Risk Factors for Cardiovascular Disease (Daphnia)

Question 1

What is a risk factor?

Answer 1

something that increases the likelihood of developing a disease called a risk factor

Question 2

What does correlation mean?

Answer 2

• correlation is a mutual relationship between one or more things
• positive correlation etc

Question 3

What do case control studies do?

Answer 3

• case control studies are a way of carrying out a medical investigation to confirm or indicate what is likely to have caused a condition
• (this is an investigation)

Question 4

What do cohort studies do?

Answer 4

• a cohort study is a type of observational study that follows a group of participants over a period of time
• they examine how certain factors (like exposure to a given risk factor) affect their health outcome
• (this is a study over a period of time)

Question 5

What is epidemiology?

Answer 5

epidemiology is the study of health and disease in populations

Question 6

What are some controllable risk factors for CVD?

Answer 6

• smoking
• high salt intake
• diet high in cholesterol
• obesity
• too much alcohol
• stress
• lack of exercise

Question 7

What are some uncontrollable risk factors?

Answer 7

• genetic predisposition
• age (old age)
• gender (male = lacks protective hormone oestrogen)
• diabetes

Question 8

What is the purpose of the daphnia practical?

Answer 8

to investigate the effect of caffeine on the heart rate of Daphnia (water fleas)

Question 9

What are the control, independent and dependent variables of the Daphnia practical?

Answer 9

• independent variable = the concentration of caffeine solution
• dependent variable = the heart rate (bpm)
• control variable = the temperature of the solution, the source of caffeine, volume of solution

Question 10

What does systolic mean?

Answer 10

• higher blood pressures than normal

Question 11

What does ischaemic mean?

Answer 11

• low oxygen state
• inadequate blood flow

Question 12

What is an ischaemic stroke?

Answer 12

• an ischaemic stroke is death of an area of brain tissue resulting from inadequate supply of blood and oxygen

Question 13

Why are daphnia suitable for investigating heart rate?

Answer 13

• they are suitable for investigating heart rate due to having transparent bodies, their hearts can be observed using a light microscope

Question 14

What equipment is needed for the apparatus on daphnia heart rate?

Answer 14

• light microscope
• cavity slide
• culture of Daphnia
• pipette
• caffeine solutions at a range of concentrations
• distilled water
• stop watch

Question 15

What is the method for the Daphnia practical (in summarised bullet points)?

Answer 15

1. prepare 5 diff caffeine concentrations & control solution of distilled water
2. add pond water into well of cavity slide & add 3 drops of distilled water
3. select large Daphnia, use pipette to transfer it to slide
4. place slide onto stage of microscope, observe under low power
5. use stopwatch to time 20 seconds & count number of heart beats
6. heart beat is fast so can use paper & pen and make dots, then count dots and express heart beat as BPM
7. return Daphnia
8. repeat steps 3-7 with diff Daphnia
9. repeat steps 3-8 with diff caffeine concentration solutions

Question 16

How can diet be a risk factor of CVD?

Answer 16

• a diet high in saturated fat increases blood cholesterol levels, increasing atheroma formation and therefore thrombosis
• a diet high in salt increases blood pressure

Question 17

How can high blood pressure be a risk factor of CVD? What can cause high blood pressure?

Answer 17

• increases risk of damage to artery walls, increasing atheroma formation and therefore thrombosis
• high blood pressure can be linked to stress, alcohol, poor diet, and inactivity

Question 18

How can smoking be a risk factor of CVD?

Answer 18

• carbon monoxide combines with haemoglobin in red blood cells, reducing its oxygen carrying compacity; this decreases respiration in the cells of the brain and heart which can lead to stroke and heart attack
  -nicotine causes increase risk of thrombosis by increase in stickiness of platelets
• smoking decreases antioxidants in the blood , tis increases risk of damage to endothelium of arteries leading to atheroma formation and therefore thrombosis

Question 19

How may genetics be a risk factor of CVD?

Answer 19

• individuals can inherit alleles making them prone to HBP or high blood cholesterol

Question 20

How may age be a risk factor of CVD?

Answer 20

• the risk of developing CVD increases with age due to blood vessels becoming more fragile and plaque building up over time

Question 21

How may sex/ gender be a risk factor of CVD?

Answer 21

• men and premenopausal women lack protective hormone oestrogen which increases levels of good cholesterol in the blood