midterm 1 ? Flashcards
ancient europe believed what?
HEART was the soul & memory
Egyptians & Chinese believes
HEART was the organ of thinking and reasoning
proof: mummification! (all organs removed except <3 for afterlife)
Greeks believed (Hippocrates vs Aristotle)
Hippocrates: BRAIN is vital
Aristotle: agreed with china and egypt (heart), believed BRAIN was A/C for heart
claudius galen
hippocratic (BRAIN) :
proof: gladiators + dissection
cerebellum = hard = muscles
cerebrum = soft = sensations
(right for wrong reasons)
psychic pneuma in ventricles (breath of life) (soul)
rene descartes
behaviour is a result of the environment
dualist (humans are different than animals BECAUSE we have the “separate” mind)
luigi galvani 🐸
electrically stimulated muscle frog leg moved
johannes muller
doctrine of specific nerve energies - all nerves carry the same message, but we perceive differently in different pathways
Pierre fluorens 🌸
🌸 experimental ablation method 🌸
- proved why claudius galen was right but for wrong reason (localization of function via ablation) (cerebellum = muscles = out , cerebrum = sensation + perception = in)
Paul Broca
Broca’s Area - ** discrete area ! **
DISCRETE REGIONS of brain responsible for DISCRETE things
Ramon Santiago y Cajal
discovered that the nervous system = billions of individual neurons
Fritsch & Hitzig
electrical stimulation to explore brain + gain understanding
Von Helmholtz
first to measure SPEED of conduction of nerves
neotony
prolongation of maturation (babies come out not fully ready and take a long time to develop)
axolotyls!
contemporary research
always evolving (ie epigenetics)
functionalism
charles darwin - theory of evolution
mental states defined by what they DO (their FUNCTION) rather than what they are made of
Nissl stain
violet stain - structure only
Golgi stain
outline of structure
the neuron doctrine
ramon santiago y cajal
NEURON = functional unit of nervous system
the doctrine of specific nerve energies
johannes muller
nerves all carry same message that is interpreted differently in different pathways/structures
CNS vs PNS
CNS: brain, spinal cord
PNS: everything else
3 types of neurons
sensory neuron - i see the cup
interneuron - perceive cup + decide to pick up the cup
motor neuron - pick up the cup
parts of neuron:
soma (body)
dendrites (dendritic spines)
axon - 1 axon = unipolar, 2 axons = bipolar, multiple axons = multipolar
terminal button
axoplasmic transport system
method of sending things to nucleus
anterograde
tracing techniques = radioactive amino acids/viruses
efficient
neuronal membrane consists of ________ bi_____
phospholipid bilayer
classifying neurons
- number of neurites - anaxonic, uni/bi-polar etc
- dentrite morphology - stellate, pyramidal etc
- type of connection - sensory / motor / interneuron
- axon length - golgi 1 = short , golgi 2 = long
- neurotransmitter released
glial cells
supporting cells
astrocytes
stellate most numerous in brain fill space btwn neurons structural support regulate ECS BBB (selectively permeable)
ependymal cells
line brain ventricles - produce CSF!
cushion + recycle
stem cell properties after injury
immune - protect against viruses
microglia
immune cells of CNS
house keepers!
phagocytosis of debris
myelinating glia (CNS vs PNS)
CNS: oligodendrocytes (1:1000)
PNS: Schwann cells (1:1) (one schwann cell = entire neuron myelin)
myelination useful for
propagation + conduction
Nodes of ranvier! - saltatory conduction (JUMPS)
phospholipid bilayer
heads = hydrophilic = polar = <3 water tails = hydrophobic = nonpolar =
neural communication (pain reflex sequence of events of neurons)
- dendrites of sensory sense pain
- interneurons
- interneurons - motor
- muscle contract
resting membrane potential
-65mV (inside more -ve than outside)
ion channels
selective of size + charge (gating)
passive
ion pumps
active transport against gradient (ATP)
membrane potential forces
diffusion
electrostatic
force of diffusion, electrostatic force
diffusion: high - low
electrostatic: likes repel likes, opposites attract
K channels vs Na channels
way more K channels
lots more K inside than out
lots more Na outside than in
Na/K pump maintains
parts of action potential
threshold rising phase overshoot / action potential falling phase undershoot / delayed rectifier
parts of action potential ion concentration levels
threshold sodium IN rising phase overshoot / action potential potassium channels open potassium OUT falling phase too much potassium OUT undershoot
hodgkin explosive cycle
depolarization = Na channels open = Na floods in = depolarization
sodium gates
M gate closed, H gate open depolarization + threshold M gate open, H gate open sodium in, rising phase peak reached M gate open, H gate closed N gate open potassium in, falling phase reset after
forwards vs backwards action potentials
forwards = orthodromic backwards = antidromic
absolute vs relative refractory period
absolute = action potential impossible (H gate closed) relative = action potential possible, harder to achieve
conduction velocity
spread (wide = fast)
path (inside axon = fast)
excitability (cable theory)
myelin (nodes of ranvier + insulation)
saltatory conduction
nodes of ranvier - jump
presynaptic - postsynaptic parts of neurons
pre = terminal buttons post = dendrite / soma
