Summary of the B7 unit.

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Bones, joints and injuries

Function of Skeleton: To Protect, Support and enable Movement. 

Ligaments= elastic-like tissues that connect bones together      Tendons=connect muscle to bone or muscle to muscle. 

Muscles work in antagonistic pairs- as one contracts the other relaxes. Joints are covered by a layer of cartilage which prevents the bones from rubbing together. Synovial fluid is found between bones and allows them to move freely and cushions the joint. 

A way of monitering progress during training is the pulse rate or BMI (Body mass/height)

Injuries. Symtoms in sprains/dislocations: Swelling(due to fluid build up), pain, redness and warmth(due to increaded blood flow to injured area.)

Treatment: RICE- Rest, Ice, Compression, Elevation. 

A physiotherapist can help people after they have injured muscles or bones. They do this by strengthening the weak muscles. 

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Heart and Blood

The Heart- the heart is a double pump.

The Blood-Blood is made up of 4 things. 

  • Red blood cells. They carry oxygen around the body to the working muscles.
  • White blood cells. They fight infection and defend the body against infection. 
  • Platelets. They clot at injury sites to prevent blood loss. 
  • Plasma. It transports nutrients around the body as well as waste, hormones and antibodies. 

Blood Vessels- There are 3 types of blood vessel

  • Arteries. These transport blood around the body and have thick walls as they are working under high pressure.
  • Veins. These take blood back to the heart, they have thinner walls as it is not such a high pressure and have valves to prevent backflow. 
  • Capilliares. These are only one cell thick for easy diffusion. 

The bloodflow in capilliary beds is slow so plasma leaves and becomes tissue fluid. This allows the nutrients to diffuse into the tissue cells. Then it returns to the capilliary bed.

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The body keeps our temp constant. If its too hot, you sweat and go red. This is caused by Vasodialation. This is when the blood vessels dilate and cause a greater blood flow near the surface so heat escapes. If its too cold, you go pale and shiver. This is caused by Vasoconscriction as the bloodvessels contract to come away for the surface so less heat is lost. 

Our body keeps our sugar levels constant. If the sugar level rises, the pancreas releases insulin which makes cells take in glucose and store it as glucagon. If the sugar level falls, the cells turn their stored glucagon into glucose and release into the blood. 

Type 1 Diabetes: when pancreas stops producing enough insulin. This can be controlled insulin injections. Often genetic.

Type 2 Diabetes: caused by lifestyle and is when body stops responding to insulin. Can be controlled by diet and exercise. 

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A Closed Loop Ecosystem- a perfect, stable, self sustaining ecosystem. There is no waste as one organism inputs their waste. The recyling of waste products is how they work. 

Human impact upsets a closed loop ecosystem as they use fertilizers, burn fossil fuels and cause waste. The input and output arent balanced so it isnt closed. They also cause deforestation(causing soil erosion, build up of CO2 and weather change) and overfish(causing loss of biodiversity and messed up food chains). 

Eutrophication-fertilizers get into rivers/lakes and cause algae to grow a lot. As algae dies the bacteria which eat the decaying matter multiply and use up oxygen. The low oxygen levels causes all organisms to die and life cannot exist there. 

Bioaccumulation in Food Chains- small amounts of waste get into the food chain. animals eat the first organism and as they eat a lot of them,the amount of chemicals in them is higher. As you go up the food chain, the amount of chemicals in individuals is at a harmful level. 

Sustainable Development- the materials must be replaced at the same rate they are used. This can happen by planting new forests or introducing quotas(restrictions) on fishing. 

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New Technologies

A fermenter can be used to grow microorganisms, proteins and enzymes. Bacteria are great for using in genetic and industy as they are simple, easy to change and maintain, they reproduce fast and are easy to get hold of. 

You can gentically modify a bacteria to make a particualr protein. You cut open the plasmid of a bacterium and insert the desired gene. Then you put the modifyed gene back into the bacterium and let it multiply and express the protein you want. 

You can use genetic modification to:

  • produce healthier or resistant to pests/herbicides/extreme weather, etc..
  • some food products
  • medicines
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New Technologies Part 2

Nanotechnology- the use of technology created at the size of atoms. You can use this in:

  • Building sensors to detect if there are harmful substances in food in packaging.
  • To make packaging which will increase shelf life. 

Stem cells- cells that are completely unspecialised and can become any other type of cell. They can be found in embryos, umbilical cords and bone marrow. Stem cells is used for:

  • Bone marrow transplants, espiecially in leukaemia cases.
  • Treating spinal injuries, by growing back neurons.
  • To grow new tissues, e.g. skin after burn wounds. 

Biomedical Engineering- using engineering structures that have been sized down for use in the body. It can be used for:

  • Pacemakers, electrical devices to help heart pump.
  • Heart Valves, to keep bloodflow in the heart efficient if natural valves dont work. 
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This helped alot, thank you 

Joseph101 - Team GR


Very good, just a little thing, when talking about vasoconstriction I think you forgot to mention that shivering increases respiration in muscle cells and the by product of this is heat.



Thanks :)

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