The Heart Flashcards
Why is too much salt bad for us?
It increases your blood pressure.
Explain why too much saturated fat is bad for us.
Produces or increases blood cholesterol
Affects heart/blood vessels
Affects blood pressure.
A build up of pladue (mainly cholesterol and white blood cells) causes the lumen to narrow.
Artery wall becomes less elastic
If it loses elasticity it cannot stretch to accommodate blood which is being forced through every time the heart contracts.
What are the main causes of coronary heart disease?
Obesity
High blood pressure
High cholesterol
Smoking
Why does obesity cause coronary heart disease?
Extra weight puts strain on the heart
Extra weight can lead to diabetes - which further damages blood vessels.
Why does high blood pressure cause coronary heart disease?
It increases the force of the blood against artery walls which leads to damage of the vessels.
Why does high cholesterol cause coronary heart disease?
Speeds up the build up of fatty plaques
Why does smoking cause coronary heart disease?
Chemicals in smoke cause an increase in plaque and an increase in blood pressure.
CO also reduces the oxygen carrying capacity of the red blood cells.
Explain the advantages to the body in the change in breathing and heart rates during work.
During exercise -
Level of CO2 in blood rises.
Increased breathing removes excess CO2
Increased breathing and heart rate takes more oxygen supply to the muscles
Increased heart rate increases the supply of sugar to muscles
Enable faster rate of energy release
Avoid cramp
Remove heat
Explain the changes in cardiac output which occur as a person increases their activity,
More energy needed; more oxygen needed; more blood needed.
When you exercise your muscles need more energy as you respire more.
You need to get oxygen to your cells and remove more CO2.
For this to happen, the blood has to flow faster so your heart rate increases.
The increase to rate of heart beat during exercise is a response to a stimulus. What is the stimulus, coordinator and effector?
The stimulus is the high concentration of CO2.
The coordinator is the brain/central nervous system.
The effector is the heart muscles.
Exercise increases the amount of CO2 in your blood.
High levels of blood CO2 are detected by the receptors in the aorta and carotid artery (artery in your neck).
These receptors send signals to your brain
The brain sends signals to the heart causing it to contract more frequently and with more force.
Explain why a person who smokes heavily may have an increased risk of heart attack.
Carbon monoxide in cigarette smoke
Nicotine in cigarette smoke
Blood vessels are more permeable to fats or cholesterol
Lack of oxygen in the blood
Stickiness of platelets
Increased risk of clotting
Carbon monoxide in cigarette smoke reduces the amount of oxygen the blood can carry. To make up for this the heart rate increases which can lead to an increase in blood pressure. High blood pressure damages artery walls, making the formation of clots more likely.
Smoking increases blood pressure which can cause damage to the inside of the coronary arteries. Chemicals from cigarette smoke can cause damage. The damage makes it more likely that fatty deposits will form, narrowing arteries.
How do arteries supplying leg muscles alter the rate of blood flow through them during exercise?
Arteries dilate (widen) to allow the blood to flow through them quicker.
Explain how an increase in heart rate helps during exercise.
During exercise,
Muscles use more energy and respire faster
An increase in heart rate supplies more oxygen glucose more quickly
Removes more CO2 and lactic acid
Removes heat
Some athletes train at high altitude for several week. The availability of oxygen at high altitude is lower so the body responds by increasing the number of red blood cells. The number of red blood cells remain high when the athletes return to lower altitude to compete. How does having more red blood cells give an advantage to those taking part in long distance races?
Training at high altitude will give the athlete more haemoglobin in the blood.
More oxygen can therefore be absorbed and transported to muscles
Cells can respire more (aerobically)
Releasing more energy
Lower rate of anaerobic respiration taking place in cells
Reducing the amount of lactic acid build up
Muscles will therefore get less fatigued during the race.
Athlete can run faster/longer/further and be less tired.
The larger the oxygen supply to the body, the more efficient the other organs in the body. This will mean that they will be able to run faster for longer.
Suggest why sprint athletes gain no advantage from training at altitude.
Sprints are very short races
Athletes rarely breathe during the race therefore oxygen carrying capacity of blood doesn’t matter
As their muscle cells respire anaerobically for these short periods of time.
