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Body Systems
Health
| Term | Definition |
|---|---|
| Building blocks of the body: | cells --> organs --> system |
| Cells | Cells are the smallest parts of the human body. Different cells have different shapes and different jobs. Cells need food and oxygen to help them grow and work. |
| Examples of cells | Nerve, skin, brain |
| Organs | An organ is a group of cells that work together. There are many different organs working in the body. |
| Systems | A body systems a group of organs that work together to do the same job. Each body system does a different job. |
| Examples of systems | Digestive, circulatory, nervous, muscular |
| The nervous system | Is the control and communication system of the body. |
| Brain | The brain is the control center of the body. Different parts of the brain do different jobs. |
| Neurons (nerve cells) | Cells which carry electrical messages to all body parts. Some nerves carry messages to the brain. |
| Spinal cord | A thick bundle of neurons that runs along the spine. (Down the neck & back bones) |
| Reflex | A quick movement that happens before the brain has time to think. |
| The circulatory system | Allows the body to move blood to tissues. |
| Heart | The muscle that pumps. Pushes blood through the blood vessels. |
| Blood vessels | Arteries & veins |
| Arteries | Carry blood away from the heart |
| Veins | Return blood to the heart |
| Blood pressure | Force of blood pushing against the vessel walls. Too much pressure can be very dangerous. |
| Pulse | Is the speed the heart beats. Exercise, stress and some drugs can make the heart beat faster. |
| Parts of blood | Plasma, red blood cells, white blood cells |
| Plasma | Liquid part of the blood |
| Red blood cells | Carry oxygen to body cells |
| White blood cells | Destroy disease germs |
| The respiratory system | Enables you to breathe air. All body cells need oxygen from the air you breathe. |
| Diaphragm muscle | Controls breathing in and out. |
| When the diaphragm pulls down you breathe in | Inhale |
| When the diaphragm moves up squeezing the lungs you breathe out | Exhale |
| Trachea | Air flows from the mouth and nose down this tube in the neck. |
| Branchial tubes | Two tubes inside the lungs. |
| Alveoli (air sacs) | Tiny air sacs covered by capillaries. Where oxygen enter the blood and carbon dioxide is removed. |
| The skeletal system | Is the body system consisting of bones and tissue. There are 206 bones in the skeletal system. |
| 3 things the skeletal system does: | 1. It's your body's framework. 2. Protects soft inner parts. 3. Allows you to stand and move. |
| Joint | A place where 2 bones come together. |
| Ligaments | Tissues which connect bones holding them together. |
| The muscular system | Made up of all muscles in your body. They allow us to move, pump blood, breath and move food. |
| Voluntary (skeletal) muscles | Can control |
| Involuntary (smooth) muscles | Can NOT control |
| Voluntary muscles (examples) | Fingers, legs, arms |
| Involuntary muscles (examples) | Heart, stomach |
| The digestive system | Controls the process by which your body breaks down food into nutrients |
| "Nutrient" | Is a substance in food that helps body cells and gives you energy. |
| Esophagus | The tube carrying food to the stomach. |
| Small intestine | Breaks down food and absorbs nutrients. |
| Stomach | Releases digestive juices and mixes food. |
| Large intestine (colon) | Absorbs water and holds solid waste. |
| The excretory system | Gets rid of waste from the body. |
| Kidneys (2 organs) | Filter blood and remove water & waste. |
| Urine | Liquid waste that is stored in the bladder. |
| To produce movement at a joint.. | One muscle must contract while the opposite muscle relaxes. |
| 2 things that can increase your pulse rate? | Exercise & stress |