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,