heart Flashcards
1
Q
2.67 what factors may increase the risk of developing coronary heart disease and how?
A
- diet: eating lots of saturated fats inc. blood cholesterol & inc. risk of fatty deposits
- smoking: inc. blood pressure & inc. risk of fatty deposits forming
- high blood pressure: damages artery lining & inc. risk of fatty deposits forming. high salt levels in diet inc risk of high blood pressure
- obesity: being obese will inc blood pressure & may be linked to poor diet
- lack of exercise: causes high blood pressure
2
Q
2.68 how does the structure of arteries relate to their function?
A
- thick outer wall: can transport blood at high pressure w/o bursting
- thick layer of elastic tissue: allows artery to stretch & recoil to keep blood flowing at high pressure
- thick layer of muscular tissue: helps to control flow of blood by widening (dilating) and narrowing (constricting)
3
Q
2.68 how does the structure of veins relate to their function?
A
- fairly thin outer wall: blood is flowing at lower pressure so thick wall not needed
- thin layer of muscle & elastic tissue: wall can contract to keep blood flowing
- semilunar valves: prevents blood flowing backwards
4
Q
2.68 how does the structure of capillaries relate to their function?
A
wall is one cell thick: short distance for diffusion of substances from blood into tissues
5
Q
explain how coronary heart disease works
A
- coronary arteries supply heart muscle w blood. this blood provides glucose & O needed for aerobic respiration & removes CO2 produced by aerobic respiration
- if fatty deposits build up in artery walls, they narrow the lumen (space) of artery. this restricts blood flow to the HMC
- this causes HMC to receive less blood, which means that HMC receive less O (and glucose) for aerobic respiration
- as result aerobic respiration reduces & anaerobic respiration inc in HMC
- lactic acid will build up due to inc in anaerobic respiration, poisoning HMC & causing heart attacks.
