SAC 1 - Chapter 2 & 3 Flashcards
Central Nervous System (CNS)
Comprises the brain and the spinal cord
Process information received from the body’s internal and external environments and to activate appropriate responses
Peripheral Nervous System (PNS)
It carries information to the CNS from the body’s muscles, organs and glands, and from the sensory organs
Sympathetic Nervous System (SNS)
Responding to dangerous or stressful situations where it activates an individual’s heart rate to speed up and delivers more blood in the areas that need more oxygen.
Focuses on the Fight and Flight acute stressor
Parasympathetic Nervous System (PNS)
Is the part of the nervous system that slows the heart.
Dilates blood vessels, decreases pupil size, increases digestive juices and relaxes muscles
Focuses on Homeostasis
Why is SNS and PNS not separate from each other?
Rather, one is dominant over the other at any given time depending on the situation
Neurotransmission VS Neruomodulation
Neurotransmitters help send messages between neurons in the brain, causing either excitatory or inhibitory effects. Neuromodulators like dopamine and serotonin have different effects on brain activity
Neuromodulation
Changing signals between neurons be boosted or reduced by a neuromodulator
Characteristics of Neuromodulators
- Neuromodulators are a type of neurotransmitters
- Neuromodulation involves chemical communication between neurons that may not be point-to-point
- It is not always fast
- They are released slower than other neurotransmitters
- Neuromodulators have longer lasting and wider range of effects
Neurotransmitters
- Description –> Chemicals released by a presynaptic neuron to send signals to the post-synaptic neuron
- Role –> To transmit chemical signals to the adjacent neuron
- Site of release –> Into the synapse
- Target –> A single post-synaptic neuron
- Speed of action –> Moderately fast
Neuromodulators
Description–> Chemicals released by neurons to alter the **effectiveness of neural transmission **
Role–> To alter the neural transmission of neurons by controlling the synthesis and release of neurotransmitters
Site of release –> Outside the synapse into the neural tissue in brain regions
Target–> Groups of neurons
Speed of action–> Moderately slow and last for longer periods
Dopamine
2 main functions as a neuromodulator:
Helps to coordinate voluntary motor movement
- produced in the substantia nigra
- released into areas involved with movement, including the **cerebellum and spinal cord **
Involved in the brain’s reward system
- travels along pathways in the limbic system (known as the dopamine reward system)
- makes us **feel happy when released **
Excitatory and inhibitory functions
Serotonin
Main functions as a neuromodulator
Regulates the sleep-wake cycle
- Produced in the brain stem (and gut) and released into the pineal gland to trigger melatonin production
Mood stabiliser
- Just the right amount of serotonin in linked to better emotional regulation and decreased depressive symptoms
Also** involved in appetite and pain perception**
Solely inhibitory functions
What is synaptic plasticity
Synpase: the connection between neurons
Plasticity: ability to be shaped or moulded
Simply put: the ability of neurons and neural connections to changein response to our experience (learning)
Sprouting
Neurons grow extensions to form new neural connections
Pruning
Weak or ineffective neural connections are eliminated
