Unit 1: Scientific Method and the Nervous System

Question 1

What are the components of the CNS and what are some of its useful functions (spinal cord)?

Answer 1

The spinal cord and the brain. The spinal cord provides motor and sensory neurons, as well as local reflex circuits.

Question 2

What is the difference between the sympathetic and parasympathetic nervous system?

Answer 2

The parasympathetic nervous system is involved in calming the body while it is resting, or when it needs to be brought down after the sympathetic nervous system affects the body.
The sympathetic nervous system, on the other hand, is involved is preparing the body for flight or fight.

Question 3

What is a glial cell?

Answer 3

A central nervous system cell that provides structural support, promotes communication, and removes cellular debris. About 90% of cells in the system are glial cells, and they are not involved in synaptic transmission.

Question 4

Explain the myelin sheath and nodes of ranvier, and how they help with neuronal communication.

Answer 4

The myelin sheath is a fatty substance that wraps around the axons, and there are breaks in the myelin called the nodes of ranvier. The mylein conserves the nerve impulse (the graded potential shrinks as it moves along), allowing it to jump from node to node, where the action potential can occur again and build up the impulse. Without the myelin, the impulse would die out and likely not make it to the next stimulation spot.

Question 5

What is white matter vs dark matter?

Answer 5

White matter refers to the part of the nervous system containing myelinated axons, whereas grey mater is the opposite. The process of myelination is a process beginning at the birth and continuing into early adulthood

Question 6

What are the two forces that allow ions to move through channels?

Answer 6

The osmotic force- where ions move from high to low concentration
The electrical force- repulsion and attraction of charges

Question 7

Explain the movement of potassium ions in the cell.

Answer 7

More abundant in the cell than out. When the channel opens the osmotic force pushes the ions out, but electrical keeps them in due to net pos charge on the outside of the membrane. So the potassium ions moved based on their equilibrium potential.

Question 8

Explain the movement of sodium ions in the cell.

Answer 8

More Na exists outside the cell than in, and when the channels open both the osmotic force and electrical forces pushes the Na in (the net neg charge on the inside of the membrane attracts the Na). Moves until it reaches its equilibrium pot.

Question 9

What is responsible for maintaining the osmotic balance between the cell and outer membrane?

Answer 9

The sodium and potassium pumps: moves the ions against their conc. gradient via ATP.

Question 10

What creates the -70mv resting potential in the cell?

Answer 10

The leaky potassium channels, creates the positive charge right outside the cell membrane, which creates the small net neg charge on the lining of the membrane on the inside.

Question 11

How are dendrite channels activated?

Answer 11

Based on neurotransmitter activation; known as transmitter-dependant channels. The dendrite can be de-polarized or hyper-polarized based on the type on neurotransmitter.

Question 12

Explain de-polarization and hyper-polarization inside the dendrite.

Answer 12

Depolarization will occur when an excitatory neurotransmitter activates the receptor, making the inside of the cell more positive.
Hyper-polarization occurs when an inhibitory neurotransmitter activates the receptor, causes the inside of the cell to become more negative.
This polarization is known as graded potential.

Question 13

Explain what happens when the graded potential reaches the threshold (-55 mv).

Answer 13

When the threshold potential is reached, it will open the voltage gates on the axons (allowing sodium to rush into the cell), hereby creating an action potential.

Question 14

Describe the process of an action potential.

Answer 14

• This occurs along the axons, at the nodes, as a process where a new action potential is created at each node, and dissipates at the previous one.
• Once the threshold potential is reached in the dendrites, it can open the voltage-gated channels on the axons, allowing sodium to rush into the cell creating a very positive membrane potential.
• Once a sufficient positive charge is reached, the sodium channels close and the potassium gates open, bringing the membrane potential back to a negative value.

Question 15

Define and explain the refractory period occurring during re-polarization.

Answer 15

When the cell is returning to its resting membrane potential, it temporarily reaches an even greater negative voltage, known as the refractory period. During this period the cell cannot generate another action potential.

Question 16

What is the role of calcium ions in synaptic transmission and how are their gates signalled to be opened?

Answer 16

The positive membrane potential created by the sodium ions triggers the voltage-sensitive calcium channels to open.
Calcium ions are important for cell signalling, and it signals for the vesicles inside the axon terminal (containing the neurotransmitters) to be released into the synaptic cleft.
* The amount of calcium that flows in will determine how much neurotransmitter is released, so the amount of action potentials created (the frequency) determines how much calcium will flow in (and calcium will always flow in due to the very positive equilibrium potential it has).

Question 17

What are the 2 ways neurotransmitters can be removed from the synaptic cleft?

Answer 17

(1) Presynaptic re-uptake
- flows back into the pre-synaptic neuron, and forms back into vesicles for re-use
(2) Enzymatic degredation

Question 18

Explain the function of the neurotransmitter Acetylcholine, and briefly explain its receptors and removal.

Answer 18

Acetylcholine’s main function is controlling muscle movement.
It has 2 receptors (with its specific binding site): Muscarinic and Nicotinic.
Its broken down by the enzyme acetylcholinesterase.
Acetylcholine is commonly found in the hippocampus, meaning it ca play a role in memory: for example in alzheimers disease.

Question 19

Explain the neurotransmitter serotonin, and its receptors + uptake.

Answer 19

• Has at least 7 receptors; meaning it can have many effects on the body, such as: mood, memory, sleep, and apetite.
• Enzyme monoamine oxidase inactivates serotonin, but there is also a reuptake method(the primary method) where it is then broken down.

Question 20

What is the serotonin theory of depression? What are the problems with it?

Answer 20

That the lack of serotonin is related to depression.
Problems include:
-only 1/3 of patients respond to the inhibition of serotonin re-uptake (the keeping of serotonin in the synapse).
- why does the drug take time to have an emotional effect when biochemically the effect is immediate?

Question 21

What are the 3 ways drugs can affect synaptic transmission?

Answer 21

(1) Act on pre-synaptic neuron to release neurotransmistter.
(2) Act on synaptic cleft by decreasing the amount of enzyme in the body that breaks the n.t down
(3) Binds to the post synaptic neuron (mimics the n.t) to block n.t from binding to cell, either increasing or decreasing activity.

Question 22

Briefly explain the function of Dopamine.

Answer 22

Plays a role in arousal, and mood (specifically pos. mood). Oversupply can correlate with schizophrenia.

Question 23

Briefly explain the function of Epinephrine/norepinephrine.

Answer 23

• Epinephrine increases ANS response: fight or flight.

- Norepinephrine affects CNS activity by increasing alertness, and attention.

Question 24

Explain the function of GABA.

Answer 24

Major inhibitory n.t: slows CNS function, correlates with anxiety and intoxication.

Question 25

Explain the 3 main glands where hormones are secreted.

Answer 25

(1) Testes
(2) Ovaries
(3) Adrenal gland (on top of the kidney)

Question 26

Explain the 2 main ways hormones can interact/send a signal with/to a cell.

Answer 26

(1) Can bind to the receptors on a neuron (not all neurons have receptors for hormones).
(2) Some hormones (such as estrogen and testosterone) can pass right through the membrane of a neuron, and bind to the receptors inside the cell.

Question 27

What is the function of the cerebellum and where is it located?

Answer 27

The cerebellum appears quite different from the other part of the brain, and it is a part of the hindbrain located at the back bottom part of the skull.
It functions to control body movement; specifically rapid body movement.

Question 28

Explain the function of the basal ganglia.

Answer 28

It is involved in slower body movements. The damage of this structure is associated with Parkinsons disease.

Question 29

Explain the function of the hypothalamus.

Answer 29

It maintains homeostasis (internal regulator for things like body temp, blood pressure) as well as eating/drinking control.

Question 30

Explain the function of the hippocampus.

Answer 30

Involved in the storing of memories (does not sotre them, but processes it, and then sends it to be stored in another part of the brain).

Question 31

Explain the function of the thalamus.

Answer 31

Involved in receiving information from all the senses (except smell) and relays the info to another part of the brain for processing.

Question 32

Explain the function of the amygdala.

Answer 32

The amygdala is involved in emotions such as rage and fear (impulsive reactions).

Question 33

Explain the function of the occipital lobe.

Answer 33

Located at the back of the skull, it is dedicated to analyzing visual information (sense goes to eyes, then thalamus, then the occipital lobe to make sense of the pixelated image).
Left visual filed processed by right side of the brain, and vice versa: this is known as contralaterality.

Question 34

Explain the function of the temporal lobe.

Answer 34

Location where the skull is the thinnest; it is involved in processing visual, and mainlly auditory, information.
Wernickes area is in the left side of the temporal lobe, and it is involved in speech comprehension.

Question 35

What is Broca’s area and where is it located?

Answer 35

It is the part of the brain responsible in making speech, located in the left side of of the frontal lobe. (mainly a motor response).

Question 36

Explain the function of the parietal lobe.

Answer 36

Involved in sensation and touch; contains the somatosensory cortex.

Question 37

Explain the motor cortex and the somatosensrory cortex.

Answer 37

The somatosensory is in the parietal lobe and it perceives different senses, and its lobes are contralateral.
The central motor cortex is in the frontal lobe, where is controls the response based on the processes by the somatosensory cortex (they are right beside each other in the brain, with their specific body part targets lined up). Its lobes are also contralateral.

Question 38

What is the structure of the brain that lets the two hemispheres communicate? What is its composition?

Answer 38

The corpus callosum is a thick band of highly myelinated neurons that allows the two hemispheres of the brain to communicate.

Question 39

What do all the letters in OPTIC stand for when using it as an acronym for the scientific method?

Answer 39

Observe
Predict
Test
Interpret
Communicate

Question 40

What is hindsight bias?

Answer 40

Also known as the “i-knew-it-all-along” phenomenon, where you over estimate your ability to predict events after it has already happened.

Question 41

Explain and give an example of why logic can’t always explain the natural world.

Answer 41

Logic tends to tell us how the world should work, even though the world does not always have obvious logical tendencies.
An example of this is Aristotle believing that heavier objects fall to the earth faster than lighter ones. This seems intuitive, however, near 2000 years later is was proven that mass does not have an effect on how quickly an objects falls, which was proven with experimentation.

Question 42

What are the 3 “attitudes” of science?

Answer 42

1. Question authority- always question theories, and think of how they could be otherwise explained. Also, always question your own ideas, as we usually are biased to our own ideas
2. Open skepticism-let the evidence speak for itself
3. Intellectual honesty-allows your results to be scrutinized

Question 43

Define and explain pseudoscience.

Answer 43

Claims that are presented as scientific yet are not supported by evidence with the scientific method: no advances in knowledge, disregards known scientific facts, doesn’t challenge own assumptions, vague/incomplete explanations, loose logic.
The key idea of this is that it claims to be a science, which makes it so wrong.

Question 44

When creating a sample to study a general population of interest, what variables are important to keep in mind?

Answer 44

Accurately represent the population (ratio-wise) in terms of age, gender, ethnicity, etc.

Question 45

What is social desirability bias?

Answer 45

The tendency for participants participating in survey to sway their answers from their true beliefs to either fit in with the social norm, or tell researchers what they want to hear.

Question 46

What are correlational studies and when are they useful?

Answer 46

Measures the relationship of two variables to one another, and it not designed to show causation. This type of study is useful when variable cannot be manipulated. Problem with this is that it does not account for a possible third variable, that causes them both.

Question 47

What is a confounding variable?

Answer 47

When a third variable has influence of the dependant variable, but cannot be separated from the independent variable being studied.

Question 48

What is the purpose of a single-blind study?

Answer 48

To prevent participant expectancy effects: sometimes if the participant knows which condition they have been administered then they will act in a biased way.

Question 49

When quantitatively describing groups what are the two main measures?

Answer 49

1. Central Tendency

2. Variability

Question 50

What are the 3 main ways the measure central tendency?

Answer 50

1. Mean
2. Median
3. Mode

Question 51

What are the 2 main ways to measure variability in a group?

Answer 51

1. Range (spread of sample)
2. Standard deviation- measures how samples vary from the mean, the higher the standard deviation the more spread out the data is.

Question 52

What is an operational definition?

Answer 52

The researchers specific description of the way the variable will be measured or manipulated.

Question 53

What are some of the problems associated with finding the connection between genes and behaviour?

Answer 53

(1) Polygenic traits-how multiple genes correlate with a specific behaviour.
(2) Poor understanding of neural circuitry
(3) Epigenetics- how he environment can directly affect genetic material

Question 54

Explain histones and how the possible affects of altering them (via the environment via?).

Answer 54

Histones are proteins in which chromatin (our genetic material) wraps around, to keep it in place. Histones also control when particular genes in our chromosomes will be expressed.
If the environment alters the structure, or damages, some of the histones, gene expression can be altered, which will affect protein production, and ultimately affect ones behaviour.

Question 55

What is natural selection?

Answer 55

The environments way of selecting genes that are favourable for a species reproductive success.

Question 56

What is an adaptation (in terms of evolution)?

Answer 56

An adaptation is a result of natural selection, in which an organism has evolved a change that is helpful for them in reproductive abilities (an inherited solution to an ancestral problem).

Question 57

What is kin selection?

Answer 57

When a family member sacrifices its own life to help the other families members with their reproductive success.