Problem 1 Flashcards
How would you describe evolution
Variations in individuals within species affects the probability of survival
What is the difference between homoplasy and homology?
Homoplasy is when different animals have similar characteristics to adapt to an enviroment (i.e. tuna vs. Dolphins)
Homology is similarities due to common ancesters
What features are shared by all vertebrate nervous systems?
- development from a hollow neuraltube
- bilateral symmetry
- Hierarchical control
- seperate systems: CNS and PNS
- localization of functions
- creation of the spinal cord
What is the encephalization factor?
The encephalization factor is the ratio between the body weight and the brain weight
What are some of the explanations for the large increase in relative brain size in humans compared to other species?
The social brain hypothesis, later becomes larger hypothesis
What is the social brain hypothesis?
The social brain hypothesis states that human brains have developed more because social interaction and relationships are complex cognitive tasks
Why are humans and chimps different dispite 99% identical DNA?
Humans and chimps are different because the location and sequence of genes can still cause differences and which genes are expressed is dictated by many factors. (Specifically the expression pattern of the gene ASPM)
What are four types of glial cells
- Astrocytes: star shaped, provide supplies and regulate bloodflow
- Microglial cells: clean up cellular debris
3&4 Oligodendrites and Schwann cells: myelation
What is the name of the inital segment of the axon?
Axon hillock
What is a dendritic spine and what is its function?
The dendritic spine are the outgrowths of dendrites, the increase the synaptic surface area
What is chemical transmission?
Action potentials leading to the release of vesicles containing chemical signals into the synaptic cleft, carrying the message over to the postsynaptic cell
What are the levels of structures of proteins?
Primary: polypeptide chain
Secondary: folded structures within the polypeptide
Tertiary: 3D folds
Quarternary: multiple polipeptides folded together
What are the two classes of postsynaptic receptors?
Directly and indirectly coupled receptors
Explain where neurotransmitters are synthesized
Small neurotransmitters are synthesizef in the synaptic terminal
Big neurotransmitters are synthesized in the cell body
Explain how neurotransmission begins in the presynaptic neuron
Neurotransmission begins with an electrical process, the electrical impulse is converted into a chemical signal at the synapses
Explain how neurotransmitterd can affect the postsynaptic neuron
The neurotransmitters bind to the receptors of the postsynaptic membrane and initiate changes. The potential of the membrane could become depolarized, this can cause either an EPSP or an IPSP as a result.
Explain the difference between classical, retrograde and volume transduction
Classical transduction: starts with an electrical process, converts this to a chemical message which is delivered to the postsynaptic neuron.
Retrograde: the same principle as classical except in the opposite direction, information is carried from the post- to the presynaptic neuron
Volume: transduction through extra chemical messengers spilling over to neighboring neurons (without going past the synapses first)
What is excitation-secretion-coupling?
Sodium slows into the synaptic nerve, which causes calcium channels to open, this results in vesicles spilling their chemical content in the synaptic cleft
What are signal transduction cascades?
A long string of chemical messages within both the pre and postsynaptic neuron. This involves numerous molecules with the neurotransmitter being the first messenger
Is the ion-channel linked system able to activate kinase, phosphatase or both?
Both, it mainly activates phosphotase however it can also cause the phosphorylation of CREB which is kinase
How does the second messenger system work?
The first messenger activates the receptor, this causes the receptor to change shape so it is conductive for the G- protein, then the G-protein changes shape to allow the enzyme that synthesizes the second messenger to bind. The enzyme makes the second messenger and the cycle continues
How do early genes influence late genes?
Early genes are rapid responders 5o neurotransmitter input, making the proteins they encode. These proteins come together to form a zipper of transcription factor which in turn activates later onset genes.
What is chromatin
Chromatin compacts the genome into the nucleus, if chromatin gets strengthened it restricts access to read proteins and thus they can’t be transcribed
Which processes take place during neurodevelopment?
- Neurogenesis
- Migration
- Differentiation
- Synaptogenesis
- Neuronal cell death
- Synapse rearrangement
