Astrocytes - Appearance
*A glial cell of the CNS
*Star shaped because of cytoplasmic processes that extend from the cell body
*These extensions widen and spread out to form foot processes
*Foot processes cover the surfaces of blood vessels, neurons and pia mater (membrane coveri
Astrocytes - Function
*Play a role in regulating the extracellular composition of brain fluid
*Release chemicals that promote the formation of tight junctions between the endothelial cells of capillaries
-These endothelial cells and tight junctions form the blood-brain barrier
Astrocytes - book caption
Astrocyte processes form foot processes, which cover the surface of neurons, blood vessels, and the pia mater. The astrocytes provide structural support and play a role in regulating what substances from the blood reach the neurons.
Ependymal Cells - book caption
*Ciliated ependymal cells lining the ventricles of the brain and the central canal of the spinal cord help move cerebrospinal fluid.
*Ependymal cells of the surface of of the choroid plexus secrete cerebrospinal fluid.
Ependymal Cells - appearance
*A glial cell of the CNS
*Line the ventricles of the brain and the central canal of the spinal cord
*The free surface frequently have patches of cilia that help move cerebrospinal fluid through brain cavities
*The basal surface has long processes that ext
Ependymal Cells - function
*Specialized ependymal cells and blood vessels form the choroid plexuses
-These are located within certain regions of the ventricles
-The choroid plexuses secrete cerebrospinal fluid
*Use cilia to keep cerebrospinal fluid moving throughout brain cavities
Microglia - book caption
Microglia are phagocytic cells within the CNS.
Microglia - appearance and function
*A glial cell of the CNS
*Become mobile and phagocytic in response to inflammation
-Phagocytize necrotic tissue, microorganisms and foreign substances that invade the CNS
*Microglia and Brain Damage:
-Numerous microglia migrate to areas damaged by infecti
Oligodendrocytes - book caption
*Extensions from oligodendrocytes form part of the myelin sheaths of several axons within the CNS
Oligodendrocytes - appearance and function
*A glial cell of the CNS
*Have cytoplasmic extensions off of the cell body.
*These cytoplasmic extensions can surround an axon
*If the cytoplasmic extension wraps many times around the axon a myelin sheath forms
*A single oligodendrocyte can form myelin s
Schwann Cells - book caption
*Schwann cells form the myelin sheath of an axon within the PNS
Schwanns Cells - appearance and function
B. Schwann Cells
*A glial cell of the PNS
*Glial cells in the PNS that wrap around axons
*If it wraps many times around an axon, a myelin sheath is formed
*Can only form part of the myelin sheath around one axon (unlike oligodendrocytes that can be around
Satellite Cells - book caption
Neuron cell bodies within ganglia (clusters of cell bodies in the PNS) are surrounded by satellite cells.
Satellite Cells - appearance and function
A. Satellite Cells
*A glial cell of the PNS
*Surround neuron cell bodies in sensory ganglia
*Provide support and nutrition to the neuron cell bodies
*Protect neurons from heavy metal poisons, such as lead and mercury, by absorbing the metals and reducing
Astrocytes - Appearance
*A glial cell of the CNS
*Star shaped because of cytoplasmic processes that extend from the cell body
*These extensions widen and spread out to form foot processes
*Foot processes cover the surfaces of blood vessels, neurons and pia mater (membrane coveri
Astrocytes - Function
*Play a role in regulating the extracellular composition of brain fluid
*Release chemicals that promote the formation of tight junctions between the endothelial cells of capillaries
-These endothelial cells and tight junctions form the blood-brain barrier
Astrocytes - book caption
Astrocyte processes form foot processes, which cover the surface of neurons, blood vessels, and the pia mater. The astrocytes provide structural support and play a role in regulating what substances from the blood reach the neurons.
Ependymal Cells - book caption
*Ciliated ependymal cells lining the ventricles of the brain and the central canal of the spinal cord help move cerebrospinal fluid.
*Ependymal cells of the surface of of the choroid plexus secrete cerebrospinal fluid.
Ependymal Cells - appearance
*A glial cell of the CNS
*Line the ventricles of the brain and the central canal of the spinal cord
*The free surface frequently have patches of cilia that help move cerebrospinal fluid through brain cavities
*The basal surface has long processes that ext
Ependymal Cells - function
*Specialized ependymal cells and blood vessels form the choroid plexuses
-These are located within certain regions of the ventricles
-The choroid plexuses secrete cerebrospinal fluid
*Use cilia to keep cerebrospinal fluid moving throughout brain cavities
Microglia - book caption
Microglia are phagocytic cells within the CNS.
Microglia - appearance and function
*A glial cell of the CNS
*Become mobile and phagocytic in response to inflammation
-Phagocytize necrotic tissue, microorganisms and foreign substances that invade the CNS
*Microglia and Brain Damage:
-Numerous microglia migrate to areas damaged by infecti
Oligodendrocytes - book caption
*Extensions from oligodendrocytes form part of the myelin sheaths of several axons within the CNS
Oligodendrocytes - appearance and function
*A glial cell of the CNS
*Have cytoplasmic extensions off of the cell body.
*These cytoplasmic extensions can surround an axon
*If the cytoplasmic extension wraps many times around the axon a myelin sheath forms
*A single oligodendrocyte can form myelin s
Schwann Cells - book caption
*Schwann cells form the myelin sheath of an axon within the PNS
Schwanns Cells - appearance and function
B. Schwann Cells
*A glial cell of the PNS
*Glial cells in the PNS that wrap around axons
*If it wraps many times around an axon, a myelin sheath is formed
*Can only form part of the myelin sheath around one axon (unlike oligodendrocytes that can be around
Satellite Cells - book caption
Neuron cell bodies within ganglia (clusters of cell bodies in the PNS) are surrounded by satellite cells.
Satellite Cells - appearance and function
A. Satellite Cells
*A glial cell of the PNS
*Surround neuron cell bodies in sensory ganglia
*Provide support and nutrition to the neuron cell bodies
*Protect neurons from heavy metal poisons, such as lead and mercury, by absorbing the metals and reducing