Neuronal Function Flashcards
What major system is involved in neuronal function
the nervous system
What are the main functions of the nervous system?
perception
learning and memory
decision making
sensing environment
motor signal delivery
Where are communication and information processing encoded?
in neuron activity and chemical signaling
What are the 2 parts of the nervous system?
central nervous system (CNS)
peripheral nervous system (PNS)
What are the components of the CNS?
the brain and spinal cord
What are the components of the PNS?
neurons and glia external to the CNS
T or F: neurons and glia are only found outside the CNS
false, they are also present in the CNS
What allows a large complexity of behaviours in humans?
the massive amount of neurons and synapses in our brains
What happens in the signal reception neural zone?
dendrites and cell body receive incoming signal and convert it into a change in membrane potential
How many neurons are in the human brain? How many synapses?
neurons: 10^11
synapses: 10^14-10^15
T or F: all neurons have the same structure and properties
false
T or F: all neurons use the same basic mechanisms to send signals
true
What are the 4 basic neural zones of a motor neuron?
signal reception:
- dendrites
- cell body (soma)
signal integration:
- axon initial segment
signal conduction:
- axon (some in myelin sheath)
signal transmission:
- axon terminals at the synapse
What happens in the signal integration neural zone?
at the axon initial segment, a signal (change in membrane potential) is converted into an action potential
What happens in the signal conduction neural zone?
the axon potential travels down the axon (sometimes covered in a myelin sheath)
What happens in the signal transmission neural zone?
the action potential reaches the axon terminals (presynaptic boutons) and causes the release of a neurotransmitter into the synapse
Where in a neuron is an action potential generated?
in axon initial segment where the membrane potential change is converted into an action potential
What are dendrites? What is their function?
fine, branching extensions projecting from the neuronal cell body
dendrites sense incoming signals and convert them into electrical signals by changing the membrane potential which is transmitted to the cell body
What is the cell body? what are its functions?
stores the nucleus, most organelles, and is the location of protein synthesis
functions in receiving incoming signals
What is the axon hillock? what are its functions?
the axon hillock is involved in signal integration
its located at the junction between the cell body and the axon
this is where an action potential can be generated
- if an incoming signal sent from the dendrites and cell body is large enough when it reaches the axon hillock, an action potential will occur in the axon
What is the axon? what are its functions?
extending from the axon hillock and cell body, a skinny extension is where the action potential is initiated if the signal at the axon hillock is large enough
What part of the neuron is specialized for signal conduction?
the axon
T or F: axons are usually really short, but some can be multiple meters long
true, most are only a few mm long but for ex. in blue whales, axons are 25m long
What is a myelin sheath? what is its function? what type of neurons have these?
a coating of Schwann cells that intermittently wrap axons of vertebrate motor neurons to increase the conduction speed of electrical signals to axon terminals