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Biology B1a Keyword list
Addictive
Because they are this, many drugs cause dependency and withdrawal symptoms if
they are suddenly removed. Heroin, cocaine and nicotine are all highly ....
Alcohol
Legal drug which slows down reaction times and may lead to lack of self-control,
unconsciousness, coma, liver and brain damage.
Analgesic
Painkilling drug which may relieve the symptoms of an infection but does not kill the
pathogens.
Antibiotic
Chemicals such as penicillin, made by microorganisms to kill each other. We can
use them as medicines. They do not kill viruses and many bacteria are evolving
resistance to them.
Antiviral
Drugs designed to kill viruses. Difficult to develop because viruses live inside our
own cells, so the drugs often damage our cells as well.
Balanced Diet
Diet containing all of the necessary nutrients in the correct amounts.
Carbon Monoxide
Chemical found in tobacco smoke which binds to haemoglobin in red blood cells,
preventing it from carrying oxygen to body cells. In pregant women this can deprive
the foetus of oxygen leading to a low birth mass.
Carcinogen
Cancer-causing chemical, many of which are found in tobacco smoke.
Cholesterol
Fat-like substance made in the liver and transported in the blood. High levels
increase risk of heart disease. Carried in 2 forms, 'LDL' which is bad, and 'HDL'
which is good. The ratio of LDL to HDL is the important factor in determining risk of
heart disease.
Drug
Substance which alters the way the body or mind works. May be medical or
recreational, legal or illegal. Many have been known about by indigenous peoples for
many years. Legal drugs have more impact on health because more people take
them.
FSH
Follicle Stimulating Hormone: made by the pituitary gland, this hormone causes a
follicle (containing an egg) to begin to mature. used in fertility treatments to stimulate
egg development.
Homeostasis
Maintaining constant internal conditions so that body processes, especially those
controlled by enzymes, function efficiently. Factors kept constant include
temperature, blood sugar concentration, water/ion balance of blood and tissue fluid.
Hormones
Chemical messengers released into the bloodstream by glands.
Immunisation
Also known as vaccination, this involves injecting a dead or inactivated form of a
pathogen into the bloodstream. The white blood cells learn how to make correctly
shaped antibodies, so that a rapid and effective response can be made if the real
pathogen is ever encountered. An example if the MMR vaccine against measles,
mumps and rubella.
IVF
A way of treating infertility by fertilising an egg cell outside the body then implanting
the embryo back into the uterus.
LH
Luteinising Hormone: made by the pituitary gland this hormone causes the follicle to
burst, releasing the egg (ovulation). Used in fertility treatments to stimulate ovulation.
Malnutrition
Occurs if the diet is unblanced,eventually leading to becoming too fat, too thin or
developing deficiency diseases.
Metabolic Rate
The rate at which the chemical reactions of your cells take place. It varies due to
temperature (higher when its cold), your activity level, your ratio of muscle to fat and
(maybe) inherited factors. It affects how much energy you need in your diet, and
stays high for some time after exercise.
Microorganism
Tiny organism, often only one cell in size, which can usually only be seen through a
microscope. May cause disease, but not always. Includes Bacteria, Fungi and
Viruses.
Motor Neurones
Nerve cells which carry impulses to effectors (muscles or glands) from the central
nervous system, causing the effectors to cause a response.
MRSA
A strain of bacterium which has evolved resistance to most antibiotics by the process
of natural selection. Overuse of antibiotics and failure to complete the course makes
resistance more likely to evolve.
Nervous System
consists of brain, spinal cord, and nerves and regulates the body's responses to
internal and external stimuli
Nicotine
Addictive part of tobacco smoke.
Obesity
Being very overweight (BMI >30). It is linked to arthritis, diabetes, high blood
pressure and heart disease.
Oestrogen
Hormone produced by the ovaries which causes the uterus lining to thicken, inhibits
FSH production and stimulates LH production. Used in contraceptive pills to inhibit
egg development.
Pathogen
Organism (often a microorganism) which causes disease in others.
Pituitary Gland
Structure in the brain which produces the hormones FSH and LH which are
important in the menstrual cycle.
Receptors
Cells which detect stimuli including light, sound, changes in position, chemicals,
touch, pressure, pain and temperature.
Reflex Action
A rapid, automatic response to a stimulus, e.g. the hand withdrawal and pupil
reflexes.
Relay Neurones
Nerve cells within the central nervous system which process incoming information.
Salt
Dietary component which can raise blood pressure and increase the risk of heart
disease.
Saturated Fat
Fats obtained from warm-blooded animals, which have no C=C double bonds in their
structure and are linked to high levels of (bad) LDL cholesterol.
Semmelweiss
Doctor who made a breakthrough in understanding the link between hygiene and
infections.
Sensory Neurones
Nerve cells which carry impulses to the central nervous system from receptors.
Synapse
A junction between 2 neurones. They slow down the speed of the impulse because
the transmission of information changes from electrical (within neurones) to chemical
(as the neurotransmitter diffuses across the synpase) then back to electrical in the
2nd neurone.
Thalidomide
Drug, originally developed as a sleeping pill, which was banned after it caused birth
defects when taken by pregnant mothers to reduce morning sickness (it had not
been tested for this purpose). Now being used to treat leprosy successfully, and
maybe useful against some cancers.
Toxin
Poison made by bacteria whihc makes us feel ill.
Undernourishment
May be caused by anorexia or famine. Llinked to reduced resistance to infection and
irregular periods in women.
Unsaturated Fat
Fats obtained from vegetable or fish sources, which have double C=C bonds in their
structures. They tend to increase HDL ('good cholesterol') levels, protecting gainst
heart disease. Polyunsaturated fats are even better than monounsaturated fats.
Virus
Type of microorganism which inject their genetic material into our body cells,where
they reproduce then burst out, killing our cells in the process and making us ill.
White Blood Cell
Specialised type of cell which helps to defend us against pathogens in many ways:
ingesting them (phagocytosis), making antibodies to stick to them or antitoxins which
inactivate the bacterial toxins.