Biological basis of behaviors Flashcards
(200 cards)
What is neuroanatomy?
Neuroanatomy relates to the parts and functions of individual nerve cells, known as neurons.
What is a neuron?
A neuron is an individual nerve cell.
Name the parts of a neuron.
- dendrites
- cell body/soma
- axon hillock
- axon
- myelin sheath
- nodes of Ranvier
- terminal buttons
- neurotransmitters
- synapse/synaptic cleft
Explain the function of the following part of a neuron:
dendrite
- branch-like arms attached to the cell body
- receive information from other neurons.
Explain the function of the following part of a neuron:
cell body/soma
- the “brain” of the neuron
- making up gray matter, and containing the nucleus.
axon hillock
connects the cell body to the axon
Explain the function of the following part of a neuron:
axon
- tube-like structures
- transmit information (via electrical impulse) from the cell body to the terminal buttons.
Explain the function of the following part of a neuron:
myelin sheath
- fatty layer around some axons
- insulates the electric impulse and allows information to travel faster
- so signals travel just to the intended neuron(s).
Explain the function of the following part of a neuron:
terminal buttons
- where information from the axon ends up
- contain neurotransmitters.
What are synonyms for “terminal buttons”?
end buttons
synaptic knobs
axon terminals
terminal branches of axons
Explain the function of the following part of a neuron:
neurotransmitters
- chemicals in the axon terminals that attempt to communicate with dendrites on other neurons
- “fit” with dendritic receptor sites to continue to the next neuron.
Explain the function of the following part of a neuron:
synapse
- also called the synaptic cleft; between pre synaptic neuron and post synaptic neuron
- gap between terminal button of one neuron and the dendrites of the next.
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Chemicals travel within the cells, but are transmitted to other neurons electrically. TRUE or FALSE?
FALSE
- electric signal within cells
- chemical signal at synapse
Can a neuron fire at different magnitudes?
No
- fire completely at depolarization threshold
- all or none principle
How is an action potential (or nerve impulse) created?
- charged chemicals enter the dendrite and then the soma
- soma is initially slightly negative charged
- some gets depolarized enough –> action potential
- electric information fired down the axon to the terminal button
Some __________ are excitatory, prodding the cell body to fire, and others are __________, which prevent the creation of a cell’s action potential.
neurotransmitters; inhibitory
Describe the path of information within a neuron from beginning to end.
Dendrite (chemical signals)⇒cell body (become electrical signals)⇒axon⇒axon terminal (become chemical signals)⇒synapse⇒dendrite of next neuron
When neurotransmitters from the axon terminal are released, they attempt to connect with __________ on the postsynaptic dendrite.
receptor sites
threshold
the level of depolarization of soma to produce an action potential
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
acetylcholine
Neuro-function: memory learning
Somatic Function: muscle contraction coordination and motor movement
Problem: Alzheimer’s disease linked to acetylcholine deficit
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
endorphins
Function: pleasure and pain control
Problem: endorphins are released when pleasure areas of the brain are stimulated, so addictions are linked to endorphins
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
dopamine
Neuro function: “reward”, pleasure and motivation
Function: motor movement and alertness
Problems: Parkinson’s disease (dopamine deficiency) and schizophrenia (excessive dopamine), linked to addiction
Dopamineis a monoamine, and part of the catecholamine class.
serotonin
Function: mood control, sleep, dream, appetite
Problem: deficiency linked to clinical depression
Serotonin is a monoamine, and part of the indolamine class.
What is the difference between afferent and efferent neurons?
Afferent neurons, or sensory neurons, carry informationtothe brain.
Efferent neurons, or motor neurons, carry informationfromthe brain to the body.