Chapter 3 Flashcards
(63 cards)
1
Q
How many neurons are in the brain?
A
85-100 billion
2
Q
How many synapses per neuron?
A
Around 1000
3
Q
What are the 3 parts of a neuron and their purpose?
A
- Dendrite
- receives messages form other neurons - Cell Body
- processes all incoming signals from dendrites
- can receive signals directly as well
- contains the vital cell structures (nucleus, DNA) - Axon
- sends OUT signals to other neurons, muscles or glands
4
Q
What is the concentration at resting potential?
A
More Na+ outside the cell, more K+ inside the cell at resting potential
5
Q
What are the 5 steps in an action potential and parts of each step?
A
- Resting Potential
- Depolarization
- Na+ flooding into the cell causing the charge to become positive relative to the outside of the cell - Repolarization
- the sodium potassium pumps are at work because the Na+ and K+ are on the wrong side of the cell membrane at this point - Hyper-polarization
- the cell becomes more negative than it needs to
- overshoot - Resting Potential
6
Q
What is a graded potential?
A
An electrical pulse that does not meet threshold, therefore an action potential does not fire.
Many graded potentials can be added together to reach the threshold.
7
Q
Glial Cells 4
A
Made to take care of the neuron
- keep them in place
- manufacture needed nutrients
- absorb toxins and waste
- in development, helps convey them to the right place
(HOLD THEM, FEED THEM, PROTECT THEM, GUIDE THEM)
also produces some myelin
8
Q
Myelin 5
A
- fatty layer pf insulation surrounding an axon
- makes sending signals much faster
- more like a string of beads
- the breaks in between are called Nodes of Ranvier
- not all neurons have a myelin sheath
- some Glial cells produce myelin
9
Q
Damage to myelin causes?
A
Multiple sclerosis
- brain and spinal problems
- vision, balance, arm or leg movement problems
- lifelong condition
10
Q
What is a neurotransmitter?
A
A chemical substance that helps neurons communicate with each other
11
Q
5 steps of chemical communication across the synapse
A
- Synthesize
- neurons make the NT - Storage
- store NT in synaptic vesicles - Release
- when action potential reaches axon terminals of presynaptic neuron, vesicles pop - Binding
- molecules of NT attach to special receptors on the postsynaptic neuron - Deactivation
- receptors and NT are pulled apart, ending the signal
12
Q
Excitation NT
A
some NT make the postsynaptic neuron more likely to fire
- binding with receptor site causes some Na+ to enter the postsynaptic neuron
- If enough excitation an action potential will fire
13
Q
Inhabitation NT
A
some NT make postsynaptic neuron less likely to fire
- makes inside even more negative
- even harder to reach threshold
14
Q
Name the 7 Neurotransmitters
A
- Glutamate
- Acetylcholine
- Serotonin
- Dopamine
- GABA
- Endorphins
- Norepinephrine
15
Q
Glutamate
A
- excitatory
- learning and memory
- too much=seizures, neuron death
16
Q
Acetylcholine
A
- excitatory
- muscle movement and memory
- too little= Alzheimer’s disease, paralysis
- too much= convulsions
17
Q
Dopamine
A
- excitatory and inhibitory
- reward, pleasure, voluntary motor control, control of thought
- too little= parkisons disease
- too much = schizophrenia
18
Q
GABA
A
- inhibitory
- motor control, lowering anxiety
- too much=limits brain function (drunk)
- too little= tremors, lose motor control, anxiety
19
Q
Serotonin
A
- inhibitory
- mood, pleasure
- too little= depression and or anxiety
20
Q
Endorphins
A
- inhibitory
- inhibiting pain
- too little= hypersensitivity to pain
- too much= insensitivity to pain
21
Q
Norepinphrine
A
- excitatory
- adrenaline, stress hormone
- vigilance and awakeness
- too little= depression, anxiety
- too much= anxiety
22
Q
Agonist drugs 3
A
- increase activity of a NT
- synthesizes, stores and releases more
- can directly activate receptor site or slow down and stop deactivation
23
Q
Antagonist drugs 3
A
- decrease activity of a NT
- synthesized, releases, stores less
- or binds to receptor without activating it (blocking it)
24
Q
4 types of methods for studying the brain & description
A
- destruction and stimulation
- ablation: removing a portion of the brain (animal)
- lesions: focused damage on a specific part of the brain (humans) usually using tiny electrodes
- stimulation: using tiny electrodes to hit a single neuron
Stimulation discovered Localization of Function (specific cognitive functions are served by specific areas of the brain) - neurological testing
- testing verbal and non verbal behaviours known to be affected by brain damage
- typically used in clinical settings - electrical reading
- use of electrodes to measure the electrical activity in the brain
- EEG hair net to map out/ measure activity - Brain imaging
- computerized PET, CAT xrays
- fMRI
25
PET scans
measure using radioactive glucose injections.
26
fMRI
much more precise than PET or CT scans
| measures the magnetic properties of the brain
27
Ablation
removing a portion of the brain in animals
28
Lesions
focused damage in a specific area of the brain
29
How was localization of function found
stimulation of awake patients
30
Hindbrain 3 parts
Medulla
Pons
Cerebellum
31
Medulla
- heart rate and respiration
| - point where motor and sensory nerve tracts cross
32
Pons
- Sleeping and wakefullness
| - somewhat involved in respiration
33
Cerebellum
- balance
- coordination
- fine motor movements, walking
- does not initiate movement but coordinates it
34
Midbrain is responsible for
- motor and sensory pathways
- relay station for visual and auditory info
- eye movements
- coordinates eye and body movements
- RETICULAR FORMATION
35
Reticular formation
- extends from hindbrain all the way to forebrain
- wake and sleep cycles
- gatekeeper of attention
36
Forebrain 3 parts
Thalamus
Basil Ganglia
Hypothalamus
also called cerebrum, two halves
37
Thalamus
- relay system for sensory input
| - visual, auditory, body senses (balance)
38
Basil ganglia
- voluntary movement
| - Parkinson's disease associated with malfunction of basil ganglia
39
Hypothalamus
- connection to pituitary gland
- basic biological urges
- pleasure from electrical stimulation
40
Limbic system 3
Nucleus accumbens
amygdala
hippocampus
41
nucleus accumbens
- reward, motivation
| - connection to hypothalamus
42
Amygdala
- emotional response
| - anger fear
43
hippocampus
- forming and retrieving memories
| - spatial awareness
44
cerebral cortex
- think wrinkly layer on very outside of brain
- this is what sets us apart from other species
- holds 80% of the neurons in the brain
45
Partial lobe holds what and its function
somatosensory cortex
- behind the central sulcus
- body senses (touch temp)
- behind the central sulcus
- left brain activates right body
46
Frontal lobes holds what and its funtion
primary motor cortex
- in front of the central sulcus
- all VOLUNTARY movement
- left brain activates right side of the body etc
47
Occipital lobe contains what and its function
primary visual cortex
| - where the visual signals go first, then they will spread to parietal and temporal lobes
48
Temporal lobe contains what and its function
auditory cortex
| - where the auditory signals go first, then each ear sends to both sides of the brain
49
Association cortex
areas of the brain that are not directly involved with receiving signals.
- found in all 4 lobes
- about 75% of the humans cortex
- involved in higher mental processes (language, problem solving)
50
Broca's area location and function
- located in frontal lobe
| - speech production- articulating words, grammar
51
Wernicke's area location and function
- located in temporal lobe
- language comprehension
- necessary to understand words, either written or spoken
- babbling, world salad
52
Frontal lobe
- speech production
- skeletal muscle movement
- planning, emotion, self-awareness, responsibility
53
Prefrontal lobe
- planning ahead
- setting goals
- judging the situation
54
Lateralization
using one side of the brain more than the other
| - pronounced in males, and right handed people
55
Left brain
- language and math
| - brocas area, wernickes area
56
Right brain
- arts, spatial awareness
| - face recognition, navigation, mental imagery
57
Genes
- sections of DNA
- instructions for building the proteins in our body
- 23 pairs of chromosomes, 46 total in every cell
58
Chromosomes
- rod like structures of DNA strands
| - all cells except eggs and sperm contain 46 total, 23 pairs. reproductive parts contain half.
59
Polygenic transmission
a single gene cannot define a trait, there are multiple genes contributing to the phenotype
60
gene engineering 2 types and what they do
- recombinant DNA: use of enzymes to cut out sections and insert into another organism, usually bacteria
- Gene knockout: knocking out the gene to see if it effects behaviour
the problem: polygenic transmission
61
Heritability coefficient
the measure of how much variation of a gene that can be attributed to genetic variation
62
Concordance rates
the likelihood of 2 people sharing a trait
- twin studies
adoption studies
63
twins share how much DNA
fraternal 50%
| identical 100%
