Carbohydrates=
Release Energy
Fats= to keep
warm and
release energy
Protein= Growth,
Cell, repair and
Cell replacement
Fibre= Smooth
running of
digestive system
Excess carbohydrate or fat
in the diet can lead to
obesity (bad diet, overeating
and lack of exercise)
Lack of food
(malnourishment)
leads to slow
growth, fatigue,
poor resistance to
infection and
irregular periods
Metabolic
rate: Speed
at which
chemical
reactions
happen in
your body
Food, Lifestyle and
Diet
Sodium (salt)
in food can
lead to health
problems such
as high blood
pressure
Saturated fats can
raise your chlorestal
level
Energy from food is measured in kJ/Calories/Kcal
Eating less
fat/carbohydrate (less
energy taken in) and
doing more exercise
(using more energy)
will allow weight to be
lost
Fighting Disease
Vaccination
Vaccination involves
Injecting small
amount of
dead/inactive
microorganisms
These
carry
antigens
causing
the body
to
produce
antibodies
(attack
them)
Live
microorganisms
of same type
appear = White
blood cells
producing
antibodies to kill
pathogen
Drugs
Painkillers= Reduce
Symptons of disease
Antibiotics= Kill/prevent
growth of bacteria
without killing body
cells. Antibiotics dont
kill viruses. Viruses
reproduce using your
own body cells.
Bacteria mutates
(causing them to be
resistant to antibiotic)
Treat infection=
non-resistant strains of
bacteria
Individual resistant
bacteria
survive+reproduce.
Population of
resistant strain will
increase (serious
infection)
Past +
Future
Ignaz Semmelweis
Saw that women were dying
(huge numbers) after childbirth
from puerperal fever
Disease spread on unwashed hands
Told doctors to wash hands in antiseptic
solution (death rate fell)
Solution= Killed bacteria.
Semmelweis could find out why it
worked so death rate rose
Bacteria are small cells
they can reproduce rapidly
inside your body. They
make you feel ill by
damaging your cells and
producing toxins
Viruses replicate
themeselves by
invading cells using
the cell to produce
copies of
themeselves,
bursting them to
release new viruses
White blood
cells travel
around your
body
engulfing
foreign cells
and digesting
them
Antibodies are
produced by white
blood cells and lock
onto + kill invading
cells. They are
produced rapidly and
carried around the
body
The
Nervous
System
Stimulus=Change in your
environment
Receptors=Groups of cells
sensitive to a stimulus
Stimulus= Light, Sound,
touch, pressure or
temperature
Eyes: Light
receptors=
Sensitive to
light,
contain a
nucleus,
cytoplasm
and cell
membrane
Ears: Sound
Receptors=
Sensitive to
sound
"Balance
Receptors"=
Sensitive to
changes in
postion
Nose: Smell
Receptors=
Sensitive to
chemical stimuli
Tongue: Taste
Receptors=
Sensitive to
sweet, salt, bitter,
savoury
Skin: Sensitive to touch,
pressure, pain and
temperature change
Neurones
Sensory: Nerve
cells which carry
signals (electrical
impulses) from
receptors in sense
organs to the central
nervous system
Relay: Nerve cells which
carry signals from sensory
neurone to motor neurone
Motor
Neurone:
Nerve cells
that carry
signals from
central
nervous
system to
the effector
muscle/gland
Effectors: Muscle + Glands which respond in different ways.
Muscles contract in responce to impulse from nervous
system. Glands secrete hormones
Hormones
Hormones:
Chemical
messengers
which travel
in the blood,
activating
target cells
Nerves: Fast
actions,
short time,
precise area
Hormones: Slower
action, long time,
general area
The Menstrual Cycle
FSH: Produced by pituitary
gland. Causes egg to
mature in ovaries and
stimulates ovaries to
produce oestrogen
OESTROGEN:
Produced in the
ovaries. Causes
pituitary to
produce LH and
inhibits the
further release
of FSH
LH (LUTEINISING HORMONE): Produced in the
pituitary gland. It stimulates the release of a
egg at the middle of the menstrual cycle
PROGESTERONE: Hormone
produced by ovaries
Synapse + Reflexes
Reflex Arc
Stimulus Detected
Stimulation of
pain receptor
Impulses travel along sensory neurone
Impulses pass
along a relay
neurone
(synapse)
Impulses travel
along a motor
neurone (synapse)
Impulse reaches muscle,
contracting. Moving hand
away from stimulus
Plant
Hormones
Auxin :
Controls
growth near
tips of
shoots and
roots
Controls its response to light
(phototropism), gravity
(geotrophism) and moisture
Auxin is
produced in the
tips, it moves
backwards
stimulating cell
elongation
process which
occurs in the
cells behind the
tips. If no auxin
is available it
may stop
growing
Shoot grows towards light=
grow faster on shaded side
bending towards light. Shoot
grows away from gravity=
lower side growing faster,
bending shoot upwards.
Roots grow towards gravity=
cells on top elongate faster,
root bends downwards.
Roots grow towards
moisture= Inhibits growth
on that side causing root to
bend in that direction
Homeostasis
Bodily levels
that need to
be controlled.
Ion, water,
sugar content
and
temperature
Ions are taken into the
body in food and absorbed
into the blood. Some ions
are lost in sweat and
kidneys remove the excess
from the blood, then got rid of
in urine.
Water is lost
through skin as
sweat, via lungs
in breath and via
the kidneys as
urine
On a hot day (more
sweat) you produce
less urine, but it will
be more concentrated.
Also when you lose
more water through
your breath when you
exercise because you
breathe faster
Enzymes
work best at
37°c so your
body trys to
remain this
temperature.
A hormone (insulin) helps
maintain the right level of
glucose in your blood so
your cells get a constant
supply of energy
Drugs
Drugs cause chemical changes leading
the body to become addicted if the drug
isnt taken a addict can suffer physical
withdrawal symptons which are
unpleasant
Medical drugs are medically
useful some that do require
prescriptions can be dangerous
if misused. Recreational drugs
are used for fun and
performance enhancing drugs
can improve a person's
performance in sport.
Medical testing of drugs
1. tested on human cells
and tissues in a lab
(only drugs that dont
affect the
whole/multiple body
systems
2. Test the drug on live animals. This is to see if it
works, find out its toxicity and best dosage. Any new
drug must be tested on two different live mammals.
3. If the drug passes it is
tested on human volunteers in a
clincal trial. First on healthy
volunteers (low dose to start of
and gradually increased)
4. Next it is tested on
people with the illness
and the optimum dose is
found. Patients are put
into two groups, one with
the new drugs and the
other with a placebo so
the doctor can see the
actual difference the drug
is making.
Clincal trials are blind,
neither the doctor nor
the patient know untill
results are gathered