Introduction Flashcards
Complete the phrase about unipolar neurones: these have 1 process arising from the soma and are usually ? cells, the cell bodies of which are grouped into ?
Sensory / ganglia
Complete the phrase about pseudounipolar neurones: only one process arises from the soma however this quickly splits into two, usually one going into the ? and one to the ? - these are usually ? neurones
Periphery / CNS / sensory
Complete the phrase about bipolar neurones: have two main processes arising from the soma and are usually located in ?
Specialised sensory organs
Complete the phrase about multipolar neurones: have many ? and one ?, and are the most ? type of neurone in the CNS
Dendrites / axon / common
What are interneurones?
Neurones which transmit information between other neurones
All types of neurones have 4 functional regions. What is meant by input?
Input comes from a pre-synaptic cell
All types of neurones have 4 functional regions. What is meant by integrative?
The soma integrates all the information coming into it
All types of neurones have 4 functional regions. What is meant by conductile?
The axons travel down the conductile area
All types of neurones have 4 functional regions. What is meant by output?
Usually involves the secretion of something
Complete the phrase about astrocytes: these are ? shaped cells which form a bridge layer between neurones and ? - one of their vital roles is the maintenance of ? which isolates and protects the brain from the rest of the body
Star / blood vessels / the BBB
Complete the phrase about capsular (satellite) cells: these are glial elements which surround the neuronal cell bodies in ?
Sensory and autonomic ganglia
Capsular (satellite) cells have a similar role to that of what type of cell? What is the difference?
Astrocytes / capsular cells function in the PNS, while astrocytes function in the CNS
Complete the phrase about microglia: these are very small glial cells which are activated by ? and are the CNS version of ? since they function as part of the ?
Trauma / macrophages / immune response
What do microglia do once they have been activated?
They remove foreign material and cellular debris through phagocytosis
Complete the phrase about ependymal cells: these are simple ? cells, which form the sheets of membrane lining the ?
Ciliated, cuboidal / ventricular system
As well as being the cells which line the ventricular system, what else do ependymal cells do?
Produce and transport CSF
What is the function of both oligodendrocytes and Schwann cells? What is the difference between the two?
They both produce the myelin sheath which forms a protective covering for the axons of neurones / oligodendrocytes myelinate the CNS while Schwann cells myelinate the PNS
What is an axon with myelin covering known as?
A fibre
Rapid communication along and between neurones is achieved by action potentials. What is this?
A transient change in electrical charge within a cell
An action potential begins at resting potential which is usually what? At this point, the inside of the cell has what kind of charge compared with the outside? This means that the membrane is what?
- 70mV / Negative / Hyperpolarised
In an action potential, depolarisation is caused primarily by what?
An influx of Na+ ions
An action potential is generates at the firing threshold, which triggers what?
The opening of all Na+ channels and a surge in Na+ influx
In an action potential, the cell repolarises how?
Via the inactivation of Na+ channels and activation of K+ channels causing K+ efflux
What is the absolute refractory period?
The period just after the overshoot when it is not possible to generate another AP
What are the nodes of Ranvier?
Myelin free areas of axons in the PNS
Describe what is meant by saltatory conduction?
Na+ influx at one node of Ranvier triggers Na+ influx at the next, with current ‘jumping’ between the nodes
What is the purpose of saltatory conduction?
It increases the speed at which an AP travels along the axon
Complete the phrase: at chemical synapses, neurotransmitters and neuromodulators are released from ? - they then bind to receptors on the ? to initiate ionic movement and generate an AP
The presynaptic terminal / the postsynaptic terminal
Complete the phrase: neurotransmitters are used for cell to cell communication to transmit a signal from one cell to the next - they are stored in ? in the ? and released with the terminal is ? during an AP
Vesicles / presynaptic terminal / depolarised
What are some neurotransmitters which are amino acids?
Glutamate, GABA, glycine
What are some neurotransmitters which are amines?
Dopamine, serotonin, histamine and noradrenaline
What is the main excitatory neurotransmitter of the CNS?
Glutamate
What are the main inhibitory neurotransmitters of the CNS?
GABA and glycine
What happens when glutamate is activated?
It activates postsynaptic cation receptors generating a depolarising response
What happens when GABA or glycine is activated?
They activate postsynaptic anion receptors generating a hyperpolarising response
What is the major neurotransmitter for both somatic and autonomic transmission in the PNS?
Acetylcholine
What is the major neurotransmitter for autonomic transmission only in the PNS?
Noradrenaline
Which specific type of ACh receptor is responsible for fast conduction in autonomic ganglia? How does this work?
Nicotinic receptors - channels conduct Na+ and K+
Which specific type of ACh receptor is responsible for slow conduction in autonomic ganglia? How does this work?
Muscarinic receptors - close K+ channels
