- Created by: olly
- Created on: 19-05-11 18:43
the Nervous systems are :- brain, spinal cords/spinal nerves, receptors
- info passes from receptors along the neurones(nerve cells) to the brain
3 neurones:- motor, sensory, relay.
-adapted cells carry a electrical signal, which is a nerve impulse.
connections between neurones. there is a small gap called a synapse.
Receptors:- light/eyes, sound/ears, change of position/ in the ears, taste/tounge, smell/nose, touch/pressure/pain/temp- skin.
- reflex actions speeds up response
-spinal cord - coordinator and passes impules.
-Body temp- 37*C- temp increased by shivering/ temps decreased by sweating
-water content - gained by drinking and lost by lungs and sweating, pee
-ion content- gained, eating and drinking. loast by sweating and pee
-bloody sugar (glucose) - provides cells with a constant supply of energy, gained- eating and drinking
-hormaones (coordinated) chemical substanes produced by glands, moved by bloodstream.
hormones and fertility
-pituitary gland and ovaries - make lining of womb thicker
-follice stimulating hormone (fsh)- pituitary gland makes ovaries produce oestrogen and eggs mature
-oestrogen- ovaries inhibts production of fhs and production of lutesining hormone (LH)
-LH- pituarity gland- stimulates release of ehh in middle of menstrual cycle
*******-all chemical ractions in the cells of the body are carried out
- more exercise- MR increases and stays same for a while
-proportion of fat to muscle in your body / could be from family history
- less exercise- the warmer it is, less food you need
-cholesterol- made in liver, found in blood.
-carried by body in chemicals called Lipoproteins (made from fat/lipid and protein)
-low density Lipoproteins - can cause heart disease
-high density Lipoproteins- are good cholesterols
-emphysema- alveoli due to coughing
-bronchitis- increaded infection to mucus production
-pregnace- carbon monoxide, reduces oxygen carrying capacity of blood which can deprive a fetus of oxygen and lead to a low birth mass
-arterial and heart disease, lung cancer
bacteria and viruses
-microorganisms that cause diseases that are called pathogens
-white blood cells that form part of the bodys immune system
-antibiotics used against bacteria
-a person can be immunte to a perticular disease by being vaccinoted
-depressant- cause reactions to slow down
-lead to a lack of self control
-excess can lead to unconsciousness and even coma or death
-liver damage, brain damage
-organisms compete with each other for space/light, food and water
-population is the total number of individuals of the same species
-a community is all the organisms in a particular area.
-adaptations are special features of behavior. which make an organism particular well suited to it environment.
-nucleas of a cell contains chromosomes which are made up if a substance called DNA
-a section of a chromosome is called a gene
-differences between individuals of the same are called a variation.
-carbohydrates, fats, protein, fibre, vitamins, minerals, water
-person mahourished diet not good blance
-poor diet = fat/thin, scurvy caused by VC
uk/usa -arthritis, diabetes, high blood pressure, heart diease
africa/asia- reduced resistance to infection, irregular periods in women
-Evolution is the change in a population over a large number of generations that may result in the formation of a new species, the members of which are better adapted to their environment.
-fossils are the remains of plants or animals from many years ago which are found in rock. they provide evidence of how organisms have changed over time.
-charles darwin :- there is much variation in a species
-more offspring are produced than the environment can support (food and breading ares)
-only the ones best suited or adapted will survive and breed. this i known as natural selection or 'survial of the fittest'
-those that survie passs their genes onto their offspring. eventually the species which is less suited will become extinct.
Dawins theory was accepted because :- religion had an important place in society. - it is difficult to prove. - many scientists didn't accept the theory. -attempts to demonstrate evolution through tests have failed.
-sexual reproduction is when a sperm from a male fuses with a egg, when that happens genes are mixed
-asexual reproduction means no variation happens at all, unless it is due to environmental causes.
-take the egg out, remove the nucleus and put the DNA of another donor in where the nucleus has and then implant into the uterus.
-all living things which exist today and many more that are now extinct, evolved from simple life forms which first developed 3 billion years ago.