Cellular Organization and Excitability Flashcards
What are the 2 classes of cells in the CNS?
Neurons
Glia
True or false: excitatory axons project locally and inhibitory axons project at a distance.
False - the opposite is true
[…] is the neurotransmitter for excitatory synapses.
Glutamate
[…] is the neurotransmitter of inhibitory synapses.
GABA
[…] are the neurotransmitters of modulatory synapses.
Serotonin
Dopamine
Acetylcholine
Norepinephrine
What are the 4 types of glial cells to know?
Oligodendrocytes
Astrocytes
Microglia
Ependymal
In the PNS, the equivalent of both astrocytes and microglia is […]
Satellite cells
What is the role of astrocytes and microglia in the CNS?
- Support of CNS
- Astrocytes are close to synapses to participate in phagocytosis and maintain homeostasis of neurotransmitters and ions by absorbing these molecules
- Microglia play a neuroimmune response and help clean up the CNS
What is the function of ependymal cells in the CNS?
- Produce and secrete CSF
- Form blood brain barrier
Unlike neurons, glial cells are […]
Mitotic
What is the choroid plexus?
- Clusters of ependymal cells in the ventricles in the brain
What aspect of the structure of ependymal cells helps them circulate CSF?
They have cilia that beat to help it circulate
Describe the pathway that CSF takes in the brain
Produced in choroid plexus, drains to ventricles, traverses brain via cerebral aqueduct and central canal, exits into subarachnoid space via foramens in skull, subarachnoid space drains to sinuses, sinuses drain to blood (venous blood supply)
Describe the smooth endoplasmic reticulum of neurons.
The smooth ER spans the entire length of dendrites of neuron. It is a continuous network within the dendrites. It stores and releases calcium and is also thought to package and process proteins. As such, it has been implicated in protein misfolding diseases and neurodegeneration.
What is a nucleus?
Neurons in the CNS with similar function
What is the equivalent of a nucleus in the PNS?
Ganglion
What does the term “layer” mean?
Collection of neurons in cortical layer (grey matter)
What does the term “Column” mean?
Group of neurons across layers but within a column of the cortex that are involved in a cogitive task
With regards to membrane potential:
- There is more […] inside the cell
- There is more […] outside the cell
K+
Na+, Ca2+, Cl-
Why does the interior of a cell have a net negative resting membrane potential?
- There is a large density of positive charge outside the cell (Na+, Ca2+)
- There is a large density of negatively charged proteins inside the cell
What is an action potential?
A sudden, brief reversal of resting membrane potential
Describe the sequence of events in an action potential.
What is a significant change in the structure of the brain from when we are children to when we are young adults?
The brain becomes more myelinated –> more connections are made and strengthened by myelination. This can appear in imaging as a loss of gray matter but it isn’t so much a loss of grey matter as it is a gain of white matter.
