“If I do a headstand will my brain get too much blood?” asks Susan (8)

Susan , I asked my friends about your question and this was their thoughts.

Thanks team, some interesting thoughts. Firstly let’s confirm that it is the heart that pumps the blood around our bodies. In a normal situation the heart is strong enough to pump the blood up to our head, so it might find it easier to pump the blood to our head when we are upside down. Any idea why? Think of gravity.

When you are doing a headstand the heart will not need to fight gravity to get the blood to your head, so it might find it a bit easier. It does however still need to get the blood to your feet (which are now above your heart) but it is strong enough to do this.

There might be some visible signs in the way the blood circulation changes. If blood has a little difficulty getting to the feet they might go a little pale. If the blood does not leave the head as quickly as usual, the face might go a little red. You might also get a change in the pulse rate if the heart has to work harder. These can all be tested with a healthy volunteer.

(edited 19/01/2017)

Tippy (5) asked -“Both my parents have brown eyes how come mine are blue?”

Tippy. Many thanks for your question. I shall not ask why you have asked it! It was an interesting question so I asked my friends to comment on it here, are their thoughts.

 

Many thanks team.

Tippy, one of my team mentioned the word ‘genetics’ . Genetics is all about people investigating how we become who we are, Wow. We have all come from a mum and dad (parents) and because of this we inherit (get) things from our parents which make us, us. I , for instance , think that I get my hair colour from my parents and the size of my feet (my parents had my hair colour and small feet). My brother inherited different things, height and eye colour.

Eye colour is something that like height is not inherited directly from parents or an individual parent. It could be inherited from your grandparents, AND even then the chance of linking it directly to a parent or grandparent is open to chance.

Tippy. I hope that your parents can ‘try’ to relay this answer to you. You could also carry out a little investigation of your own, good scientific practice, try making a list of people in your extended family and the colour of their eyes. You could also look at the eye colour of your friends, to find out what is the most common eye colour?

Malina (13) asks – If blood has iron in it , is it magnetic?

magnetic-blood

Apologies accepted. Yes Malina, it was an interesting question.

What I need to ask you, is do you know about electrons? If you do then you will know that elements like iron are made up of atoms. Each atom of iron has a nucleus of protons (positively charged particles, 26) and neutrons (uncharged particles, 30) and surrounding the nucleus are the electrons (26 negatively charged  particles). It’s the way the electrons behave that makes thing interesting. In normal elements like carbon, silicon and sulphur all the electrons are ‘tied’ to the nucleus. They cannot leave the nucleus. In the metallic elements some of the electrons are ‘tied’ but the others are free to move away from the nucleus. This is why metals can conduct electricity (which is the movement of electrons along a metallic wire). It is the free electrons which dictate whether an element is magnetic or not.

Still with me? Hope so – if not you could ask another question.

The electrons themselves are like small magnets and some of them ‘pair up’ as magnets can do. For some elements who have an odd number of free electrons you end up with a lot of free electrons for the others you get complete pairing. See below  for a pairing image.

magnetic-electrons

A metal is classified as ferromagnetic (very magnetic) if it has a lot of unpaired free electrons. iron and nickel are two examples.

When the iron atom begins to combine with other elements to form your hemoglobin there is further pairing of electrons between the iron atoms and the things it is combining with so it loses it’s magnetism.

That was a lot to understand. Hope you have managed.

 

“Where do dogs come from?” – asks Sidrah

evolution2

Thanks for the suggestion. Lets see if I can explain it?

The dictionary definition of evolution is: It is a process of formation or growth. An aeroplane evolves from a collection of its parts. A picture evolves from the actions of a painter. A plant evolves from a seed.

In the biological sciences it has a special meaning as it studies the how and why living organisms change over time.

Living things pass on their traits (characteristics) from one generation to the next. All of us inherit a set of genetic blueprints from our parents. But those blueprints are never copied exactly from one generation to the next. Little changes occur with each passing generation and those little changes can become very big changes over a long period of time. These changes can reshape living things, and biological evolution has then taken place. Look at the video below it shows the changes that resulted in who you are now.

Dogs, like humans were very different millions of years ago.

Have more questions …. then ask another question.

Ciera (7) How did people first appear on Earth?

Ciera, many thanks for the question. I have decided to try to answer your question myself rather than ask my friends. They can be confusing sometimes.

I think that the best way of describing how people first appeared on the Earth is that it happened very, very slowly. We would probably not be able to recognise the first people as people like you and me. It is likely that they had a lot more hair than we have. Maybe because they lived in a much colder part of the world and they would not have houses to live in. They would however be able to talk to each other, in their own language, they would walk in an upright way, not like chimpanzees, They would be able to hunt for food and probably live in groups.

Slowly, ever so slowly they would change (evolve) and become more like us.

It is thought that the first humans appeared on Earth about 150,000 years ago.

If you have another question linked to this answer please………

Miles (age 7) asks “How come when you pull your hair out it doesn’t bleed even though it’s inside your body?”

hair follicle copy

Miles, my friends drifted of the question slightly so I would like to add a few words. Firstly no experiment this time. We cannot have you tearing your hair out looking for bloodstains. You can see from the diagram that the hair is attached to the blood system so it is very likely that removing it would create a very, very small bleed. This would most likely be contained within the follicle (the follicle is the gland/cavity in which the hair grows) so you will not be able to see it.

Hair also goes through three stages of development. In the first stage it is growing quite fast and this can last for up to 5 years. In the second phase the hair growth is transitionary. It will only last for a couple of months but during that time it loses its blood supply, so pulling it out will not cause bleeding. In the third phase the hair starts to fall out on it’s own. As you are seven years old it is likely that you have all of these phases going on at the same time.

Many thanks Miles – a fascinating question.

Marcus (11) asks – “How does our brain control our body”

Marcus. Many thanks for your question. I must admit that I am happiest with questions relating to the physical world rather that the biological world. But like a good scientist I was curious so I asked my friends to tell me about how the brain might control the body. For once they came up with some answers.

brain1

This is certainly interesting. for the brain and different parts of the body to contact each other they use nerves (bit like wires), they also use electricity – but a different type of electricity to what we usually meet The nerves use positively charged particles to send the messages, we in the real world, use negatively charged particles.

I found out that there are two types of circuits. Some are linked to things that the brain has put on automatic and some are linked to response/reply circuits. These are the autonomic nervous system and the others are the ones which your brain can control are called the somatic nervous system. Can you draw up a list of the autonomic  functions that you brain controls. How many items do you come up with. Want to let me know click on the Reply button below or leave another question. Thanks for the question.

Chiara (10) asks “Where does sweat come from’

Chiara, many thanks for your question. Below are some interesting comments that my friends came up with.

sweat

Their answers were quite informative, but, as usual they presented me with more questions.

Sweat helps the body cool down by evaporating. To help it change from a liquid into a gas it takes some heat from your body so you feel cooler. Try doing some exercise until you get a small amount of sweat and then stop and then in your mind ‘feel’ your skin. Slowly it will lose the hotness and also lose the sweat.

Sweat is mainly water. You could lose a lot of water when you are exercising a lot so you will need to replace it. Sweat also contains some other chemicals. Lick your arm after doing the exercise and cooling down. What do you taste? I will let you find out. You will have to make it a fair test. How will you do that.

There is also another question – did all parts of your body sweat?  Dogs for example only have a small number of sweat glands (in their paws)  so they cool down by panting which is linked to evaporation on other parts of the body. (revised 7/8/16)

Thanks again for the question?

Balqisa asks “Do adults have have a different eye sight to kids”

An excellent question.

Balqisa asked a question on how does the eye work and what is it made of. I have tried to make the image below to show you how it works. The eye is complex and is made of lots of different things. For example it has it’s own sets of muscles which can stretch the lens and allow your eye to focus. It is filled with a special fluid that allows light to pass through it and gives the whole eyeball a very ‘squashy’ feeling. It is also connected to the brain by something which we call the optic nerve.

The eye
How is the adult eye different from this?. Not very much, BUT the older person’s eye does change. Early into adulthood the liquid in the lens begins to solidify, this causes a lack of focus on objects close to you. As we get even older the muscles that control pupil size get weaker, these control our reaction to light, so glare is to be avoided. We also have less tears and more importantly our peripheral vision decreases.
Thank you Balqisa for making me feel old.