Flashcards in Brain Cells Deck (20):
Two cell types in nervous system
Neurons and glia
Three functions of myelin sheath:
- speeds action potential
- decreases metabolic demands
- decreases space requirements to propagate action potential
Three morphologies of neurons and example of where they exist:
- Bipolar: single axon and single dendrite emerging from opposite ends of soma (retinal ganglion cell)
- Pseudo-unipolar: dendrite and axon emerge from same process (DRG)
- Multi-polar: more than two dendrites (spinal motor neuron)
Two types of multipolar neurons:
- Golgi I = neurons with long axons
- Golgi II (granule neurons) = neurons with short, locally projecting axons
Most neurons, whether sensory, motor, interneuronal, or neuroendocrine, have 4 functional components in common:
Which are functions of dendrites and soma?
1. Input component (excitatory or inhibitory)
2. Integrative component
3. Conductive component
4. Output component
Synapses occur at which dendritic structure?
T or F. A spine receives a SINGLE synaptic input.
FALSE - a single spine has multiple synapses
Where does Action potential initiation occur
What appears first during neuronal differentiation? Dendrites or axons?
Axons, then dendrites
What do we have more of: glia or neurons?
Glia - 1-5x more than neurons
What glial cells form myelin?
Oligodendrocytes and Schwann cells
What glial cells are macrophages of the brain that scavenge and remove debris after injury, disease, and neuronal death?
What glial cells guide migrating neurons and direct outgrowth of axons?
What glial cells participate in formation and maintenance of blood-brain barrier?
T or F. Glial cells fire action potentials.
What glial cells take up neurotransmitters like glutamate to regulate synaptic transmission?
What glial cells buffer K+ concentrations in CNS?
Name the 4 types of microglia.
- Amoeboid - present during development, phagocytose debris, do not present Ag
- Ramified - common morphology of resting microglia
- Activated - phagocytic and Ag presenting
- Gitter cells - full of debris, unable to phagocytose any more material
Where do ion channels cluster in axons?
Nodes of Ranvier