No problem, my first degree was in Biology and this is precisely how we were taught it.

The walls of human blood vessels are twice as thick in the lower half of our body, to account for gravity and the fact we live standing upright.

Bats do not have this because they have evolved to vary their body position much more than humans have.

Arteries carry blood away from the heart.

Veins carry blood via (towards) the heart.

That is the difference between them.

The sun is not burning the way a fire on earth burns.

It is a huge ball of plasma undergoing nuclear fusion, a process which generates incredible heat, so it burns from within due to the process, not because it is using oxygen as a fuel.

They are coded genetically, simple as that.

Eyebrow hair has a different string of proteins in its DNA coding for its design, meaning when they form they are constructed differently.

Like the blueprints for them contain different instructions.

Your heart has a little part called the AVN which generates it own electric current, which causes the heart muscles to contract in a regular pattern.

An electric shock overwhelms the AVN, causes a kind of shot circuit effect where it overloads, and the heart loses its rhythm, killing you.

Because the lower down the food chain you go, the more calories energy a food contains.

So imagine a simple food chain: Sun > Grass > Buffalo > Bear.

To make 1kg of Buffalo, you need 10kg of grass.

To make 1kg of bear, you need 10kg of Buffalo.

The bear needs the caloric equivalent of 100kg of grass, whereas the buffalo requires only 10kg because it eats the plant directly.

From a calorie/energy point of view, the further up the food chain you go, the more energy is lost at each stage and the harder it becomes to get enough energy, which reduces your potential to grow your population.

This is why there will always be significantly more buffalo than bears.

In terms of efficient calories, it is best to be a plant and take your energy directly from the sun.

But since animals cannot do that, being a herbivore is the next most efficient way, with the minimum possible energy lost.

Digestion requires huge energy.

It is diverted away from all other bodily systems, making us feel sleepy.

No worries, happy to help.

Its kind of like being hijacked.

Adrenaline is a hormone with incredible "go go go" power, so let's pretend your brain is a car.

When you are drunk, the driver (you) is just slowly cruising along, swaying around, minding their own business, but oh no! A truck is heading straight for you.

Suddenly you passenger, adrenaline, sees you don't know what the fuck you are doing, so they yell in your face to step on the gas, grab the wheel from you and swerv you out of the way to safety.

After the danger has passed and you both quit shitting your pants from fear, you both chill out again and you can resume swaying slowly down the road like the drunk monkey you are.

Make sense?

The parts of the brain effected by adrenaline are parts related to immediate survival.

It is like giving a surge to your drunk brain so that you can temporarily not die, but it doesn't rid you of your drunkeness at all, it just gives you a chance to fight off your attacker, or whatever is happening.

Yes, I can tell you truly get it. I am happy to have met a fellow traveller of pointless journeys.

They are capillaries (like small veins) which are cushions that help with controlling your poo.

They can become swollen, which is a disease, also called Hemorrhoids after the structures in your anus.

The swollen hemorrhoids can be either insane or outside of your butthole.

When they are internal, you can get bright red blood in your poo, but no pain.

When they are external pain and swelling is noticeable around your butthole. This can make sitting down uncomfortable to painful. External ones don't usually bleed, but can. When they heal, they can leave behind skin tags.

Constipation, sitting on the toilet too long, and diarrhoea are common causes. Also pressure in the abdomen causes them, so they are very common in pregnant women.

Normally no treatment is needed and they will clear up in a few days. Drinking plenty of water and eating plenty of fibre will be useful. In extreme cases, medications and even surgery may be necessary to resolve them.

Surface area, the area available for your stomach enzymes to attack to break molecules down, increases with the smaller a particle is.

So the more you masticate (chew), the smaller the pieces, the greater the surface area, and the easier time the enzymes have digesting the food.

It was accidental evolution. Millions of different fruits evolved with different tastes, but some happened to be sweet.

The sweet ones were able to outcompete the non-sweet fruits because more animals ate the sweet ones, spreading their seeds.

This gave them a huge advantage in reproduction and eventually they became the more dominant fruit tree, and the fact that animals enjoyed them meant they would not die out.

When object A acts on object B, object B also acts on object A, but on the opposite way.

For example, picture a cat sitting on the floor.

The earth is pulling the cat down through gravity, but the cat is also pulling the earth up through its gravity.

These forces are opposite but equal to each other.

They are not winds in an earth bound sense. They are charged particles released by stars, and are plasma made of electrons. They are projected outwards by reactions in the star, and essentially vibrate their way through space. They do not "blow" like air molecules moving on earth.

It is inspiring to know there are other people out there on pointless journeys like myself. Thank you for this.

Not sight-seeing, but not commuting to work either. I mean literally just riding the bus because I enjoy riding on a bus.

Ride buses to the end of the line and back just for fun.