Unit 3, topic 1 - role of the brain Flashcards
what are motor association areas responsible for?
Motor association areas:
Are responsible for mental processes such judgement, problem-solving, aspects of personality. People with damage to their mental lobe may fail to learn from experiences and lack foresight and will likely make mistakes in planning.
what are sensory association areas responsible for ?
Sensory association areas:
Integrate sensory information, construct spatial coordinate system of our environment.
what are visual association areas responsible for?
Visual association areas:
Integrate visual stimuli.
what are auditory association areas responsible for?
Auditory association areas:
Process and encode memory.
what do association areas do ?
help analyse and interpret particular sensory information. Also integrates information from several senses and memories.
what are the steps/what is the process of a spinal reflex process ?
Spinal reflex process:
Receptor – registers the stimulus and transfers it to a chemical response.
Afferent (sensory) neurons – transmit electrical impulse from the receptor to the spinal cord (CNS).
Integration – interneuron transfers electrical impulse to lower motor neurone.
Efferent (motor) neuron – sends info to an effector.
Effector (muscle or gland) - performs action.
differentiate monosynaptic and polysynaptic spinal reflexes
Monosynaptic – involving one synapse, where an affector neuron brings a sensation from the receptors and an effector neuron carries motor messages to the muscles of the body.
WHEREAS
Polysynaptic reflex arc – involving at least two synapses, when interneurons connect the affector and effector neurons.
compare the parasympathetic and sympathetic NS
compare = similarities and differences + significance.
both part of PNS and autonomic NS
Sympathetic NS – becomes active when organism is exposed to a threatening stimulus. It arouses the body and prepares one for flight or fight.
Increases heartrate & dilates pupils.
Parasympathetic NS – controls the ‘freeze’ response. Activated when one is aware they are unable to fight or flee a threatening stimulus. Also maintains homeostasis (maintaining daily day-to-day bodily functions. EG: digestion, normal heart rate, breathing).
Slows heartrate & constricts pupils.
what brain structures are involved in voluntary movement?
basal ganglia, cerebellum and primary motor cortex
what happens during an action potential
stimulus is applied to the neuron, sodium channels open and an influx of sodium ions moves inside the membrane increasing the overall positive charge of the membrane potential.
what is the role of the basal ganglia?
The basal ganglia enables voluntary movement by gathering information from various areas of the brain and channelling it to the motor cortex.
It also acts to block movements that may not suit the end goal.
Consists of a group of structures that include the caudate nucleus, putamen, globes pallidus and the subthalamic nucleus.
what is the role of the cerebellum in voluntary movement?
Stores sequences of movements that have been previously learnt (implicit/procedural memory).
It also coordinates and integrates information about movements from other areas in the brain to help make movements smooth and well sequenced.
The cerebellum communicates with the PMC by sending signals through a dense nerve bundle that consists of a large number of axons.
what is the role of the PMC?
Responsible for activating neural impulses that initiate voluntary movement of skeletal muscles.
what are the four main structures of the limbic system
amygdala, hypothalamus, hippocampus and prefrontal cortex
what are the two emotional pathways proposed by Le Doux?
and what are they
the short route - goes from the thalamus to the amygdala for induction of emotional response.
the long route - passes via cerebral cortex and hippocampus and hippocampus before reaching an emotional response.
what is the role of the prefrontal cortex in the limbic system
The ventral (underside) of the PFC is associated with and connects brain regions that are involved in emotional processing and production.
The PFC is involved in regulating and modifying emotions, also executive functioning and deciding between good and bad actions.
what is the role of the amygdala in the limbic system
Almond shaped structure found in the temporal lobe.
Involved in the activation of emotions – particularly fear and anxiety
The right side is involved in we perceive emotion, particularly negative emotions.
The amygdala is responsive to fear stimulus and fear conditioning.
what is the role of the hypothalamus in the limbic system
The hypothalamus is implicated in homeostasis and basic survival actions such as feeding, running, fighting and reproduction.
Part of the
HPA (hypothalamus-pituitary-adrenal gland response).
Involved in physiological responses to ear inducing emotional stimuli.
what is the role of the hippocampus in the limbic system
Involved in the regulation and expression of emotion and memory.
Recalls information relevant to an emotionally charged situation.
what is neurotransmission
Occurs when a neuron is activated, stimulated by pressure, light, temperature, or chemical information from other cells.
If the level of stimulation is high enough, the neuron converts the stimulus into an action potential (starts at –70millivolts)
An action potential is an electrical impulse that travels along the surface of the membrane of a neuron.
Sodium ions move into the inside of the membrane.
describe the lock and key process
At the axon terminal of the presynaptic neuron, vesicles bind to the cell membrane and release chemical neurotransmitters to cross the synaptic gap and propagate the information to the post-synaptic neuron.
In the synaptic gap, some of the neurotransmitters will bind to the receptors (protein molecules). the receptors act as a ‘lock’, that can only be opened with a particular ‘key’ or neurotransmitter.
When a receptor binds with the neurotransmitter that ‘fits’ (has the appropriate electrical charge and molecular structure), the post synaptic neuron is either activated or inhibited – this is referred to as the lock and key process.
what are the two types of synapses?
There are two main types of synapses involved in communication between neurons:
Excitatory synapses:
Cause the target cell to become excited and more likely to fire and cause an action potential.
Inhibitory synapses:
Cause the target to become inhibited and less likely to fire and cause an action potential.
what is glutamate?
Glutamate – the main exhibitory neurotransmitter in the central nervous system; increasing the odds of an action potential.
Involved in learning and memory, too much can cause seizures.
Low levels may interfere with ability to learn and focus.
Abnormally high levels may contribute to schizophrenia and other mental disorders because in hihg amounts is damaging to neural receptors.
what is GABA ?
GABA (gamma-amino butyric acid) - is the main inhibitory neurotransmitter; damps neural activity.
Helps you feel calm and relaxed, important in regulating anxiety.
Mood regulation
Important for attention span, sleep and arousal.
Low levels are correlated to depression, anxiety, panic attacks and insomnia.
Alcohol and anxiety drugs bind the GABA receptors increasing GABA receptors and contributing to suppression of overactive brain areas.
identify the five neurotransmitters
acetylcholine dopamine serotonin epinephrine norepinephrine
describe the role of acetylcholine
involved in:
muscle contractions (PNS)
learning and memory (CNS)
both excitatory and inhibitory
- excitatory at the neuromuscular joint
- inhibitory to smooth muscles and focus
in Alzheimer’s, neurons containing acetylcholine are gradually destroyed leading to deficits in memory functioning.
describe the role of dopamine
involved in motor control and learning, motivation and reward and reinforcement
dopamine neural pathways in the basal ganglia are involved in motor functions.
the release of dopamine can explain addiction behaviour. - excitatory
can also be inhibitory
Parkinson’s disease can be alleviated by dopamine injections.
describe the role of serotonin
serotonin (‘feel good drug) is involved in mood regulation, social behaviour, memory, appetite and digestion and sexual functioning.
also regulates the sleep-wake cycle.
inhibitory
compare epinephrine and norepinephrine
Epinephrine and norepinephrine
Stress response – affects emotional arousal, anxiety and fear.
Both neurotransmitters also serve as hormones (excreted by adrenal glands) that influence different parts of your body.
Epinephrine (adrenaline)
Regulated by ANS, mobilises the fight or flight response.
discuss Parkinson’s disease
Parkinson’s disease
A progressive nervous system disorder that affects movement.
Symptoms:
- Tremor
- Slowed movements
- Rigid muscles
- Impaired posture & balance
- Loss of automatic movements
- Speech changes (slurs, difficulty)
- Writing difficulty
Nerve cells that produce dopamine neurotransmitters and are responsible for relaying messages that plan and control motor movement.
Causes – genes or environmental risk factors.
Treatment – dopamine injections alleviate symptoms.
discuss Alzheimer’s disease
Alzheimer’s disease
A progressive neurological disorder that causes atrophy and death of brain cells.
Symptoms:
Memory loss
Difficulty reasoning and planning
Difficulty making judgements and decisions
Personality changes (apathy or depression etc).
Reduced concentration and functioning of acetylcholine.
Causes – breakdown of tangle proteins and clustering of plaques.
Treatment – donepezil medication.
