Zusammenfassung der Ressource
Nerves + Hormones.
- nervous system
uses electrical
impulses to enable
reactions
- cells called receptors detect stimuli (changes in the environment)
- Receptor cells have:
- nucleus
- cell membrane
- cytoplasm
- Impulses from
receptors pass
along sensory
neurone to
brain/spinal cord
(CNS).
- Impulses are sent
along motor
neurons from
brain (CNS) to
effector organs.
- receptor
- sensory neuron
- CNS (co-ordinator)
- motor neuron
- effector
- Reflex actions
- sensory
neurons - 5
senses
- motor neurons
- messages to
muscles
- relay neurons - connect sensory
and motor - located in CNS
- reflex arc
electrical
impulses bypass
the conscious
area of brain.
- time between stimulus and
response is as short as possible
- only motor, relay + sensory neurons involved.
- stimulus
- receptor
- co-ordinator
- effector
- response
- Synapses
- gap between 2 neurones.
- nerve impulses diffuse
neurotransmitters out of the
synaptic knob + bind with
post-neuron.
- nervous system reacts slower
than endocrime system.
- Menstrual Cycle
- mature
egg
released
from ovary
every 28
days
- FSH (follicle stimulating
hormone)
- causes egg to
mature,
stimulates ovary
to produce
oestrogen
- oestrogen
- causes lining of womb to
develop, inhibits FSH
production, stimulates
release of a mature egg.
- Artificial Control of Fertility
- oral contraceptives
- stop FSH
production
therefore no
eggs mature.
- FSH used as
drug to stimulate
egg maturity.
- FSH+LH
used in IVF
to stimulate
eggs to
mature.
- LH is Luteinising hormone
- produced in pituitary gland,
stimulates release of egg.
- Controlling conditions
- water levels
and ions,
blood sugar
+ temp.
- water - urine
in kidney
- blood sugar -
pancreas monitors by
hormones
- temp. - 37oC enzymes work best
- Homestasis
- sweating
causes body
to cool,
energy from
body used to
evaporate the
water in
sweat.
- Plant growth
control
- PHOTOTROPISM= sensitivity to light
- GRAVITROPISM= respose to gravity
- moisture=responses co-ordinated by plant hormone auxin
- responses of roots/shoots to stimuli due to unequal distribution of plant hormones.