Cells types and nuerotransmitters Flashcards
Neurons ___.
Injury to axon = ___.
Signal-relaying cells with dendrites (receive input), cell bodies, and axons (send output). Cell bodies and endrites can be seen on Nissl staining (stains the RER, axons don’t have RER).
Injury to axon = Wallarian degeneration. Degeneration distal to injury and axonal retraction proximally. Potential regeneration if in PNS.
Astrocytes ___.
If injured ___.
Marker ___.
Derived from ___.
Physical support, repair, K+ metabolism, removal of excess neurotransmitter, component of BBB.
Reactive gliosis in response to injury.
Marker: GFAP.
Derived from neuroectoderm.
Microglia ___.
Derived from __.
If HIV infection ___.
Phagocyte/marcophage of CNS. Activated when tissue damage. Not readily discernible by Nissl stain.
Derived from mesoderm (mononuclear origin).
HIV infected microglia fuse to form mutinucleated giant cells in CNS.
Myelin __.
Made by ___ in CNS.
Made by ___ in PNS.
Increase conduction velocity (and increase space constant) via saltatory conduction of AP at nodes of Ranvier where there’s high concentration of Na + channels.
CNS - oligodendrocytes.
PNS - Schwann cells.
Schwann cells ___.
Derived from ___.
Can be injured in ___ and ___.
Each Schwann cell myelinates only 1 PNS axon.
Derived from neural crest.
Promote axonal regeneration.
Injured in GBS and Vestibular schwannoma (on CN VIII).
Oligodendroglia ___.
Derived from ___.
Injured in ___ and __ and ___.
Myelinates axons of CNS, each oligodendrocyte can myelinate many axons. Predominant glial cell type in white matter.
Derived from neuroectoderm.
Injured in MS, multifocal leukoencephalophathy (PML), leukodystrophies.
Free nerve endings sense ___ via ___ fiber type(s).
Sense: Pain and temperature
Via:
1. C fibers - slow, unmyelinated
2. A-delta fibers - fast, myelinated
Light touch and position are sensed by ___ receptors via ____ fibers and are located ___.
Meissner corpuscles.
Via: Large, myelinated fibers that adapt quickly.
On hairless skin (glabrous)
Vibration and pressure are sensed by ___via ___ fibers and are located ___.
Pacinian corpuscles.
Via: Large, myelinated fibers that adapt quickly.
In deep skin layers, ligaments, joints.
Pressure, deep touch, and position sense, are sensed by ___via ___ fibers and are located ___.
Merkel discs.
Via: Large, myelinated fibers, adapt slowly.
In finger tips, superficial skin.
Pressure, slippage of objects along surface of skin, and joint angle changes are sensed by ___via ___ and are located ___.
Ruffini corpuscles.
Via dendritic endings with capsule, adapt slowly.
In finger tips, joints.
Endonuerium ___.
Surrounds single nerve fibers. Inflamed in GBS.
Perinuerium ___.
Surrounds fascicle of nerve fibers. Permeability barrier. Must be rejoined for limb reattachment.
Epineurium __.
Dense connective tissue that surrounds the entire nerve (fascicles and blood vessels).
Acetylcholine synthesized in ___.
Changes in these diseases ___.
Basal nucleus of Meynart. Decreases in: 1. Alzheimer 2. Huntington 3. Parkinson
Dopamine synthesized in ___.
Changes in these diseases ___.
Ventral tegmentum, Substantia nigra pars compacta (SNpc). Decreases in: 1. Depression 2. Parkinson Increases in: 1. Schizophrenia 2. Huntington
GABA synthesized in ___.
Changes in these diseases ___.
Nucleus accumbens.
Decreases in:
1. Anxiety
2. Huntington
Norepinephrine synthesized in ___.
Changes in these diseases ___.
Locus ceruleus.
Decreases in: Depression
Increases in: Anxiety.
Serotonin synthesized in ___.
Changes in these diseases ___.
Raphe nucleus. Decreases in: 1. Anxiety 2. Depression Inreases in: Parkinson
BBB is formed by __.
___ cross slowly by carrier transport.
___ cross rapidly by diffusion.
Formed by:
- Astrocyte foot processes
- Basement membrane
- Tight junctions between nonfenestrated capillary endothelial cells. Destroyed by infarction/neoplasm!
Glucose and amino acids cross slowly by carrier transport.
Nonpolar/lipid-soluble cross rapidly by diffusion.
Areas of brain without BBB and with fenestrated capillaries: ___
- Area postrema - vomitting after chemo
- OVLT (organum vasculosum of the lamina terminalis ) - osmotic sensing.
- Neurohypophysis - ADH release.
