Nervous system, neuromodulators, neurotransmitters (copy)

Describe the function of the CNS

Consists of the brain and spinal cord. Transmission and reception of neural information to and from the peripheral nervous system

Function of the brain in the CNS

Organising, interpreting and integrating neural information.

Function of the spinal cord in the CNS

A relay station between the brain and PNS

Function of interneurons

Relays messages between sensory and motor neurons within the CNS

Function of the somatic nervous system

Carries sensory information to the CNS and motor information from the CNS to skeletal muscles to initiate voluntary movements.

Function of sensory neurons in the somatic NS

AKA afferent neurons
Carries sensory information form sensory receptors in the body to the spinal cord.

What does afferent pathway refer to

Towards the brain

Function of motor neurons in the somatic NS

AKA efferent neurons. Carries/ relays motor information from the spinal cord to activate skeletal muscles for voluntary movement.

Function of autonomic NS

Carries neural messages between the CNS and internal muscles, organs and glands.
Is self-regulating and controls involuntary movements.

Function of parasympathetic NS in the autonomic NS

Calms body down after arousal and maintains homeostasis.

Function of the sympathetic NS in the autonomic NS

Prepares the body for actions by activating visceral muscles, organs and glands for vigorous activity or to deal with a threatening situation.

Define neurons

Individual, specialised nerve cells that receive, process and transmit information within the nervous system.

Define neurotransmitters

Chemicals produced by neurons that carry messages to other neurons or cells within the NS

Function of neurotransmitters.

Transmission of chemical signals from a pre-synaptic neuron to the adjacent post-synaptic neuron

Function of GABA

GABA is a primary inhibitory neurotransmitter that supresses post-synaptic neuron activity, decreasing the likelihood of firing.
Maintains neurotransmission at an optimal level and regulates CNS arousal.

Function of glutamate

Primary excitatory neurotransmitter.
Enhances information transmission by making post-synaptic neurons more likely to fire.

Define neuromodulators

Subclass of neurotransmitter that is also a chemical molecule.

Function of neuromodulators

Alters the strength of neural transmission by increasing or decreasing the responsiveness of many neurons to neurotransmitter signals.
Slower than neurotransmitters, diffuses.

Define dopamine

A multifunctional neurotransmitter with both excitatory and inhibitory effects.

Function of dopamine

Involved in CNS functions such as movement, attention, mood, cognition and motivation.
Reinforces the neural activity in regions of the brain associated with these functions.

Describe the function of the reward pathway of dopamine

A group of structures in the brain are activated by stimuli that act as rewards or reinforcements. The more stimulus is processed within the reward centre, the more that stimulus is seen as a reward leading to a desire to repeat the behaviour.

What does the release of dopamine lead to?

Feelings of pleasure and euphoria

Define serotonin

An inhibitory neurotransmitter or neuromodulator

Function of serotonin

Modulates virtually all human behavioural processes as it influences a variety of brain activities.

Describe the function of the serotonin pathway

Originates in the brain stem and extends to almost all areas of the cerebrum. Serotonin is produced in the brain stem and travels, modulating brain activity in these areas.

What can occur due to impairments in the serotonin pathway

Anxiety, depression, Parkinson's

Compare neurotransmitters and neuromodulators

Both are chemical molecules. Neurotransmitters are released by a single pre-synaptic neuron to a single post-synaptic neuron, whereas neuromodulators are released by neurons to alter neural transmission. Neurotransmitters are faster than neuromodulators.

How do GABA and glutamate work together?

They both counteract each others effects. GABA will counteract the excitatory effects of glutamate vice versa.