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• What is the rate of blood flow?

  Volume of blood divided by the number of minutes
• What do veins do?

  -Capillaries join up to form veins

  -The blood is at low pressure in the veins so the walls aren't as thick as an artery's

  -They have the biggest lumen to help the blood flow despite the lower pressure

  -They have valves to help keep the blood flowing in the right direction
• What do capillaries do?

  -Arteries branch into capillaries

  -They are really tiny - too small to see

  -They carry blood really close to every cell in the body to exchange substances with them

  -They have permeable walls - substances can diffuse in and out

  -They supply food and oxygen and take away waste like carbon dioxide

  -Their walls are one cell thick - this increases the rate of diffusion
• What do arteries do?

  -They carry blood under high amounts of pressure

  -Their walls are strong, elastic and thick

  -They have the smallest lumens

  -They contain thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back
• What are the three types of blood vessels?

  Arteries, capillaries and veins
• How does the heart pump blood around the body?

  Blood flows into the two atria from the vena cava (right atrium) and the pulmonary vein (left atrium). The atria contract, pushing the blood into the ventricles through valves. The ventricles contract and force the blood through more valves into the pulmonary artery (right ventricle) and the aorta (left ventricle) and out of the heart
• What happens on the left side of the heart?

  Oxygenated blood flows in through the pulmonary vein and into the left atrium. The atrium contracts and pushes the blood through the bicuspid valve, into the left ventricle. The valve closes and the ventricle contracts to push the blood through the left semi-lunar valve. The valve will then close and the blood flows out of the aorta to all the cells in the body for gas exchange
• What happens on the right side of the heart?

  Deoxygenated blood flows in through the vena cava and into the right atrium. The atrium contracts and pushes the blood through the tricuspid valve, into the right ventricle. The valve closes and the ventricle contracts, to push the blood through the right semi-lunar valve. The valve will close and the blood is pushed out of the pulmonary artery to go up to the lungs
• What makes up the circulatory system?

  The heart, blood vessels and blood
• What happens when blood reaches body cells?

  Oxygen is released from the red blood cells and diffuses into the body cells. At the same time, carbon dioxide diffuses out of the body cells and into the blood. It's then carried back to the heart
• What surrounds the alveoli?

  Lots of blood capillaries
• What happens in an alveolus?

  Gas exchange. The blood passing next to the alveoli contains lots of carbon dioxide and little oxygen. The oxygen diffuses out of the alveoli (high concentration) and into the blood (low concentration) and the carbon dioxide diffuses out of the blood (high concentration) and into the alveoli (low concentration) to be breathed out.
• What are the small bags at the end of bronchioles called?

  Alveoli
• What do the bronchi split off into?

  Bronchioles
• What tubes join onto the trachea?

  The bronchi
• What goes down the trachea?

  The air that you breathe in
• What protects the lungs?

  The ribcage
• What are the lungs surrounded by?

  Pleural membrane
• Where are the lungs?

  The thorax
• What does the liver do?

  It produces bile which neutralises stomach acid and emulsifies fat
• What does the gall bladder do?

  It stores bile before it's released into the small intestine
• What does the large intestine do?

  It's where excess water is absorbed from the food
• What does the rectum do?

  It stores faeces
• What does the small intestine do?

  It contains protease, amylase and lipase to complete digestion. Digested food is absorbed into the blood here
• What does the pancreas do?

  It produces amylase, protease and lipase then releases them into the small intestine
• What does the stomach do?

  -It pummels the food with its muscular walls

  -It produces pepsin

  -It produces hydrochloric acid to kill bacteria and give the right pH for pepsin to work
• What do the salivary glands do?

  They produce amylase in the saliva
• Name three substances and what they test for

  Benedict's Test - testing for sugars - goes red

  Iodine solution - tests for starch - goes blue-black

  Biuret Test - tests for proteins - goes purple
• Where are lipases found?

  They're made in the pancreas and work in the small intestine
• Where are proteases found?

  They're made in the stomach (called pepsin here) and the pancreas and found in the small intestine
• What do proteases break down?

  Proteins into amino acids
• What do carbohydrases break down?

  Carbohydrates into simple sugars
• What does amylase break down?

  It catalyses the breakdown of starch to maltose
• What is the optimum pH for enzymes?

  The pH level that they are most active at. E.g., pepsin has an optimum pH of 2
• What is the name of the substance when the enzyme's active site has turned the substrate into two products?

  Enzyme product complex
• What is the name of the substance when a substrate fits into the enzyme's active site?

  Enzyme substrate complex
• What are the tissues in the stomach and what do they do?

  Muscular tissue - moves the stomach wall to churn up the food

  Glandular tissue - makes digestive juices to digest food

  Epithelial tissue - covers the inside and outside of the stomach
• What are organs?

  Organs are groups of tissues that work together to perform certain functions
• What does bile do?

  It emulsifies fats into smaller, more soluble pieces which gives the fat a bigger surface area for lipase to work on. It also neutralises the stomach acid to make the conditions alkaline, therefore the enzymes can work in the small intestine
• Where is bile made and stored?

  It's made in the liver and stored in the gall bladder