Chapter 3 Flashcards
how many pairs of chromosomes are in the human karyotype
23
where do the two chromosomes in a pair come from
one from mom one from dad
what does the y chromosome contain
the gene that makes a male offspring
what chromosome is responsible for the sex of the child and why
the Y chromosome - because females cannot make males, therefore the sperm has the determining factor in whether or not there will be a girl or boy
what is your genotype
all of the genes you inherit, your genetic map of your body.
what are the two copies of each gene called
alleles
what is a homozygote
when you have the same two alleles one from dad and the same one from your mom
what is a zygote
the embryo in the first two weeks after conception
what is heterozygous
when you inherit two different alleles from mom and dad
what is a phenotype
the specific genes that are turned on/ expressed. These are the characteristics that come about according to how those genes are expressed
What is a dominant allele
the allele that will always win when paired with anotger allele, dominant or recessive.
what is a recessive gene
a gene that is less commonly expressed and needs another recessive gene to be expressed
what do genes do
they code for proteins
what is behaviour genetics
genetucs that deals with behaviour differences in animals and humans
what is a kinship study
a type of study done on identical and fraternal twins, separated twins, and comparing biological vs adopted siblings.
type of behavioural study
what is the fundamental unit of the nervous system
neuron
What are glial cells
support system for the neuron’s, facilitate the operation of the nervous system. They protect neurons from outside influences
what are Pyramidal cells
Cells that line up like little soldiers and incoming info fills in through the dendrites and out through the axon
what is a myelinated neuron
a neuron with insulation that allows action potentials to jump from one cell to the next
what are inter-neurons
neurons tgat send “slow” messages between diff brain areas
what is the basic anatomy of a cell
dendrites for info input, the soma for cell body, the axon which takes messages from the cell body towards other cells, tge nodes of ranvier, the terminal buttons, the synapse, dendritic spines
what are the nodes of ranvier
little pieces of bare neuron inbetween the myelin sheath, this is the only place where the neuron can generate action potential
what are the terminal buttons
the oart that are full of little vesicles that have little packets of chemicals, when the action potential reaches the cell it can split the vesicles open and target receptors on the next neuron
what is the synapse
a tiny space isolated from the other chemical environments that is very small. it is where the end of a neuron ends with the dendritic spine.
what are dendritic spines
little fuzzies that reach closer to the synapse, which makes the gap smaller
What are purkingie cells
they are little cells that line up in sheets and they smooth out the list of limb movements. Usually when your brain sends impulses for you to move, it happens in a stop motion kind of way, the purkingie cells smooth this out, like animation.
what is the blood-brain barrier
sets of astrocytes and keep things out of the brain that would be harmful (drugs)
what are schwann cells and what is the other name for them in the brain
Oligodendrocytes are insulating cells. in the body, when a neuron is cut, it might react, but the schwan cells can help regenerate it. in the brain, when a neuron is damaged, one oligodendrocyte insultes multiple fibres, and there is not enough of it to regrow the nerves
how does MS happen
when there is degenerating myelin that causes the brain to lose its ability to send fast and coordinated messages
How is electrical energy generated in the neurons
it is a separation of ions across the neural membrane. Its a potential difference like a battery
what is a semi-permeable membrane
a membrane that surrounds a neuron and allows some thing in but not others, its like a collander
What is the resting potential of a neuron
-70mV
what two elements are present in a neuron
sodium and potassium
what ions are inside vs outside a neuron
inside- potassium ions and larger anions.
outside- sodium ions and some chloride ions
what is an excitatory message
causes the cell to lose the negative charge, and the cell becomes depolarized
Inhibitory messages
cause the cell to become more negatively charged
what happens when a neuron becomes depolarized
it hits a point where it becomes activated and throws open voltage gated sodium channels that allow sodium to come inside the neuron
wgat happens to the potential difference when sodium rushes into the ion
more positive charge = more polarization
where is the only place turnover of ions can happen
the nodes of ranvier
what happens when the action potential gets to the end of the neuron and we want to pass the signal on
when the AP reaches the end of the neuron, it triggers vesicles filled with neurotransmitters to be released, they bind with specific receptor molecules and that neurotransmitter is able to produce an AP.
what does it mean when a receptor is excititatory vs inhibitory
they either stop more chemicals and neurotransmitters from being transferred or they ramp up the production and transferring of that neurotransmitter.
what is acetylcholine
A neurotransmitter tgat runs your diaphragm, is involved in the central nervous system, and is involved in learning, memory, and sleep.
what is dopamine
involved with reward NOT pleasure. it is involved in motivated behaviour
what is norepinephrine
associated with arousal, it wakes you up in the morning and makes you pay attention