leaks in and out of capillaries and in and out of cells, carrying out the exchange of oxygen and CO2 between the cells and the blood.
This fluid needs to be cleaned before it can return to the blood, and the lymphatic system does this.
This fluid is called interstitial fluid, but while in the network called the lymphatic system, it is called lymph.
The cleaning sites along the lymphatic system are called lymph nodes.
(See image)

I won't go into it here since you can read about it in your textbook or google it to learn more, but a lymph node has quite a job.



Endocrine System
I'm sure you've heard of hormones.  But what do they do?
Hormones send chemicals to cells, causing them to change their behavior in a specific way.
There are several kinds of endocrine glands.  (see image)
The hypothalamus has several jobs, including controlling the pituitary gland.  The pituitary gland is only the size of a pea, but controls other glands, and is often called the "master endocrine gland."
There is also the thyroid gland which affects the basal metabolic rate.
Adrenal glands, through a complicated series of one thing causing another to happen, are responsible for the production of adrenaline.
The pancreas is a digestive gland and an endocrine gland, and makes insulin.


These body systems are all rather complicated, and I don't know of one that isn't!
I can't imagine how someone can believe in evolution.  We NEED all these body processes to work correctly, and if they don't work correctly at birth, there are immediate problems.
How can someone say we evolved to be how we are today?
We wouldn't even live long enough to bear offspring!
I'm glad I know Who the Creator is!  =)


sMiLeS,