AOS 1 - How Does Nervous System Enable Psychological Functioning Flashcards
Central Nervous System
Process information received from our internal and external environments and activate appropriate responses
Brain
Processes information received through neural pathways from the body receives and analyses sensory info, controls all bodily functions
Spinal Cord
Receives sensory info from the body (via PNS) and sends it to the brain for processing.
Receives motor info from the brain and sens it to the body (via PNS) to control muscles, glands, and organs.
Peripheral Nervous System
Carries info to CNS from body’s muscles, organs, glands, and sensory info.
Carries info from the CNS to the body’s muscles, organs, and glands.
PNS - Somatic Nervous System
Sensory function - Transmission of info to the brain (CNS) from sensory receptors located throughout the body
Motor function - Voluntary movement of muscles
PNS - Autonomic Nervous System
Connects CNS to body’s main internal organs and glands and gives feedback to the brain about their activities
ANS - Sympathetic Nervous System
Activates internal muscles, glands, and organs to prepare the body to deal with vigorous activity or a stressful/threatening situation
ANS - Parasympathetic Nervous System
In times of minimal stress and absence of threats, maintains the internal body environment in a balanced state of normal functioning (homeostasis)
Neurons
Individual nerve cells that are specialized to receive, process, and transmit info
Sensory neuron - affarent
Receives and carries sensory info from both the external and internal environments and transmits to the CNS
Motor Neuron - efferent
Carries messages from the CNS to cells in skeletal muscles, organs, and glands to stimulate activity.
Interneuron
Sends messages between sensory and motor neurons within the CNS, relaying info from one to the other
Dendrites
An extension of a neuron that detects and receives info from other neurons
Axon
A single, tube-like extension that transmits neural info to other neurons (or cells in muscles and glands)
Myelin Sheath
White, fatty substance (made up of certain types of glial cells) that surrounds and insulates the axon
Axon terminals/buttons
Terminal buttons store and secrets neurotransmitters to carry the message to the next neuron
Communication pathway
- dendrites
- soma
- down the axon
4, axon terminals then out the terminal buttons
Neuron communication
Do so by sending neurotransmitters across the space between the terminal buttons of one neuron and the dendrites of another neuron SYNAPTIC GAP
Neurotransmitters
A chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, organs or other tissue
Effects of neurotransmitters
Excitatory effect - when a neurotransmitter stimulates or activates a postsynaptic neuron to perform its functions - glutamate
Inhibitory effect - when a neurotransmitter blocks or prevents a postsynaptic neuron from firing - GABA
Excitatory effect & Glutamate
The main excitatory neurotransmitter in CNS - accelerates brain activity
Glu enhances info transmission by making postsynaptic neurons more likely to fire
Inhibitory effect & GABA
The primary inhibitory neurotransmitter in the CNS - slows down brain activity
Works throughout the brain to make postsynaptic neurons less likely to fire
Balance of excitation and inhibition
Creates a critical state
Too much excitation - seizures
Too much inhibition - hampering neural computations that depend on complex signaling
Agonists & Antagonists
Agonists almost mimic glutamate by stimulating receptors to fire more quickly
Antagonists almost mimic GABA because they stimulate receptors in neurons to slow/reduce firing
Conscious responses
A conscious response to a sensory stimulus is a reaction that involves awareness
Unconscious responses
An unconscious response to a sensory stimulus is a reaction that doesn’t involve awareness
Spinal reflex
An unconscious, involuntary and automatically occurring response to certain stimuli without any involvement of the brain
Spinal reflex - the process
1, sensory receptors respond to stimulation
2. sensory neurons carry the message along a sensory pathway to the spinal cord
3. Interneurons in the spinal cord relay the message to motor neurons
4. Motor neurons carry the message along a motor pathway to hand muscles causing a withdrawal reflex
5. While the spinal reflex occurs, neurons are also carrying the message further up the spinal cord to the brain
6. The message is received in the area of the brain that processes this type of sensory info and interprets pain
Parkinson’s disease
Is a CNS progressive neurodegenerative disorder characterised by both motor and nonmotor symptoms
Symptoms of Parkinson’s
- Tremors
- Muscles Rigidity
- Slowness of voluntary movements
- Postural instability
How is Parkinson’s treated
- Medication that can be converted into dopamine by neurons
- Medication mimics the role of dopamine and stimulates the reception of dopamine by causing neurons to react as they would to dopamine.
lock and key process
- nts released by pre synaptic neuron
- not searches for correctly shaped receptor site on dendrites of postsynaptic neuron
- must precisely match in order to bind receptors like 2 keys in 2 locks
- binding ‘unlocks’ postsynaptic neuron response so that nt can cause change to neuron resulting in an excitatory or inhibitory effect
parkinson’s cause
Neurons in Substantia nigra produce dopamine
- if damaged dopamine levels for motor activity - gradually reduce as neurons die
- dopamine from the substantial nigra carries messages on how to control body movements to basal ganglia than to motor cortex in frontal loves
- primary motor cortex receives inadequate info due to impaired activation by dopamine - disrupted motor commands
