The Magnificently Revamped Superduper Shiny Revision Thread 2011/12
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Original post by KingMessi
A flawed but inevitable plan....
Which poetry are you doing? I quite like some of the poetry, it can be quite interesting once you delve into it...
Which exams do you have left?
Oh, it's not hard; it's just that it's an absolute nightmare to learn as there's so much of it...
Which poetry are you doing? I quite like some of the poetry, it can be quite interesting once you delve into it...
Which exams do you have left?
Oh, it's not hard; it's just that it's an absolute nightmare to learn as there's so much of it...
Lyrical Ballads by Wordsworth and Coleridge. Lots of homeless people and nature, basically. I wish I could spend all my time on Hamlet but alas, I know it quite well!
I've not started exams yet- got history, English and economics. Nicely spaced out though, I had 6 in 4 days last year and it nearly gave me a nervous breakdown. How about you?
Today:
* Learn notes from mistakes made in all the exam papers.
* Make and learn notes on 2 physics websites.
* Make and learn notes from physics youtube videos.
* Make and learn notes on 2 physics websites.
* Make and learn notes from physics youtube videos.
Original post by riotgrrl
Lyrical Ballads by Wordsworth and Coleridge. Lots of homeless people and nature, basically. I wish I could spend all my time on Hamlet but alas, I know it quite well!
I've not started exams yet- got history, English and economics. Nicely spaced out though, I had 6 in 4 days last year and it nearly gave me a nervous breakdown. How about you?
I've not started exams yet- got history, English and economics. Nicely spaced out though, I had 6 in 4 days last year and it nearly gave me a nervous breakdown. How about you?
Oh okay, completely different to me...which board are you??
Oh okay, that sounds awful...the stress would have just been overwhelming. Do you feel prepared?
I start on the 16th, four exams in seven days...pretty nice exam period....
Comparison of the endocrine system and nervous system
-Endocrine system transmits through chemicals called hormones; nervous system transmits by means of action potentials, or nerve impulses.
-Endocrine system transmits hormones through the blood plasma; nervous system through the axons of neurones
-Nervous transmission is rapid, hormonal transmission is relatively slow
-Nervous response is rapid, hormonal response is slow
-Nervous response is short-lived, hormonal response is more lasting.
-Nervous response is widespread, hormonal response is localised
-Nervous response is reversible and temporary, hormonal responses are often permanent and irreversible.
-Nervous response affects target cells, hormonal response affects target organs.
-Endocrine system transmits through chemicals called hormones; nervous system transmits by means of action potentials, or nerve impulses.
-Endocrine system transmits hormones through the blood plasma; nervous system through the axons of neurones
-Nervous transmission is rapid, hormonal transmission is relatively slow
-Nervous response is rapid, hormonal response is slow
-Nervous response is short-lived, hormonal response is more lasting.
-Nervous response is widespread, hormonal response is localised
-Nervous response is reversible and temporary, hormonal responses are often permanent and irreversible.
-Nervous response affects target cells, hormonal response affects target organs.
Chemical mediators
At the cellular level, coordination is carried out by chemicals named chemical mediators. They are produced by mast cells and affect cells in their immediate vicinity. Two types are prostaglandins and histamines, both of which cause vasodilation of small arteries and arterioles, as well as increased permeability of capillaries. This leads to increased leakage from capillaries, as well as redness, itching and swelling of that area.
At the cellular level, coordination is carried out by chemicals named chemical mediators. They are produced by mast cells and affect cells in their immediate vicinity. Two types are prostaglandins and histamines, both of which cause vasodilation of small arteries and arterioles, as well as increased permeability of capillaries. This leads to increased leakage from capillaries, as well as redness, itching and swelling of that area.
Establishing of a resting potential
Sodium ions are actively transported out of the axon by the sodium-pump; potassium ions are actively transported into the axon by the sodium potassium pump. This movement of ions occurs at a rate of three sodium ions out of the axon for every two potassium ions transported into the axon; this means that there is a potential difference between the cytoplasm and tissue fluid, as well as electrical and chemical gradients, with the concentration of each ion being different on the inside and outside of the axon. Sodium ions begin to diffuse back into the axon down their electrical and chemical gradients, whereas potassium ions begin to diffuse back out of the axon down their chemical gradient. However, most of the sodium gates are closed, whereas most of the potassium gates are open. This means that the axon membrane is around 100x more permeable to sodium ions than to potassium ions, and the resulting efflux of potassium ions is far greater than the influx of sodium ions, causing a huge reversal of the electrical charge across the membrane and making the tissue fluid far more positive than the cytoplasm. Further efflux of potassium ions becomes difficult because, being positively charged, they are attracted to the negative inside of the axon, and repelled by the positively charged tissue fluid. Therefore, an equilibrium is established in which there is no net movement of ions and the electrical and chemical gradients are balanced.
Sodium ions are actively transported out of the axon by the sodium-pump; potassium ions are actively transported into the axon by the sodium potassium pump. This movement of ions occurs at a rate of three sodium ions out of the axon for every two potassium ions transported into the axon; this means that there is a potential difference between the cytoplasm and tissue fluid, as well as electrical and chemical gradients, with the concentration of each ion being different on the inside and outside of the axon. Sodium ions begin to diffuse back into the axon down their electrical and chemical gradients, whereas potassium ions begin to diffuse back out of the axon down their chemical gradient. However, most of the sodium gates are closed, whereas most of the potassium gates are open. This means that the axon membrane is around 100x more permeable to sodium ions than to potassium ions, and the resulting efflux of potassium ions is far greater than the influx of sodium ions, causing a huge reversal of the electrical charge across the membrane and making the tissue fluid far more positive than the cytoplasm. Further efflux of potassium ions becomes difficult because, being positively charged, they are attracted to the negative inside of the axon, and repelled by the positively charged tissue fluid. Therefore, an equilibrium is established in which there is no net movement of ions and the electrical and chemical gradients are balanced.
Establishing of an action potential
During resting potential, many of the sodium voltage-gated channels are closed; however, the energy of a stimulus causes some of the sodium voltage-gated channels to open, and therefore an influx of sodium ions results. This reversal of the potential difference across the membrane causes an even greater influx of sodium ions, due to more sodium voltage-gated channels opening, and this continues until the membrane potential is established at +40mV, at which point the sodium voltage-gated channels close. However, some potassium voltage-gated channels are open-namely the ones that are always open-and so there is an efflux of potassium ions. This continues to such an extent that there is a temporary overshoot of the potential difference across the membrane (i.e. membrane potential becomes more negative than -65mV). This is known as hyperpolarisation. The sodium-potassium pump then actively transports sodium ions out of the axon and potassium ions into the axon in a process known as repolarisation.
During resting potential, many of the sodium voltage-gated channels are closed; however, the energy of a stimulus causes some of the sodium voltage-gated channels to open, and therefore an influx of sodium ions results. This reversal of the potential difference across the membrane causes an even greater influx of sodium ions, due to more sodium voltage-gated channels opening, and this continues until the membrane potential is established at +40mV, at which point the sodium voltage-gated channels close. However, some potassium voltage-gated channels are open-namely the ones that are always open-and so there is an efflux of potassium ions. This continues to such an extent that there is a temporary overshoot of the potential difference across the membrane (i.e. membrane potential becomes more negative than -65mV). This is known as hyperpolarisation. The sodium-potassium pump then actively transports sodium ions out of the axon and potassium ions into the axon in a process known as repolarisation.
Original post by KingMessi
Oh okay, completely different to me...which board are you??
Oh okay, that sounds awful...the stress would have just been overwhelming. Do you feel prepared?
I start on the 16th, four exams in seven days...pretty nice exam period....
Oh okay, that sounds awful...the stress would have just been overwhelming. Do you feel prepared?
I start on the 16th, four exams in seven days...pretty nice exam period....
WJEC- we do two essays, one where you have to choose from a selection of unseen poetry (my worst nightmare!) and compare it to 2-3 of the Lyrical Ballads and then another one on Hamlet with the Revenger's Tragedy (which is nice for me, cos I did Hamlet in Scotland, albeit at a lower level)
I feel ok-ish, English is the one I'm worried about cos Economics I only need 40/100 UMS or something lame like that and history I've revised loads for because it's the first one. You're on this thread all the time, you must have done loads, right?
Original post by riotgrrl
WJEC- we do two essays, one where you have to choose from a selection of unseen poetry (my worst nightmare!) and compare it to 2-3 of the Lyrical Ballads and then another one on Hamlet with the Revenger's Tragedy (which is nice for me, cos I did Hamlet in Scotland, albeit at a lower level)
I feel ok-ish, English is the one I'm worried about cos Economics I only need 40/100 UMS or something lame like that and history I've revised loads for because it's the first one. You're on this thread all the time, you must have done loads, right?
I feel ok-ish, English is the one I'm worried about cos Economics I only need 40/100 UMS or something lame like that and history I've revised loads for because it's the first one. You're on this thread all the time, you must have done loads, right?
Ah okay...that would explain it. I've never actually read Hamlet, one of the Shakespeares I still need to read...is it good?
Haha, I need something like half marks in Psychology for an A...gotta love modulated A-Levels...
History I've heard is a horrible exam, everyone I know is worried about it...but I'm sure you'll be fine...
Erm, I've done a decent amount, but the flipside is I don't revise very efficiently-for example, I don't cut down from the textbook, I just learn the textbook (and any interesting related trivia from Wikipedia etc I can find), I'm on here revising etc, etc...I'm sure if others revised for the same length of time as I do, they'd get full marks in everything because of greater revision 'efficiency'.
Original post by KingMessi
Ah okay...that would explain it. I've never actually read Hamlet, one of the Shakespeares I still need to read...is it good?
Haha, I need something like half marks in Psychology for an A...gotta love modulated A-Levels...
History I've heard is a horrible exam, everyone I know is worried about it...but I'm sure you'll be fine...
Erm, I've done a decent amount, but the flipside is I don't revise very efficiently-for example, I don't cut down from the textbook, I just learn the textbook (and any interesting related trivia from Wikipedia etc I can find), I'm on here revising etc, etc...I'm sure if others revised for the same length of time as I do, they'd get full marks in everything because of greater revision 'efficiency'.
Haha, I need something like half marks in Psychology for an A...gotta love modulated A-Levels...
History I've heard is a horrible exam, everyone I know is worried about it...but I'm sure you'll be fine...
Erm, I've done a decent amount, but the flipside is I don't revise very efficiently-for example, I don't cut down from the textbook, I just learn the textbook (and any interesting related trivia from Wikipedia etc I can find), I'm on here revising etc, etc...I'm sure if others revised for the same length of time as I do, they'd get full marks in everything because of greater revision 'efficiency'.
You should read it, or even better, go see it being performed! I dragged my stepdad (who is not a literary person) to see it at the Globe a few weeks ago and he loved it, we're gonna go see Twelfth Night soon.
History can be a bit of a bitch but hopefully it will be alright.
I'm sure you'll do great
I wish I had your work ethic!Factors affecting speed of transmission in a neurone
The action potential remains the same size as it moves throughout a neurone; however, factors can affect the speed at which an action potential is propagated. These are as follows:
1. Myelination. Myelination means that saltatory conduction can occur, because myelin provides electrical insulation, meaning that action potentials can only be generated between separate nodes of Ranvier, as opposed to between localised electrical circuits. Therefore, the action potential is propagated faster in a myelinated neurone.
2. Temperature. Temperature affects the rate of diffusion of ions; the greater the temperature, the greater the rate of diffusion of ions. Furthermore, the sodium-potassium pump functions by means of active transport, and, therefore, it requires ATP for this process. ATP is made as a result of respiration, which is an enzyme-controlled process. The greater the temperature, the greater the rate of enzymatic action and the greater the rate of respiration; this will quicken the rate of ATP production, which will in turn increase the rate at which the sodium-potassium pump functions. This is less of a consideration in endothermic animals, which can maintain a relatively constant internal body temperature, but is a consideration in ectothermic animals, whose temperature varies with the environmental temperature.
3. The diameter of the axon. The greater the diameter of the axon, the faster the rate of conductance; this is because there is less leakage from a larger axon. Leakage makes membrane potentials harder to maintain.
The action potential remains the same size as it moves throughout a neurone; however, factors can affect the speed at which an action potential is propagated. These are as follows:
1. Myelination. Myelination means that saltatory conduction can occur, because myelin provides electrical insulation, meaning that action potentials can only be generated between separate nodes of Ranvier, as opposed to between localised electrical circuits. Therefore, the action potential is propagated faster in a myelinated neurone.
2. Temperature. Temperature affects the rate of diffusion of ions; the greater the temperature, the greater the rate of diffusion of ions. Furthermore, the sodium-potassium pump functions by means of active transport, and, therefore, it requires ATP for this process. ATP is made as a result of respiration, which is an enzyme-controlled process. The greater the temperature, the greater the rate of enzymatic action and the greater the rate of respiration; this will quicken the rate of ATP production, which will in turn increase the rate at which the sodium-potassium pump functions. This is less of a consideration in endothermic animals, which can maintain a relatively constant internal body temperature, but is a consideration in ectothermic animals, whose temperature varies with the environmental temperature.
3. The diameter of the axon. The greater the diameter of the axon, the faster the rate of conductance; this is because there is less leakage from a larger axon. Leakage makes membrane potentials harder to maintain.
Original post by riotgrrl
You should read it, or even better, go see it being performed! I dragged my stepdad (who is not a literary person) to see it at the Globe a few weeks ago and he loved it, we're gonna go see Twelfth Night soon.
History can be a bit of a bitch but hopefully it will be alright.
I'm sure you'll do great I wish I had your work ethic!
History can be a bit of a bitch but hopefully it will be alright.
I'm sure you'll do great
I wish I had your work ethic!Oh, I intend to...I like Twelfth Night, that should be good...
I'm sure you'll be fine...
Thank you.
Let's hope so...
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