CHAPTER 3 Flashcards
What is the central region of the neuron? and what is the synonym?
Cell body also known as the soma
NOTE this is the cell’s life support centre also referred to as the cell executive
Define Neuron
nerve cell specialized for communication
AKA cell executive
define dendrite
These branchlike extensions. They “LISTEN IN” on conversations from neurons and pass them to cell body
Define Axon
Axons are the transmitters. They specialize in “SENDING MESSAGES” to other neurons. Axons “SPEAK”
What are the actions of dendrites and axons compared to?
Dendrites = listen Axons = speak
Define synaptic vesicles
Tiny sacs that contain neurotransmitters
What is the sequence for an impulse?
dendrites, soma, axon, axon terminal
define Synapse
fluid-filled space between neurons through which neurotransmitters travel
Define synaptic cleft
a gap into which neurotransmitters are released form the axon terminal
What is the purpose of Glial cells?
they communicate with neurons, help control blood flow to the brain and developing embryo, memory and immune cells.
What are the most abundant type of glial cells?
astrocytes
what do glial cells produce?
myelin
Define myelin sheath
glial cells wrapped around axons that act as insulators of the neuron’s signal.
What condition comes from the result of the deterioration of myelin sheath?
Multiple sclerosis
When do neurons fire?
On impulse when it receives a chemical signals or messages from sense receptors
What is the impulse called when neurons fire?
Action potential
What is the mV for resting potential?
-60mV to -70 mV
what is the threshold mV?
-55 mV
Define resting potential, threshold, action potential
1) Resting potential: Electrical charge difference when the neuron is not being stimulated or inhibited.
2) Threshold: membrane potential necessary to trigger an action potential.
3) Action potential: electrical impulse that travels down the axon, triggering the release of neurotransmitters.
Explain the process of an action potential
so enough stimuli is needed first before an action potential can occur. when enough stimulation is there, the depolarization of channels occur allow the inside of the cell to have positive ions in order to release neurotransmitters at the axon terminals. at its peak, the repolarization where the positive ions rush back (outside of the cell) to maintain resting potential where the outside of the cell has more positive ions and inside has an excess of negative ions.
What law do neurons follow?
All or none
How can we describe the relationship between neurotransmitters and receptor sites?
Describe it like a “Lock and Key” relationship
What blocks dopamine receptors?
Anti-psychotic drugs
What drugs increase serotonin?
Anti-depressants
What is the Absolute refractory period?
time during which another action potential can occur. this limits the maximal firing rate.
What is re-uptake?
recycling of neurotransmitters
define plasticity
ability of the nervous system to change
Acetylcholine
muscle movement, learning and memory
Which lack of neurotransmitters causes Alzheimer’s disease?
Breakdown of neurons containing Acetylcholine
Dopamine
Involved in learning, attention, movement and reinforcement.
Which neurotransmitter makes you happy?
Dopamine (aka DOPE)
Norepinephrine
Remember Snore
affects eating habits, arousal, and wakefulness.. Predominate when experiencing fear
Which neurotransmitter is present when experiencing fear?
Norepinephrine
Serotonin
Remember The Sorrow Tone of Her Sweet Voice tells you she’s Sad
plays role in regulating mood, sleep, impulsivity, aggression. Low levels of serotonin are linked to depression and increased levels linked to improve mood.
Which neurotransmitter when found to be low in the body causes depression?
Serotonin
GABA
learning, controls anxiety;
To treat Parkinson’s disease, we administer drugs with high levels of which neurotransmitter?
Dopamine
The activity of GABA is increased by which 2 factors?
1) consumption of alcohol
2) anti-anxiety medication (why? because GABA suppresses the overactive part of the brain linked to anxiety)
Endorphins
relive pain, produce feelings of pleasure and well being
Agonists
Similar to the transmitter to imitate it and its effects
Antegonists and how do they work?
inhibits transmitters action
how do they work? attach themselves to the opioid receptor without activating them.
What is an example of an Antegonists drug?
Naloxene
