LESSON 3 Flashcards
2 principal kinds of cells
neuroglia
neuron
the “nerve glue” or the cells that support the neurons of the CNS
NEUROGLIA
-glia means
glue
Function of neuroglia
support
insulation
nutrition
protection
6 types of neuroglia
SESAMO:
schwann cells
ependymal
satellite cells
astrocytes
microglia
oligodendrocytes
astro means
star
-cyte means
cell
- star-shaped cells with many processes
astrocytes
2 types of astrocytes
protoplasmic
fibrous
- astrocytes with many short branching processes (location: gray matter)
protoplasmic astrocytes
- long unbranched processes (location: mainly
white matter)
fibrous astrocytes
- help to maintain the appropriate chemical environment for the generation of nerve impulses.
astrocytes
- Also play a role in learning and memory by influencing the formation of neural synapses
astrocytes
Help forms the Blood Brain Barrier
astrocytes
it restricts the movement of substances between the blood and interstitial fluid of the CNS
blood-brain barrier
3 components of BBB
- astrocytes and astrocytic feet/processes
- capillary basement membrane/basal lamina with embedded pericytes
- tight junction between overlapping endothelial cells of the brain capillaries
encircle the capillaries secrete chemicals that maintain the permeability characteristics of the tight junctions
astrocytes and astrocytic feet/processes
cover the basal lamina of the endothelium and
contribute to the structural integrity of the BBB
pericytes
Substances may cross the BBB primarily by two mechanisms:
paracellular transport
transcellular transport
oligo means
few
o-dendro means
trees
these resemble astrocytes but are smaller and contain fewer processes
oligodendrocytes
Give support by forming semi-rigid connective tissue rows between neurons in the CNS
oligodendrocytes
Produce phospho-lipid for the myelin sheath around axons of neurons in the CNS - responsible for forming and maintaining the myelin sheath around CNS axons
oligodendrocytes
These neuroglia are small cells with slender processes that give off numerous spinelike projections
microglia/brain macrophages/microglial cells
act as macrophages
microglia
epen means
above
-dym means
garment
cuboidal to columnar cells arranged in a single layer that possess microvilli and cilia
ependymal cells
FUNCTION:
a. Form a continuous epithelial lining for the ventricles of the brain & the central canal of the spinal cord
b. Assist in the formation & circulation of CSF in the ventricles of the brain & the central canal of the spinal cord
ependymal cells
outer nucleated cytoplasmic layer of the schwann cell which encloses the myelin sheath
neurolemma
participate in axon regeneration, which is more easily
accomplished in the PNS than in the CNS
Schwann cells
- form myelin sheath around axons of neurons of the peripheral nervous system
schwann cells
These flat cells surround the cell bodies of neurons of PNS ganglia
satellite cells