Unit 3: Essay Questions Flashcards
Give an account of short term memory under the headings:
1) Increasing memory span (3)
2) Serial position effect (5)
3) Transfer from STM to LTM (2)
1) - Memory span is the number of items that can be retained in STM.
- The normal short-term memory is 7 items.
- Information is retained in STM for 15-30s.
- “Chunking” of memory helps short-term memory in particular as several items are grouped as one.
2) - A large number of items is shown briefly to the subjects so that they cannot all be retained in short.
- Items recalled by the subject are recorded.
- Subjects usually recall items presented early an late in the series.
- Items at the end of the series are still retained in STM (the recency effect).
- Items from the start of the series have been transferred to long term memory (the primary effect).
- Items from the middle of the list have been displaced from STM……
- and have not been transferred to LTM.
3) - Rehearsal - repetition of information.
- Elaboration of meaning by linking to other memories/emotions.
- Organisation - linking to other similar memories.
Give an account of the nervous system under the following headings:
1) The somatic nervous system(3)
2) The autonomic nervous system(7)
1) - The somatic nervous system controls the body’s skeletal muscles.
- It controls (mainly) voluntary actions.
- Sensory neurones (of the SNS) carry impulses into the CNS/brain from the senses.
- Motor neurones (of the SNS) carry impulses out of the CNS/brain to muscles.
- SNS does control some reflex actions.
2) - The ANS works automatically/without conscious control.
- Impulses originate in the medulla (region of the brain.
- It is made up of the sympathetic and parasympathetic systems.
- These two systems are work antagonistically.
- The sympathetic system prepares the body for fight or flight.
- The parasympathetic system prepares the body for rest and digest.
- Correct description of the effect of the ANS in controlling:
- heart rate
- breathing rate
- peristalsis
- intestinal secretions
Give an account of memory under the following headings:
1) Transfer from short-term to long-term memory(6)
2) Retrieval from long term memory(2)
1) - STM capacity - limited/approx 7 items.
- Chunking - breaking down into groups e.g. phone numbers/car numbers.
- Time in STM very short/30 seconds.
- Will be displaced if other information comes in.
- Rehearsal - repeating or practicing.
- Elaboration - adding meaning or more information.
- Organisation - putting into categories
- Unlimited capacity of LTM.
2) - Contextual cues.
- Example or description - related information aids retrieval
- Named memory aid e.g. mnemonics/mind maps/spider maps/acrostics.
- Any example of of a memory aid (e.g. letters and what they stand for).
Discuss memory under the following headings:
1)- The transfer of information between short and long-term memory (5)
1) - Rehersal named and described (repetition/rehearsing of items to be memorised).
- Organisation named and described (putting items into groups or categories).
- Elaboration named and described (adding meaning to information).
- Retrieval named and described (talking information out of long-term memory).
- Contextual cues aid retrieval/remembering.
- Example of contextual cue given.
Give an account of the nervous system under the following headings:
1) - The role of neurotransmitters at the synapse (6)
2) - The Structure and function of neural pathways (4)
1) - The synapse/synaptic cleft is the junction/gap between neurons/nerve cells.
- Neurotransmitters are stored in/released from vesicles.
- Neurotransmitters are released on arrival of an impulse.
- Neurotransmitters diffuse across the gap.
- Neurotransmitters bind with/reach receptors.
- A threshold/minimum number of neurotransmitters is needed (for the impulse to continue).
- Neurotransmitters are removed by enzymes and re-uptake/reabsorption.
- Neurotransmitters must be removed to prevent continuous stimulation.
- Two named neurotransmitters - acetylcholine, noradrenaline, dopamine, endorphins.
2) - A converging pathway has several neurones linked to one neurone.
- This increases the neurotransmitter concentration/chances of impulse generation/sensitivity to excitatory or inhibitory signals.
- A diverging pathway has one neurone linked to several neurones.
- This means that impulses are sent to/influence several destinations at the same time.
- Reverberating pathways - neurones later in pathway synapse link with neurones earlier in the pathway.
- New neural pathways can bypass areas of brain damage/create new responses/suppress reflexes/create plasticity.
Give an account of the transmission of a nerve impulse at a synapse (10)
1) Synapse is a small gap between two nerve cells.
2) Synapses can filter out weak stimuli/threshold required.
3) Impulses cause release of neurotransmitter, which diffuses across the gap.
4) Released from vesicles.
5) Any example of neurotransmitter e.g. acetylcholine/noradrenaline.
6) Bind with receptor on post-synaptic neurone.
7) Impulses in next neurone can be excitatory or inhibitory.
8) It is the receptor which determines nature of signal.
9) Removed by reabsorption or degradation by enzyme activity
10) Acetylcholine by degradation
11) Noradrenaline by reabsorption
12) Need for much energy supplied by mitochondria.
Compare and contrast sensory and motor neurons and describe events that occur at a synapse (7)
1) Sensory neurones pass messages from sense organs to the central nervous system whereas motor neurons transfer messages from the CNS to muscles and glands.
2) Both neurones consist of cell body, axon and dendrites.
3) The cell body is found part way along the axon of a sensory neuron, whereas the axon grows out from one side of the motor neurone.
4) In each case, the axon is wrapped in a myelin sheath with nodes every few millimetres.
5) At a synapse, neurotransmitters cross from the the pre-synaptic dendrite to the post synaptic dendrite.
6) Neurotransmitters include acetylcholine and noradrenaline.
7) The type of receptor on the post-synaptic dendrite to which the transmitter chemical binds determines wether the next neurone is inhibited or excited.
8) Acetylcholine is immediately degraded by an enzyme.
9) Noradrenaline is reabsorbed by active uptake.
10) Synapses filter out single weak impulses, but can summate several weak impulses.
Describe how recreational drugs can affect the brain (10)
1)Many affect (neurotransmission in) the reward circuit to the brain.
2) They alter mood/cognition/perception/behaviour.
3) They may stimulate the release of neurotransmitters.
4) They may act as agonists or antagonists.
5)Antagonists imitate the actions of neurotransmitters.
6) Antagonists prevent the binding of neurotransmitter/bind to receptors.
7) Drugs may inhibit the re-uptake/enzyme degradation of neurotransmitters at a synapse.
8) Sensitisation may occur with an increase in the number/sensitivity of receptors.
9) Antagonists cause sensitisation leading to addiction.
10) Desensitisation May occur with a decrease in the number/sensitivity of receptors.
11) Agonists cause desensitisation leading to drug tolerance.
12) Any suitable era ample of a drug and how it affects the brain:
A) Cocaine blocking dopamine re-uptake channels.
B) Cannabis binding to receptors.
C) Alcohol binding to receptors which result in increase in the release of dopamine.
D)Nicotine activating receptors which result in an increase in the release of dopamine.
Describe non-specific defences that the body uses to protect itself from pathogens (8)
1) The skin prevents the entry of pathogens/is a physical barrier.
2) Epithelial cells in cavity linings produce protective chemical secretion.
3) Description of one non-specific defence e.g. mucus in windpipe/ acid in the stomach/ lysosome or anti bacterial substances in tears/ coughing or sneezing/ blood clotting.
4) The inflammatory response is caused by the release of histamine from mast cells.
5) Vasodilation/increased capillary permeability/increased blood flow.
6) Increased blood flow/ secretion of cytokines resulting in the accumulation of phagocytes.
7) It also results in the dilevery of clotting elements to the site.
8) Phagocytes recognise surface antigens/proteins markers on pathogens.
9) They then destroy the pathogen by engulfing it/by phagocytosis.
10) Phagocytes release cytokines that stimulates the specific immune response.
Give an account of cellular defence mechanisms in animals under following headings:
1) Phagocytosis (4)
2) Antibody Production (6)
1) - Carried out by phagocytes.
- Non - specific nature of process.
- Bacteria/ foreign material/ virus engulfed.
- Into a vacuole/vesicle.
- lysosomes fuse/join to vacuole and digestive enzymes to vacuole.
- Bacteria/ foreign material/ virus digested/destroyed/broken down by enzymes.
2) - Antibodies are proteins.
- They are produced by B lymphocytes.
- They are released into bloodstream and lymphatic system.
- Production stimulates in response to foreign/non-self antigens.
- Antibodies are specific to a certain type of antigen.
- Antibody renders harmless/destroys/attacks/combats/neutralises/combines/with antigen.
- This can also make them more susceptible to phagocytosis.
