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FITNESS AND BLOOD PRESSURE
Systolic pressure - is the maximum pressure the heart produces
Blood pressure is produced when muscles contract
Low blood pressure causes poor circulation, dizziness and fainting.
HEALTHY
free of disease
FITNESS
how well you can perform physical activity
Blood pressure is highest when the heart contracts (Systolic Pressure)
A healthy persons blood pressure shouldn't be higher than
135 - systolic
-----
85 - diastolic
HIGH BLOOD PRESSURE
Low blood pressure means that the tissues aren't getting enough oxygen and food.
when eating too much cholesterol, it starts to build up in your arteries. This forms plaques in the artery wall, which narrow the arteries. This restricts restricts the blood flow and ultimately leads to heart attack/
EATING HEALTHY
6 essential nutrients are:
carbohydrates, proteins, vitamins, fats, water, minerals
FATS
Provide energy, Act as a energy store and provide insulation
VITAMINS/MINERALS
Various, vitamin C NEEDED FOR scurvy, Iron needed to make haemoglobin
Carbohydrates are made of sugars like glucose.
Fats are made of fatty acids and glycerol. They can be stored under the skin and around the organs as adipose tissue
The balance of different nutrients a person needs are dependent on things like their age, gender.
DIET PROBLEMS
EAR(g)=0.6 x body mass (kg)
Bmi is used to help decide whether someone is underweight,normal,overweight or obese.
INFECTIOUS DISEASE
Infectious diseases are caused by Pathogens
Fungi - athletes foot
Bacteria - cholera
Viruses - Flu
Protozoa - (single celled) dysentry
The protozoan is a parasite, An organism that loves off another (called a host)
Every time a mosquito feeds on another animal, it infects it.
Once pathogens enter the body, they reproduce rapidly unless they're destroyed
1.White blood cells ENGULF foreign cells and DIGEST them.
2. Anti-toxins counter the effect of any poisons produced by the invading pathogens
Antibodies are released all around the body and rapidly kill all similar bacteria or virus
PREVENTING AND TREATING INFECTIOUS DISEASE
immunisation prevents you getting infections
Immunisation is classed as active immunity
Passive: when you use antibodies made by another organism.
only temporary
Antivirals are drugs you can take to stop viruses from reproducing
CANCER & DRUG DEVELOPMENT
Cancer is cause by cells dividing out of control, This forms a tumor.
Benign:
Where tumors grow until there's no more room. The cells stay where they are and its not normally dangerous.
smoking increases your risk of getting lung cancer
DRUG DEVELOPMENT
1. computer models used first.
These stimulate a humans response to a drug
3. Test on animals.
the law in UK states that any new drug must be tested on at least 2 live mammals
Clinical trials are blind, sometimes double blind so neither the patient nor scientist knows which is the real drug
DRUG USE AND HARM
some drugs are medicinally helpful eg. antibiotics, some can be harmful if misused
Stimulants (nicotine,ecstasy,caffeine)
increase activity of the brain, make you feel more alert and awake.
Performance enhancers (anabolic steroids) taken by athletes, help build muscle and allow the athletes to train harder.
Class A: heroin, LSD, ecstasy, cocaine
Class B: cannabis, amphetamines
Class C: anabolic steroids, tranquilizers.
SMOKING AND ALCOHOL
alcohol is poisonous.
If you drink too much alcohol over a long period of time, these toxic products can cause the death of liver cells, forming scar tissue that stops blood reaching the liver, this is called cirrhosis.
Smoking causes:
Lung, throat, mouth and cesophageal cancer. Tar from the cigarette smoke collects in the lungs. Its full of toxic chemicals, some of which cause cancer.
smoking can cause low birth weight babies.
RECEPTORS - THE EYE
Cornea:
Refracts light into the eye
Lens:
Focuses light onto the retina
Rods:
more sensitive in dim light but cant sense colour
Optic Nerve:
carries impulses from the receptors to the brain.
to look at near objects:
the cilliary muscle contracts which slackens the suspensory ligaments - ROUND LENS
Convex-Long sighted
Concave- short sighted
NEURONES AND REFLEXES
The CNS;
consists of brain and spinal chord
-3 types of neurone
sensory, relay, motor
.
reflex actions are automatic
2) stimulation of the pain receptor
4) message is then passed along the RELAY NEURONE
6) when message reaches muscle, it contracts, causing it to move away.
The electrical impulse is passed down the axon of the cell.
the electrical impulse triggers the release of transmitter chemicals which diffuse across the gap.
stimulants increase the amount of transmitter chemicals at some synapses
HOMEOSTASIS
maintaining a constant internal environment
changes in the environment triggers a response that counteracts the changes.
when you're too hot hot,
hairs lie flat, lots of sweat is produced, blood vessels close to the surface widen (VASODILATON)
CONTROLLING BLOOD SUGAR LEVELS
insulin controls blood sugar levels
if blood glucose is too high, insulin is added.
glycogen can be stored in the liver until the blood sugar level is low again
type 3 diabetes:
where a person becomes resistant to insulin.
avoid carbohydrate rich foods
PLANT HORMONES AND GROWTH
Auxins are plant hormones
auxin is produced in the tips and diffuses backwards to stimulate the cell elongation process.
when exposed to light, it makes more auxin in the SHADY side so the shoot bends towards the light.
auxin gathers on the lower side when a plant grows sideways.
roots are NEGATIVELY PHOTOTROPHIC - meaning thry grow away from light.
COMMERCIAL USE OF PLANT HORMONES
plant hormones can be extracted
GENES AND CHROMOSOMES
NUCLEUS - contains genetic material in the form of chromosomes.
chromosomes carry genes - different genes control the different characteristics development
DNA is coiled up to form the arms of a chromosome
genetic variation
fertilization - the gametes join together
a new gene may mutate,
