Unit 3, topic 1 - role of the brain

Question 1

what are motor association areas responsible for?

Answer 1

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.

Question 2

what are sensory association areas responsible for ?

Answer 2

Sensory association areas:

Integrate sensory information, construct spatial coordinate system of our environment.

Question 3

what are visual association areas responsible for?

Answer 3

Visual association areas:

Integrate visual stimuli.

Question 4

what are auditory association areas responsible for?

Answer 4

Auditory association areas:

Process and encode memory.

Question 5

what do association areas do ?

Answer 5

help analyse and interpret particular sensory information. Also integrates information from several senses and memories.

Question 6

what are the steps/what is the process of a spinal reflex process ?

Answer 6

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.

Question 7

differentiate monosynaptic and polysynaptic spinal reflexes

Answer 7

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.

Question 8

compare the parasympathetic and sympathetic NS

Answer 8

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.

Question 9

what brain structures are involved in voluntary movement?

Answer 9

basal ganglia, cerebellum and primary motor cortex

Question 10

what happens during an action potential

Answer 10

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.

Question 11

what is the role of the basal ganglia?

Answer 11

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.

Question 12

what is the role of the cerebellum in voluntary movement?

Answer 12

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.

Question 13

what is the role of the PMC?

Answer 13

Responsible for activating neural impulses that initiate voluntary movement of skeletal muscles.

Question 14

what are the four main structures of the limbic system

Answer 14

amygdala, hypothalamus, hippocampus and prefrontal cortex

Question 15

what are the two emotional pathways proposed by Le Doux?

and what are they

Answer 15

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.

Question 16

what is the role of the prefrontal cortex in the limbic system

Answer 16

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.

Question 17

what is the role of the amygdala in the limbic system

Answer 17

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.

Question 18

what is the role of the hypothalamus in the limbic system

Answer 18

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.

Question 19

what is the role of the hippocampus in the limbic system

Answer 19

Involved in the regulation and expression of emotion and memory.

Recalls information relevant to an emotionally charged situation.

Question 20

what is neurotransmission

Answer 20

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.

Question 21

describe the lock and key process

Answer 21

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.

Question 22

what are the two types of synapses?

Answer 22

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.

Question 23

what is glutamate?

Answer 23

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.

Question 24

what is GABA ?

Answer 24

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.

Question 25

identify the five neurotransmitters

Answer 25

acetylcholine 
dopamine 
serotonin 
epinephrine 
norepinephrine

Question 26

describe the role of acetylcholine

Answer 26

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.

Question 27

describe the role of dopamine

Answer 27

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.

Question 28

describe the role of serotonin

Answer 28

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

Question 29

compare epinephrine and norepinephrine

Answer 29

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.

Question 30

discuss Parkinson’s disease

Answer 30

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.

Question 31

discuss Alzheimer’s disease

Answer 31

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.