Biopsychology (P2)

Question 1

Which neuron carries electrical impulses towards the brain

Answer 1

Sensory neuron

Question 2

What are the 4 methods of studying the brain

Answer 2

fMRI, EEG, ERP, Post-mortems

Question 3

Describe the divisions of the nervous system (6 marks)

Answer 3

1) The nervous system is divided into the central and peripheral nervous systems
2) The CNS comprimises the brain and the spinal cord
3) The peripheral nervous system is further divided into the somatic nervous system and autonomic nervous system
4) The somatic nervous system consists of sensory and motor neurons to carry sensory and information to and from the CNS and also enable relex actions
5) The ANS acts largely unconsciously/involuntary
6) The ANS is divided into the symapthetic nervous system (SNS) and the parasymapathetic nervous system (PNS)
7) The SNS prepares us for fight or flight
8) The PNS balanced the sympathetic nervous system provding ‘rest and digest’ functions.

Question 4

Describe the structure and function of a neuron (6 marks)

Answer 4

1) Neurons enable communication within the nervous system
2) The cell body (soma) contains the genetic material
3) Branch-like dendrites extend from the cell body (often with dendritic spines)
4) Dendrites carry functional information towards the cell body
5) Dendrites can recieve information from other neurons
6) Axons carry messages away from the cell body
7) Axons can be myelinated to increase speed of nerve transmission (saltatory conduction between nodes of Ranvier)
8) terminal buttons are at the end of axons, these make synaptic connections with other cells
9) axon terminals contain neurotransmitters

Question 5

Outline the difference in function between Broca’s area and Wernicke’s area ( 2 marks)

Answer 5

1) Broca’s area is responsible for speech production whereas Wernicke’s area is responsible for language comprehension
2) Broca’s area enables speech to be fluent, whereas Wernicke’s area enables speech to be meaningful;.

Question 6

Explain the process of synaptic transmission through inhibition

Answer 6

-Stimulation of postsynaptic receptors by an inhibitory neurotransmitter result in inhibition (hyperpolarisation) of the postsynaptic membrane
-When an inhibitory neurotransmitter binds to post-synaptic receptors it makes the post-synaptic cell less likely to fire
-Summation- if inhibitory inputs are higher than excitatory they can cancel out excitation and inhibit an action potential from occurring
-This decreases activity in the post-synaptic cell, making it less likely to fire

Question 7

AO1 fMRIs

Answer 7

-Uses magnetic fields and radio waves to monitor blood flow
-Measures the change in energy released by haemoglobin, reflecting activity of the brain (oxygen consumption) to give a moving picture of the brain during specific activities

Question 8

AO3 fMRIs

Answer 8

-fMRI captures dynamic brain activity opposed to MRI/post-mortem examinations which purely show physiology
-interpretation of fMRI is complex and affected by temporal resolution, biased interpretation and of the baseline task used
-fMRI research is expensive, leading to reduced sample sizes, which negatively affects the validity of of the research.

Question 9

AO1 EEGs

Answer 9

-Electrodes are placed on the scalp and detect neuronal activity directly below where they are placed; differing numbers of electrodes can be used depending on the focus of the research.

Question 10

AO3 EEGs

Answer 10

-Cheaper than fMRIs, so can be more widely used in research, with larger sample sizes, increasing the validity of the research.
-Poor spatial resolution

Question 11

AO1 ERPs (event related potential)

Answer 11

-Electrodes are placed on the scalp and detect neuronal activity (directly below where they are placed) in response to a stimulus introduced by researcher

Question 12

AO1 Post-mortem

Answer 12

-brain is examined after death to try and correlate structural abnormalities or damage with behaviour

Question 13

AO3 post-mortems

Answer 13

-may lack validity due to small sample sizes and neuronal changes during death
-Case study of HM- did not give informed consent so ethical issues

Question 14

Describe synaptic transmission

Answer 14

This refers to the process by which a nerve impulse passes across the synaptic cleft from one neuron to another (from the presynaptic neuron to the postsynaptic neuron.)

Question 15

What is the pituitary gland?

Answer 15

-attached to the base of hypothalamus and called ‘master gland’ as it controls the release of hormones from all of the other glands in the body

Question 16

What are the gonads?

Answer 16

-The gonads secrete sexual hormones, which are important in reproduction- they also mediate both sexual motivation and behaviour.
-The female gonads are the ovaries and male gonads are testes
-ovaries secrete oestrogen and progesterone, testes secrete androgens such as testosterone.

Question 17

What is the adrenal gland?

Answer 17

-Releases adrenaline, which creates the physiological arousal, preparing the body for the fight or flight response and increased parasympathetic nervous system activation.

Question 18

What is the thyroid gland?

Answer 18

-Releases thyroxine, which increases heart rate and therefore increases the rate of growth.

Question 19

What is the pineal gland?

Answer 19

-A small pea shaped gland in the brain, main function is the production and regulation of melatonin, crucial for regulating sleep.

Question 20

Glands and hormones

Answer 20

-Glands produce hormones
-Hormones distributed in the bloodstream eg. Thyroid gland produces thyroxine, pineal gland melatonin and gonads secrete reproductive hormones
-Pituitary ‘master gland’ attached to base of hypothalamus and controls release of all other hormones

Question 21

Fight or flight response

Answer 21

-Sympathetic arousal: hypothalamus + pituitary->adrenal gland->adrenaline
-Adrenaline leads to increased heart rate, faster breathing, sweating, inhibits digestion.

Question 22

What are the two outcomes that can occur when a neurotransmitter crosses the synaptic gap?

Answer 22

-When a neurotransmitter crosses the synaptic gap from the pre-synaptic neurone from the post-synaptic neurone it can either have an excitatory or inhibitory effect
-Inhibition means less likely to fire as negatively charged
-Exhibition means more likely to fire as positively charged

Question 23

What is excitation?

Answer 23

-Excitation occurs when the receptor stimulation results in an increase in the positive charge of the postsynaptic neurone and increases the likelihood of the neurone firing and passing on the electrical impulse.
-This is known as an excitatory post-synaptic potential (EPSP)

Question 24

What is inhibition?

Answer 24

-Inhibition occurs when a receptor stimulation results in an increase in the negative charge of the post synaptic neurone and decreases the likelihood of the neurone firing an passing on the electrical impulse.
-This is known as Inhibitory post synaptic potential (IPSP)

Question 25

What is summation?

Answer 25

-Summation is the addition of positive and negative post-synaptic potentials.
-A nerve cell can receive both IPSP (inhibitory post synaptic potentials) and EPSPs (excitatory post synaptic potentials) simultaneously.
The EPSPs and IPSPs are summed and if the net effect on the post synaptic neurone is negative and inhibitory, the neurone will be less likely to fire and if the net effect is positive and excitatory the neurone will be more likely to fire.

Question 26

Example of excitatory neurotransmitter

Answer 26

-Makes a nerve impulse more likely to be fired (positive charge)
-Eg. Dopamine and serotonin which produce states of excitement and activity in the nervous system, and in our mental state and behaviour.

Question 27

Example of inhibitory neurotransmitter

Answer 27

-Make a nerve impulse less likely to fire (negative charge)
-Eg. GABA calms activity in nervous system and produces a state of relaxation (as does anti-anxiety medication such as Valium)

Question 28

Broca’s area

Answer 28

-Located in the frontal lobe (both hemispheres)
-Area responsible for speech production
-Damage causes Broca’s Aphasia: slow speech, lacks fluency

Question 29

Wernicke’s area

Answer 29

-Located in left temporal lobe (just LH, not RH)
-Responsible for speech interpretation
-Damage: Wernicke’s Aphasia: production of nonsense words