Nervous System: Structure and Function

• The nervous system is responsible for processing and sending information throughout the body.

Structural Organisation of the Nervous System

• The central nervous system (CNS) comprises the brain and spinal cord, handling information processing and distribution.
• The peripheral nervous system (PNS) links the CNS to the rest of the body.

Functional Divisions of the Peripheral Nervous System

• The somatic nervous system controls voluntary movements.
• The autonomic nervous system (ANS) manages involuntary functions.
• The sympathetic division activates the "fight or flight" response, increasing heart rate etc.
• The parasympathetic division activates the "rest and digest" response, slowing heart rate etc.
• Sensory neurons carry information from senses to the CNS.
• Motor neurons carry signals from the CNS to muscles for movement.

Features of Neurons

• Dendrites receive signals from other neurons.
• The soma (cell body) processes information.
• The axon transmits electrical impulses.
• Axon terminals send signals to the next neuron.
• The myelin sheath speeds up signal transmission.
• Sensory neurons carry sensory information to the CNS.
• Motor neurons send movement instructions from the CNS to muscles.
• Interneurons connect sensory and motor neurons within the CNS.

Neural Transmission

• Signals travel from dendrites to soma to axon to axon terminals.
• The neuron sends an electrical signal (action potential), converted to a chemical signal at the synapse.
• The synapse is the gap between neurons where neurotransmitters transfer signals.
• Neurotransmitters, such as dopamine and serotonin, transmit signals between neurons.

Location, Structure, and Function of the Brain

• The medulla controls automatic functions like breathing and heart rate.
• The cerebellum coordinates movement and balance.
• The reticular formation regulates sleep, arousal, and attention.
• The hypothalamus regulates body temperature, hunger, and hormones.
• The thalamus relays sensory information to the brain.
• The left and right cerebral hemispheres control opposite sides of the body.
• The corpus callosum connects the two hemispheres for communication.

Lobes of the Brain

• The frontal lobe handles decision-making, emotions, and movement, and includes Broca’s area for speech.
• The parietal lobe processes touch and spatial awareness.
• The temporal lobe processes sound and memory, and includes Wernicke’s area for language comprehension.
• The occipital lobe processes vision.

Historical Research on the Brain

• Phineas Gage’s frontal lobe damage revealed its role in personality and decision-making.
• Roger Sperry’s split-brain research showed how the two hemispheres function separately.
• Walter Freeman developed the frontal lobotomy, revealing the prefrontal cortex's role in personality and behavior.

Ethical Guidelines and Practices in Psychological Research

• Ethics committees approve and monitor research to protect participants.
• Protection from harm requires no physical or psychological harm.
• Informed consent requires participants to agree with knowledge of the risks.
• Participants have withdrawal rights and can leave at any time.
• Deception must be justified and followed by debriefing.
• Confidentiality and privacy require protection of participants' identities and data.
• Participation must be voluntary without coercion.
• Debriefing requires researchers to explain the study's true purpose afterward.

Use of Animals in Research

• Replacement involves using alternatives to animals where possible.
• Reduction involves using the smallest number of animals needed.
• Refinement involves minimizing distress and improving animal welfare.