The Nervous System, Brain Structure, and Human Behaviour & Stress

Comprehensive vocabulary flashcards covering the Central and Peripheral Nervous Systems, cerebral cortex lobes, limbic structures, spinal reflex arcs, synaptic transmission, neural plasticity, human behaviour, the biopsychosocial model, biological stress mechanisms, General Adaptation Syndrome (GAS), and Lazarus and Folkman's Transactional Model of Stress and Coping.

Nervous System

A complex network of nerves and cells that transmit signals between different parts of the body, responsible for controlling and coordinating all bodily activities.

Central Nervous System (CNS)

The primary control centre of the body consisting of the brain, which processes information and sends out instructions, and the spinal cord, which transmits messages between the brain and body.

Peripheral Nervous System (PNS)

The network of nerves branching out from the spinal cord to the rest of the body, muscles, and organs; divided into the somatic and autonomic nervous systems.

Somatic Nervous System (SNS)

A division of the PNS that connects the CNS to sensory organs and skeletal muscles, receiving environmental sensory input and carrying motor signals to control voluntary movements.

Autonomic Nervous System (ANS)

A division of the PNS that regulates involuntary processes such as heart rate, digestion, respiratory rate, and glandular secretions to maintain homeostasis without conscious effort.

Sympathetic Nervous System

The branch of the ANS that prepares the body for rapid action and 'fight or flight' during stressful or threatening situations, causing pupil enlargement, increased heart rate, and inhibited digestion.

Parasympathetic Nervous System

The branch of the ANS that restores the body to a state of calm and rest after a threat or stressor has passed, decreasing heart rate, constricting lung passages, and stimulating digestion.

Lobes of the Brain

The four anatomical cerebral divisions: the frontal lobe (planning and motor control), parietal lobe (somatosensory processing), occipital lobe (vision), and temporal lobe (hearing and memory).

Frontal Lobe

A region located at the front of each cerebral hemisphere responsible for higher-order cognitive functions (reasoning, decision-making, planning, problem-solving), emotional regulation, and voluntary movements.

Primary Motor Cortex

A region in the rear portion of the frontal lobe that controls voluntary bodily movements, dedicating larger cortical areas to body parts requiring precise control, such as the hands and face.

Parietal Lobe

A lobe located at the top of the brain that processes sensory information such as touch, temperature, pressure, and pain, and enables spatial awareness and physical coordination.

Primary Somatosensory Cortex

A strip located in the front part of the parietal lobe that receives and interprets signals from the skin, muscles, and joints, maintaining a sensory map with larger representation for sensitive areas like fingers and lips.

Occipital Lobe

The lobe situated at the back of the brain dedicated entirely to receiving and processing visual information such as shapes, colours, and movement.

Primary Visual Cortex

The cortical area within the occipital lobe where signals from the eyes are transformed into images and organized by size, distance, and direction.

Temporal Lobe

A region located on the sides of the brain near the ears that is central to sound processing, language comprehension, face and object recognition, and memory formation for speech.

Primary Auditory Cortex

The area within the temporal lobe that receives sound signals from the ears and processes acoustic features such as pitch, volume, and rhythm.

Limbic System

A interconnected network of subcortical structures—including the hippocampus, amygdala, and hypothalamus—that plays an essential role in regulating emotions, memory, and survival behaviours.

Hippocampus

A limbic system structure crucial for spatial navigation, learning, and consolidating short-term memory into long-term memory; damage leads to memory deficits or amnesia.

Amygdala

A limbic system structure responsible for scanning the environment for threats, processing emotions (particularly fear and aggression), and forming and storing emotional memories.

Hypothalamus

A limbic structure regulating vital homeostatic functions (hunger, thirst, body temperature, sleep) and controlling hormone release from the pituitary gland during stress and metabolic processes.

Spinal Cord

A major communication highway of the CNS containing over $1\text{ billion}$ neurons and supported by over $120$ muscles and $220$ ligaments; transmits sensory/motor messages and coordinates reflexes.

Reflex Arc

An automatic, involuntary motor response to a stimulus mediated by a neural pathway within the spinal cord, bypassing direct brain involvement for rapid defense against danger.

Sensory Neurons (Afferent Neurons)

Specialized nerve cells that detect external and internal stimuli through sensory receptors and transmit impulses from sense organs toward the central nervous system.

Motor Neurons (Efferent Neurons)

Nerve cells that transmit instructions from the central nervous system outward to effector sites, such as skeletal muscles, organs, and glands, to initiate action.

Interneurons

Neurons located entirely within the central nervous system that relay information and establish connections between sensory and motor neurons.

Neuron

The fundamental cellular unit of the nervous system responsible for receiving sensory inputs, conducting electrical impulses, and sending commands across neural circuits.

Dendrites

Branch-like extensions of a neuron that receive chemical and electrical signals from the axon terminals of other neurons and conduct impulses toward the cell body.

Soma (Cell Body)

The central metabolic region of a neuron containing the nucleus and organelles, responsible for maintaining cell health and integrating incoming electrical messages to determine action potential firing.

Axon

A long, slender nerve fibre extending from the soma that propagates electrical impulses away from the cell body toward other neurons, muscles, or glands.

Myelin Sheath

A protective fatty layer surrounding the axon that acts as an electrical insulator, increasing the speed and efficiency of nerve impulse transmission.

Axon Terminal

The swollen ending of an axon branch that houses synaptic vesicles containing neurotransmitters and releases them to communicate with target cells.

Synapse

The microscopic junction between neurons consisting of the presynaptic terminal, the synaptic cleft, and the postsynaptic membrane with specialized receptor sites.

Neurotransmitters

Chemical messengers released from synaptic vesicles across the synaptic cleft that bind to receptor sites on adjacent cells (e.g., dopamine, serotonin, acetylcholine).

Neural Plasticity

The brain's overall ability to change, grow, and reorganize its neural connections and pathways across the lifespan in response to experience, learning, or injury.

Long-Term Potentiation (LTP)

The long-lasting strengthening of synaptic connections across a neural pathway caused by repeated, high-frequency stimulation at glutamate synapses.

Long-Term Depression (LTD)

The long-lasting weakening of synaptic connections across a neural pathway caused by repeated low-level activation, allowing the brain to prune away unneeded connections.

Human Behaviour

The full range of actions, reactions, and interactions exhibited by individuals in response to their environment, personal experiences, and internal physiological or cognitive processes.

Biopsychosocial Model

A framework stating that human behaviour and health result from the dynamic interaction of biological (genetics, physiology), psychological (cognition, emotions), and social (culture, relationships) factors.

Stress

A psychobiological state of physiological, mental, and emotional tension that occurs when a person perceives that demands exceed their ability to cope.

Stressor

Any internal or external stimulus, person, event, or situation that produces stress.

Acute Stress

Short-term stress that arises rapidly in response to an immediate, distinct challenge or threat and resolves once the situation is managed.

Chronic Stress

Long-term, persistent stress lasting weeks, months, or years without a clear endpoint, keeping the physiological stress response active and depleting mental and physical resources.

Prefrontal Cortex (in Stress Regulation)

The brain area responsible for rational thinking, evaluating whether a threat is real or exaggerated, regulating emotional reactivity, and suppressing amygdala activity.

HPA Axis

The Hypothalamic–Pituitary–Adrenal endocrine axis that coordinates the body's prolonged stress response by triggering the release of cortisol into the bloodstream.

Cortisol

The body's primary steroid stress hormone released by adrenal glands; it elevates blood glucose and energy in the short term, but prolonged release suppresses immune function and impairs memory.

General Adaptation Syndrome (GAS)

Hans Selye's three-stage biological model explaining the body's predictable physiological changes during prolonged exposure to stress.

Alarm Reaction Stage

The first stage of GAS occurring when a stressor is first recognized; begins with a brief shock phase where resistance dips, followed by countershock where the sympathetic nervous system activates.

Resistance Stage (GAS)

The second stage of GAS where the body adapts and copes with the stressor at high physical cost; cortisol remains elevated, while immune defenses drop, increasing vulnerability to infections.

Exhaustion Stage (GAS)

The final stage of GAS where physical energy and stress hormones are depleted; resistance collapses, leading to extreme fatigue, severe illness, or anxiety and depression.

Transactional Model of Stress and Coping

A cognitive model developed by Richard Lazarus and Susan Folkman proposing that stress involves a dynamic transaction between a person and their environment, determined by primary and secondary cognitive appraisals.

Primary Appraisal

The initial evaluation of an incoming stimulus in the Transactional Model to determine whether it is irrelevant, benign-positive, or stressful (categorized as harm/loss, threat, or challenge).

Secondary Appraisal

The cognitive stage in the Transactional Model where an individual assesses their internal and external coping options and resources to determine if they can handle a stressor.

Problem-Focused Coping

A coping method aimed at directly resolving or altering the stressor through actionable measures such as planning, problem-solving, or acquiring new skills; best used when situations are changeable.

Emotion-Focused Coping

A coping method aimed at managing or reducing emotional distress caused by a stressor through strategies like relaxation, journaling, or seeking emotional comfort; best used when situations are unchangeable.

Approach Coping Strategies

Proactive coping actions directed toward confronting a stressor and dealing directly with its causes, generally recognized as the most effective long-term method for managing stress.

Avoidant Coping Strategies

Coping behaviors focused on evading or denying a stressor; while reducing distress in the short term, they prevent constructive problem solving and increase physiological stress and long-term illness.

Context-Specific Effectiveness

The degree of appropriate match or 'good fit' between a chosen coping strategy and the specific situational and environmental demands of a stressful event.

Coping Flexibility

An individual's ability to evaluate whether a coping strategy is working, discontinue ineffective approaches, and select and implement alternative strategies to adapt to changing stress demands.