It's AumSum Time
Why do we have 5 fingers?
So that we can lick our hand 5 times.
A theory suggests that we have 5 fingers because, together they make a perfect strong grip.
Using them, we can operate small objects with great control and precision.
Second theory suggests that 3 molecules called Bmp.
Wnt and Sox9 are responsible for the five fingers, since in our embryonic stage.
They mark out spaces specifically for these 5 fingers.
Another theory is related the Limb law.
Based on the length of the fingers.
This law helps us calculate the number of fingers we should have.
Now, limb’s law using its mathematical model comes up with the answer 9.42 fingers per hand.
But we need fingers only on 1 side of the palm as other side is connected to an arm.
Hence, the final answer comes out to be 4.78, that is, 5 fingers per hand.
Why do our fingers get wrinkly?
Because they want to look like raisins.
No.
A popular research suggests that wrinkly fingers are a reaction of our nervous system.
When our fingers are in water for a long time.
Our nervous system causes the blood vessels present in the deeper layers of our skin to constrict.
This in turn causes the deeper layers to shrink or contract.
But as the topmost layer does not shrink, it becomes loose thus, forming small folds or wrinkles.
But why does this happen?
Scientists suggest that this could be an evolutionary adaptation.
Wrinkly fingers help in getting a better grip to pick up wet objects.
Preventing them from slipping from our hands.
Even our feet get wrinkly.
Helping us to walk in water without slipping.
Pins and needles.
Why do limbs fall asleep?
Because they are tired.
No.
It basically happens because of nerves.
Through nerves, our brain communicates with our limbs.
Wow.
Nerves are so amazing.
Yup.
However, when we cross our legs or sleep on an arm for very long.
We apply pressure causing the nerve pathways and its surrounding arteries to squeeze.
Hence, the nerves do not work properly.
And the arteries cannot supply required nutrients to the nerves.
As a result, the signals sent by our brain do not reach the limb.
Thus, we cannot move it.
So, we say that our limb has fallen asleep.
Also, in some situations.
Some of these squeezed nerves stop sending signals while some fire hyperactively.
This gives us the sensation of pins and needles.
Human Bones.
How does a bone heal?
Ha, simple.
By a bandage.
No.
Bones are one of the most important parts of our body.
They not only provide structural support but also produce red blood cells.
What?
Our bones produce red blood cells??
Absolutely!!
Hence, when we crack or break a bone, it is very important to heal it.
In the healing process, cells called chondrocytes produce collagen which forms cartilage.
This cartilage bridges the gap between the broken bones, thus producing a soft callus.
Then, special cells called osteoblasts create a hard bony callus using collagen.
And minerals like calcium and phosphorus.
Thus forming our new bone.
However, this new bone is irregular in shape.
Hence, cells called osteoclasts start remodelling the bone.
Resulting in the formation of bone similar to the original shape.