PSYCHOLOGY

UNIT 3 & 4

UNIT 3

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What are the types of neurons?

• Sensory neuron (afferent) - Send signals to CNS from sensory receptors.

• Interneuron - Connects neurons together.

• Motor neuron (efferent) - Sends signals from CNS to sensory receptors

What does the structure of the human nervous system contain?

• Consists of the central nervous system (CNS) and peripheral nervous system (PNS)

What does the CNS consist of? what does each do?

• Two major divisions:

• The brain - processes information and coordinates it to different parts of the body or brain

• Spinal cord- sends info between body and the the brain, controls reflexes

What does the PNS do and consist of?

• Connects the CNS to the sensory receptors and the muscles and organs throughout the human body

• The PNS is divided into two branches somatic nervous system and autonomic nervous system

• comprised of all neural pathways (outside of CNS)

distinguish between somatic and autonomic nervous system

Somatic:

• sends sensory info to the CNS

• controls voluntary movement by sending motor signals from CNS to skeletal muscles

• controls involuntary reflex-arc

Autonomic:

• Regulates functions that are involuntary. E.g. breathing, heart rate, and digestion.

• branches to sympathetic and parasympathetic nervous system

compare sympathetic and parasympathetic nervous system, provide an example for each

Similarity

• both are part of the autonomic nervous system

differences:

• sympathetic: increases body functions or activity (often activating flight-flight-freeze response) such as heart rate or promoting adrenaline during extreme emotional or physical arousal.

• parasympathetic: slows down the body allowing it to return to a homeostasis state

What is the role of the spinal cord?

• carries sensory info to brain

• carries motor signals to the body from the brain

how is a reflex action produced?

• when the spinal cord coordinates a rapid automatic response without the need for the brain to process the information first.

what is a reflex arc?

The pathway in which a nerve impulses in

What is a reflex response?

• Reflexes can be conscious (involving somatic) or unconscious (involving automatic)

• A reflex is a fast unplanned sequence of actions in response to a stimulus to enhance survival and safety.

Distinguish between monosynaptic and polysynaptic spinal reflexes.

monosynaptic reflex arc - involves two neurons (affector and effector) in the spinal cord one sensor and one motor

polysynaptic reflex arc - involves multiple neurons with one or more interneurons in the spinal cord

Describe the steps in a reflex response includes the 5 main components of a spinal reflex arc

1.        Receptor – A special transducer that registers the stimulus and transfers it to a chemical response.

2.        Sensory afferent neurons – Transmits electrical response from the receptor to the spinal cord (CNS)

3.        Integration centre – (Interneuron) transfers electrical impulses to lower motor neurone

4.        Motor (efferent) neuron – Sends information to an effector

5.        Effectors (muscles or gland activates) – Performs action

Describe neurotransmission, with reference to action potentials and synaptic transmission.

• Neurotransmitters are chemical messages from the neurons which transmit across the synaptic cleft.

• During synaptic transmission, an action potential triggers the presynaptic neuron to release neurotransmitters from the synaptic vesicles and to the synaptic gap

• Neurons communicate through a electrochemical process. A neuron’s electrical signalling occurs within the neuron through an action potential.

• while chemical signalling occurs between neurons by neurotransmitters.

Contrast excitatory and inhibitory neurotransmitters, e.g. glutamate (Glu) and gamma-amino butyric acid (GABA).

• Excitatory - Enhances the likelihood of the post-synaptic neuron generate an action potential

• Glutamate (Glu) - Primary excitatory neurotransmitters in the CNS

• Inhibitory - Reduces the likelihood of the post-synaptic neuron from generating an action potential

• Gamma-amino butyric acid (Gaba) - Primary inhibitory neurotransmitter which has a calming effect on the brain

Describe the physical and psychological function of acetylcholine, epinephrine,

norepinephrine, dopamine and serotonin.

Transmitters:	Physical function:	Psychology function:
Acetylcholine	Activates muscle contraction (Somatic nervous system) and regulates autonomic functions	Crucial for learning, short term memory and attention.
Epinephrine	Triggers the fight-flight response and increases physical arousal	Increases fear and emotional arousal
Norepinephrine	Releases glucose and regulates physiological arousal	Controls focus, attention and the amygdala
Dopamine	Assists in voluntary muscle movement	Helps the brains motivation, and reward system. Creating a sense of pleasure when achieving a goal
Serotonin	Regulates sleep-wake cycle and digestion	Controls mood and emotional processing

what is the general interference cause of transmitter impaired functioning?

• Oversupply - Overproduction of neurotransmitters

• Hypoer active Enzymes - deactivating of too many neurotransmitters

• Undersupply - Neurons not manufacturing enough neurotransmitters

 Explain the impact of interference in neurotransmitter function, with reference to Parkinson’s disease, considering causes, symptoms and treatments.

cause - dopamine deficiency neurons occurs in the substantia nigra (located in the basal ganglia)

symptom:

motor - Tremors, muscle rigidy, bradykinesia (slow movement), and postural instability

non-motor - depression, anxiety and slow thinking, speech or behaviour

treatment - Dopamine Precursors, for example L -DOPA. which crosses the blood-brain barrier to be converted into dopamine to restore motor control within the brain.

 Explain the impact of interference in neurotransmitter function, with reference to Alzheimer’s disease, considering causes, symptoms and treatments.

• Cause - deficiency or significant reduction of the Acetylcholine neurotransmitter within the brain due to the continuing destruction of Acetylcholine-producing neurons

• symptoms - amnesia (loss of memory), confusion, cognitive decline, visual-spatial challenges and personality changes.

• treatment - Acetylcholinesterase inhibitors which prevent the enzymes responsible, from breaking down Acetylcholine in the synapse, this increases the availability while prolonging the effect of Acetylcholine.

Describe the concept between localised and distributed brain function.

Localised function - The theory that a specific area/lobe in the brain are responsible for distinct physiological or psychological functions.

Distributed function - The theory that a complex cognitive process for example memory or language cannot occur in one area, instead it is spread across large interconnected brain regions

Describe how brain function can be viewed as both localised and distributed, with

- some functions being identified with specific areas in the cerebral cortex, including the

frontal, occipital, parietal and temporal lobes

• all located in the cerebral cortex

• Frontal Lobe: Higher mental processes (reasoning, planning), decision-making, emotional regulation, and voluntary motor movement.

• Parietal Lobe: Processing bodily/somatosensory information (touch, temperature, pain, and spatial awareness).

• Occipital Lobe: Processing visual information (colour, shape, motion).

• Temporal Lobe: Processing auditory information, language comprehension, and memory.

functions of hippocampus, the neo-cortex and the amygdala

hippocampus - Memory process and spatial navigation.

Neo-cortex - Integration process and long term storage.

Amygdala - Threat detection, emotional processing

Describe how brain function can be viewed as both localised and distributed, with- some functions being distributed across large or multiple brain regions, e.g.

 the storage of explicit memory is associated with the hippocampus, the neo-cortex and the amygdala

• Explicit memory incorporates the distribution function

• Hippocampus - Crucial for the initial consolidation by turning the explicit memory from short term to long term.

• Neo-cortex (Cerebral cortex) - Where the long term explicit memories are permanently stored.

• Amygdala - Adds emotional content and intensity to explicit memories

 Describe how brain function can be viewed as both localised and distributed, with the formation of implicit memories relies upon the basal ganglia and cerebellum.

• Implicit memories (habits and motor skills) rely on a seperate network than Explicit memories

• Basal Ganglia - Crucial for organising and learning and executing motor habits, for example riding a bike.

• Cerebellum - Crucial for encoding and storing classical reflexes, motor coordination and balance

 Explain that Broca’s area, has a specific roles in language processing.

• Function: Responsible for clear and fluent speech

• Works: coordinates muscle movement (mouth, tongue, lips and vocal cord) to physically generate words and manage grammar structure

• Location: Left frontal lobe

 Explain that Wernicke’s area, has a specific roles in language processing.

• Function: Responsible for language interpretation and comprehension

• Works: Allows the understanding of both spoken and written words and language. also crucial role in choosing the appropriate words to create sentences.

• Location: Left temporal lobe

 Explain that Geschwind’s territory, has a specific roles in language processing.

• Function: Structured interconnected bridge linking Broca’s and Wernicke’s area together by a dense bundle of nerve fibres.

• Works: enables the integration of multi-sensory language information, helping the brain rapidly combine the sound of words, the sight of written text, and the meaning of a concept.

Explain the importance of the limbic system and the prefrontal cortex for the experience of emotion.

1. The limbic system - detects stimulus and generates immediate, automatic raw response often emotional

2. The signal is sent to the prefrontal cortex which processes, evaluates and regulates the emotional signal to modulate the emotional response

3. Result: Balance between activity from the limbic system and control from the prefrontal cortex

 Explain the individual role of the primary motor cortex, cerebellum and basal ganglia in coordinating voluntary movement.

• Primary Motor Cortex: Initiates and executes voluntary motor commands by sending neural signals down the spinal cord.

• Basal Ganglia: Filters and organises movement loops; activates the desired action while suppressing unwanted movements.

• Cerebellum: Fine-tunes movements in real-time using sensory feedback to maintain balance, posture, and coordination

 Explain the interaction of the primary motor cortex, cerebellum and basal ganglia in coordinating voluntary movement.

• The primary motor cortex proposes an action and sends out the initial commands.

• The basal ganglia filters this plan, giving the green light to the correct movement and eliminating errors.

• The cerebellum monitors the ongoing physical movement, making live micro-adjustments for perfect accuracy and balance.