The Biological Approach – Key Assumptions (pg 11)

The influence of Neurons and Neurotransmitters

What do you have in common with your parents?

The biological approach combines psychology and biology to provide physiological explanations for human behaviour. Biological psychology tries to explain how we think, feel and behave in terms of physical factors within the body.The biological approach explains human behaviour in terms of neurotransmitters, hormones, genes and brainstructures. With regards to the nature vs. nurture debate, the biological approach falls on the side of nature/nurture [cross out the wrong one]

What do you already know neurotransmitters, hormones, genes and brainstructures?

THE STRUCTURE AND FUNCTION OF NEURONS (pg 11)

The whole of the nervous system is composed of interconnected neurons. These are long thin cells that convey messaged from one place to another. They can be smaller than 1mm, or longer than a meter! The brain contains billions of these neurons. Neurons pass messages from one neuron to the next via small gaps between the neurons called a synapse. These messages are passed from neuron to neuron by neurotransmitters.

Neurotransmitters are chemical messengers that act between neurons within the brain. This allows the brain to process thoughts and memories.

• At one end they have dendrites (which are finger like structures surrounding a nucleus). • From the nucleus there is a long extension called an axon, which reaches to an axon terminal.• The axon terminal of one neuron reaches to the dendrites of other neurons. • Between the terminal and the dendrites there is a gap called a synapse• On the dendrites, there are receptors of a certain shape prepared to receive the

neurotransmitter from the axon terminals of other neurons.

How are messages sent?Describe how messages are sent through neurons:

Label the diagrams below

VesicleNeurotransmittersReceptor molecules

Dendrite of receiving neuron

Direction of nerve impulseAxon terminal Direction of nerve impulse

Cell BodyAxon Terminals Dendrites

Axon

Synapse

Neurotransmitters and mental health

Explain the role serotonin plays in mental health, and why low levels can have a negative effect.

Explain the role high levels of Dopamine plays in Schizophrenia.

THE STRUCTURE AND FUNCTION OF THE BRAIN

The central nervous systemThe central nervous system is made up of two parts

_________________________ _________________________

The brainThe brain made up of vast numbers of interconnected neurons and is separated into two halves called ___________________________. There are roughly ___________________________ neurons in the brain and spinal cord. The brain receives information from various sensory organs such as the eyes or tongue, as well as information about the position of the body, pain etc. The cerebral cortex of the brain is the outer few millimetres, and is divided into four lobes. Each lobe has a number of functions. Underneath the cerebral cortex are the sub-cortical regions.

The brain is separated into many highly specialised areas, each part performing a specific function. This organisation of the brain is called ____________________. This means that if one part of the brain is damaged it could lead to loss of a particular function.

What do you think the consequences would be if the parts labelled above were damaged?A: ________________________________________________________________________________________ __________________________________________________________________________________________B: ________________________________________________________________________________________ __________________________________________________________________________________________C: ________________________________________________________________________________________ __________________________________________________________________________________________

The Central Nervous System

A

CB

Parietal Lobe – Sensory Cortex

Occipital Lobe - Vision

Temporal Lobe – Hearing, Understanding Language

Frontal Lobe – Speech Production, Movement

The two hemishperes of the brain have different functions. In theory, if you have to do two tasks at the same time you will be slower if both tasks use the same hemisphere.

Think of an example of two tasks that use the same hemisphere.

THE ENDOCRINE SYSTEM (pg 3)The endocrine system is what controls the release of hormones into our blood stream. The endocrine system communicates information from the brain to the body. Hormones are released, and they have an effect on target organs such as the heart, liver or lungs. Hormones are produced in large quantities, and have an immediate effect (although it’s much slower than the nervous system).

Do you know what the following hormones do?

Testosterone: _________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________

Oestrogen: _____________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________

Adrenaline: _________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________

Left SideSpeechAnalysisTimeSequence

RecognisesWordsLettersNumbers

ControlsThe right side of the body

Right SideCreativityPatternsSpatialContext

RecognisesFacesObjectsPlaces

ControlsThe left side of

We will look in more detail at the endocrine system when we look at Selye’s GAS theory.GENETIC EXPLANATIONSA fourth assumption of the biological approach is that behaviour can be explained by the influence of genes. Some physical traits (such as eye or hair colour) are controlled by one gene. However, most of the time, genes interact with one another to produce an effect on behaviour (such as intelligence or mental illness). Genes however, do not control all human characteristics because the environment also has a part to play.

We inherit 23 chromosomes from each parent, and it is thought that our genes can account for many of the similarities between family members.

Can you think of a family where many of the members have something in common? It could be a physical trait (hair, eye colour, height etc) or a personality trait or talent (music, running, annoying laugh etc).

Do you think the similarities you have mentioned above are due to genetic or environmental factors?

Although experience and social factors may play a part, biological psychologists believe our personality, intelligence and even the tendency to develop mental illnesses are largely inherited. They investigate whether abnormalities are inherited from our parents, and if so, does the child inherit exactly the same abnormality as their parent, or is it a vulnerability to abnormality?

How could genes and environment interact to produce a person who is good at football?

What about someone who suffers from depression?

Matching task

Receptor The name for the system that controls the release of hormones into our bloodstream

Hormones A part of the neuron that responds to the presence of neurotransmitters.

Brain lateralisation

A nerve cell. They send electrical messages called nerve impulses along their length.

Motor neuron Chemicals that are released into the bloodstream and change the function of the body in some way.

Neurotransmitter

A chemical released at the end of a neuron to pass a message on to another neuron, a muscle or a gland.

Genes A part of the cerebral cortex. There are four in total

Neuron These cells make our muscles move and control the release of hormones

The endocrine system

A junction between two neurons where information can be passed from one to the other.

Synapse The extent to which brain functions are controlled by each hemisphere of the brain.

Lobe Units of information that are inherited from our parents. They influence physical or mental characteristics.