Prelim 2 Flashcards
Five tasks of the brain for all animals
1- Eating and drinking
2- Fighting
3- Courting
4- Mating
5- Caring for offspring
Brain stem structures
Medulla, pons, midbrain, cerebellum, basal ganglia
?
Medulla
Sits on top of spine and regulates heart rate, blood pressure, rate of respiration, basic essential functions
Pons
Switch for sleep and wakefulness
Midbrain
Sits on top of pons, controls body movement in fight and sex, lowers pain during both, carries out orders from cortex, calls shots in lower mammals
Cerebellum
Takes sensory info from nervous system and communicates with frontal lobes, makes physical motion precise and nuanced, when damaged movements are jerky
Basal ganglia
Higher level of motor control, involved with control of slow movements, large muscles, learning specific actions
Thalamus
Evolved to process sensory information more deeply and with more detail before sending it on to frontal lobes, has two parts- one for each hemisphere
Hypothalamus
Smaller than thalamus, takes info from sensory organs, regulates pituitary gland which releases hormones, so involved with eating, drinking, sexual behavior
Limbic system
Border of cerebral hemispheres and brain stem, bringing information from cerebellum, routing it to the centers of the brain generating conscious thought while also contributing to awareness, emotion, aggression and memory
Hippocampus and amygdala
Hippocampus
Episodic memory, directs memory storage and retrieval, encodes spatial memories, in rats hippocampi shown responsible for remembering way through mazes
Amygdala
Instinctive aggression, fight or flight in lower mammals, plays a role in our response to threats or trauma, increased activation in PTSD
Cerebral cortex
Two hemispheres connected by corpus callosum, each hemisphere has four lobes
Occipital lobe
Visual cortex, generates images from information sent up through brain stem, and visual association cortex which generates visual memories, categories, focus
Temporal lobe
Primary auditory cortex and its association area
Parietal lobe
Primary somatosensory cortex and somatosensory association area
Frontal lobes
Fine movement, language, thought, judgement generated, prefrontal cortex rewires during adolescence and results in abstract thinking and higher orders of analysis and creativity
Computed tomography
Images from narrow x-rays passed through the brain
Magnetic resonance imaging
Magnetic field around brain agitated by radio waves, scanner measures rate by which molecules return to resting state
fMRI
Detects levels of oxygen in brain’s blood vessels
Micro-electrodes
Measure electrical charges of individual neurons
EEG
Sensors placed on forehead measures seizure activity and stages of sleep
PET
Images brain activity by measuring positrons emitted by radioactive particles injected into brain, scientists combine specific chemicals with radioactive material to observe specific brain activity
Functioning system
Luria
You learn a complex action by first learning the separate actions which compose it
Once you’ve mastered the separate actions, your brain writes a “macro” for the whole action
This is stored in a different part of the brain
Ways to misuse brain imaging
- Reverse mind/body dualism to “prove” “brain theory” ie using neuroimaging to show that a difference in behavior has an associated difference in the brain
- Using data to reduce complexity of brains to something simply physical
- Ignoring that fact that the brain constructs itself from experience (if time come back to practice slide 35), what we learn in adolescence constructs the brain
To use brain imaging well
- Think of brain as a collection of verbs, parts derive meaning from experience and contribute to awareness
- Explore how brain constructs itself
Brain organization
Nervous system and sensory organs feed information to spinal column which goes to hindbrain, hindbrain gives info to midbrain, where information is processed and refined and shared with cortex through clusters of neurons that project from midbrain to lobes of brain, bringing information that is experienced as thought, anxiety, and mood
Neuron structure
Dendrites receive messages to other cells, connect to cell body (soma) which connects to axon which passes messages away from cell body to other cells
How neurons are build
Fluid inside- cytoplasm- and outside- extracellular fluid
Generating energy with ATP?
Myelin coating made by glial cells, thicker coating faster conduction
Chromosomes inside
Neuron firing
Neurons change the polarity of other neurons by flooding them with ions until they fire or sending neurotransmitters into synapses that switch on genes in other neurons causing them to produce proteins that change them- generate new receptors, make more NTs, etc
Why and how neurons fire
Neuron has resting electrical charge, high levels of potassium in cell, when sodium enters cell, charge rises, neuron fires and releases NTs or passes charge to another neuron
Excitatory post synaptic potential
Charge builds and then stops before charging
Inhibitory post synaptic potential
Charge drops lower than resting
Ionotropic receptors
NTs open channels at the receptor’s center allowing ions to enter the cell