- Relays information between
brain and body, allows
monitoring and contains nerve
cells to allow simple reflexes
The brain
Contains the cerebrum,
diencephalon, brain
stem and cerebellum
Cerebrum is split
into 2
hemispheres
which
communicate
through the
corpus collosum
Diencephalon
contains
hypothalamus and
thalamus where the
hypothalamus
regulates body temp,
hunger etc
Brain stem regulates the
autonomic functions
such as breathing, heart
beat and swallowing
Cerebellum monitors motor
skills, balance,
co-ordination
Peripheral Nervous System
(relays nerve impulses from CNS
to the body and back)
Somatic Nervous System
- Has 12 pairs of cranial nerves
and 31 pairs of spinal nerves.
They both have sensory
neurons and are involved in
reflex actions
Autonomic Nervous System
Contains the sympathetic
branch (hypes up the body)
and the parasympathetic brain
(brings body back to normal)
Sympathetic Branch - helps to
deal with flight or fight and
releases noradrenaline
Parasympathetic Branch -
relaxes the body and
releases acetylcholine (rest
and digest)
Neurons and Synaptic Transmission
Structure and function of
neurons
They carry neural
information and consist of
a cell body, dendrites and
an axon.
Sensory Neurons carry
impulses from sensory
receptors TO the CNS
Relay Neurons allow sensory and motor
neurons to communicate
Motor Neurons form synapses with
muscles and control contractions
Synaptic Transmission
Is an electrical impulse (action potential)
arrives at end of axon. Crosses synaptic gap
and neurotransmitters are released. They
bind to receptors and produce excititary or
inhibitory effect.
Excitatory Neurotransmitters
releases noradrenaline and is a
positive charge.
Inhibitory Neurotransmitters
releases serotonin and has a
negative charge
The Endocrine System
A network of glands that manufacture
and secrete chemical messengers
known as hormones
Signals are sent from the hypothalamus to the
piuitary gland in the form of a releasing
hormone. This causes the pituitary gland to
secrete a stimulating hormone into the
bloodstream.
Too many hormones or too
little hormones at one time
can result in dsyfunction of
bodily systems
Adrenal glands
Adrenal glands sit on top of the
kidneys. It contains the adrenal
cortex (outer part) and the
adrenal medulla (inner part)
Pituitary glands produce hormones
whose primary function is to influence
the release of hormones to other glands.
It is the master gland and is controlled by
the hypothalamus
Anterior hormones release ACTH as a
response to stress and posterior
hormones releases oxytocin to help
stimulate contractions in childbirth
Fight or flight response
Homeostasis is the tendency of
an organism to maintain an
internal equilibrium by
adjusting physiological
processes
Amydgala TO hypothalamus TO autonomic
nervous system (sympathetic) TO adrenal
medulla - HANSAM
Amydgala and Hypothalamus - brain area is
mobilised and a distress signal is given to
hypothalamus (acute and chronic stressors)
Sympathetic Nervous System begins process of
preparing body for fight or flight and sends a signal to
the adrenal medulla which releases adrenaline and
noradrenaline
Adrenaline makes the heart beats faster, pushes
blood to the muscles and triggers the release of
glucose to supply energy
Parasympathetic Nervous System dampens
down the stress response and slows down
processes
I; Gray argues that the first phase of
a reaction to a threat is not to fight
or flee but to avoid confrontation. J;
He suggested that many animals
show the 'freeze' response before
making a response and that this
response is essentially 'stop, look
and listen'. E; This shows that fight
or flight doesn't tell the whole story.
I; Research shows that there are some negative consequences of
fight or flight. J; The problem arises when the stress response is
repeatedly activated, as the blood pressure is induced from the
SNS can damage blood vessels. E; This means that it is a problem
for modern day life
I; Taylor suggested females behaviour response to stress is more
characterised by tend and befriend. J; Studies show there may be a
physiological response as the release of oxytocin in women
increases relaxation and makes them more nurturing. E; This shows
there are some gender differences.