Biopsychology Notes:
Divisions of the nervous system; central and peripheral (somatic and autonomic)
Nervous System:
o Complex network of nerve cells that carry messages to and from the brain and the spinal
cord.
CNS – comprises of the brain and the spinal cord. Controls behaviour and regulates the body’s
physiological processes, also sends messages to the muscles and glands
o Spinal cord – relays info between the brain and rest of the body and coordinates voluntary
movements
o Brain – regulates automatic functions that are needed for life e.g., breathing
Peripheral Nervous System – relay nerve impulses from the CNS to the rest of the body
o Somatic nervous system- transmit and receive messages from senses
o Autonomic nervous system – involuntary actions are regulated
o Parasympathetic – relaxes them again once the emergency has passed e.g., the
heartbeat slows down.
o Sympathetic – responses that help with emergencies such as increasing heart rate.
Structure and functions of Neurons
Dendrites – the end of the neuron
that receive signals from other
neurons or sensory receptors
Axon – the electrical impulse is
carried along the axon and
terminates at the axon terminal.
Myelin sheath – insulating layer of
the axon which allows nerve
impulses to travel more rapidly
Motor Neuron – carry signals from the CNS to both glands and muscles for them to carry put the
response
Sensory Neuron – tell the CNS about external and internal environment by processing info from the
senses.
Relay neuron – carry messages from one part of the CNS to another. They decide how your body
responds and connect motor and sensory neurons
, Neurons communicate with each other in neural networks. Neurones are separated by synapses.
Within neurons signals are transmitted electrically. Between neurons signals are transmitted
chemically across the synapse.
The process of synaptic transmission, including reference to neurotransmitters, excitation, and
inhibition
Synaptic transmission – the process for transmitting messages from one neuron to another.
Examples of neurotransmitters – serotonin and dopamine
The neurotransmitters (which were chemicals) diffuse across the gap between the pre and post
synaptic neuron. It then binds to specialised receptors that are activated by that particular
neurotransmitter. The vesicles hold the neurotransmitter into it is released into the synaptic cleft.
The chemical message is then converted back into an electrical impulse.
Excitatory and inhibitory neurotransmitters
o Different action potentials prompt different responses in the post synaptic neuron.
o Excitatory potentials – make the neuron more likely to fire e.g noradrenaline
o Inhibitory potentials – less likely to fire and he potential stopped at the post synaptic
neuron.
Summation= if the net effect on the post synaptic neuron is inhibitory, the neurone will be less likely
to fire and if the net is excitatory, the neurone will be more likely to fire.
The function of the endocrine system.
Glands:
o Pituitary- called the “master gland”. Hormones released regulate the endocrine system
o Adrenal- facilitates the release of adrenaline in the “fight or flight” response
o Testes- release testosterone
o Ovaries- release oestrogen and progesterone
Endocrine system is regulated by feedback to ensure stable concentrations of hormones. The
hypothalamus shuts down secretion of a stimulating hormone when concentration is stable. This
slows down secretion of the target glands hormones.
Pituitary Gland:
o Produces hormones whose primary function is to release other hormones from other glands.
o It is controlled by the hypothalamus
Adrenal Glands
o Sits at the top of the kidneys
o Split into adrenal cortex (outer) and adrenal medulla (inner).
o Adrenal cortex releases hormones necessary for life.
o Adrenal medulla releases hormones that aren’t.
Divisions of the nervous system; central and peripheral (somatic and autonomic)
Nervous System:
o Complex network of nerve cells that carry messages to and from the brain and the spinal
cord.
CNS – comprises of the brain and the spinal cord. Controls behaviour and regulates the body’s
physiological processes, also sends messages to the muscles and glands
o Spinal cord – relays info between the brain and rest of the body and coordinates voluntary
movements
o Brain – regulates automatic functions that are needed for life e.g., breathing
Peripheral Nervous System – relay nerve impulses from the CNS to the rest of the body
o Somatic nervous system- transmit and receive messages from senses
o Autonomic nervous system – involuntary actions are regulated
o Parasympathetic – relaxes them again once the emergency has passed e.g., the
heartbeat slows down.
o Sympathetic – responses that help with emergencies such as increasing heart rate.
Structure and functions of Neurons
Dendrites – the end of the neuron
that receive signals from other
neurons or sensory receptors
Axon – the electrical impulse is
carried along the axon and
terminates at the axon terminal.
Myelin sheath – insulating layer of
the axon which allows nerve
impulses to travel more rapidly
Motor Neuron – carry signals from the CNS to both glands and muscles for them to carry put the
response
Sensory Neuron – tell the CNS about external and internal environment by processing info from the
senses.
Relay neuron – carry messages from one part of the CNS to another. They decide how your body
responds and connect motor and sensory neurons
, Neurons communicate with each other in neural networks. Neurones are separated by synapses.
Within neurons signals are transmitted electrically. Between neurons signals are transmitted
chemically across the synapse.
The process of synaptic transmission, including reference to neurotransmitters, excitation, and
inhibition
Synaptic transmission – the process for transmitting messages from one neuron to another.
Examples of neurotransmitters – serotonin and dopamine
The neurotransmitters (which were chemicals) diffuse across the gap between the pre and post
synaptic neuron. It then binds to specialised receptors that are activated by that particular
neurotransmitter. The vesicles hold the neurotransmitter into it is released into the synaptic cleft.
The chemical message is then converted back into an electrical impulse.
Excitatory and inhibitory neurotransmitters
o Different action potentials prompt different responses in the post synaptic neuron.
o Excitatory potentials – make the neuron more likely to fire e.g noradrenaline
o Inhibitory potentials – less likely to fire and he potential stopped at the post synaptic
neuron.
Summation= if the net effect on the post synaptic neuron is inhibitory, the neurone will be less likely
to fire and if the net is excitatory, the neurone will be more likely to fire.
The function of the endocrine system.
Glands:
o Pituitary- called the “master gland”. Hormones released regulate the endocrine system
o Adrenal- facilitates the release of adrenaline in the “fight or flight” response
o Testes- release testosterone
o Ovaries- release oestrogen and progesterone
Endocrine system is regulated by feedback to ensure stable concentrations of hormones. The
hypothalamus shuts down secretion of a stimulating hormone when concentration is stable. This
slows down secretion of the target glands hormones.
Pituitary Gland:
o Produces hormones whose primary function is to release other hormones from other glands.
o It is controlled by the hypothalamus
Adrenal Glands
o Sits at the top of the kidneys
o Split into adrenal cortex (outer) and adrenal medulla (inner).
o Adrenal cortex releases hormones necessary for life.
o Adrenal medulla releases hormones that aren’t.
