Chapter 2 - The Nervous System Flashcards
What is the Central Nervous System (CNS)? Include the functions?
The CNS comprises the brain and its extension, the spinal cord. Its primary or overarching roles are to process information received from the body’s internal and external environments and to activate appropriate responses.
What is the spinal cord?
The spinal cord is the long, thin bundle of nerve fibres that extends from the base of the brain to the lower back. It is encased in a series of bones called the vertebrae that extend further than the actual cord.
What are the spinal cords functions?
The spinal cords functions are to receive sensory information from the body and sends these messages to the brain for processing and to receive motor information from the brain and sends it to relevant parts of the body and sends it to the muscles, glands, and internal organs so that appropriate actions can be taken.
What is the Peripheral Nervous System (PNS)? Include the functions?
The PNS is the entire network of nerves located outside the CNS. It extends from the top of the head, throughout the body to the tips of the fingers and toes and to all parts of the skin. Its primary, overarching role is to carry information to and from the CNS.
What are the 2 sub-divisions of the PNS?
The Sonamic Nervous System (SNS) and the Automatic Nervous System (ANS).
What is the Sonamic Nervous System (SNS)? Include the functions?
The SNS carries messages from sensory receptors in the body to the CNS, and motor messages from the CNS to skeleton muscles.
What is the difference between afferent and efferent?
Afferent means sensory information coming to the brain (incoming). Efferent means motor information coming from the brain (outgoing).
What is the Automatic Nervous System (ANS)? Include the functions?
The ANS connects the CNS to the body’s internal organs (such as heart, stomach, and liver) and glands (such as sweat, salivary, and adrenal glands), providing feedback to the brain about their activities.
What are the the 3 sub-divisions of the ANS?
The Sympathetic Nervous System, the Parasympathetic Nervous System, and the Enteric Nervous System.
What is the Sympathetic Nervous System?
The Sympathetic Nervous System increases the activity of most visceral muscles, organs, and glands in times of stress or threat.
What is the Parasympathetic Nervous System?
The Parasympathetic Nervous System decreases the activity of most visceral muscles, organs, and glands, and restores them to its normal state.
What is the Enteric Nervous System?
The Enteric Nervous System monitors the physiological conditions of the gut and integrates information about its state to control muscle contractions, gastric juice secretion, and blood flow. It is capable of functioning independently of the brain.
What is Synaptic Plasticity?
Synaptic Plasticity refers to the ability of the synapse to change in response to experience. This controls how effectively two neurons communicate with each other. It is the biological basis of learning and memory formation.
What is Sprouting?
Sprouting is the creation of new extensions on a neuron to allow a presynaptic neuron to form new connections to other neurons.
What is Rerouting?
Rerouting is the creation of a new neural pathways or modification of existing neural pathways to create alternate neural pathways to bypass pre-existing pathways or damaged neural circuits.
What is Pruning?
Pruning is the elimination of weak, ineffective, or unused synapses to maintain cognitive efficiency and ensures the brain can adapt to new and changing environments.
What is Long-Term Protentiation (LTP)?
LTP is long-lasting enhancement of synaptic transmission due to repeated strong stimulation by neurotransmitters between presynaptic and postsynaptic neurons.
What is Long-Term Depression (LTD)?
LTD is long-lasting decrease in the strength of synaptic transmissions and neuronal response due to a lack of stimulation of presynaptic and postsynaptic neurons (except in the cerebellum where LTD is due to persistent strong stimulation)
What are Neurotransmitters?
A Neurotransmitter is a chemical substance produced by a neuron that carries a a message to other neurons or cells in muscles, organs, or other tissue.
What is a Presynaptic neuron?
A Presynaptic neuron is the neuron sending the neurotransmitter.
What is a Postsynaptic neuron?
A Postsynaptic neuron is the neuron receiving the neurotransmitter.
What are the most commonly found neurotransmitters in the CNS?
Glutamate (Glu) and Gamma-Amino Butyric Acid (GABA).
What is Glutamate (Glu)? Include functions.
Glutamate is the main excitatory neurotransmitter in the CNS. This means that Glutamate enhances information transmission by making postsynaptic neurons more likely to fire. Glu promotes the growth and strengthening of connections between neurons.
What is Gamma-Amino Butyric Acid (GABA)? Include functions.
GABA is the primary inhibitory neurotransmitter in the CNS. It works throughout the brain to make postsynaptic neurons less likely to fire. It regulates anxiety and maintains the ‘best possible’ level.
What are Neuromodulators?
A neuromodulator is a neurotransmitter that can influence the effects of other neurotransmitters.
What are 2 commonly found Neuromodulators?
Dopamine and Serotonin.
What is Dopamine? Include functions.
Dopamine is a neuromodulator with multiple functions depending on where is acts. Functions include roles in coordinating involuntary movement, learning, and behaviours that are rewarding.
What is Serotonin? Include functions.
Serotonin is a neuromodulator with multiple functions depending on where it acts. Functions include emotional processing, mood, and sleep onset.
