Chapter 3 Flashcards
what are the methods for examining the human brain?
examining autopsy tissue, testing behaviour of patients with damage to certain parts of the brain, recording brain activity through multiple electrodes and through animal studies
what is neuroimaging?
method for studying brain activity and structure by obtaining visual images in awake humans.
what are the three methods of neuroimaging?
CAT or CT scans, MRI and DTI
what are CT scans?
produce clear two dimensional images of brain and other organs, computer combinations of many x rays can produce 3d images that can be virtually sliced.
what is an MRI?
uses a strong magnetic field to produce images of anatomy, Produces 3d images, produce much clearer images than CT scans and does NOT use radiation.
Why are CT scans used?
better at detecting brain diseases or blood vessel abnormalities, detecting many forms of cancer, faster and cost less.
What is DTI?
measures orientation of white matter,
What is an EEG?
examines bran function and allows to visualize na localize it very crudely.
what is a PET?
harmless radioactive substance is injected into a persons blood, radiation detectors are then use to scan the persons brain.
what is an fMRI?
allows for detection in changes of blood flow, does not use radiation and is much faster.
what is the advantage os an MRI over a CT?
less risk and produce better images
what is a neuron?
nerve cell
what is a group of neurons that work together called?
networks
what are glial cells?
cells in addition to neurons that make up the nervous system
what are the categories of glia?
astroglia, oligodendroglia, shwan cells, ependymal cells,, microglia
what do astroglia do?
regulate the flow of blood into different brain regions, absorb or clean up chemicals released by other neurons
what do shwan cells do?
provides a fatty sheath, myelin that insulates axons of neurons
what are ependymal cells?
line the walls ventricles, fluid filled spaces within the brain
what do microglia do?
cleaning up debris and de generating dead neurons
what are the two types of cells in the nervous system?
neurons and glia
what does the central nervous system involve?
motor, sensory, and cognitive information
what is a neurotransmitter?
a chemical released by other neurons
what is action potential?
overal charge inside a neuron differs from the overall charge outside creating a difference in charge across the neuron membrane
what does it mean when a neuron is polarized?
inside of a neuron is negatively charged compared to the outside
what is resting potential?
electrical charge of a neuron at rest
what is selective permeability?
membrane in not equally permeable to all ions
what are sodium potassium pumps?
protein molecules that push out sodium ions and push out potassium ions. (3 sodium, 2 potassium)
what are the two affects of neurotransmitters?
depolarize (inside of neuron becomes less negative) or hyper polarize (inside of neuron becomes more negative)
what is the absolute refractory period?
breif period where a neuron is completely unable to fire again
what is relative refractory?
neuron can only fire if it receives stimuli stronger than its usual threshold
what are synapses?
spaces between axon terminal of one neuron (communication occurs)
what is serotonin involved in?
activity levels and mood regulation
what is postsynaptic potential?
neurotransmitter binds to one of its receptors, exitory or inhibitory
what is dopamine?
mood, control of voluntary movement
what drugs increase dopamine levels in the brain?
heroin, alcohol, nicotine, assosiated with schitzophrenia(too much) parkinsons(too little)
what is norepinephrine?
affects arousal and mood, raises blood pressure, memory sleep and emotion, low level can cause depression
what is serotonin involved in?
regulation of mood appetite and sleep, elevates mood
what is the most common inhibitory neurotransmitter in the brain?
GABA, implicated in eating disorders
what is the most important neurotransmitter for normal brain function?
Glutamate, learning and formation of new memories, associated with Huntington’s disease,
what neuroplasticity?
create new pathways, form new connections
what neurotransmitter is responsible for mood regulation?
seretonin
approximately how many neurons does a person have in their brain?
86 billion
what does the central nervous system consist of?
brain and spinal cord
what does the peripheral nervous system consist of?
nerves that deliver information back and forth
what is the difference between afferent and efferent neurons?
afferent (carry sensory information from the body to the central nervous system)
efferent (carry information out from the central nervous system to the muscles and glands)
what are interneurons?
relay between different classes of neruons
what does the peripheral nervous system consist of?
somatic, automatic, sympathetic, and parasympathetic nervous system
what is the somatic nervous system?
nerves that gather sensory information, touch and pain,
what is the automatic nervous system?
consists of parasympatheitc, and sympathetic
what is the difference between the parasympatheitc, and sympathetic nervous system?
parasympatheitc (kicks in after emergency, calms body down, puts to rest)
sympathetic (fight or flight)
what neuron types are important for simple reflexes?
sensory, interneurons, motor neurons
how much does the human brain weigh?
3 pounds
what is the hindbrain?
part of brain closest to spinal cord, consists of medula pons and cerebellum
what is the medulla?
basic bodilly functions, reflexes, respiration and heart rate, damage is often fatal
what does the pons control?
acts as a bridge between the medulla and other areas, sleep breathing, swallowing, eye movements.
what does the cerebellum control?
motor coordination, learning involving movement.
what is reticular formation?
network of nuclei, extends from hindbrain to the midbrain, regulates the sleep wake cycle, wakefulness and arousal
what does the midbrain consist of?
above pons, very small in humans
what is the forebrain?
largest subdivision, controls complex cognitive, emotional, sensory and motor functions
what is the thalamus?
relay station for incoming sensory information
what is the hypothalamus?
important for motivation and control of the endocrine system
what is the pituitary gland?
controls endocrine system, growth reproduction, metabolism
what is the limbic system?
involved with learning memory and basic emotions
what does the amygdala do?
region referred to as the temporal lobe, responding to stimuli that induced fear
what does the amygdala communicate with?
hypocampus
what does the hypocampus do?
learning and memory, learning how to navigate, spacial environments
what is neurogenesis?
production of new neurons
what is responsible for motivation and reward learning?
nucleus accumbens
what is the area of the brain involved with eye and fluid movements?
substantia nigra
what does the cerebral cortex involve?
complex behaviours including language and thought
what are the four lobes of the cerebral cortes?
frontal lobe, parietal lobe, occipital lobe, temporal lobe
what lobe is responsible for visual stimuli?
occipital lobe
what is the temporal lobe responsible for?
auditory stimuli and language
where is wernickes area located and what does it do?
temporal lobe, left side in most humans, language area
what is brocas area and where is it located?
frontal lobe and responsible for speech
what is the parietal lobe responsible for for?
processing information related to touch and complex visual information, locations
what and where is the somatosensory strip?
tactile information, touch, presssure, vibration and pain,, in the cortex of parietal lobe
what is the frontal lobe responsible for?
movement and speech production, way larger in humans compared to animals, contains primary motor strip (voluntary non reflexive movement)
what is the prefrontal lobe?
higher order thinking, memory, moral reasoning and planning
what function is most closely linked to the hippocampus?
spacial environment and memory
what is a bundle of axons that allows communication from one side of the cortex to the other?
corpus callosum
where are werneckies and brocas area located?
it depends on whether you are right or left handed
what is the theory of evolution?
all life on earth is inter related and derives from one common ancestor
what are the 3 kingdoms of life forms?
eukaria, bacteria, archaea
what is convergent evolution?
development of similar physical characteristics that do not share a common ancestor
what were Darwin’s 4 observations?
- there were subtle changes in the way animals were fossilized, changing over time
- aspects that seemed different on the surface, human hand and bats wing had structural similarities underneath
- selective breeding leads to changes in appearance
- not all animals that are born will survive to maturity and reproduce
what sets humans apart from primates?
size of our cortex
what was darwins key piece of learning?
survival of the fittest
