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Blood pressure

The contraction of heart muscles forces the blood through arteries under pressure.

Measured in mmHg

2 measurements of blood pressure:
-Systolic pressure is the maximum pressure the heart produces.
-Diastolic is the pressure between the heart beats.

*Increase: high alcohol intake/smoking/stress/unbalanced diet
*Decrease: exercise/balanced diet

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Fitness and health

Fitness: The ability to be able to do physical activity

Health: Being free from disease caused by viruses or bacteria

*Fitness can be measured in cardiovascular efficiency

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-carbon monoxide in the smoke can cause blood to carry less oxygen meaning the heart rate will increase so that the tissues receive enough oxygen

-Also nicotine itself increases the heart rate

The smoke contains chemicals that stops cilia moving. Cilia are tiny hairs that are found in the epithelial lining of the trachea, bronchi and bronchioles.

Smokers cough:
Dust and particles are in smoke are collecting and irritating the epithelial lining.
Also mucus is not being moved by the cilia

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Diet and heart disease

*Heart disease is caused by a restricted blood flow to the heart muscle which is increased by saturated fats which leads to a build up of cholesterol (a plaque) on the arteries.

Increase of heart disease:
-high blood pressure
-saturated fats
-high levels of salts

Blood pressure is increased by:
-high levels of salt

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Balanced diet

Should consist of:
-protein= growth and repair

-carbohydrates= energy source

-fats= energy source

-minerals= to make haemoglobin

-vitamins= to prevent scurvy (vitamin c)

-fibre= to stop constipation

-water= keep hydrated

3 chemicals needed found in food
*glucose (carbs)
*amino acids (protein)
*fatty acids and glycerol

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Protein intake

Proteins are needed for growth so we need to eat the corrects amount. Our EAR will tell us our intake needed.

Formula: EAR in g= 0.6 X body mass in kg

High protein foods are expensive and short supply so in poorer countries their diets are deficient in protein. This could cause a disease called Kwashiorkor

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To work out if someone's overweight or underweight, you calculate their BMI


BMI= Mass in kg/(Height in m)*




30+: obese

  • means squared
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Fight against illness

Pathogens produce symptoms of an infectious diseases by damaging the body cells or just by producing a poisonous waste products called toxins.

Antibodies will kill the pathogen by locking onto antigens which is on the surface of a pathogen. .White blood cells are what produces the antibodies, resulting in active immunity

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Malaria is caused by a protozoan called plasmodium that feeds on red blood cells.

-carried by mosquitoes which is a vector

-it's a parasite and the human is the host
a parasite is a living organism that feeds off another living organism, causing it harm.

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Treatment and trials

Tested on animals/human tissues/computer models before human trials!!

Antibiotics: against fungi and bacteria, it destroys the pathogen

Antiviral drugs:against viruses, slows down the pathogens development

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Parts of the eye

Coloured Iris: controls amount of light that enters eye

Pupil: Allows light rays to enter eye

Cornea: Refracts (bends) light rays

Cillary Muscle: Conrols suspensory ligaments

Lens: Refracts (bends) light rays and focuses light onto retina. Long sighted or short sighted when lens is wrong shape

Retina: where focused image forms, has light receptors, some are sensitive to some colours. Causes colour blindness when lack of specialised cells.

Optic nerve: Carries nerve impulses to brain

Suspensory Ligaments: Alters shape opf lens when focusing

Binocular vision helps judge distance by comapring the 2 images from each eye, the more different the image the closer the object is.

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parts of the eye


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Nerve cells

Nerve impulses (electrical signals) pass through the axon in a neurone.

A reflext action is shown by a reflex arc. The links in a reflex arc are:

stimulus-receptor-sensory neurone-central nervous system-motor neurone-effector-response

Pathway for a spinal reflex:

receptor-sensory neurone-relay neurone-motor neurone-effector

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Depressants- slows down the brain activity (Alcohol)

Pain killers- Block nerve impulses (aspirin/paracetamol)

Stimulants- increases brain activity (nicotine/MDMA/caffeine)

Performance enhancers- increase muscle development (anabolic steroids)

Hallucinogens- distorts what is seen or heard (LSD)

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Plant hormone- Auxin

Auxin is made in the tip of the plant

Phototropism- plant growth response towards the light
Geotropism-plant growth response towards the gravity
(Negative and positive)

Plant hormones are used in agriculture to speed up or down plant growth

The hormone can be used:
~as weed killer
~as a rooting powder when taking cuttings
~to control dormancy in seeds
~to delay fruit ripening

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Human characteristic can be inherited or an environmental factor

-domainant or recessive

Alleles:different versions of the same gene

Humans have 23 pairs

Females: **

Males: xy

Genetic variation is caused by:
-mutation (random changes in genes or chromosomes)
-rearrangement of genes during the formations of garmetes
-fertilisation (results in zygote from the fathers and mother)

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Alcohol increases reaction times and increases accidents

Short term effects: blurred vision/slurred speech/increased blood flow to skin

Long term effects: liver and brain damage

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Homeostasis- keeping constant internal environment
-involves balancing bodily inputs and outputs

Automatic control systems keeps the levels of water, temperature and carbon dioxide steady. To make sure cells can work at their optimum level

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Temperature control

37 Degrees is this regular body temperature

High temperature can cause:
-heat stroke

Avoid overheating,sweating increases heat transfer from the body to the environment. Evaporation of sweat require body to change liquid sweat into water vapour

Low temperature can cause:

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Blood sugar levels

Pancreas produce the hormone insulin
-insulin controls blood sugar levels

Type 1 diabetes: pancreas can't produce insulin

Type 2 diabetes: the body produces very little insulin or the body can't react to it can be controlled by diet

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