Final Exam

Question 1

Define Dualism. Who proposed this theory?

Answer 1

Dualism- the soul, mind, or spirit is distinct from the body or brain; spirit and brain control our thoughts and actions

Proposed by Rene Descartes: “I think, therefore I am.”

Question 2

Describe the specific parts of the neuron and the role of myelin.

Answer 2

1. Dendrites: branched, tree-like structures attached to the soma; receive information from the terminal buttons of the other neurons.
2. Soma/Cell body: contains the nucleus; organizes messages from dendrites and “decides” whether neuron should convey messages to other neurons
3. Axon: long, thin, cylindrical structure that carries electrical messages known as action potential to terminal buttons
4. Terminal Buttons: the buds at the end of a branch of an axon; forms synapses where they relesase neurotransmitters that tell other neurons or muscles what to do.

Myelin: a sheath that surrounds axons and insulates them, preventing mesages from spreading between adjacent axons (if disrupted, messages will not be carried correctly)

Question 3

Identify the types and functions of glial cells

Answer 3

1. Schwann Cells: insulate axons in the peripheral nervous system
2. Oligodendrocytes: insulate neurons in the central nervous system
3. Astrocytes: bring nutrients to brain neurons, remove waste, and insulate synapses
4. Microglia: assist in healing from brain injury

Question 4

What is the blood- brain barrier?

Answer 4

A semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain’s capillaries

• restricts entry of toxic substances into the brain
• also restricts entry of potentially therapeutic drugs into the brain.

Question 5

What is DNA?

Answer 5

Deoxyribonucleic Acid: mainly composed of four nucleic acids or bases

1. cytosine
2. guanine
3. adenine
4. thymine

The C-G are always paired together as a rung and the A-T are always paired together as a rung.

Genes are composed of DNA

Question 6

RNA: Ribonucleic Acid

How is DNA transcribed into RNA?

How is RNA translated into a Protein?

Answer 6

How DNA is transcribed into RNA

Gene transcription: when a gene needs to be turned into a protein, the double helix unwinds.

A copy of the DNA sequence of the gene is made into RNA

How RNA is translated into a protein

1. The RNA is edited into messenger RNA (mRNA) and then sent to the ribosome.
2. The ribosome translates the mRNA three nucleic acids at a time (These groups of three are known as codons or triplets.)
3. Individual codons specify what individual amino acid should be used to make the proteins.

Question 7

What is the function of a transcription factor?

Answer 7

Transcription factors alter rate of gene transcription.

Question 8

What is meant by alternative splicing of mRNA?

Answer 8

RNA is edited before it is translated into a protein.

Alternative Splicing is the process by which Pre-RNA is edited; it allows for different functional proteins to emerge from the same gene.

• Pre-mRNA contains complimentary copies of each axon.
• The final product of eidting is known as a “RNA splice variant.”

Question 9

What is a protein?

Answer 9

A protein is a large strand of amino acids that can provide structure to a cell or perform functions for the cell by acting as enzymes (enzymes control chemical reactions.)

Question 10

What is post-translational processing?

How might post-translational processing go wrong in Alzheimer’s Disease?

Answer 10

Post-translational Processing

Once a protein is made, it can be broken down into many different smaller proteins or peptides with different functions.

     Precursor Protein xxxxx\>*Enzyme cuts precursor* xxxxx\>Three New Proteins or Peptides

How it might go wrong in AD

The amyloid precursor protein (APP) is cut incorrectly by an enzyme, causing the build-up of a peptide known as beta amyloid (Aß) in the AD brain.

Question 11

Define Reductionism. Name the leading scientist who championed this theory.

Answer 11

Only the body and the brain control thoughts and actions.

Championed by Thomas Hobbes: Consciousness is a by-product of the brain’s activity- no soul or “mind”

Question 12

What is meant by a membrane potential and what are the principal ions involved in maintaining them?

Answer 12

A membrane potential is a relative difference in electrical charge (i.e., ions) between the inside and outside of a cell.

Principle Ions:

1. Na+ = Sodium
2. K+ = Potassium
3. Ca+2 = Calcium
4. Cl- + Chloride

Question 13

What are three reasons that explain why the resting membrane potential is negative?

Answer 13

1. Sodium-potassium pumps: Three Na+ ions out/ two K+ ions in
2. Most proteins are anions
3. Ions maintain concentration gradients: ions seek areas of lesser concentrations

Question 14

Define depolarization (EPSP) and hyperpolarization (IPSP).

Answer 14

Depolarization/Excitatory PSP(EPSP)

an Increase in the membrane potential; due to influx of Ca2+ or Na+ into the dendrite

Hyperpolarization/Inhibitory PSP(IPSP)

a Decrease in the membrane potential; due to a brief influx of Cl- into the dendrite

Question 15

Describe the six steps involved in an action potential.

Answer 15

1. Summation of EPSPs in cell body at beginning of axon
2. Threshold of excitation is met
3. Na+ enters the neuron
4. K+ leaves the neuron
5. Na+ stops entering the neuron
6. K+ stops leaving the neuron

Question 16

What is the All-Or-None Law?

Answer 16

Either an action potential occurs or it does not occur; in a given neuron, every action potential achieves the same voltage.

Question 17

What are the names and functions of each of the four lobes of the cerebral cortex?

Answer 17

1. Frontal Lobe: sequencing, inhibition, speech, movement
2. Parietal Lobe: visual/spatial abilities and bodily sensations
3. Occipital Lobe: visual information
4. Temporal Lobe: recognition of objects and places, hearing

Question 18

What are the names and functions of the three areas of the Limbic System?

Answer 18

1. Hippocampus: encoding of new information
2. Amygdala: activation of fear and aversive memory
3. Cingulate: recognizes cognitive or emotional conflicts

Question 19

What are the names and functions of the two areas of the basal ganglia?

Answer 19

1. Caudate Nucleus: regulates execution of movement and habits
2. Nucleus Accumbens (NA): becomes active during states of pleasure

Question 20

What are the functions of the Thalamus?

Answer 20

The Thalamus acts as a relay between sensory input and the cortex.

Question 21

What are the functions of the hypothalamus?

Answer 21

The hypothalamus regulates endocrine function as well as metabolic functions like libido, body temperature, hunger and thirst. It also controls our fight or flight response and coordinates circadian rhythms

Question 22

What are the functions of the sypathetic division of the autonomic nervous system?

What are the functions of the parasympathetic division of the autonomic nervous system?

Answer 22

Sympathetic Division of ANS

Like the gas pedall in a car, the sympathetic nervous system accelerates functions needed for responding quickly to stress, like breathing, heart rate, and pupil dilation, and slows functions not immediately necessary like digestion

Parasympathetic Division of ANS

The PNS is like the brake pedal of a car, counteracting sympathetic nervous system after stress has passed. It is also active during periods of “sex, sleep, and sustenance.”

Question 23

What is the rate law?

Answer 23

The frequency of action potentials (or firing) determines the strength of responding.

More APs = More intense responses

If more neurons fire, there will be more intense responses

Question 24

The outermost layer of gray matter of the cerebral hemispheres

Answer 24

Cerebral Cortex

Question 25

Gene expression can be turned on or off by _______.

Answer 25

Transcription factors

Question 26

Receptors for the neurotransmitter glutamate allow calcium and sodium into neurons. One form of the receptor can come in two varieties - one called flip that allows calcium into the cell and another called flop that does not allow calcium into the cell. The difference in the two receptors is based on how the mRNA for the receptor gets edited before the protein is synthesized. The process by which proteins with different functions can emerge from the same gene is known as __________.

Answer 26

Alternative splicing

Question 27

What is the role of calcium in neurotransmission?

Answer 27

?

Question 28

What are the “rules” regarding neurotransmitters and receptors?

Answer 28

A given neuron only produces one neurotransmitter for release, but the same neuron can have receptors for many neurotransmitters.

Question 29

What are ionotropic receptors?

Answer 29

Chemically-gated ion channel which opens when bound by a NT:

• When open, it directly alters membrane potential in a neuron
• The NT only remains bound to the receptor for a short time and then returns to the synapse

Question 30

What are metabotropic receptors and what types of processes can they regulate?

Answer 30

Receptors that, when bound with a NT, activated other proteins within neurons (The “other proteins” are G proteins or second messengers)