Nervous system Flashcards
Sensory neurons
Transmit sensory information from receptors to the CNS via afferent tracts
Interneurons
Connect sensory and motor neurons, and coordinate responses.
Motor Neurons
Transmit messages from the CNS to effector muscles, organs, and glands
Dendrites
Recieve informations from other neurons
Soma
Integrates information from dendrites
Axon
Transmits messages from soma to axon terminals
Myelin
Fatty substance surrounding the axon that insulates the neuron, and increases the speed of neural transmission
Axon terminals
Stores and secretes neurotransmitters
Central Nervous System
Processes sensory information and coordinates motor responses
Brain
Receives and processes sensory information. Coordinates motor responses such as voluntary movement, emotions, concious thought and homeostasis.
Spinal cord
Allows for communication between brain and peripheral nervous system. Coordinates spinal reflexes.
Peripheral Nervous system
All nerves outside the CNS. Carries sensory information to the CNS, and relays motor informations from the CNS to effectors.
Somatic Nervous System
Controls concious/voluntary movement of skeletal muscles, and spinal reflexes.
Muscles constrict or relax
Autonomic nervous system
Regulates activity of visceral muscles, organs and glands.
Doesn’t depend on control from the brain, generally operating without concious awareness.
Sympathetic nervous system
Responsible for increasing arousal, activated by a stressor.
Releases adrenaline and noradrenaline.
Parasympathetic Nervous system
Maintains homeostasis, counterbalancing sympathetic nervous system activity.
Enteric Nervous system
Nerves located in the lining of the gastrointestinal tract.
Can function independent from the brain.
Neurotransmitters
Chemical messengers that relay signals across synapses.
Binds to complementary-shaped receptor sites on post-synaptic neurons.
Synapse
The point of communication between two neurons or a neuron and target cell.
Glutamate
An excitatory neurotransmitter.
Increases likelihood of post-synaptic neuron firing an action potential.
GABA
An inhibitory neurotransmitter.
Blocks/suppresses post-synaptic neuron activity
Neuromodulators
Chemicals that effect a widespread brain region/many neurons
Increase/decrease the excitability/responsiveness of neurons
Neuromodulation
The process where synaptic communication is either enhanced or decreased
Dopamine
Regulates: voluntary motor movements, reward-based learning, memory, and motivation
Serotonin
Regulates: mood, sleep and the gut-brain axis
Synaptic plasticity
The ability of synaptic connections to change in response to activity
Long term potentiation
Long-lasting strengthening of neural pathways as a result of repeated stimulation, resulting in increased efficacy of synaptic transmission.
- additional axon terminals
- additional dendrites
- additional receptor sites
- more synapses
- increased glutamate release
- dopamine release
Long term depression
Long-lasting weakening of synaptic connections due to prolonged low-level stimulation, resulting in decreased efficacy of synaptic transmission
- reduction of axon terminals
- reduction of dendrites
- reduction of receptor sites
- less/weaker synapses
- decreased glutamate release
- dopamine release
Sprouting
The formation of new synapses
Rerouting
Reorganisation of neural pathways to establish alternate pathways
Pruning
Elimination of neural pathways to increase efficacy of neural transmission
Stress
A state of physiological or psychological arousal caused by internal or external stressors that is percieved by the individual as exceeding their ability to cope.
* Cumulative
* Psychobiological process
Stressors
Stimuli that causes or produces stress
Internal stressors
Originate from within the individual
Bio/psycho
External stressors
Originate from outside the individual
Social
Acute stress
Stress that occurs for a short period of time
Chronic Stress
Stress that occurs for a prolonged period of time
Non-specific stress response
Regardless of the stressor, the body will respond with the same physiological changes.
Hypothalamic-pituitary-adrenal (HPA) axis
Responsible for the release of cortisol when confronting a stressor.
Fight-flight-freeze response
Adaptive response to acute stress
Fight response
Individual will confront the threat directly
Flight response
Individual will attempt to evade the stressor
Freeze
Body will immobilise to avoid detection from the threat
Coping strategies
Specific methods used by an individual to manage or reduce stress
Approach coping strategy
Address the stressor directly
Avoidance coping strategy
Individual directs their energy away from the stressor
Context-specific effectiveness
The extent to which a coping strategy is appropriate for the unique demands of a stressor
Coping flexibility
The ability to swap coping strategies to meet the changing demands of a stressor
Gut brain axis
Bidirectional communication link between the enteric and central nervous systems
sensory to brain, motor to gut, both control voluntary bowel movements
Microbiota
The organisms within the gut that aid digestion
