Neuron Structure & Function

Neurons

Neurons are the main building blocks of the nervous system and they have a structure that is specialised to their function.

Neurons

Neurons are the central building blocks of the nervous system. There are 100 billion present at birth.
Like all cells, neurons are made up of several different parts. Each part has a specialised function.

Neuron membranes

A neuron’s outer surface is made up of a semipermeable membrane.
This membrane allows smaller molecules and molecules without an electrical charge to pass through it. It also stops larger or highly charged molecules.

Structure of neurons

The nucleus of the neuron is located in the soma, or cell body.
The soma has branching extensions known as dendrites.
The neuron is a small information processor. Dendrites act as input sites where signals are received from other neurons.

Axon and terminal buttons

Electrical signals received from other neurons are transmitted electrically across the soma and down a major extension from the soma known as the axon. The axon ends at multiple terminal buttons.
The terminal buttons contain synaptic vesicles that house neurotransmitters, the chemical messengers of the nervous system.

Signal transmission

The action potential from an electrical impulse moves rapidly down the axon to the terminal buttons.
At the terminal button, synaptic vesicles release neurotransmitters into the synapse.

Synapses and Neurotransmitters

Synapses and neurotransmitters are essential components of communication between neurons.

Synapses and neurotransmitters

A synapse is a very small space between two neurons. It is an important site where communication between neurons happens.
The synaptic cleft or gap is the space between two neurons.
The synaptic knob is the bulb shaped end of a neuron where it meets another neuron.
The synaptic vesicles are in the synaptic knob and are where neurotransmitters are stored before release into the synaptic cleft.
A neurotransmitter is a chemical messenger that carries information from one neuron to another.

Neurotransmitter release

Once neurotransmitters are released into the synapse, they travel across the small space and bind with corresponding receptors on the dendrite of an adjacent neuron.

Receptors

Receptors (proteins on the cell surface where neurotransmitters attach) vary in shape. Different shapes “match” different neurotransmitters.
The neurotransmitter and the receptor have what is known as a lock-and-key relationship - specific neurotransmitters fit specific receptors similar to how a key fits a lock.

Generating an action potential

The neurotransmitter binds to any receptor that it fits.
This binding triggers an action potential in the adjacent neuron, and the electrical impulse (i.e. the information) is transferred.

Types of Neurons

You need to understand the role of sensory, relay and motor neurons.

Sensory neurons

They carry nerve impulses (information) from sensory receptors (e.g. vision, taste, touch) to the spinal cord and towards the brain. Sensory receptors are found in various locations in the body, for example in the eyes, tongue and skin.
Sensory neurons convert information from these sensory receptors into neural impulses. When these impulses reach the brain, they are translated into sensations of, for example, visual input, heat, pain etc., so that the organism can respond appropriately.

Quick reflex action

Not all sensory information travels as far as the brain, with some neurons terminating in the spinal cord.
This allows reflex actions to occur quickly without the delay of sending impulses to the brain.

Relay neurons

Most neurons are neither sensory nor motor, but lie somewhere between the sensory input and the motor output. Relay neurons allow sensory and motor neurons to communicate with each other. These relay neurons (or interneurons) lie wholly within the brain and spinal cord.

Motor neurons

The term motor neuron refers to neurons located in the CNS that project their axons outside the CNS and directly or indirectly control muscles. Motor neurons form synapses with muscles and control their contractions.
When stimulated, the motor neuron releases neurotransmitters that bind to receptors on the muscle and trigger a response which leads to muscle movement. When the axon of a motor neuron fires, the muscle it has formed synapses with contracts. Muscle relaxation is caused by inhibition of the motor neuron.

1Social Influence

1.1Social Influence

1.1.1Conformity

1.1.2Asch (1951)

1.1.3Sherif (1935)

1.1.4Conformity to Social Roles

1.1.5BBC Prison Study

1.1.6End of Topic Test - Conformity

1.1.7Obedience

1.1.8Analysing Milgram's Experiment

1.1.9Agentic State & Legitimate Authority

1.1.10Variables of Obedience

1.1.11Resistance to Social Influence

1.1.12Minority Influence & Social Change

1.1.13Minority Influence & Social Impact Theory

1.1.14End of Topic Test - Social Influences

1.1.15Exam-Style Question - Conformity

1.1.16Top Grade AO2/AO3 - Social Influence

2Memory

3Attachment

3.1Attachment

3.1.1Caregiver-Infant Interaction

3.1.2Condon & Sander (1974)

3.1.3Schaffer & Emerson (1964)

3.1.4Multiple Attachments

3.1.5Studies on the Role of the Father

3.1.6Animal Studies of Attachment

3.1.7Explanations of Attachment

3.1.8Attachment Types - Strange Situation

3.1.9Cultural Differences in Attachment

3.1.10Disruption of Attachment

3.1.11Disruption of Attachment - Privation

3.1.12Overcoming the Effects of Disruption

3.1.13The Effects of Institutionalisation

3.1.14Early Attachment

3.1.15Critical Period of Attachment

3.1.16End of Topic Test - Attachment

3.1.17Exam-Style Question - Attachment

3.1.18Top Grade AO2/AO3 - Attachment

4Psychopathology

4.1Psychopathology

4.1.1Definitions of Abnormality

4.1.2Definitions of Abnormality 2

4.1.3Phobias, Depression & OCD

4.1.4Phobias: Behavioural Approach

4.1.5Evaluation of Behavioural Explanations of Phobias

4.1.6Depression: Cognitive Approach

4.1.7OCD: Biological Approach

4.1.8Evidence for the Biological Approach

4.1.9End of Topic Test - Psychopathy

4.1.10Exam-Style Question - Phobias

4.1.11Top Grade AO2/AO3 - Psychopathology

5Approaches in Psychology

5.1Approaches in Psychology

5.2Comparison of Approaches (A2 only)

5.2.1Psychodynamic Approach

5.2.2Cognitive Approach

5.2.3Biological Approach

5.2.4Behavioural Approach

5.2.5End of Topic Test - Comparison of Approaches

6Biopsychology

6.1Biopsychology

6.1.1Nervous System Divisions

6.1.2Neuron Structure & Function

6.1.3Neurotransmitters

6.1.4Endocrine System Function

6.1.5Fight or Flight Response

6.1.6The Brain (A2 only)

6.1.7Localisation of Brain Function (A2 only)

6.1.8Studying the Brain (A2 only)

6.1.9CIMT (A2 Only) & Postmortem Examinations

6.1.10Biological Rhythms (A2 only)

6.1.11Studies on Biological Rhythms (A2 Only)

6.1.12End of Topic Test - Biopsychology

6.1.13Top Grade AO2/AO3 - Biopsychology

7Research Methods

7.1Research Methods

7.1.1Experimental Method

7.1.2Observational Techniques

7.1.3Covert, Overt & Controlled Observation

7.1.4Self-Report Techniques

7.1.5Correlations

7.1.6Exam-Style Question - Research Methods

7.1.7End of Topic Test - Research Methods

7.2Scientific Processes

7.2.1Aims, Hypotheses & Sampling

7.2.2Pilot Studies & Design

7.2.3Questionnaires

7.2.4Variables & Control

7.2.5Demand Characteristics & Investigator Effects

7.2.6Ethics

7.2.7Limitations of Ethical Guidelines

7.2.8Consent & Protection from Harm Studies

7.2.9Peer Review & The Economy

7.2.10Validity (A2 only)

7.2.11Reliability (A2 only)

7.2.12Features of Science (A2 only)

7.2.13Paradigms & Falsifiability (A2 only)

7.2.14Scientific Report (A2 only)

7.2.15Scientific Report 2 (A2 only)

7.2.16End of Topic Test - Scientific Processes

7.3Data Handling & Analysis

7.3.1Types of Data

7.3.2Descriptive Statistics

7.3.3Correlation

7.3.4Evaluation of Descriptive Statistics

7.3.5Presentation & Display of Data

7.3.6Levels of Measurement (A2 only)

7.3.7Content Analysis (A2 only)

7.3.8Case Studies (A2 only)

7.3.9Thematic Analysis (A2 only)

7.3.10End of Topic Test - Data Handling & Analysis

7.4Inferential Testing

7.4.1Introduction to Inferential Testing

7.4.2Sign Test

7.4.3Piaget Conservation Experiment

7.4.4Non-Parametric Tests

8Issues & Debates in Psychology (A2 only)

8.1Issues & Debates in Psychology (A2 only)

8.1.1Culture Bias

8.1.2Sub-Culture Bias

8.1.3Gender Bias

8.1.4Ethnocentrism

8.1.5Cross Cultural Research

8.1.6Free Will & Determinism

8.1.7Comparison of Free Will & Determinism

8.1.8Reductionism & Holism

8.1.9Reductionist & Holistic Approaches

8.1.10Nature-Nurture Debate

8.1.11Interactionist Approach

8.1.12Nature-Nurture Methods

8.1.13Nature-Nurture Approaches

8.1.14Idiographic & Nomothetic Approaches

8.1.15Socially Sensitive Research

8.1.16End of Topic Test - Issues and Debates

9Option 1: Relationships (A2 only)

9.1Relationships: Sexual Relationships (A2 only)

9.1.1Sexual Selection & Human Reproductive Behaviour

9.1.2Intersexual & Intrasexual Selection

9.1.3Evaluation of Sexual Selection Behaviour

9.1.4Factors Affecting Attraction: Self-Disclosure

9.1.5Evaluation of Self-Disclosure Theory

9.1.6Self Disclosure in Computer Communication

9.1.7Factors Affecting Attraction: Physical Attributes

9.1.8Matching Hypothesis Studies

9.1.9Factors Affecting Physical Attraction

9.1.10Factors Affecting Attraction: Filter Theory 1

9.1.11Factors Affecting Attraction: Filter Theory 2

9.1.12Evaluation of Filter Theory

9.1.13End of Topic Test - Sexual Relationships

9.2Relationships: Romantic Relationships (A2 only)

9.2.1Social Exchange Theory

9.2.2Evaluation of Social Exchange Theory

9.2.3Equity Theory

9.2.4Evaluation of Equity Theory

9.2.5Rusbult’s Investment Model

9.2.6Evaluation of Rusbult's Investment Model

9.2.7Relationship Breakdown

9.2.8Studies on Relationship Breakdown

9.2.9Evaluation of Relationship Breakdown

9.2.10End of Topic Test - Romantic relationships

9.3Relationships: Virtual & Parasocial (A2 only)

9.3.1Virtual Relationships in Social Media

9.3.2Evaluation of Reduced Cues & Hyperpersonal

9.3.3Parasocial Relationships

9.3.4Attachment Theory & Parasocial Relationships

9.3.5Evaluation of Parasocial Relationship Theories

9.3.6End of Topic Test - Virtual & Parasocial Realtions

10Option 1: Gender (A2 only)

10.1Gender (A2 only)

10.1.1Sex, Gender & Androgyny

10.1.2Gender Identity Disorder

10.1.3Biological & Social Explanations of GID

10.1.4Biological Influences on Gender

10.1.5Effects of Hormones on Gender

10.1.6End of Topic Test - Gender 1

10.1.7Kohlberg’s Theory of Gender Constancy

10.1.8Evaluation of Kohlberg's Theory

10.1.9Gender Schema Theory

10.1.10Psychodynamic Approach to Gender Development 1

10.1.11Psychodynamic Approach to Gender Development 2

10.1.12Social Approach to Gender Development

10.1.13Criticisms of Social Theory

10.1.14End of Topic Test - Gender 2

10.1.15Media Influence on Gender Development

10.1.16Cross Cultural Research

10.1.17Childcare & Gender Roles

10.1.18End of Topic Test - Gender 3

11Option 1: Cognition & Development (A2 only)

11.1Cognition & Development (A2 only)

11.1.1Piaget’s Theory of Cognitive Development 1

11.1.2Piaget's Theory of Cognitive Development 2

11.1.3Schema Accommodation Assimilation & Equilibration

11.1.4Piaget & Inhelder’s Three Mountains Task (1956)

11.1.5Conservation & Class Inclusion

11.1.6Evaluation of Piaget

11.1.7End of Topic Test - Cognition & Development 1

11.1.8Vygotsky

11.1.9Evaluation of Vygotsky

11.1.10Baillargeon

11.1.11Baillargeon's studies

11.1.12Evaluation of Baillargeon

11.1.13End of Topic Test - Cognition & Development 2

11.1.14Sense of Self & Theory of Mind

11.1.15Baron-Cohen Studies

11.1.16Selman’s Five Levels of Perspective Taking

11.1.17Biological Basis of Social Cognition

11.1.18Evaluation of Biological Basis of Social Cognition

11.1.19Important Issues in Social Neuroscience

11.1.20End of Topic Test - Cognition & Development 3

11.1.21Top Grade AO2/AO3 - Cognition & Development

12Option 2: Schizophrenia (A2 only)

12.1Schizophrenia: Diagnosis (A2 only)

12.1.1Classification & Diagnosis

12.1.2Reliability & Validity of Diagnosis

12.1.3Gender & Cultural Bias

12.1.4Pinto (2017) & Copeland (1971)

12.1.5End of Topic Test - Scizophrenia Diagnosis

12.2Schizophrenia: Treatment (A2 only)

12.2.1Family-Based Psychological Explanations

12.2.2Evaluation of Family-Based Explanations

12.2.3Cognitive Explanations

12.2.4Drug Therapies

12.2.5Evaluation of Drug Therapies

12.2.6Biological Explanations for Schizophrenia

12.2.7Dopamine Hypothesis

12.2.8End of Topic Test - Schizoprenia Treatment 1

12.2.9Psychological Therapies 1

12.2.10Psychological Therapies 2

12.2.11Evaluation of Psychological Therapies

12.2.12Interactionist Approach - Diathesis-Stress Model

12.2.13Interactionist Approach - Triggers & Treatment

12.2.14Evaluation of the Interactionist Approach

12.2.15End of Topic Test - Scizophrenia Treatments 2

13Option 2: Eating Behaviour (A2 only)

13.1Eating Behaviour (A2 only)

13.1.1Explanations for Food Preferences

13.1.2Birch et al (1987) & Lowe et al (2004)

13.1.3Control of Eating Behaviours

13.1.4Control of Eating Behaviour: Leptin

13.1.5Biological Explanations for Anorexia Nervosa

13.1.6Psychological Explanations: Family Systems Theory

13.1.7Psychological Explanations: Social Learning Theory

13.1.8Psychological Explanations: Cognitive Theory

13.1.9Biological Explanations for Obesity

13.1.10Biological Explanations: Studies

13.1.11Psychological Explanations for Obesity

13.1.12Psychological Explanations: Studies

13.1.13End of Topic Test - Eating Behaviour

14Option 2: Stress (A2 only)

14.1Stress (A2 only)

14.1.1Physiology of Stress

14.1.2Role of Stress in Illness

14.1.3Role of Stress in Illness: Studies

14.1.4Social Readjustment Rating Scales

14.1.5Hassles & Uplifts Scales

14.1.6Stress, Workload & Control

14.1.7Stress Level Studies

14.1.8End of Topic Test - Stress 1

14.1.9Physiological Measures of Stress

14.1.10Individual Differences

14.1.11Stress & Gender

14.1.12Drug Therapy & Biofeedback for Stress

14.1.13Stress Inoculation Therapy

14.1.14Social Support & Stress

14.1.15End of Topic Test - Stress 2

15Option 3: Aggression (A2 only)

15.1Aggression: Physiological (A2 only)

15.1.1Neural Mechanisms

15.1.2Serotonin

15.1.3Hormonal Mechanisms

15.1.4Genetic Factors

15.1.5Genetic Factors 2

15.1.6End of Topic Test - Aggression: Physiological 1

15.1.7Ethological Explanation

15.1.8Innate Releasing Mechanisms & Fixed Action Pattern

15.1.9Evolutionary Explanations

15.1.10Buss et al (1992) - Sex Differences in Jealousy

15.1.11Evaluation of Evolutionary Explanations

15.1.12End of Topic Test - Aggression: Physiological 2

15.2Aggression: Social Psychological (A2 only)

15.2.1Social Psychological Explanation

15.2.2Buss (1963) - Frustration/Aggression

15.2.3Social Psychological Explanation 2

15.2.4Social Learning Theory (SLT) 1

15.2.5Social Learning Theory (SLT) 2

15.2.6Limitations of Social Learning Theory (SLT)

15.2.7Deindividuation

15.2.8Deindividuation 2

15.2.9Deindividuation - Diener et al (1976)

15.2.10End of Topic Test - Aggression: Social Psychology

15.2.11Institutional Aggression: Prisons

15.2.12Evaluation of Dispositional & Situational

15.2.13Influence of Computer Games

15.2.14Influence of Television

15.2.15Evaluation of Studies on Media

15.2.16Desensitisation & Disinhibition

15.2.17Cognitive Priming

15.2.18End of Topic Test - Aggression: Social Psychology

16Option 3: Forensic Psychology (A2 only)

17Option 3: Addiction (A2 only)

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