Describe the path of a nerve impulse across a synapse
The arrival of an impulse triggers the release of a transmitter substance which diffuses across the synapse. The transmitter substance binds with receptor molecules in the membrane of the next neuron causing the impulse to continue
What does the nerve impulse pass along?
What are the five different types of drugs?
Depressants, painkillers, stimulants,performance enhancers and hallucinogens
How do stimulants work?
They cause more neurotransmitter substances to cross the synapses
How is the alcoholic content of the alcoholic drinks measured?
Units of Alcohol
What does drinking alcohol increase?
Increases the risk of accidents
What does cigarette smoke cause in the lungs?
It contains many chemicals that stop the cilia moving
What are carcinogens?
Cancer causing chemicals
What is 'smokers cough' a result of?
Dust and particulates in the cigarette smoke collecting and irritating the epithelial lining
Mucus not being moved by the cilia
How do depressants work?
They block the transmission of nerve impulses across synapses by binding with receptor molecules in the membrane of the receiving neurone.
What is Homeostasis?
Keeping a constant internal environment
What does Monocular vision provide?
A wider field of view but poorer distance judgement than binocular vision has.
What is genetic variation caused by?
Mutations and fertilisation
What does ' Homozygous' mean?
Having identical alleles
What does 'Hetrozygous' mean?
Having different alleles
What are inherited disorders caused by?
Faulty alleles, most of which are recessive
What are alleles?
Different versions of the same gene
What is a placebo?
A harmless pill which is used as a comparison in drug testing so the effect of a new drug can be assessed
What do antibiotics do?
The help fight bacteria and fungi they destroy a pathogen
How do antivirals work?
They fight against viruses they slow down the pathogen's development
What are pathogens?
Disease causing organisms
How does the eye focus on distant objects?
The ciliary muscles relax and the suspensory ligaments tighten so the lens has a less rounded shape