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Organ Systems What is the human body? The human body is made up of several organ systems that all work together as a unit to make sure the body keeps functioning. There are eleven major organ systems in the body, each of which plays a different role in helping the body work. The 11 body systems 1. Nervous system 7. Muscular system 2. Integumentary system 8. Circulatory system 3. Respiratory system 9. Endocrine system 4. Digestive system 10. Reproductive system 5. Excretory system 11. Lymphatic (immune) system 6. Skeletal system Nervous System The nervous system is the control centre of the human body. It is made up of the brain, spinal cord, and nerves. It receives and interprets stimuli and transmits impulses to organs. Your brain uses the information it receives to coordinate all of your actions and reactions. Integumentary system This system consists of the skin, hair, nails, and sweat glands. Its main function is to act as a barrier to protect the body from the outside world. It also functions to retain body fluids, protect against disease, eliminate waste products, and regulate body temperature. Excretory System The Excretory system is responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process, such as sweat glands, the liver, the lungs and the kidney system. Skeletal System The skeletal system provides the shape and form for our bodies in addition to supporting and protecting our bodies, allowing bodily movement, producing blood cells, and storing minerals. This system consists of bones, cartilage, and joints. Muscular System This system is made up of muscle tissue that helps move the body and move materials through the body. Quite simply, muscles move you. Muscles are bundles of cells and fibers that work in a simple way: they tighten up and relax. Endocrine System This system is made up of a collection of glands, including the pituitary and thyroid glands, as well as the ovaries and testes. It regulates, coordinates, and controls a number of body functions by secreting chemicals into the bloodstream. These secretions help control moods, growth and development, and metabolism. Reproductive System The human reproductive system ensures that humans are able to reproduce and survive as a species. It is made up of organs such as the uterus, penis, ovaries, and testes. Lymphatic (Immune) System The immune system helps our body fight infection. White blood cells, lymphocytes and antibodies form part of the defence We will be learning about these particular systems in detail… What were cells again? Cells make up all living things! REMEMBER… Cells Tissue Organ Organ System What do humans need to survive? There are two simple things that all living things need to survive, including humans. 1. Oxygen 2. Nutrients How do we get these into our bodies? Which systems are important to ensure we get these things? How do we get our nutrients? The digestive system breaks down food and provides nutrients to every cell in the body. The digestive tract starts at the mouth and ends at the anus. What organs are part of the digestive system? Using your textbook (Chapter 4) , label the organs that belong to the digestive system. Glue the diagram into your book. You need to be able to label any digestive system diagram I give you so start becoming familiar with the shapes and sizes of the organs. Were you right? A. B. C. D. E. F. G. H. Mouth (salivary glands) Oesophagus Stomach Pancreas Small Intestine Large Intestine Liver Gall Bladder From sandwich to sewage… What exactly happens when we eat something? Food goes into our mouths of course but what happens in there? What things inside your mouth assist with digestion of the food? What type of digestion is this? So, did you find out the different types of teeth you have in your mouths? Mechanical vs Chemical Digestion Mechanical: when food is physically broken down (like chewing or organ movement) Chemical: food broken down by chemicals like saliva. There are some special things in your saliva called ENZYMES. Enzymes will break down food into different components so your body can absorb the nutrients faster. Without enzymes in your body, an average dinner meal can take many years to fully digest! Today’s Practical Does temperature affect enzymes? Refer to Practical sheet given to you by Ms Wasif Can you eat upside down? What was your answer? OF COURSE YOU CAN! HOW AND WHY? What makes your food go down your oesophagus? PERISTALISIS Peristalsis is a wave-like movement (by muscular contractions) that pushes food in one direction down into your stomach. Watch video Food just doesn’t ‘slip’ into your stomach… At the junction of the oesophagus and stomach, there is a ring-like muscle, called the lower oesophageal sphincter, closing the passage between the oesophagus and stomach. As food approaches the closed sphincter, the sphincter relaxes and allows the food to pass through to the stomach. Oesophagus After biting and chewing… Oesophagus In your stomach, you have an acid called hydrochloric acid along with enzymes that continue to chemically digest food. Your stomach also acts like a punch bag that will mechanically break down any food that has not been properly chewed in the mouth. Digestion in your stomach involves both chemical and mechanical digestion. Let’s demonstrate…. From the stomach to the small intestine (6m worth!) Food moves through it by peristalsis. The small intestine makes enzymes that complete the digestion process. It is in the small intestine that nutrients (like proteins, carbohydrates, fats etc) from now almost totally digested food are absorbed into your bloodstream. (Blood then carries the nutrients to all of the cells of your body). Question time! 1. What is peristalsis? 2. What will sometimes slow food down from entering your stomach all at once? 3. Describe the chemical digestion that continues in your stomach. 4. Describe the mechanical digestion that takes place in your stomach. 5. Where does the food go after your stomach and why is this organ so important? Homework Question What structure in the small intestine allows for nutrients to absorbed through the walls? Find out as much as you can about it! Let’s re-cap… Refer to labelled diagram. Small intestine Most nutrients are absorbed into your blood stream when they get to the last section of your small intestine. The walls of this part of your intestine are lined with finger-like projections called villi. ‘Fingers’ of absorption The shape of villi increases the surface area through which nutrients can pass through them. Nutrients are then transported to other parts of your body. Design your own experiment Aim: Design your own experiment that will test surface area vs. absorbency. Parameters: materials (able to get from a hardware shop or supermarket) water to test for absorbency. FIRST: find out what exactly is surface area and what materials differ in this property (flat paper towel vs. wavy paper towel) SECOND: what method will you put together to test for absorbency using these materials. Finally… the LARGE intestine Using your textbook, very quickly find out what is so unique about the large intestine. Is it really larger than the small intestine and why is named the way it is? What happens in the large intestine and what happens to the food after it has passed through this organ? What are the similarities between the small and large intestine? Small Intestine Large Intestine Which organs haven’t we studied? That’s right! That’s because so far, we have just learnt about the digestive TRACT! The digestive tract is the pathway in which food goes into your mouth and all the way to your anus. Mouth Oesophagus Stomach Small Intestine Large Intestine Rectum Anus Assistants TO the digestive TRACT PANCREAS This is where pancreatic juices are made. It neutralises the stomach acid. The enzymes used to break down food in the stomach are created in the pancreas. Assistants TO the digestive TRACT LIVER: It is in fact the LARGEST internal organ in the human body. It helps to break down fats into small droplets in the stomach by creating a substance called bile. It also controls blood sugar, destroys poisons and stores some vitamins and iron. Assistants TO the digestive TRACT GALL BLADDER Bile made in the liver is stored here and ready to be released when required by the stomach. So, what does the digestive system involve? All the organs we have spoken about over the past few weeks make up the digestive system. This is different to the digestive tract. Can you explain how the digestive system is different to the digestive tract? So, after all this… A short video. Looking at a real digestive system! An assignment! Revise for a short test on the Digestive System.