Module 11: The Human Body: Fearfully and Wonderfully Made

This class is always so much fun.   Keeping in the spirit of "hashbrowns"... or just food in general, we made our own fun and colourful skeletal systems.  Of course after we put them together and named the bones, we ate them.  Mmm.  Yes, science is fun and yummy.  You'll notice that there are a few extra bones in some skeletons, while others have pony tales and hair.  :) 

In this module we looked at:

The skeletal system.  The kids labeled a diagram of the bones in the skeletal system and began a detailed drawing of a bone.  (If they haven't finished these, I would like them done for next class.) A detailed drawing does a lot more for understanding and retention than simply looking at a picture.  These should be detailed and labeled.  Pg. 268 has a diagram.

Minerals in your bones make them hard and strong.
Collegen in your bones makes them flexible.  Without the calcium in them, they would be veerrry flexible.

The experiment that the kids were to do at home and bring their lab report for was called Minerals in Bone.   They used a clean chicken bone, dried overnight and soaked in vinegar for a week. 

In vinegar for a week

In bleach for a week.

The kids handed in their lab reports, and I will be marking them this term.  Their conclusion ideally should have explained why collagen and minerals are important in bones.



It's pretty obvious which bone was left with minerals but no collagen, and therefore was brittle; and which had collagen, but little or no minerals, and is too flexible to be of any use for humans or animals.








We also learned more about the composition of bones, such as compact bone and spongy bone.
Spongy bone is just as hard as compact bone!  Spongy bone just has spaces in it (like a sponge).  These spaces are filled with bone marrow.  Did you know that your bones are alive and that bone marrow makes your red blood cells?





We talked about bone marrow transplants and why that is such an incredible procedure.

In this unit we also learned the difference between tendons and ligaments?

Tendons are what connects your muscles to the bones.  When you exercise, the tendon pulls on the bone, making it grow stronger.
Ligaments are strips of tissue that hold bones together in a joint.  Your upper arm bone, the humerus, is held in the elbow joint by ligaments.
Your elbows and knees have hinge joints, which is pretty easy to understand.  A hinge joint has limited mobility compared to some other joints, but it is more stable that way.
A ball-and-socket joint, such as the shoulder or hip, has a lot of mobility, but is not as stable as a hinge joint.
The more mobility, the less stability.  The more stable, the less mobile.
Cartilage is between the bones so that they don't rub together.
Most joints are surrounded by a "bag" that holds synovial fluid.  It is slippery, like egg white, and keeps joints lubricated for ease of movement.


Skeletal muscles are voluntary and make the skeleton move; smooth muscles are involuntary and make up the muscles of your organs; and the cardiac muscle is also involuntary and is the muscle of your heart.

Other organisms don't all have muscles.  For example, plants don't have muscles. 
But plants can move by tropisms.  I'm sure you've had a plant in a sunny window, and after a day or two, you may have had to turn it to keep the plant looking "balanced."
This is because plants want to grow toward light.  Growing toward light is called phototropism.
If a plant isn't growing toward the light, but turning like sunflowers that track the sun across the sky, this is called heliotropism.  Gravitropism is a plants tendency to sense which way is "up" and to grow that way.  Roots growing toward water is hydrotropism.

This is an example of heliotropism, as well as gravitropism.  The plant does not take long before it grows back up, and towards the sun after being placed on its side.

Heliotropism - movement toward the sun and Gravitropism - sense which way is "up".

We learned about the layers of our skin: epidermis, dermis, and hypodermis, and a few things about each layer.
Our hair and nails are also a part of this organ.
Our hair, nails, and the outer layer of skin are formed by keratinization, which is a process that kills the cell, but leaves it quite sturdy and hard to destroy.
Your outer layer of skin, the epidermis, is made up of dead skin cells and living cells. These living cells move upwards toward the outer layer and eventually fall off and are replaced with new keratinized cells.
The hair follicles  on your head are active for months at a time and have short periods of "rest" and can grow very long, unlike eyelashes or eyebrows.
Each hair is connected to a small, smooth (involuntary) muscle in the dermis.  When you get cold or nervous, this muscle contracts, pulling the hair straight up.  This is how you get goose bumps and your hair "stands on end."  This increases the amount of warm air trapped next to the body.

There are good bacteria living on our skin, and perspiration feeds this bacteria!  This beneficial bacteria produce lactic acid which is a good defense against many types of pathogenic (disease-causing) bacteria and fungi.

When two or more different organisms benefit from each other, this is called symbiosis.
We learned a little bit about symbiosis in our ecosystems unit, and will be learning a lot more about it when we get to Biology down the road.  I just don't see how, with all the marvelous things that work together (every time), that anyone can believe it happened by chance!

We are truly "fearfully and wonderfully made".


Thanks to Marty (with permission) for her contributions and pictures that we weren't able to get in class.  (Or forgot!)