Ch.1 Flashcards
Neuroscience
Multidisciplinary study of the brain
Injuries, chemical imbalances, development, language processing, drug usage, plasticity, memory, spatial navigation
CNS
Brain, spinal cord, retina: all encased in bone (spinal cord encased by vertebrae, brain encased in skull)
Retina develops as an outpocketing of developing diencephalon
Central location and role in all our behaviors
PNS
Everything else: all nerves that carry signals in and out of the CNS
Nerves: bundle of nerve fibers
Somatic NS: all conscious/voluntary, ALL senses,
Autonomic (ANS): involuntary, viscera/internal organs, solarplexus,
Somatosensation: somato (body), pain, movement of joints and body awareness, vestibular
Spinal and cranial nerves: somatic and autonomic
Neurons
In CNS AND PNS
Specialized nerve cells engaged in info processing
Carry signals from one body location to another
Dendrites
Info comes in at dendrites: unidirectional
Glial Cells
Glial Cells: non-neuronal cells, support function of neurons, immune cells, can shut off responses
originally got is name from “glue” because it was thought that they held brain areas together which is not true
Sagittal section of the brain
Sagittal Section, separating
Behaviour; learned vs innate
Behavior consists of patterns in time
Animal behavior varies enormously and indicates the diverse functions of the brain
Innate Behavior: inherited ways of responding, no experience needed to perform, fixed, genetically encoded (suckling in infants)
Learned Behaviors: require experience, dependent on brain plasticity (ability to change in response to a learning experience), have to learn it from society MORE COMPLEX NERVOUS SYSTEM = MORE CAPACITY FOR CHANGE
Mentalism
Mentalism: an explanation of behavior as a function of the non-material mind
Psyche: synonym for mind; suggests that human intellect is produced by this; marks the beginning of modern psychology
It was believed that brain cooled the blood
Dualism, brain regions and problems
Both a non-material mind and a material body contribute to behavior
Mind-body problem: quandary of explaining how a nonmaterial mind and material body interact
Descartes believed that mind resides in the pineal gland, where it directs the flow of cerebrospinal fluid through the ventricles and into the muscles to move the body
Problem: DOESN’T REALLY EXPLAIN HOW THE NONMATERIAL ENTITY INFLUENCES A MATERIAL GLAND
Chose the pineal gland based on a “guess”: it doesn’t have a mirror structure like other parts of the brain, he thought it was floating in the ventricles but this isnt true
Materialism; evolution and unity of diversity
what modern neuroscience uses
Behaviour can be explained as a function of the nervous system without recourse to the mind
Darwin and Alfred Russel Wallace: both contributed to the theory of evolution
Russel published his work a year before Darwin
Darwin published Origin of Species, provided biological mechanism for every single function you can think of
Evolution explains the UNITY AND DIVERSITY OF LIFE
UNity: all living organisms share common ancestor that is now extinct
Diversity: as the ancestor produced descendants, it started to diversify into different adaptations, lead to speciation, and diversity arises from this (all organisms use DNA bc we all had this common ancestor)
Extant species
Species today (STILL ALIVE) are descendants of ancestral species = descent with modification; evolution and descent with modification are EQUIVALENT TERMS, as adaptations are accumulated, you add on to the ancestral forms
Mechanism for evolution (aka descent with modification) is natural selection
Descent with Modification
Descendants of remote ancestors spread into diverse habitats thatpresented new environmental challenges or pressures
Time scale of evolution is over millions of years
Adaptations were accumulated
Evolution formula
EVOLUTION FORMULA: Heritable (genetic) variations in individuals which arise from random mutations (raw material for evolution, END UP WITH VARIATIONS IN PHYSICAL CHARACTER) + overproduction of offspring competed for limited sources under selection pressures = natural selection and individuals well suited to the environment leave more offspring (reproductive successs_
Over time, favourable adaptations accumulate
why can individuals not evolve
Individuals cannot evolve, POPULATIONS do (populations are groups of individuals that interbreed with each other)
Natural selection acts on HERITABLE characteristics only, cannot act on acquired characteristics (muscles cannot be passed down generations)
wh
why is evolution not goal directed
Evolution is NOT goal directed, and does not lead to perfectly adapted organisms
Random variation in a population (mutations in the genome) — enhanced reproductive success (variation is random, but if it is beneficial, then there is more likely chance of survival)
Evolution and origin of life
Evoltuion doesn’t explain the origins of life: evolution explains how all organisms have evolved from single common ancestor
Natural selection can only work on EXISTING characteristics, no organism is perfectly engineered for their environments
species
Species: can interbreed and produce viable and fertile offspring
Phenotype, genotype, gene, allele
Phenotype: set of individual characteristics that can be seen or measured (MORPHOLOGICAL CHARACTERISTICS, physical structure)
Genotype: genetic makeup of an individual, dictate what phenotype is
Gene: discrete unit of hereditary info consisting of a specific nucleotide sequence in DNA, codes for heritable character (flower color)
Allele: alternative version of a gene, variations (allele = trait, purpose vs. white flowers) ALLELES LEAD TO GENETIC VARIATION IN POPULATION
“Highly Conserved” species
Highly Conserved: species tend to be very similar; genes that produce the nervous system in different animal species that tend to be very similar
Epigenetics and transgenerational epigenetics
differences in gene expression related to environment and experience
Greek word for beyond genetics: studies differences in gene expression related to environment and experience
The markers that get added to our DNA impact whether that gene is on or off
Environment can leave markers on our genes which impact how they express
Histones
Complex has to be loosened otherwise DNA cannot get access to
DNA Methylation: gene cannot be expressed, ball is very tightly wound (as we are exposed to different things in the environment, markers on DNA Impacts the genetics we are expressing)
Environment things influencing the parent can be passed down transgenerationally (trauma could be ‘passed down’ based on epigenetics)
why are neurons evolutionarily older than brains
Neurons are evolutionary older than brains which make sense: brain cells first, AND THEN BRAINS and after
difference between taxonomy and cladograms
Classifying species, doesn’t have anything to do with ancestry
Based on fairly arbitrary morphological data: BASED ON PHENOTYPIC/STRUCTURAL DATA
Bottom is broadest category of the species; top is the most specific
Cladograms
Based on phylogeny: evolutionary descent of different species, tells us about ancestry
Bacteria:
single celled, no nucleus, prokaryotes, no membrane bound organelles
Eukaryotes:
have a nucleus
Archea:
prokaryotes, extremophiles, live in earth’s most extreme environments
(King Philip Couldn’t Order Fried Greens)
Kingdom, phylum, class, order, family, genus NEED TO REMEMBER THIS (King Philip Couldn’t Order Fried Greens)
Chordata:
true brain and backbone
How classifications are written
First word: genus, second word species, italics, first word capitalized
protists
(Single celled organisms that have a nucleus, plants, animals, fungi)
Human classification
Monera: bacteria, archea, which are now separate domains) Eukarya: protists (Single celled organisms that have a nucleus, plants, animals, fungi)
Kingdom: animals; neurons and muscles
Phylum: chordates, true brain and spinal chord
Class: mammals; larger brain social behavior
Order: Primates, very good visual system, hands for control
Family: great apes, hominidae
Genus: human (homo)
Species: modern human (homo sapiens), complex culture “sapiens” = wise
HOW TO READ A CLADOGRAM:
starting from left to right; furthest left is evolutionary the oldest, right side evolved the most recently
All branch points are important: A, B, C, D, E: represent common ancestor (and these ancestors are now extinct)
ALL ORGANISMS ON TOP: NOT EXTINCT, EXTANT (still living)
Brain evolution stages from 1-4
(1), LEAST COMPLEX; HUMANS HAVE THIS Nerve Net: first type of nervous system to involve; cranial nerves and spinal nerves are like this, no centralized brain or spinal cord however, sea anemone, has a nervous system
(2) HUMANS HAVE THIS Segmented Nerve Trunk: bilaterally symmetrical organization, what is on the left side is also on the right side (divide body in two, sides mirror each other) also have a head and tail region, segmentation as well (like our spinal cords)
(3) Ganglia: structures that resemble and function somewhat like a brain, sacs of neurons, each sac is called a ganglion, still not a true brain
(4) MOST COMPLEX, LAST THING TO EVOLVE: true brain and spinal cord
Which brain regions are getting larger and why?
Cerebrum and cerebellum: getting larger with evolution (cerebellum, motor learning, muscle coordination) cerebrum (planning?? And what else) animals that have the most complex behavior have these
The cerebrum and cerebellum become more prominent and extensively folded: the folding increases the surface area and MEANS WE ARE GETTING MORE NEURONS = MORE INTELLIGENT SPECIES/MORE COMPLEX
first human
1st animal designated as “genus” homo was HOMO HABILIS (handy human), first human, first one to use tools
What is more important than brain size?
cELL COUNT MATTERS MUCH MORE and the amount of connections (synapses)
1973 Harry Jerison’s Encephalization Quotient:
quantitative measure of brain size obtained from the ratio of actual brain size to expected brain size; allows for comparisons among different species; RATIO OF BRAIN TO BODY SIZE
Low EQ: smaller brain that expected
Humans: VERY HIGH EQ
Hypothesis, theory, natural law
Hypothesis, MOST SPECIFIC: proposed and tentative explanation for set of observations, cannot proven to be true, MUST BE TESTABLE
Theory: well-substantiated and widely accepted explanation of natural phenomena, subject to testing, revision, and refutation (evolution proceeds via natural selection), HAS TO HAVE A MECHANISM AND BE MECHANISTIC LIKE EVOLUTION
Natural Law: broadest, describes events in nature that occur exactly the same way every time under the same conditions, not an explanation, but a DESCRIPTION (LAW OF THERMODYNAMICS)
Inductive vs, Deductive
Inductive: specific to general, starting with hypothesis, anecdotes, collecting data, recognizing patterns and forming general conclusions
Deductive: general to specific (testing hypothesis),
