Unit 3- Biological Basis of Behavior Flashcards
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 seven parts of a neuron.
- dendrites2. cell body/soma3. axon4. myelin sheath5. terminal buttons6. neurotransmitters7. synapse/synaptic cleft
Explain the function of the following part of a neuron:dendrite
Dendrites are branch-like arms attached to the cell body that receive information from other neurons.
Explain the function of the following part of a neuron:cell body/soma
The cell body/soma is the “brain” of the neuron, containing the nucleus.
Explain the function of the following part of a neuron:axon
Axons are tube-like structures that transmit information from the cell body to the terminal buttons.
Explain the function of the following:myelin sheath
The myelin sheath is the fatty layer around some axons that allows information to travel faster from the cell body to the terminal buttons.The myelin sheath also acts as insulation so that signals don’t travel to every adjacent neuron, but just to the intended neuron(s).
Explain the function of the following part of a neuron:terminal buttons
Terminal buttons are where information from the axon ends up, and 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
Neurotransmitters are chemicals in the axon terminals that attempt to communicate with dendrites on other neurons.Neurotransmitters must “fit” with dendritic receptor sites, like a key in a lock, to continue to the next neuron.
Explain the function of the following part of a neuron:synapse
The synapse, also called the synaptic cleft, is the gap between the axon terminal of one neuron and the information-seeking dendrite of the next neuron. This role as a gap between the terminal buttons and dendrite helps pass chemical or electrical signals from one neuron to the next.
True or false:Chemicals travel within the cells, but are transmitted to other neurons electrically.
FALSE## FootnoteWithin the cells, information is transmitted as an electric signal, but when it reaches the axon terminal, it is converted into chemicals that move between one neuron and the next.
Can a neuron fire at different magnitudes?
No, a neuron will fire completely if it reaches or exceeds the depolarization threshold, or not at all, which is called the all-or-none principle.
How is an action potential created?
Positively or negatively charged chemical signals enter the dendrite and move to the cell body, which is slightly negatively charged. If these chemical signals depolarize the cell body enough, an action potential will occur, which will fire electrical information down the axon to the axon terminal.
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
Define:threshold
The threshold is the level of depolarization a cell body must reach 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
- Function: 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?dopamine
- Function: motor movement and alertness* Problems: Parkinson’s disease (dopamine deficiency) and schizophrenia (excessive dopamine)
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?endorphins
- Function: 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?serotonin
- Function: mood control* Problem: deficiency linked to clinical depression
What is the difference between afferent and efferent neurons?
- Afferent neurons, or sensory neurons, carry information to the brain.* Efferent neurons, or motor neurons, carry information from the brain to the body.
What are the subdivisions of the nervous system?
- central nervous system * brain and spinal cord* peripheral nervous system * somatic * autonomic * sympathetic * parasympathetic
What is the difference between the central nervous system and the peripheral nervous system?
The central nervous system includes the nerves in bones. The peripheral nervous system includes the nerves not encased in bone.