Blood Pressure 1 of 22 Boardworks Ltd 2011

Transcription

1 Blood Pressure 1 of 22 Boardworks Ltd 2011

2 2 of 22 Boardworks Ltd 2011

3 Heart rate 3 of 22 Boardworks Ltd 2011 Heart rate is the rate at which your heart beats. It can be measured by taking a pulse. A pulse is caused by the push of the blood through the arteries under the skin. Pulse, or heart rate, is measured in beats per minute (bpm). This can be found by putting your fingers over an artery and counting the number of pushes in a minute. Machines like pulse oximeters can also be used to monitor and measure the pulse rate.

4 A resting heart rate 4 of 22 Boardworks Ltd 2011

5 Blood in the arteries 5 of 22 Boardworks Ltd 2011 The heart is a pump and pushes blood all around your body. The blood leaves the heart through blood vessels called arteries. arteries Arteries have thick elastic walls because the blood in them is under high pressure. High pressure is needed so that the blood reaches all the parts of the body.

6 What is blood pressure? 6 of 22 Boardworks Ltd 2011 Blood pressure is a measure of the pressure exerted by the blood against the walls of the artery. Blood pressure is measured as two numbers, e.g. 120/80 The numbers show pressure readings in mm of mercury (mmhg). What do these numbers mean?

7 Systolic and diastolic 7 of 22 Boardworks Ltd 2011 Blood pressure one-twenty over eighty. 120/80 The big number ( 120 ) is the systolic pressure. This is the blood pressure during the push of a heartbeat. The small number ( 80 ) is the diastolic pressure. This is the blood pressure in-between heartbeats.

8 Pressure during a heartbeat 8 of 22 Boardworks Ltd 2011

9 Blood pressure 9 of 22 Boardworks Ltd 2011

10 Collecting data 10 of 22 Boardworks Ltd 2011 When researching a topic, like blood pressure, there are many different ways of gathering data (information). Sources of data are either: Primary sources collecting data yourself by making measurements, conducting a survey or doing an experiment. Secondary sources using data that someone else has collected. You need to be careful when using secondary data. Only take data from sources you trust, such as a text book or websites belonging to large trustworthy organisations.

11 Primary or secondary? 11 of 22 Boardworks Ltd 2011

12 12 of 22 Boardworks Ltd 2011

13 How does blood pressure affect health? 13 of 22 Boardworks Ltd 2011 High blood pressure can make blood vessels more likely to burst, and can cause strokes, brain damage and kidney damage. It significantly increases the risk of heart disease. Low blood pressure can cause dizziness, fainting and poor circulation. The older you get, the higher your blood pressure naturally becomes. Age Systolic Diastolic Kevin is 38 years old and his blood pressure is 180/90. How would you describe his blood pressure?

14 What affects blood pressure? 14 of 22 Boardworks Ltd 2011 There are many factors that can increase a person s blood pressure, including: increasing age stress being overweight smoking high alcohol intake poor fitness diet high in saturated fats. What advice would you give to someone who has been diagnosed with high blood pressure?

15 What is cholesterol? 15 of 22 Boardworks Ltd 2011 Cholesterol is a lipid found in cell membranes and is used in the production of hormones and bile. Cholesterol is transported in the blood by molecules called lipoproteins, of which there are two types: high-density lipoprotein (HDL): often called good cholesterol low-density lipoprotein (LDL): often called bad cholesterol. Cholesterol levels depend on diet and genes, but high levels of LDL have been linked to eating lots of saturated fats and few mono/polyunsaturated fats.

16 Cholesterol and heart attacks 16 of 22 Boardworks Ltd 2011

17 17 of 22 Boardworks Ltd 2011 How does smoking affect blood pressure? Red blood cells contain a chemical called haemoglobin. This chemical bonds to oxygen and carries it around in the blood, ensuring that all the cells get enough oxygen. When people smoke they breathe in chemicals, including: nicotine which increases heart rate carbon monoxide which binds with haemoglobin, preventing it from carrying oxygen. As the blood carries less oxygen, the heart has to beat faster to keep cells supplied. These effects increase your blood pressure.

18 How does salt affect blood pressure? 18 of 22 Boardworks Ltd 2011 Table salt, or sodium chloride (NaCl), contains sodium ions. These are important for regulating the amount of water in the body, the movement of muscles, maintaining the ph of blood and transmitting signals in nerves. Eating a diet high in salt can cause an increase in the volume of water in the blood. This causes blood pressure to increase and artery walls to thicken. An adult is recommended to have no more than 6g of salt per day, but most people eat about 9g.

19 Factors affecting blood pressure 19 of 22 Boardworks Ltd 2011

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21 Glossary 21 of 22 Boardworks Ltd 2011

22 Summary quiz 22 of 22 Boardworks Ltd 2011