Cells and Tissues of the Nervous System Flashcards
What does a typical neuron consist of?
Multiple dendrites
One axon.
How does impulse transmission by can action potential travel?
In one direction from cell body to synaptic terminal.
What are some typical characteristics of a neurone?
Long living
Amitotic (divide without producing chromosomes)
High metabolic rate
Nucleus made of loose chromatin.
What is the function of the myelin sheath?
Increase conduction speeds in axons.
How is the myelin sheath formed?
Schwann cells in PNS
Oligodendrocytes in CNS.
What are multipolar neurons?
Interneurons and motor neurons.
What are bipolar neurone?
Olfactory mucosa
Retinal nerve fibres.
What are pseudounipolar neurones?
Sensory neurons.
What are Glial cells?
Support cells.
Non-excitable
Much smaller than neurons but more of them.
Name some different types of glial cells?
Satellite cells - surround neuronal cell bodies in PNS.
Schwann cells - myelination in PNS.
Astrocytes - have end feet. Surround synapses and capillaries. Help in K+ buffering.
Oligodendrocytes - myelination in CNS.
Microglia- Phagocytosis and scar tissue formation in CNS.
Ependymal cells - line ventricles.
What is the blood brain barrier?
Protective mechanism that helps maintain a stable environment and prevents harmful amino acids and ions in the blood, entering the brain.
Where is the blood brain barrier absent?
Parts of hypothalamus and posterior pituitary.
Where do the lateral ventricles lie?
Cerebral hemispheres.
What connects the lateral ventricles and the 3rd ventricle?
Interventricular foramen
Where does the 3rd ventricle lie?
Diencephalon.
