You probably don’t understand shiok. It’s a Singlish word we use to express how awesome something is.
Kids are fond of McDonald’s, as I’m sure you can relate.
In our Science curriculum, we focus primarily on these five systems: Muscular, Circulatory, Digestive, Respiratory and Skeletal. Students learn about the reproductive system too, but it is taught at a different timing than these systems. Probably because we cover reproduction of plants and animals together.
Here are my painstakingly curated notes on these systems. Meant for elementary school students, but maybe you will learn something new to you.
Digestive system
- The oesophagus in our throat is for food and leads to our stomach.
- If we talk while we eat, we may choke on our food. This is because the small balls of food may accidentally enter our windpipe, which is very near our gullet.
- Touch the centre of your body just above your waist. This is where your stomach is.
- Find your belly button. Your small intestine lies under it.
- The upper part of your large intestine is just below your waist. Don’t use ‘big intestine’
- Stomach acid is so strong that our bodies have to regularly add a new layer to the surface of the stomach. If our body didn’t do this, the acid would start to burn holes in the stomach lining, and would eventually burn right through the stomach wall.
- If the digestive system of an adult were to be stretched out, it would be about 9m long. This is almost four times the width of a bus.
- Digested food is transported via the hepatic portal vein to the liver.
- Water and minerals are absorbed at the large intestine, not water only.
- The large intestine had absorbed too much water from the undigested food. This lack of water caused the stools to be hard and difficult to pass out.
- The rectum is part of the large intestine, not separate.
- Diarrhoea is the passing of loose or liquid stools. It can caused by microorganisms that irritate the lining of the large intestine, resulting in an abnormally large quantity of water in our faeces.
- An average adult carries about 1.5kg of good bacteria in their intestines.
Circulatory system
- Press the blood vessels to feel your pulse
- The heart needs to pump blood all the time to circulate oxygenated blood to all parts of the body and to remove waste from the body.
- A heart attack is also called a cardiac attack. The heart stops because the blood supply to a coronary artery has stopped. This means there is no blood getting to part of the cardiac (heart) muscle. The heart muscle can’t function without blood, and stops.
- When the heart stops, CPR keeps oxygenated blood flowing to the brain until emergency services arrive.
- When we exercise, our heart rate increases to pump blood more quickly around our body. More oxygen and digested food transported in the blood will be converted to more energy needed for exercise during respiration. Wastes like carbon dioxide will also be transported in the blood to be removed more quickly.
- Our heart also needs to pump faster to send more oxygen-rich blood from the lungs to the muscles. Lactic acid may build up in the muscles if the muscle cells do not receive enough oxygen, causing fatigue. To remove this lactic acid, we need to breathe harder to obtain more oxygen.
- When we exercise, our breathing rate increases to take in more oxygen for respiration and to remove wastes like carbon dioxide more quickly. More oxygen, together with digested food, would be converted to produce more energy needed for us when running.
- Breathing rate increases to take in more oxygen and the heart rate increases to pump blood faster to all parts of the body.
- During breathing, the diaphragm contracts and relaxes, not contracts and expands
- Red blood cells don’t contain a nucleus to allow them to carry and transport more oxygen around the body.
- In general, the larger an animal, the slower its heart rate.
- If you put all the blood vessels together, end to end, they would reach twice around the world.
Skeletal system
- Babies are born with about 300 bones, but adult skeletons have 206 bones. As babies grow, their bones lengthen and change shape. Some bones also fuse together with others to become one. For example, five bones in the thigh fuse to become the femur (found in the upper leg).
Respiratory System
- Respiration is the process by which oxygen is used to act on digested food to release energy.
- Air enters the nose.
- There are two nostrils in the nose. We breathe in air through them. There are short hairs in our nasal cavity. They help to keep out dust. The mucus in the nasal cavity makes the air warm and damp before it enters the lungs.
- The trachea in our throat is for breathing and leads to our lungs.
- When we drink water, it might accidentally enter the windpipe and enter the lungs and make us choke.
- The air then passes through the throat to the windpipe.
- Tiny hairs are found in the lining of the windpipe. They are coated with mucus which traps germs, dirt and other foreign particles in the air that is breathed in. They help to sweep the particles up to the nose or mouth, which are then expelled through coughing, sneezing or swallowing.
- From the windpipe, air enters into two tubes. One tube is joined to the right lung and the other is joined to the left lung.
- Lungs contain many small air sacs which allow the exchange of gases. The exchange of carbon dioxide for oxygen happens in the layer of water which lines the air sacs in our lungs.
- Our lungs are under our ribs, above our stomach, below our throat. Our left lung is smaller than our right lung to make room for our heart. Our left lung has only two sections: the superior lobe and the inferior lobe.
- The air sacs increase the surface area in contact with the blood vessels to facilitate the exchange of gases.
- Lungs have a greater area and more air sacs to absorb more oxygen and remove more carbon dioxide from the blood quickly so more energy can be released from the body.
- When air is blown through the plastic tube, it will cause balloons to inflate and the plastic sheet to move downwards. The balloons represent our lungs. When we breathe in, the lungs expand. The plastic sheet represents the diaphragm which moves downwards to make room for expansion of the lungs when we breathe in.
- Function: enable the exchange of gases with the surroundings
- In an air conditioner, the filter is akin to the nose as it removes dirt from the air outside the room. There are many small folds in the filter because this increases of the exposed surface area for it to trap more dirt in the surrounding air and keep the air clean.
- A cough is a rapid explosion of air out of your lungs. Your body uses a cough reflex to make sure nothing but air gets into your lungs. If you accidentally breathe in something else, like dust or the mucus that comes with a cold, you will cough to push it straight back out again.
Random
- You are as wide as you are tall.