Login | Register
Enrol now for our new online tutoring program. Learn from the best tutors. Get amazing results. Learn more.

Welcome, Guest. Please login or register.

July 30, 2021, 05:15:50 am

Author Topic: Unit 3 in a Nutshell  (Read 2468 times)

0 Members and 1 Guest are viewing this topic.

K.Smithy

  • QLD MVP - 2019
  • Moderator
  • Forum Obsessive
  • *****
  • Posts: 365
  • "We are the cosmos made conscious." B.C. (she/her)
  • Respect: +365
Unit 3 in a Nutshell
« on: December 29, 2019, 01:50:29 am »
+11
Hi all - just your friendly neighbourhood psychology student passing through ;D

The QCE forums are a bit quiet, so here is another attempt to try to help liven them up a bit :)
This thread will contain my class notes that I will write up as I am completing unit 3 Psychology - so I hope that it is of some use to other QCE (maybe even VCE?? Who knows...) students out there 8) I will also include any thoughts or questions (and hopefully some answers to those questions) that I have had throughout unit 3. If my notes are any good I might also upload them to the notes section of ATAR notes.

I will also make one of these threads for Biology and Physics - so feel free to come say hi ;D

This thread will follow a simple structure, and I will try to be as consistent as possible to ensure comprehensibility. I will follow the criteria set out by the syllabus - which can be accessed here. If you haven't checked out the syllabus, I recommend you do so. After all, on the external exam QCAA can't ask any questions relating to content outside of the syllabus. Anywho, please feel free to contribute your own notes and help this thread grow :D Also, don't be shy to ask/answer any questions :)

Thread index - jump ahead to your relevant topic :)
Localisation of Function
Visual Perception
Memory
Learning

So lets kick this thread off, shall we!

*note: I haven't covered topic 1 in class yet (we started backwards and learnt about memory and learning first because we can... ;D) but this topic does have a syllabus link to unit 1 topic 2 - which I have lots of notes on. So, I will fill in what I can with my notes from unit 1, and I will check back over this post once I cover unit 3 topic 1 in class :)

Topic 1
Localisation of Function in the Brain

The key points for this section are:
-   Ethical guidelines protect the safety and wellbeing of participants within psychological research
-   All human behaviour has a biological basis
-   Changes to neurotransmission function may have beneficial and/or harmful and/or unintended consequences

- recall the structure of the human nervous system, with reference to the central (i.e. brain and spinal cord) and peripheral (i.e. somatic and autonomic) nervous systems

The human nervous system has many different parts. It may be daunting to wrap your head around it at first, but I find drawing it out helpful. But for those of you who prefer worded explanations, here we go:

The human nervous system can be broken down into the central nervous system (CNS) and the peripheral nervous system (PNS).
- The central nervous system consists of the brain and spinal cord (*note: it is important that you say spinal cord and not spine. These are two different things). As for neurons, the CNS contains only interneurons (these may also be called relay neurons or association neurons - however, you don't hear association neurons very often). Interneurons are found exclusively in the CNS and cannot be found in the peripheral segments of the nervous system. The CNS plays a primary role in receiving information from many areas of the body and uses that information to produce the body's conscious actions. The CNS controls the body by processing and responding to sensory input from the PNS.

more info on the CNS that isn't necessary but is interesting
Due to the importance of the CNS, it is protected by many different structures. These include: bone and cerebrospinal fluid. The skull encases the brain, and the spinal cord is protected by the vertebra of the spinal column. Both the brain and spinal cord alike are covered by a protective tissue known as meninges. Furthermore, the entire CNS is immersed in a substance known as cerebrospinal fluid. This forms a chemical environment that allows for the effective transmission of information through the nerve fibres and also offers another layer of protection.
- The peripheral nervous system lies in the periphery of the body (hence the name). The PNS is comprised of nerves and ganglia outside of the brain and spinal cord - they communicate information to the CNS. It has two functions: 1) communicate information from the body's organs, glands and muscles to the CNS (from both the external and internal environments) and 2) communicate information from the CNS to the body's organs, glands and muscles via motor neurons. There are two subdivisions of the PNS: the somatic nervous system and the autonomic nervous system.

more info on the PNS that isn't necessary but is interesting
Unlike the CNS, the nerves of the PNS are not enclosed by bone and are therefore more susceptible to trauma
- The somatic nervous system transmits sensory information to the CNS and carries out motor commands. It is responsible for the voluntary movement of skeletal muscles (striated muscles). It contains two types of neurons: sensory (afferent) neurons and motor (efferent) neurons. Afferent neurons carry information towards the CNS, efferent neurons carry information away from the CNS. The somatic nervous system is not only involved in voluntary movement, but is also responsible for reflex arcs (which will be explored later).
- The autonomic nervous system is responsible for communication between the CNS and the non-skeletal (visceral) muscles of the body, as well as internal organs and glands that are responsible for bodily functions vital for our survival. The autonomic nervous system operates unconsciously (you can think of this... autonomic sounds a lot like automatic. But don't get these two words mixed up) - which enables organisms to pay attention to other matters. The autonomic nervous system can be broken down into the sympathetic nervous system and the parasympathetic nervous system. While both of these divisions have different roles, they work together complementarily.
- The sympathetic nervous system readies the body in response to a threat or stress by increasing heart rate, dilating pupils, inhibiting digestion and redirecting blood flow towards the muscles (this ensures that extra oxygen is available for any possible urgent responses). You may know this as the fight-flight-freeze response. The sympathetic nervous system prepares the body to use up energy and deal with potential threats.
- The parasympathetic nervous system is responsible for maintaining normal bodily functions - homeostasis. This system helps conserve resources. Once a threat passes, the parasympathetic nervous system is responsible for allowing the body to return to its normal, resting state.

For those of you who like a visual representation and are visual learners, this is for you :):

flow chart of the human nervous system

Photo credits: Pinterest

- describe the role of the spinal cord in the human nervous system, with reference to the spinal reflex

Spinal reflexes are simple innate behaviours, mediated through part of the nervous system which is referred to as the reflex arc (the reflex arc is just a neural pathway that allows one to act before information reaches the brain). The sensory stimuli that results in the reactions by-passes the brain. It is actually synapses in the spinal cord that produce the reactions (hence the name spinal reflex), allowing for a faster response time (which, when considering a longer response time may result in serious harm to an individual it makes sense that it is not controlled by the brain). The nervous system is programmed to produce these responses when stimuli exceeds a certain point. Although the reflexes aren't produced by the brain, the brain will still receive sensory input while the reflex is being performed. There are two types of reflex arcs: the autonomic reflex arc (affecting internal organs) and the somatic reflex arc (affecting muscles) - however, we will probably only need to know about somatic reflex arcs. Reflex arcs can further be broken down into being either monosynaptic or polysynaptic - but I don't believe that we will need to know this (*note: all the information in this post is from unit 1 or research I did this year in my spare time - once I have learnt this topic in class I will check over all of this information to see if I need to modify anything. However, if there are any factual inaccuracies, please let me know :)). An example of a reflex is the withdrawal reflex. Lets say you touch a hot stove top, your hand pulls away without you having to think about it, right? Well, what has happened there? Your nociceptors ("pain receptors"), along with thermoreceptors, have identified that the stimuli you are experiencing (heat) exceeds a comfortable limit and may be potentially harmful. This stimuli triggers a sensory impulse travels via sensory neurons to the synapses of interneurons in the spinal cord (part of the CNS), which also happen to be connected to motor neurons. Motor impulses can then be sent to the flexors, allowing for your arm to withdraw from the hot stove top. At the same time, the sensory information continues on its journey through the CNS to the brain - where the pain is then processed. That is why there might be a delay between you withdrawing your hand from the stove top and say "Ow!".

diagram of withdrawal reflex

Photo credits: Quizlet

*note: I do not recommend that you try to test your withdrawal reflex - please try to refrain from touching hot stove tops, thank you :)

In short: a spinal reflex occurs when stimuli exceeds a comfortable point and may become harmful. It consists of a series of neural impulses that travel through the reflex arc, bypassing the brain, in order to produce a response at a much faster rate (e.g. stimuli --> afferent neurons --> interneurons --> efferent neurons --> reflex).

- recognise that the cerebral cortex can be divided into a number of discrete areas, which have specific functions, including the frontal, occipital, parietal and temporal lobes

The cerebral cortex (the outmost layer neural tissue - covers the cerebrum) consists of 4 divisions; these being, the frontal, occipital, parietal and temporal lobes. As the brain has two hemispheres, there exists two of each type of lobe. The human brain is mostly symmetrical, however, there are many subcortical neural structures and formations that exist only in one hemisphere - e.g. Broca's Area, Wernicke's Area and Geschwind's Territory usually reside in the left hemisphere.

The Frontal Lobe
The frontal lobe occupies the forward half of the cerebral cortex. Towards the rear of the frontal lobe - at the boundary between the parietal lobe and the frontal lobe - is the motor cortex. The motor cortex is involved in initiating voluntary movements. The front of the frontal lobe is involved in judging, planning and using initiative. Furthermore, the frontal lobe is involved in the expression of characteristics related to personality and emotional behaviour. Additionally, it contains Broca's Area - which, you would know from Unit 1 is important in regard to the production of language. 

*note: the frontal lobe and it's involvement in memory will be addressed in another post

The Occipital Lobe
The occipital lobe is located at the back of the brain and is involved in receiving and processing visual information. Visual association areas bring together all visual information and allows for us to think visually and remember images.

*note: the occipital lobe and it's involvement in memory will be addressed in another post

The Parietal Lobe
The parietal lobe is located behind the frontal lobe, at the top of the brain. It contains the somatosensory cortex - meaning it is involved with receiving and analysing messages from the body's sensory receptors in the skin (this can be information about touch, pressure, temperature, muscle movement and position). Furthermore, it contains Geschwind's territory which is important for the acquisition of language in childhood.

*note: the parietal lobe and it's involvement in memory will be addressed in another post

The Temporal Lobe
The temporal lobe is located at the sides of the brain. It is known as the auditory cortex and it receives auditory information. Sounds of different frequencies and amplitudes are received and processed in different parts of the lobe. Furthermore, it plays an important role in memory (each hemisphere contains a hippocampus) - for example, it is involved in linking emotion to memory. The temporal lobe contains Wernicke's Area which is involved in interpreting sounds and locating appropriate words from memory to express an intended meaning.

*note: the temporal lobe and it's involvement in memory will be addressed in another post

4 lobes of the cerebral cortex

Photo credits: Queensland Brain Institute

- recall that language processing occurs within Broca’s area, Wernicke’s area, and Geschwind’s territory

Broca's Area makes up part of a region known as the inferior frontal gyrus, which can be found in the frontal lobe (found in the association area the left frontal lobe). It is involved in expressive aspects of communication and language (both spoken and written) - namely, the production of sentences constrained by rules of grammar and syntax. Furthermore, it controls the motor functions required to produce speech. Damage to this area may result in Broca's Aphasia - a deficit in the ability to produce language; additionally, reading and writing are often impaired. However, language comprehension is generally preserved.

Wernicke's Area resides in the left cerebral hemisphere, near the junction between the parietal and temporal lobes. This region of the brain is important for the development of language and the comprehension of speech. It is responsible for starting receptor codes that interpret the meaning of language and for creating grammatically correct speech. Damage to this area may result in Wernicke's Aphasia - a deficit in the ability to produce comprehensible speech (those with Wernicke's Aphasia can speak fluently, however none of what they say makes sense). Additionally, there is also usually a deficit in the ability to understand language.

Geschwind's Territory resides within the posterior parietal lobe. It connects Broca's Area and Wernicke's Area via the arcuate fasciculus (a bundle of nerves). It has been identified that this region of the brain may be important for the acquisition of language during childhood and it provides a platform for abstract thinking by enabling the interpretation and classification of stimuli.


- recognise that voluntary movement is coordinated from the primary motor cortex, cerebellum and basal ganglia


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)


- recognise that emotion occurs within the limbic system, amygdala and prefrontal cortex


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)


- communicate neurotransmission using a diagram

The dictionary definition of neurotransmission is: "the transmission of nerve impulses between neurons or between a neuron and a muscle fibre or other structure." It is the process in which neurotransmitters (signalling molecules) are released by the axon terminal of a presynaptic neuron and bind to and react with the receptors on the dendrites of a postsynaptic neurons. Neurotransmitters are released at the presynaptic terminal in response to a threshold action potential. The neurotransmitter is then able to move across the synapse and will then bind with the receptor of a postsynaptic neuron. This may influence that neuron in a inhibitory or excitatory way (an inhibitory postsynaptic potential (IPSP) will make a neuron less likely to generate an action potential. Whereas an excitatory postsynaptic potential (EPSP) will make a neuron more likely to generate an action potential).

flowchart of neurotransmission

Photo credits: Christopher David Richards

diagram of neurotransmission

Photo credits: Khan Academy

Quote from: Bri MT
You might be expected to give a little more information than this. E.g. referring to ion channels on the postsynaptic membrane opening, there being specific & complementary fit between neurotransmitters and receptors, and the storage of neurotransmitters in vesicles in the axon terminal.

- distinguish between excitatory and inhibitory neurotransmitters, with reference to glutamate (Glu) and gamma-amino butyric acid (GABA)


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)


- compare the physical and psychological function of acetylcholine, epinephrine, norepinephrine, dopamine and serotonin     


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)
Fun fact: I competed at the state finals for the Australian Brain Bee in 2018 (I didn't get any further than states however - I think I only got like 10/30 of the questions correct... that's what you get for studying the night before ;D) and I think I learnt that stress causes the release of epinephrine and glucocorticoids, which after prolonged release can cause you to store energy as fat. I don't know if this is correct, the competition was like almost two years ago so I don't remember very much  :P

I did find some of my Brain Bee notes on acetylcholine though... "acetylcholine (ACh) is released by neurons that are connected to voluntary muscles, causing them to contract. ACh is synthesised in axon terminals; when an action potential arrives, electrically charged calcium ions rush in and ACh is released - attaching to ACh receptors on other cells. This action opens up sodium channels, causing muscles to contract. ACh is broken down by acetylcholinesterase (an enzyme) and is resynthesised in the nerve terminal. There are antibodies that block ACh, this can result in a disease known as myasthenia gravis - which is characterised by fatigue and muscle weakness. Research suggests that ACh is important for attention, memory and sleep - because ACh releasing neurons die in Alzheimer's sufferers."



  - discuss the impact of interference in neurotransmitter function, with reference to Parkinson’s disease and Alzheimer’s disease (symptoms and treatments).   

HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)
All I know rn is that Alzheimer's relates to beta amyloid plaques and tangles which build up in the brain and are usually cleared during sleep and stuff. But if they don't get cleared they can join together and become worse. I think, I might be wrong. I guess I'll find out soon enough
I also know that Parkinson's has something to do with dopamine
« Last Edit: July 06, 2021, 02:44:41 am by K.Smithy »
QCE 2020: Physics (92) || Psychology (96) || Biology (93) || Methods (79) || English (98) || SOR (91)
ATAR: 98.40
2021-2024: Bachelor of Advanced Science (Honours) @ UQ

Uni Journal ; U3 Bio ; U3 Psych ; U3 Physics

Erutepa

  • VIC MVP - 2019
  • Victorian Moderator
  • Forum Leader
  • *****
  • Posts: 720
  • evenin'
  • Respect: +769
Re: Unit 3 in a Nutshell
« Reply #1 on: December 29, 2019, 12:04:53 pm »
+3
Just like your biology thread, this is awesome work!
I am personally enjoying reading through these notes to get an idea of how similar/different the VCE and QCE courses are. So far alot of the evolution stuff from biology has been rather different, however the psych course seems to be moderately similar so far (although for VCE a lot of the structure/function of different brain areas is now in units 1/2)
I am certainly looking forward to continuing to read through this and hopefully others can find this a good resource for their own study/curiosity.

In terms of Alzheimer's I am not sure what depth they want you to go into, but the syllabus point does not state you need to know the mechanisms of how it arises. As such, I think it is suffice to say that there is an accumulation of beta-amyloid plaques and tau tangles (albeit very interesting, I think the details you've talked about it aren't that necessary to the course but I could be wrong). Adding to this, the specific roles of beta-amyloid and tau tangles aren't really that well understood from what I have read from the scientific literature, so I wouldn't expect they would want you to describe it in anymore detail than 'abnormal aggregations of beta-amyloid plaques outside of the cell and tau tangles within the cell are associated. Even this isn't all that essential, the main focus (from VCE at least) was the impact of lowered levels of certain neurotransmitters on neural functions (i.e. the ability of hippocampus to consolidate explicit memories)

Good luck with Psychology this year!
« Last Edit: December 29, 2019, 12:08:23 pm by Erutepa »
Qualifications
 > Have counted to 227
 > Can draw really good spiders
 > 2 Poet points
 > 6.5 insanipi points
 > 1 Bri MT point

K.Smithy

  • QLD MVP - 2019
  • Moderator
  • Forum Obsessive
  • *****
  • Posts: 365
  • "We are the cosmos made conscious." B.C. (she/her)
  • Respect: +365
Re: Unit 3 in a Nutshell
« Reply #2 on: December 29, 2019, 12:19:12 pm »
+2
Just like your biology thread, this is awesome work!
I am personally enjoying reading through these notes to get an idea of how similar/different the VCE and QCE courses are. So far alot of the evolution stuff from biology has been rather different, however the psych course seems to be moderately similar so far (although for VCE a lot of the structure/function of different brain areas is now in units 1/2)
I am certainly looking forward to continuing to read through this and hopefully others can find this a good resource for their own study/curiosity.

Thank you so much! ;D Yeah, I've heard it a couple times that VCE and QCE psych are fairly similar - it's nice to have that overlap as it provides more resources (e.g. I'm planning to find as many VCE 3/4 psych practice exams as I can before my externals). In 1/2 we cover the very basics of brain structure/function, but in 3/4 it becomes a lot more specific - for example, we look at the specific areas involved in memory and how exactly they are involved.

In terms of Alzheimer's I am not sure what depth they want you to go into, but the syllabus point does not state you need to know the mechanisms of how it arises. As such, I think it is suffice to say that there is an accumulation of beta-amyloid plaques and tau tangles (albeit very interesting, I think the details you've talked about it aren't that necessary to the course but I could be wrong). Adding to this, the specific roles of beta-amyloid and tau tangles aren't really that well understood from what I have read from the scientific literature, so I wouldn't expect they would want you to describe it in anymore detail than 'abnormal aggregations of beta-amyloid plaques outside of the cell and tau tangles within the cell are associated. Even this isn't all that essential, the main focus (from VCE at least) was the impact of lowered levels of certain neurotransmitters on neural functions (i.e. the ability of hippocampus to consolidate explicit memories)

Yeah, I'm excited to learn it in class - it's such an interesting topic! I suspect that it will be around February/March when I update this post - by then I should have learnt all of topic one, so it'll be interesting to see how much of the information about Alzheimer's I remove or add in.

Good luck with Psychology this year!

Thank you, gonna need it aha! ;D
QCE 2020: Physics (92) || Psychology (96) || Biology (93) || Methods (79) || English (98) || SOR (91)
ATAR: 98.40
2021-2024: Bachelor of Advanced Science (Honours) @ UQ

Uni Journal ; U3 Bio ; U3 Psych ; U3 Physics

Sine

  • Werewolf
  • National Moderator
  • Great Wonder of ATAR Notes
  • *****
  • Posts: 5043
  • Respect: +2042
Re: Unit 3 in a Nutshell
« Reply #3 on: December 29, 2019, 01:31:27 pm »
+4
Beyond scope of QCE/VCE psychology

I haven't done psychology in VCE but from a biological perspective for Alzheimers Disease is that the main pathology as Erutepa said is Beta Amyloid (Aβ) plaques extracellularly with neurofibrillary Tangles (Tau) intracellularly. The Amyloid plaques come from the cleavage of a type I membrane protein (passes through the membrane once with an intracellular and extracellular component). The original protein is called APP (amyloid precursor protein) and supposedly has a normal everyday function. The actual Aβ plaques come from the cleavage of APP. Cleavage is done by gamma and beta-secretase. There is an alpha-secretase enzyme however that is involved in a non-pathogenic pathway. The Aβ peptides begin as monomers which then oligomerise together to form the plaques. The Tau protein originally stabilises microtubules which are used for transport across a cell and in Alzheimer's they are liberated and free in the intracellular space which allows them to aggregate producing neurofibrillary tangles. There are other pathologies that are possible to occur but they are not specific Alzheimer's - such as Lewy Bodies, TDP-43 etc.

Also, it is important to note that whilst Amyloid aggregation exhibits Alzheimer's pathology it doesn't necessarily always equate to cognitive impairment.  Some people can be worse off without any pathology than someone with both Tau and Amyloid aggregation. So in the diagnosis, there is a difference between a pathological diagnosis of Alzheimers and a clinical diagnosis.

Ultimately years after these biological pathologies people start getting neurodegeneration and a decline in cognitive function, memory, etc Also as Erutepa said there is no evidence showing why Tau and Amyloid correlate with Alzheimers. There has been a heap of drugs developed to inhibit the production of Aβ peptides and thus stopping amyloid aggregation. They try to do this by inhibiting those enzymes beta and gamma secretase or destroying the amyloid plaque (this has shown to actually worsen the condition) and after 33 attempts none of them has worked.

A lot of this is probably not relevant to anyone doing psych but hopefully, it gives a decent overview.
« Last Edit: December 29, 2019, 01:45:54 pm by Sine »

Bri MT

  • VIC MVP - 2018
  • Administrator
  • ATAR Notes Legend
  • *****
  • Posts: 4648
  • invest in wellbeing so it can invest in you
  • Respect: +3621
Re: Unit 3 in a Nutshell
« Reply #4 on: December 29, 2019, 01:41:22 pm »
+2
Just like your biology thread, this is awesome work!
I am personally enjoying reading through these notes to get an idea of how similar/different the VCE and QCE courses are. So far alot of the evolution stuff from biology has been rather different, however the psych course seems to be moderately similar so far (although for VCE a lot of the structure/function of different brain areas is now in units 1/2)
I am certainly looking forward to continuing to read through this and hopefully others can find this a good resource for their own study/curiosity.

In terms of Alzheimer's I am not sure what depth they want you to go into, but the syllabus point does not state you need to know the mechanisms of how it arises. As such, I think it is suffice to say that there is an accumulation of beta-amyloid plaques and tau tangles (albeit very interesting, I think the details you've talked about it aren't that necessary to the course but I could be wrong). Adding to this, the specific roles of beta-amyloid and tau tangles aren't really that well understood from what I have read from the scientific literature, so I wouldn't expect they would want you to describe it in anymore detail than 'abnormal aggregations of beta-amyloid plaques outside of the cell and tau tangles within the cell are associated. Even this isn't all that essential, the main focus (from VCE at least) was the impact of lowered levels of certain neurotransmitters on neural functions (i.e. the ability of hippocampus to consolidate explicit memories)

Good luck with Psychology this year!

Unit 4 qce psych is more different and has most of it's overlap with unit 2 VCE psych, but unit 3 mostly overlaps with unit 1 VCE psych and unit 3 VCE psych.

The QCE syllabus has more emphasis on neurotransmitter functioning in Alzheimer's so you can definitely expect that in QCE the role of impaired neutrotransmitter functioning is more of a focus than tau tangles etc.

(I'll come back and do more comprehensive feedback for psych like I did for bio, great work again! :D )

I haven't done psychology in VCE but from a biological perspective for Alzheimers Disease is that the main pathology as Erutepa said is Beta Amyloid (Aβ) plaques extracellularly with neurofibrillary Tangles (Tau) intracellularly. The Amyloid plaques come from the cleavage of a type I membrane protein (passes through the membrane once with an intracellular and extracellular component). The original protein is called APP (amyloid precursor protein) and supposedly has a normal everyday function. The actual Aβ plaques come from the cleavage of APP. Cleavage is done by gamma and beta-secretase. There is an alpha-secretase enzyme however that is involved in a non-pathogenic pathway. The Aβ peptides begin as monomers which then oligomerise together to form the plaques. The Tau protein originally stabilises microtubules which are used for transport across a cell and in Alzheimer's they are liberated and free in the intracellular space which allows them to aggregate producing neurofibrillary tangles. There are other pathologies that are possible to occur but they are not specific Alzheimer's - such as Lewy Bodies, TDP-43 etc.

Also, it is important to note that whilst Amyloid aggregation exhibits Alzheimer's pathology it doesn't necessarily always equate to cognitive impairment.  Some people can be worse off without any pathology than someone with both Tau and Amyloid aggregation. So in the diagnosis, there is a difference between a pathological diagnosis of Alzheimers and a clinical diagnosis.

Ultimately years after these biological pathologies people start getting neurodegeneration and a decline in cognitive function, memory, etc Also as Erutepa said there is no evidence showing why Tau and Amyloid correlate with Alzheimers. There has been a heap of drugs developed to inhibit the production of Aβ peptides and thus stopping amyloid aggregation. They try to do this by inhibiting those enzymes beta and gamma secretase or destroying the amyloid plaque (this has shown to actually worsen the condition) and after 33 attempts none of them has worked.

A lot of this is probably not relevant to anyone doing psych but hopefully, it gives a decent overview.

Really interesting! Definitely beyond the scope of the psych syllabus but still connected and fascinating to learn about.

K.Smithy

  • QLD MVP - 2019
  • Moderator
  • Forum Obsessive
  • *****
  • Posts: 365
  • "We are the cosmos made conscious." B.C. (she/her)
  • Respect: +365
Re: Unit 3 in a Nutshell
« Reply #5 on: December 29, 2019, 01:43:08 pm »
+1
I haven't done psychology in VCE but from a biological perspective for Alzheimers Disease is that the main pathology as Erutepa said is Beta Amyloid (Aβ) plaques extracellularly with neurofibrillary Tangles (Tau) intracellularly. The Amyloid plaques come from the cleavage of a type I membrane protein (passes through the membrane once with an intracellular and extracellular component). The original protein is called APP (amyloid precursor protein) and supposedly has a normal everyday function. The actual Aβ plaques come from the cleavage of APP. Cleavage is done by gamma and beta-secretase. There is an alpha-secretase enzyme however that is involved in a non-pathogenic pathway. The Aβ peptides begin as monomers which then oligomerise together to form the plaques. The Tau protein originally stabilises microtubules which are used for transport across a cell and in Alzheimer's they are liberated and free in the intracellular space which allows them to aggregate producing neurofibrillary tangles. There are other pathologies that are possible to occur but they are not specific Alzheimer's - such as Lewy Bodies, TDP-43 etc.

Also, it is important to note that whilst Amyloid aggregation exhibits Alzheimer's pathology it doesn't necessarily always equate to cognitive impairment.  Some people can be worse off without any pathology than someone with both Tau and Amyloid aggregation. So in the diagnosis, there is a difference between a pathological diagnosis of Alzheimers and a clinical diagnosis.

Ultimately years after these biological pathologies people start getting neurodegeneration and a decline in cognitive function, memory, etc Also as Erutepa said there is no evidence showing why Tau and Amyloid correlate with Alzheimers. There has been a heap of drugs developed to inhibit the production of Aβ peptides and thus stopping amyloid aggregation. They try to do this by inhibiting those enzymes beta and gamma secretase or destroying the amyloid plaque (this has shown to actually worsen the condition) and after 33 attempts none of them has worked.

A lot of this is probably not relevant to anyone doing psych but hopefully, it gives a decent overview.

Wow, this is really interesting! Thank you for this insight! :D
QCE 2020: Physics (92) || Psychology (96) || Biology (93) || Methods (79) || English (98) || SOR (91)
ATAR: 98.40
2021-2024: Bachelor of Advanced Science (Honours) @ UQ

Uni Journal ; U3 Bio ; U3 Psych ; U3 Physics

Bri MT

  • VIC MVP - 2018
  • Administrator
  • ATAR Notes Legend
  • *****
  • Posts: 4648
  • invest in wellbeing so it can invest in you
  • Respect: +3621
Re: Unit 3 in a Nutshell
« Reply #6 on: December 31, 2019, 11:15:12 am »
+2
Hi all - just your friendly neighbourhood biology psychology student passing through ;D

The QCE forums are a bit quiet, so here is another attempt to try to help liven them up a bit :)
This thread will contain my class notes that I will write up as I am completing unit 3 biology psychology - so I hope that it is of some use to other QCE (maybe even VCE?? Who knows...) students out there 8) I will also include any thoughts or questions (and hopefully some answers to those questions) that I have had throughout unit 3. If my notes are any good I might also upload them to the notes section of ATAR notes.

I will also make one of these threads for psychology biology and physics - so feel free to come say hi ;D

This thread will follow a simple structure, and I will try to be as consistent as possible to ensure comprehensibility. I will follow the criteria set out by the syllabus - which can be accessed here. If you haven't checked out the syllabus, I recommend you do so. After all, on the external exam QCAA can't ask any questions relating to content outside of the syllabus. Anywho, please feel free to contribute your own notes and help this thread grow :D Also, don't be shy to ask/answer any questions :)

So lets kick this thread off, shall we!

*note: I haven't covered topic 1 in class yet (we started backwards and learnt about memory and learning first because we can... ;D) but this topic does have a syllabus link to unit 1 topic 2 - which I have lots of notes on. So, I will fill in what I can with my notes from unit 1, and I will check back over this post once I cover unit 3 topic 1 in class :)


The vast majority of this section does overlap with either unit 1 or unit 3 of VCE psychology :)
(The brain anatomy stuff is only in Unit 1 for VCE & the physical and psychology function of neurotransmitters isn't in any VCE unit. Treatments for the diseases aren't explicitly part of the study design but are included in textbooks in Unit 3 VCE)

Topic 1
Localisation of Function in the Brain

The key points for this section are:
-   Ethical guidelines protect the safety and wellbeing of participants within psychological research
-   All human behaviour has a biological basis
-   Changes to neurotransmission function may have beneficial and/or harmful and/or unintended consequences

- recall the structure of the human nervous system, with reference to the central (i.e. brain and spinal cord) and peripheral (i.e. somatic and autonomic) nervous systems

The human nervous system has many different parts. It may be daunting to wrap your head around it at first, but I find drawing it out helpful. But for those of you who prefer worded explanations, here we go:

The human nervous system can be broken down into the central nervous system (CNS) and the peripheral nervous system (PNS).
- The central nervous system consists of the brain and spinal cord (*note: it is important that you say spinal cord and not spine. These are two different things). As for neurons, the CNS contains only interneurons (these may also be called relay neurons or association neurons - however, you don't hear association neurons very often). Interneurons are found exclusively in the CNS and cannot be found in the peripheral segments of the nervous system. The CNS plays a primary role in receiving information from many areas of the body and uses that information to produce the body's conscious actions. The CNS controls the body by processing and responding to sensory input from the PNS.

more info on the CNS that isn't necessary but is interesting
Due to the importance of the CNS, it is protected by many different structures. These include: bone and cerebrospinal fluid. The skull encases the brain, and the spinal cord is protected by the vertebra of the spinal column. Both the brain and spinal cord alike are covered by a protective tissue known as meninges. Furthermore, the entire CNS is immersed in a substance known as cerebrospinal fluid. This forms a chemical environment that allows for the effective transmission of information through the nerve fibres and also offers another layer of protection.
- The peripheral nervous system lies in the periphery of the body (hence the name). The PNS is comprised of nerves and ganglia outside of the brain and spinal cord - they communicate information to the CNS. It has two functions: 1) communicate information from the body's organs, glands and muscles to the CNS (from both the external and internal environments) and 2) communicate information from the CNS to the body's organs, glands and muscles via motor neurons. There are two subdivisions of the PNS: the somatic nervous system and the autonomic nervous system.

more info on the PNS that isn't necessary but is interesting
Unlike the CNS, the nerves of the PNS are not enclosed by bone and are therefore more susceptible to trauma
- The somatic nervous system transmits sensory information to the CNS and carries out motor commands. It is responsible for the voluntary movement of skeletal muscles (striated muscles). It contains two types of neurons: sensory (afferent) neurons and motor (efferent) neurons. Afferent neurons carry information towards the CNS, efferent neurons carry information away from the CNS. The somatic nervous system is not only involved in voluntary movement, but is also responsible for reflex arcs (which will be explored later).
- The autonomic nervous system is responsible for communication between the CNS and the non-skeletal (visceral) muscles of the body, as well as internal organs and glands that are responsible for bodily functions vital for our survival. The autonomic nervous system operates unconsciously (you can think of this... autonomic sounds a lot like automatic. But don't get these two words mixed up) - which enables organisms to pay attention to other matters. The autonomic nervous system can be broken down into the sympathetic nervous system and the parasympathetic nervous system. While both of these divisions have different roles, they work together complementarily.
- The sympathetic nervous system readies the body in response to a threat or stress by increasing heart rate, dilating pupils, stopping digestion and redirecting blood flow towards the muscles (this ensures that extra oxygen is available for any possible urgent responses). You may know this as the fight-flight-freeze response. The sympathetic nervous system prepares the body to use up energy and deal with potential threats.
- The parasympathetic nervous system is responsible for maintaining normal bodily functions - homeostasis. This system helps conserve resources. Once a threat passes, the parasympathetic nervous system is responsible for allowing the body to return to its normal, resting state.

For those of you who like a visual representation and are visual learners, this is for you :):

flow chart of the human nervous system

Photo credits: Pinterest

Rather than "stopping digestion" it's better to refer to "inhibiting digestion" which is less absolute. It's very clear that you have comprehensive knowledge in this section - more than most VCE students have or are expected to display in this topic.

- describe the role of the spinal cord in the human nervous system, with reference to the spinal reflex

Reflexes are simple innate behaviours, mediated through part of the nervous system which is referred to as the reflex arc. The sensory stimuli that results in the reactions by-passes the brain. It is actually synapses in the spinal cord that produce the reactions, allowing for a faster response time (which, when considering a longer response time may result in serious harm to an individual it makes sense that it is not controlled by the brain). The nervous system is programmed to produce these responses when stimuli exceeds a certain point. Although the reflexes aren't produced by the brain, the brain will still receive sensory input while the reflex is being performed. There are two types of reflex arcs: the autonomic reflex arc (affecting internal organs) and the somatic reflex arc (affecting muscles). Reflex arcs can further be broken down into being either monosynaptic or polysynaptic - but I don't believe that we will need to know this (*note: all the information in this post is from unit 1 or research I did this year in my spare time - once I have learnt this topic in class I will check over all of this information to see if I need to modify anything. However, if there are any factual inaccuracies, please let me know :)). An example of a reflex is the withdrawal reflex. Lets say you touch a hot stove top, your hand pulls away without you having to think about it, right? Well, what has happened there? Your nociceptors ("pain receptors"), along with thermoreceptors, have identified that the stimuli you are experiencing (heat) exceeds a comfortable limit and may be potentially harmful. This stimuli triggers a sensory impulse travels via sensory neurons to the synapses of interneurons in the spinal cord (part of the CNS), which also happen to be connected to motor neurons. Motor impulses can then be sent to the flexors, allowing for your arm to withdraw from the hot stove top. At the same time, the sensory information continues on its journey through the CNS to the brain - where the pain is then processed. That is why there might be a delay between you withdrawing your hand from the stove top and say "Ow!".

diagram of withdrawal reflex

Photo credits: Quizlet

*note: I do not recommend that you try to test your withdrawal reflex - please try to refrain from touching hot stove tops, thank you :)

The syllabus uses the language "spinal reflex" so you should use this language in your notes and in your responses. What you have written displays more knowledge but strictly speaking it does not answer the question "what is a spinal reflex?". I would just keep the information on the somatic reflex arc and adjust your language to better fit the syllabus.

It is highly unlikely you will be expected to differentiate between monosynaptic and polysynaptic. Otherwise a very good description - all you need to do is adjust for the presented scenario in a question & that's an easy full mark response.

I'll try to refrain from touching hot stoves :P

- recognise that the cerebral cortex can be divided into a number of discrete areas, which have specific functions, including the frontal, occipital, parietal and temporal lobes

The cerebral cortex (the outmost layer neural tissue - covers the cerebrum) consists of 4 divisions; these being, the frontal, occipital, parietal and temporal lobes. As the brain has two hemispheres, there exists two of each type of lobe. The human brain is mostly symmetrical, however, there are many subcortical neural structures and formations that exist only in one hemisphere - e.g. Broca's Area, Wernicke's Area and Geschwind's Territory usually reside in the left hemisphere.

The Frontal Lobe
The frontal lobe occupies the forward half of the cerebral cortex. Towards the rear of the frontal lobe - at the boundary between the parietal lobe and the frontal lobe - is the motor cortex. The motor cortex is involved in initiating voluntary movements. The front of the frontal lobe is involved in judging, planning and using initiative. Furthermore, the frontal lobe is involved in the expression of characteristics related to personality and emotional behaviour. Additionally, it contains Broca's Area - which, you would know from Unit 1 is important in regard to the production of language. 

*note: the frontal lobe and it's involvement in memory will be addressed in another post

The Occipital Lobe
The occipital lobe is located at the back of the brain and is involved in receiving and processing visual information. Visual association areas bring together all visual information and allows for us to think visually and remember images.

*note: the occipital lobe and it's involvement in memory will be addressed in another post

The Parietal Lobe
The parietal lobe is located behind the frontal lobe, at the top of the brain. It contains the somatosensory cortex - meaning it is involved with receiving and analysing messages from the body's sensory receptors in the skin (this can be information about touch, pressure, temperature, muscle movement and position). Furthermore, it contains Geschwind's territory which is important for the acquisition of language in childhood.

*note: the parietal lobe and it's involvement in memory will be addressed in another post

The Temporal Lobe
The temporal lobe is located at the sides of the brain. It is known as the auditory cortex and it receives auditory information. Sounds of different frequencies and amplitudes are received and processed in different parts of the lobe. Furthermore, it plays an important role in memory (each hemisphere contains a hippocampus) - for example, it is involved in linking emotion to memory. The temporal lobe contains Wernicke's Area which is involved in interpreting sounds and locating appropriate words from memory to express an intended meaning.

*note: the temporal lobe and it's involvement in memory will be addressed in another post

4 lobes of the cerebral cortex

Photo credits: Queensland Brain Institute

- recall that language processing occurs within Broca’s area, Wernicke’s area, and Geschwind’s territory

Broca's Area makes up part of a region known as the inferior frontal gyrus, which can be found in the frontal lobe (found in the association area the left frontal lobe). It is involved in expressive aspects of communication and language (both spoken and written) - namely, the production of sentences constrained by rules of grammar and syntax. Furthermore, it controls the motor functions required to produce speech. Damage to this area may result in Broca's Aphasia - a deficit in the ability to produce language; additionally, reading and writing are often impaired. However, language comprehension is generally preserved.

Wernicke's Area resides in the left cerebral hemisphere, near the junction between the parietal and temporal lobes. This region of the brain is important for the development of language and the comprehension of speech. It is responsible for starting receptor codes that interpret the meaning of language and for creating grammatically correct speech. Damage to this area may result in Wernicke's Aphasia - a deficit in the ability to produce comprehensible speech (those with Wernicke's Aphasia can speak fluently, however none of what they say makes sense). Additionally, there is also usually a deficit in the ability to understand language.

Geschwind's Territory resides within the posterior parietal lobe. It connects Broca's Area and Wernicke's Area via the arcuate fasciculus (a bundle of nerves). It has been identified that this region of the brain may be important for the acquisition of language during childhood and it provides a platform for abstract thinking by enabling the interpretation and classification of stimuli.


- recognise that voluntary movement is coordinated from the primary motor cortex, cerebellum and basal ganglia


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)


- recognise that emotion occurs within the limbic system, amygdala and prefrontal cortex


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)


Nice succinct summaries :)

- communicate neurotransmission using a diagram

The dictionary definition of neurotransmission is: "the transmission of nerve impulses between neurons or between a neuron and a muscle fibre or other structure." It is the process in which neurotransmitters (signalling molecules) are released by the axon terminal of a presynaptic neuron and bind to and react with the receptors on the dendrites of a postsynaptic neurons. Neurotransmitters are released at the presynaptic terminal in response to a threshold action potential. The neurotransmitter is then able to move across the synapse and will then bind with the receptor of a postsynaptic neuron. This may influence that neuron in a inhibitory or excitatory way (an inhibitory postsynaptic potential (IPSP) will make a neuron less likely to generate an action potential. Whereas an excitatory postsynaptic potential (EPSP) will make a neuron more likely to generate an action potential).

flowchart of neurotransmission

Photo credits: Christopher David Richards


diagram of neurotransmission

Photo credits: Khan Academy

You might be expected to give a little more information than this. E.g. referring to ion channels on the postsynaptic membrane opening, there being specific & complementary fit between neurotransmitters and receptors, and the storage of neurotransmitters in vesicles in the axon terminal.

- distinguish between excitatory and inhibitory neurotransmitters, with reference to glutamate (Glu) and gamma-amino butyric acid (GABA)


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)


- compare the physical and psychological function of acetylcholine, epinephrine, norepinephrine, dopamine and serotonin     


HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)
Fun fact: I competed at the state finals for the Australian Brain Bee in 2018 (I didn't get any further than states however - I think I only got like 10/30 of the questions correct... that's what you get for studying the night before ;D) and I think I learnt that stress causes the release of epinephrine and glucocorticoids, which after prolonged release can cause you to store energy as fat. I don't know if this is correct, the competition was like almost two years ago so I don't remember very much  :P

I did find some of my Brain Bee notes on acetylcholine though... "acetylcholine (ACh) is released by neurons that are connected to voluntary muscles, causing them to contract. ACh is synthesised in axon terminals; when an action potential arrives, electrically charged calcium ions rush in and ACh is released - attaching to ACh receptors on other cells. This action opens up sodium channels, causing muscles to contract. ACh is broken down by acetylcholinesterase (an enzyme) and is resynthesised in the nerve terminal. There are antibodies that block ACh, this can result in a disease known as myasthenia gravis - which is characterised by fatigue and muscle weakness. Research suggests that ACh is important for attention, memory and sleep - because ACh releasing neurons die in Alzheimer's sufferers."



  - discuss the impact of interference in neurotransmitter function, with reference to Parkinson’s disease and Alzheimer’s disease (symptoms and treatments).   

HAVEN'T COVERED THIS IN CLASS YET, I WILL FILL THIS SECTION IN ONCE I HAVE NOTES ON IT :)
All I know rn is that Alzheimer's relates to beta amyloid plaques and tangles which build up in the brain and are usually cleared during sleep and stuff. But if they don't get cleared they can join together and become worse. I think, I might be wrong. I guess I'll find out soon enough
I also know that Parkinson's has something to do with dopamine

I'll leave feedback on this bit for when it's been updated




Overall, really fantastic job again. Thank you for writing this - I'm sure it will help many students in the future :D

K.Smithy

  • QLD MVP - 2019
  • Moderator
  • Forum Obsessive
  • *****
  • Posts: 365
  • "We are the cosmos made conscious." B.C. (she/her)
  • Respect: +365
Re: Unit 3 in a Nutshell
« Reply #7 on: December 31, 2019, 12:07:24 pm »
+2
Rather than "stopping digestion" it's better to refer to "inhibiting digestion" which is less absolute. It's very clear that you have comprehensive knowledge in this section - more than most VCE students have or are expected to display in this topic.

The syllabus uses the language "spinal reflex" so you should use this language in your notes and in your responses. What you have written displays more knowledge but strictly speaking it does not answer the question "what is a spinal reflex?". I would just keep the information on the somatic reflex arc and adjust your language to better fit the syllabus.

Coolio, I can fix those up easy :)

You might be expected to give a little more information than this. E.g. referring to ion channels on the postsynaptic membrane opening, there being specific & complementary fit between neurotransmitters and receptors, and the storage of neurotransmitters in vesicles in the axon terminal.

Cool as, I'll take note of this and once I touch on it again in class and feel more comfortable with it I'll come back and modify the post :)

Overall, really fantastic job again. Thank you for writing this - I'm sure it will help many students in the future :D

Thanks again for all the feedback :D
QCE 2020: Physics (92) || Psychology (96) || Biology (93) || Methods (79) || English (98) || SOR (91)
ATAR: 98.40
2021-2024: Bachelor of Advanced Science (Honours) @ UQ

Uni Journal ; U3 Bio ; U3 Psych ; U3 Physics