Fitness and blood pressure
- Being fit is not the same as being healthy.
- Healthy - being free from any infections or diseases.
- Fit -is a measure of how well you can perform physical tasks.
- possible consequences of having high blood pressure (burst blood vessels, damage to brain, stroke, kidney damage)
possible consequences of having low blood pressure (dizziness, fainting, poor circulation).
- blood is under pressure due to contractions of heart muscles - so it reaches all parts of the body.
blood pressure varies according to - age, lifestyle, diet, exercise, weight, alcohol, stress.
- Respiration - when glucose reacts with Oxygen in cells to release energy.
- During exercise - breathing + pulse rates increase to deliver Oxygen + Glucose to muscles quicker - to remove carbon dioxide from muscles quicker.
- There are two types of respiration - aerobic and anaerobic
- Aerobic respiration
- word equation for respiration with oxygen(aerobic respiration) - Glucose + Oxygen = Carbon dioxide + water (+energy)
- the symbol equation for aerobic respiration:C6 H12 O6 + 6O2 = 6CO2 +6H2O + (energy)
- Aerobic respiration is what happens when there's plenty of Oxygen available
- this is the respiration you use most of the time
Explain fatigue in terms of lactic acid build up (oxygen debt) and how this is removed during recovery: hard exercise causes lack of oxygen in cells; incomplete breakdown of glucose; continued panting replaces oxygen allowing aerobic respiration; increased heart rate ensures blood carries lactic acid away to the liver.
- Anaerobic respiration releases much less energy than aerobic respiration
- Anaerobic respiration - Glucose = lactic acid (+energy)
- Anaerobic respiration is when you do vigorous exercise your body can't supply enough oxygen to your muscles for aerobic respiration - even though your heart rate and breathing rate increases as much as they can.
- Anaerobic means without oxygen.
- In Anaerobic respiration, the glucose is only partly broken down, and lactic acid is also produced.
- The lactic acid builds up in the muscles, which gets painful and makes your muscles fatigued.
- After resorting to anaerobic respiration, when you stop exercising you'll have an oxygen debt.
- Basically your muscles are still short of oxygen because they haven't been getting enough for a while. You also need extra oxygen to break down all the lactic acid that's built up in your muscles.
- carbohydrates - provide energy
- fats - provide energy, energy stores and insulation
- proteins - needed for growth and repair of tissues
- Vitamins - vitamin C - prevent scurvy
- Minerals - iron - needed to make haemoglobin for healthy blood
- water - replaces water loss from urinating, breathing and sweating
- Fibre - stops constipation (keeps gut in working order)
Age - children/ teenagers need more protein for growth - older people need more calcium to fight against degenerative bone diseases like Osteoporosis.
Gender - Females need more iron to replace the iron lost in menstrual blood.
Physical activity - Active people need more protein for muscle development, and more carbohydrates for energy.
- Obesity is a common eating disorder - it is defined as being 20 percent or more over the recomended body weight.
- Obesity can increase the risk of diabetes, arthritis, high blood pressure, coronary heart disease (CHD) and even some forms of cancer.
- Eating too little protein can cause a condition called Kwashiorkor - a common symptom is a swollen stomach.
- Calculate the reccomended daily allowance (RDA) of protein using this formula: RDA (grams) = 0.75 times body mass (kg)
- Some psychological disorders cause under - nutrition, e.g. anorexia nervosa and bulimia nervosa. Anorexia leads to self - starvation. Bulimia invloves binge eating, followed by self - induced vomiting.
- there both usually caused by low self - esteem.
- these disorders can also cause a lot of other illnesses e.g. liver failure, kidney failure, heart attacks, muscle wastage, low blood pressure and mineral deficiencies. Bulimia can lead to tooth decay ( the acid in vomit eats away at the tooth enamel ) - both orders can be fatal.
- The body mass index (BMI) is used as a guide to help decide whether someone is underweight, normal, overweight or obese.
- Its calculated from their height and weight.
- BMI = body mass ÷ (height)²
- BMI isn't always reliable - Athletes have alot of muscle, which weights more than fat, so they get a high BMI even though their not overweight.
- Carbohydrates are broken down by carbohydrase into simple sugars*.
- Proteins are broken down by protease into Amino acids*.
- Fats are broken down by lipase into fatty acids and glycerol*.
- *these are produces of digestion and are small enough to pass through the walls of the small intestine and into the blood stream.
- First our teeth physically break down the food
- second - food gets coated in saliva - makes food slippy so easy to swollow - and adds enzymes
- third - proteins, fats and carbohydrates are too large for our body to use
- forth - we have to break them down into small soluble molecules - so they are able to be absorbed into our blood stream and be transported around the body.
- infectious diseases are caused by pathogens (diseases causing micro organisms such as fungi, bacteria, viruses and protozoa.
- Fungi - athlete's foot
- viruses - flu
- bacteria - cholera
- protozoa - dysentery
- the human body is protected against pathogens by : the skin, blood clotting, mucous membranes in the respiratory system, and hydrochloric acids in the stomach.
- Malaria is an example of an infectious disease caused by a protozoa.
- Your immune system deals with pathogens
- White blood cells travel around your body and patrol for micro - organisms.
Infectious diseases 2
- When they come across an invading micro - organism they have three lines of attack:
- 1. consuming them - White blood cells can engulf foreign cells and digest them.
- 2. Producing Antitoxins - antitoxins counter the effect of any poisons (toxins) produced by the invading bacteria.
- 3. producing antibodies -
- 1. every pathogen has unique molecules on the surface of its cells - no two species have the same ones. these molecules are called antigens.
- 2. When your white blood cells come across a foreign antigen they'll start to produce proteins called antibodies, which lock on to other pathogens.
- 3. Antibodies produced are specific to that pathogen - they won't lock on to other pathogens.
- 4. If the person is infected with the same pathogen again the white blood cells will quickly produce the antibodies to kill it - the person is naturally immune to that pathogen and won't get ill.