Exam 1 Flashcards
first candidate for the “seat of the mind”? Why? (2)
- heart
- heart rate increases during many emotional situations
- damage to heart = death
- damage to brain = not necessarily death
famous philosopher that proposed that the heart was the seat of the mind?
Aristotle
famous pholisopher who lived from 460-370 BC and claimed that brain was the seat of the mind?
- “from the brain come joys, delights, sorrows, etc.”
Hippocrates
What was trepanation? Why was it done? what does this tell us? what time period?
- drilling a hole in the skull
- thought to alleviate migrains, mental disorders, seizures, etc
- they saw a connection between brain and mental processes
- 1400s
with what two scientists did the scientific study of the brain begin? explain what each did
- time period?
- Andreas Versallius - first to draw a complete atlas of the brain
- Da Vinci - also did drawings of brain
- 1400s - 1500s
Descartes’ view on relationship between mind and body? How do they interact?
- time period?
- Dualism: body is made of material substance and mind is made of immaterial substance
- mind interacts with body through a hydraulic system of tubes connected to pineal gland (thought to not be bilateral). “Mind/soul” resides in those tubes/cavities
- 1600s
Explain what Paul Broca discovered
- what did this prove?
- damage to a certain area (thereafter deemed ‘Broca’s Area’) caused impairments in language production
- the mind is grounded in the brain. Damage to a certain portion of brain = specific impairment.
What did Luigi Galvani discover? How?
- time period?
- The brain interacts with the body through electric signals
- delivering current to an exposed nerve on a frog makes frog nerve contract
- 1700s
When did the neuroscientific revoluntion begin? what caused this?
- 1980s
- dramatic breakthroughs in medical technologies . Noninvasive live brain imaging allows us to see live brain activity.
what are the two types of cells in the nervous system?
- neurons
- glia
neurons are units of what?
- work in?
- essence of?
- do they last? regenerate?
- brain function
- large networks
- plasticity
- yes, longevity. But they DON’T regenerate.
function of glial cells? - do they regenerate?
- support, nourish, insulate, and repair neurons. W/O these, neurons wouldn’t work.
- YES
formal definition of neuron
cells in the nervous system that communicate with one another to perform information-processing tasks
approximately how many neurons are in the brain?
100 billion
function of the cell body
coordinates information-processing tasks and keeps the cell alive
functions of the dendrites
receive information from other neurons and relay it to cell body
what are dendritic branches?
branches off of dendrites (DUH)
what are dendritic spines? what do they do?
- little bulges on dendrites
- they increase surface area of dendrite so dendrite to reach more neurons
axon function
transmits information to other neurons, muscles, or glands
what is the axon hillock? what occurs here?
- where axon emerges from soma
- the AP starts here
what is a collateral?
any bifurcation in an axon (any place where axon splits)
what’s the myelin sheath?
insulating layer of fatty material around axon
what’s found w/in the soma?
nucleus
2 portions/extensions of dendrites
- dendritic branches
2. dendritic spine
4 portions/extensions of axons
- hillock
- collateral
- axon terminal (end branches)
- terminal buttons
all neurons are _____
interconnected
what are synapses?
connections through which neurons communicate
generally, info from neuron to neuron is what?
uni-directional
Each neuron can be activated and do what?
fire an AP when it reaches a threshold potential
2 different types of synapses. Explain what they do.
- Excitatory - increases the likelihood that the target neuron will fire
- Inhibitory - decreases the likelihood that the target neuron will fire
nodes of ranvier involved in what?
propagation of electric impulse
myelin is made of?
glial cells
size of:
- soma?
- axon?
- synapse?
- 10 micrometers
- millimeters to a meter
- 20 nanometers
what are the three types of neurons
- sensory neuron
- motor neuron
- interneuron
what do sensory neurons do?
- polarity?
receive info from the external world and convey it to the brain via the SC
- bipolar or unipolar
what do motor neurons do?
- polarity?
carry signals from the SC to the muscles to induce movement
- multipolar
what do interneurons do? - polarity?
connect sensory neurons, motor neurons, and other interneurons
- multipolarity
study and know what polarities of different neurons look like - presentation 2 slides 21 - 24 and notes in notebook
STUDY
list the 5 steps of a basic circuit for an arc reflex
- Receptor: a sensory neuron/cell that transforms external energy into electrical energy (the nervous impulse)
- Sensory Neuron
- Interneuron
- Motor Neuron
- Effector: cell that transforms the nervous impulse into an external response (muscle, gland, or organ)
what is the reflex arc?
causes the body to react to external stimuli quickly - the info doesn’t have to travel all the way to the brain. it bypasses the brain and goes through the SC.
practice labeling on slides 27 and 28 of Presentation 2
practice
what are ions?
small electrically charged molecules that flow in and out of the cell
what are membrane channels?
gates that open/close letting some molecules pass in/out of the neuron
what generates the membrane potential?
unequal concentration of ion charges across the semipermeable membrane
define resting potential? what are human’s resting potentials? explain what this means
electrical potential of a neuron in the absence of stimulation
- -70 mv
- inside of the neuron is more negative
what are the major ions that are part of neuron potentials? explain their concentration
- Na+ (more outisde)
- K+ (more inside)
define threshold potential
- what value is it?
the point at which an AP fires
- -50mv
excitatory stimulation makes what more likely?
- how does it do this? what’s this called?
makes the neuron more likely to generate an action potential
- brings the potential closer to -50mv. The intracellular side becomes LESS negative.
- depolarization