neurons and drugs Flashcards
what is the value of an action potential and what does it represent?
+70mV , this is a short reversal of the electrical charge of an axon
what is an action potential caused by?
Ion channels and transporters opening allowing sodium ions in, then potassium ions are pumped out to restore balance
Name the two submicroscopic proteins which allow ions in and out
- ion transporters (active pumping)
- ion channels
Describe the structure of a neuron
Soma Dendrites axon myelin terminal buttons
Th two subsystems of the nervous system
Central nervous system
Peripheral nervous system
What is the central nervous system?
The brain and the spinal cord
What is the spinal cord?
a collection of nerve cells attached to the base of the brain running down the spine.
How are the brain and spinal cord protected?
both enclosed by menegies (three layer set of membrane). Spaces between menegies are filled with cerebrospinal fluid (CSF)
What are modules?
nerve cells are organised into modules. These are clusters of nerve cells that communicate to each other. They are connected to neural circuits. Different modules may do different things (modularity)
What is the peripheral nervous system?
This is the nerves which connect the CNS to the sense organs, muscles and glands
whats the difference between spinal nerves and cranial nerves?
Spinal nerves are attached to the spinal cord and serve the body below the neck whereas the brain nerves serve the neck and head
What do glia do?
Glia provide physical and mechanical support to neurons
What may glia be involved in according to research?
glia may determine the number of synapses in the brain as neurons exposed to glia formed 7 times as many synapses
What are three types of glia?
Astrocytes (opendak and Gould 2015) act on damage to neurons, regulate blood flow to cells and remove toxins
Microglia (schafe et al 2013) immune cells which clean up debris
Oligodendroglia form myelin
What is a synapse?
A synpase is the conjuction of a terminal button of one neuron and the mmebrane of another cell
How does neuron activity affect rate of musclecontraction?
rate of neuron firing determines the stregth of contractions
What are excitatory synapses?
this is where neurotransmitters excite post synaptic nurones making it more likely for the post synaptic neuron to fire. Excitiatory synapses allow NA+ to enter the neuron
What is an inhibitory synapse?
lower the likelihood that the axons of the post synaptic neuons firing. Inhibitory synapses enable K+ to leave the neuron.
How do transmitter molecules activate receptors?
They open the ion channels
How are the effects of the transmitter terminated?
By reuptkwe of molecuyles so the transmitter is not staying in the synoase and continually actibating the receptors
brisfly explain how transmitters move throughout the systen
vesicles in the presynaptic neuron these then bind with eh cell membrane and are then released into the cleft where they attach to recptor molecules
Discuss nucleus accumbens and the reward system
It is part of the reward system, evaluating salience of things. It is also involved in impulsivity. It responds to reward and adversive stimuli.
What does glutamate do?
very prevalent in sensory and motor systems. It is excitatory
What is GABA
it is evrywhere in the brain and is inhiobitory
