Nerve Tissue Flashcards
What is the definition of the term nucleus for the nervous system?
A group of neuron cell bodies in the CNS ( within similar function )
What is the definition of the term ganglion for the nervous system?
A group of neuron cell bodies in the PNS
What is the definition of the term tract for the nervous system?
A bundle of axons in the CNS
What is the definition of the term nerve for the nervous system?
A bundle of axons in the PNS
What is the function of dendrites?
Form connections with many neurons and receive impulses from them, forming a network for easy communication
What is the function of a myelin sheath?
Speeds up the conduction of action potential
What is the function of the nodes of ranvier?
Enable saltatory conduction (electrical impulse travelling from node to the next), increasing speed
What are the three structural classes of neurons and where are they found ?
-Multipolar neurons= brain
-Bipolar neurons= nose, eyes and ears
-Unipolar neurons= dorsal root ganglion of the spinal cord
Which structural class does this neuron belong to ?
Multipolar
Which structural class does this neuron belong to?
Bipolar
Which structural class does this neurone belong to?
Unipolar ( pseudounipolar)
What is the function of astrocytes?
-They regulate the exchange between capillaries and neurons, influence capillary permeability, and guide neuron migration.
-communicate with each other through calcium pulses and chemical signals,
What is the function of microglial cells?
Act as immune cells, monitor neural tissue and respond to injuries
What is function of endymal cells?
-Line the brain’s ventricles and the spinal cord’s central canal.
-Contribute to the production and circulation of CSF, which cushions the brain and spinal cord and removes waste.
-Use their cilia to help move CSF, ensuring proper flow and distribution
What is the function of oligodendrocytes?
They wrap their processes around thicker nerve fibers , forming an insulating myelin sheath.
What is the function of satellite cells?
surround neuron cell bodies in the peripheral nervous system (PNS) and are thought to have similar functions to astrocytes in the CNS.
What is the function of Schwann cells/ neurolemmocytes?
-wrap around all nerve fibers in the PNS, forming myelin sheaths around thicker fibers
-play a crucial role in the regeneration of damaged peripheral nerve fibers.
Describe the process?
- Depolarisation of pre-synaptic membrane causes opening of voltage-gated Ca2+ channels
○ Ca2+ diffuse into pre-synaptic neurone / knob - Causing vesicles containing ACh to move and fuse with pre-synaptic membrane
○ Releasing ACh into the synaptic cleft (by exocytosis) - ACh diffuses across synaptic cleft to bind to specific receptors on post-synaptic membrane
- Causing Na+ channels to open
○ Na+ diffuse into post-synaptic knob causing depolarisation
○ If threshold is met, an action potential is initiated
State the process
