Neuroanatomy Week 3 Flashcards
A neuronal membrane resting potential is..?
-70mV
What is the mV of an axon during action potential stimulation?
+40mV
What area of the neuron initiates an action potential upon depolarization?
Axonal hillock
In what area do neurons communicate?
The synapses
What reduces the likelihood of neuronal impulse initiation?
Hyperpolarisation
Where are the glia satellite cells found?
In the ganglia of the PNS
Where are Schwann cells found?
In the PNS nerve cells
Where are ependymal cells derived from?
Neural tube ectoderm
Where are microglia derived from?
Mesoderm
What is another name for neuroglial cells?
glia
What is a neuron, and what are its parts?
Neurons are cells specialized for sending and receiving chemically mediated electrical signals.
A neuron contains:
- cell body
- dendrites
- axon
What is the name of a neuronal cytoplasm?
Perikaryon
What is a neurite?
The term neurite refers to any neuronal process: axon or dendrite.
What does the neuron doctrine define?
The fact that each neuron is a structural and functional unit
What are the most abundant ions in the extracellular fluid?
NA+ and Cl-
What is the most abundant ion intracellularly?
K+ is the main positive ion
What organelles are found within the neuronal cytoplasm?
rough endoplasmic reticulum
polyribosomes
mitochondria
Golgi apparatus
Lysosomes
What is the cytoplasm of the axon called?
axoplasm
What does the axoplasm include?
Neurofilaments
microtubules
mitochondria
smooth endoplasmic reticulum
What cells lay down myelin sheaths in the PNS?
Schwann cells
What cells lay down myelin sheaths in the CNS?
oligodendocytes
What is it called when one action potential jumps from node to node?
Saltatory conduction
Nissle stain helps to?
Helps to study the cytoarchitecture in the CNS
Stains nuclei & cytoplasms
What is the Golgi stain good for?
Cell morphology
What are neurites?
Combination of dendrites & axons
What did Cajal hypothesise about neurons?
- Neurons communicate by contact, not continuity
What does the nucleus do?
- gene expression
- transcription
- RNA processing
What is a neuronal membrane?
Barrier that encloses the cytoplasm
What is the cytoskeleton?
Internal scaffolding of neuronal membrane
What are 3 structures associated with the cytoskeleton?
- Microtubules
- Microfilaments
- Neurofilaments
Fast axoplasmic transport is associated with…
Slow axoplasmic transport is associated with…
Do dendrites receive or send information?
receive
What are the 4 types of neuroglia in CNS?
Astrocytes
Oligodendrocytes
Microglia
Ependymal Cells
What are the 2 types of glia in the PNS?
Schwann cells
Satellite cells
What do astrocytes do?
- fill spaces between neurons
- Supports neurite growth
- REgulates chemical content of extracellular space
How many types of astrocytes are there?
2
Where does the fibrous astrocyte occur?
in White matter
What astrocytes are found in the gray matter?
- Protoplasmic astrocytes
What is the most prominent glia in the CNS?
Astrocytes
What are the 2 main myelinating glia ?
- Oligodendrocytes
- Schwann cells
What do ependymal cells do?
- Assist in production, circulation & monitoring for CSF
