Biology B1 Revision notes.
Blood pressure is measured in millimetres of mercury (mmHg). There are two measurements;
Systolic Pressure- The higher measurement when the heart beats, pushing blood through the arteries ect.
Diastolic Pressure- The lower measurement when the heart rests between beats.
High Blood Pressure- Blood vessels burst, cause damage to; Brain (stroke) and kidney damage.
Low Blood Pressure- Dizziness and fainting. Blood supply to brain is reduced. Poor circulation to fingers and toes.
Diet and Exercise;
A healthy diet has the right balance of food types. Carbohydrates, fat and protein are used to release energy and build cells.
Mineral ions and vitamins are needed to keep the body healthy. If someone’s diet is unbalanced they can become malnourished.
If you exercise more energy is used by the body. Exercise increases the metabolic rate which means that chemical reactions in cells work faster. The proportion of muscle to fat in your body and your inherited factors can also affect your metabolic rate.
Made up of....
Fatty acids and glycerol
Eat too much fat and carbohydrates, they get stored in your body.
Where they are stored....
Stored in liver as glycogen or converted into fats.
Stored under the skin and around organs as adipose tissue.
Can’t be stored, can be converted into other amino acids.
Fitness and Health;
Fitness- Ability to do physical activity.
Health- Being free from diseases.
Fitness- Measured by Cardiovascular efficiency.
What you have to do...
You can do well in some but not well in others.
Ways of measuring fitness should be evaluated in particular situations.
Increases blood pressure.
Carbon monoxide- Blood carries less oxygen, so heart rate increases.
Nicotine increases heart rate.
Carbon monoxide combines with haemoglobin preventing it combining with oxygen.
Heart disease- Caused by restricted blood flow to the heart muscle.
Risk is increased by- High level of saturated fat in diet. This leads to a build up of cholesterol in arteries.
High levels of salt- Increase blood pressure.
REMEMBER: It is the blood vessel into the heart muscle that is blocked not the blood flowing into the heart.
Narrow arteries- Caused by plaques. Reduces blood flow to heart muscle.
Build up of plaques- Blood clots or thrombosis more likely to happen. Also block the artery.