Chapter 1 Flashcards
Monism
Universe consists of only one type of being
What are the 4 explanations of behavior?
Physiological, functional, ontogenetic and evolutionary
What is the kind-body problem?
How mind relates to Brain activity
What are the 3 “r”s?
Reduce replacement refinement
Name two kinds of cells the nervous system consists of?
Glia and neurons
What do neurons do?
They receive information and transmit them to other cells
Who found a way to stain cells with silver salts?
Camilo Golgi
Who was Santiago Ramon rajal?
Showed small gap separates the tips of one neuron fibers from the surface of the next neuron
What is a membrane?
The surface of a cell
What does a membrane do?
Separates the inside of the cell from the outside environment
What is a Nucleus
Structure that contains the chromosomes
Mitochondrion
Performs metabolic activities, providing energy that the cell uses for all activities
Ribosome
Sites at which the cell synthesizes new protein molecules
Some float freely
What are some ribosomes attached to?
Endoplasmic reticulum
Dualism
Mind is one type of substance and matter another
3 major parts of neuron
Dendrites
A soma
Axon
Presynaptic terminals
Dendrites
Branching fibers
Surface lined with synaptic receptors to receive info from other neurons
Dendritic spines
Short outgrowths increase surface area available for synapses
Cell body/soma
Contains neucleus, ribosomes and mitochondria
Metabolic work
Axon
Thin fiber of constant diameter
Conveys an impulse toward other neurons, organ or a muscle
Myelin sheath
Insulating material of vertebrate axons
Nodes of ranvier
Interruptions
Presynaptic terminal
Swells at the tip of the branches
Efferent axon
Carries information information away from a structure
Afferent axon
Brings information into a structure
Different types of glia
Amors
Radial glia Astrocytes Microgila Oligodendrocytes Schwann cells
Astrocytes
Star shaped
Wrap around the presynaptic terminals
Helps synchronize the activity of neurons enabling them to send msgs in waves
Remove waste material
Dilate blood vessels
Microglia
Part of the immune system removing waste material viruses, fungi from brain
Survival of neurons in early life
Oligodendrocytes / Schwann cells
Build myelin sheath that surround and insulate
Supply axon with nutrients necessary for functioning
Radial glia
Guide the migration of neurons
after embryo logical development finish they differentiate into neurons/Astros/Oligodendrocytes
Blood brain barrier
Keeps out viruses and also most nutrients
Which chemicals cross blood brain barrier?
Oxygen, water, carbon dioxide
chemicals that dissolve in fats of the membrane
Which chemicals cross blood brain barrier by active transport?
Glucose, amino acids, purines, choline, certain vitamins, iron, few hormones
Electrical gradient
Known as polarization
A difference in charge between inside and outside cell
Resting potential
Difference in voltage / 70 mV millivolts
Neuron inside has slightly negative electrical potential with respect to outside. (Negative charged proteins inside cell)
Like bow and arrow stable until it’s ready to fire
Selective permeable
Some chemicals pass through more freely than others
Concentration gradient
Difference in distribution of ions across the membrane
Sodium more concentrated outside so it enters the cell
Sodium potassium pump
Continues pulling potassium into the cell, so it always remains extra concentrated inside
Where are sodium ions more concentrated?
Outside
Where are potassium ions more concentrated?
Inside the cell
What drives the potassium ions out the cell?
Concentration gradient
What draws the potassium ions into the cell?
Electrical gradient
Action potential
Messages sent by axons
Hyperpolarization
Increased polarization
Is an exaggeration of the usual negative charge within a cell. A depolarization is a decrease amount of negative charge
Subthreshold
Stimulation produces s response that quickly decays
What is the relationship between the threshold and action potential?
A depolarization that passes the threshold produces an action potential. One that falls short does not
During action potential sodium ions go where?
Move into the cell
After the peak of action potential what brings back the resting potential?
Potassium exits the cell driving the membrane back to resting potential
All or none law
All stimuli that exceed the threshold produce same response to the neuron
Threshold of excitation
Produces massive depolarization of the membrane
Opens sodium channels and allows to come
In. Shoots up far beyond the strength of the stimulus (action potential)
Name the refractory periods
Absolute refractory period
Relative refractory period
The refractory period
What is the refractory period ?
Immediately after an action potential which resists the production of further action potentials
What is the absolute refractory period?
The membrane cannot produce an action potential regardless of stimulation
What is a relative refractory potential?
A stronger than usual stimulus is necessary to initiate an action potential
Na ?
Sodium
K
Potassium
Saltatory conduction
The jumping of action potentials from node to node
Providing rapid conduction of impulses
Conserves energy by: a myelinated axon admits sodium only at its nodes
Local neuron
Neurons without an axon exchange information only from closest neighbors
Don’t follow all or none law
Graded potential
When local neuron receives information from other neurons
A membrane potential that varies in magnitude in proportion to the intensity of the stimulus
Inside cell of resting neuron is what charge?
Negative charge
Electrical and concentration gradient
At rest, act in competing directions for potassium, almost balancing out
Potassium ions have slow net flow out
Both tend to push sodium into cell but sodium doesn’t cross while at rest
What’s a synapse
Specialized gap between neurons
The point of communication between two neurons
Who found the synapse?
Sherrington
What did Sherrington find?
Communication between one neuron and the next differs from comm along a single axon
Reflexes
Automatic muscular responses to stimuli
Reflex arc
The circuit from sensory neuron to muscle response
Temporal summation
Summation over time
Combined effect of quickly repeated stimulation at a single synapse
Spatial summation
Summation over space
Pinch two points at once
Combined effect of several stimulation at several synapses onto one neuron
Presynaptic neuron
Delivers transmission
Post synaptic neuron
Receives transmission
What evidence led Sherrington to conclude transmission of synapses is different from among an axon?
Speed of conduction through a reflex arc was slower than that of an action potential of axon.
Some delay must occur at the junction between one neuron and the next
Eccles
Excitatory postsynaptic potential EPSP
What gates open during EPSP?
Graded depolarization
From flow of sodium ions into neuron producing temporal summation
Sodium gates open
What gates open during Inhibitory postsynaptic potential IPSP?
Occurs when synaptic input selectively opens the gates for potassium to leave
Potassium or chloride gates open
Can inhibitory message flow along axon?
No. Only action potentials propagate along axon.
IPSP decay over time and distance
Who was Otto Loewi
Nerves send messages by releasing chemicals
What is a neurotransmitter?
Neuron releases chemicals that affect another neuron
What do neurons release in highly active brain areas?
Nitric oxide NO
Name 3 catechloamines
Epinephrine
Norepinephrine
Dopamine
Tryptophan ?
Amino acid, precursor to serotonin crosses blood brain barrier by special transport system
amount of this in diet controls amount of serotonin in the brain
Where are neurotransmitters stored?
In vesicles (tiny spherical packets)
How is excessive build up of neurotransmitter prevented?
By an enzyme called MAO that breaks down these transmitters into inactive chemicals
What are bursts of release of neurotransmitters from the presynaptic neuron called?
Exocytosis
Ionotropic effects are gated by what?
Transmitter gated or ligand gated
What neurotransmitter uses the excitatory ionotropic synapses?
Glutamate
What do inhibitory ionotropic synapse use?
GABA opens chloride gates
What are two receptors called?
Ionotropic effects and megabotropic effects
What are ionotropic synapses for?
Vision and hearing- rapid quick changing information
What are metabotropic synapses for?
More enduring effects like taste smell and pain . Timing not important
Arousal attention pleasure and emotion
Where are neuropeptides released? And when
Dendrites cell body and sides of axon
Only after prolonged stimulation but when, in large amounts not just axon terminal (neurotransmitter)
Diffuse widely producing long lasting effects
LSD
Lsd binds to one type of serotonin receptor
They provide Stimulation at inappropriate times and cause distorted perception
Hormone
Chemical secreted by cells in one part of the body and conveyed by blood to influence other cells
Difference between neurotransmitter and hormone
Hormone like radio station, u have to tune in to the right station to get the message
Neurotransmitter like phone. From one sender to another
Name 3 brains neurotransmitters
Serotonin
Gaba
Glutamate
Brains most abundant excitatory neurotransmitter is______, and inhibitory Neurotransmitter _______.
Glutamate…gaba
A chemical released inside a cell after stimulation at a metabotropic synapse is called what?
Second messenger
Anterior pituitary
Glandular tissue that produces hormones that Control other endocrine organs
Which neurotransmitter is broken down into 2 pieces
Acetylcholine
