A: Histology of nerves Flashcards
Names of bundles of processes (axons + dendrits) in PNS and CNS?
Tracts in CNS
Nerves in PNS
Neuron cell body
- Perikaryon (cytoplasm in neuron cell body)
- Many mitochondria
- Nissl bodies are clusters of RER at base of dendrites + axon hillock
- Neurofilaments (bundles of intermediate filaments that provide shape)
- Microtubules for transport
- Axon hillock (cone shaped area where axon arises)
Types of synapses:
Axodendritic: Axon from one neuron meets dendrites of another neuron.
Axosomatic: Axon of one neuron meets nerve cell body of another neuron
Axoaxonic: Axon meets axon
Epineurium
Outer covering: surrounds entire nerve
Perineurium
Surrounds each nerve fascicle (group of axons)
Endoneurium
Surrounds each nerve fibre
Identify structures
F = fascicle
E = epineurium
P = perineurium
V = blood vessel
Identify structures
M = myelinated axon
N = non-myelinated axon
S = schwann cell
Mi = mitochondria
F = fibroblasts of endoneurium
Multiple sclerosis
Multiple Sclerosis is an autoimmune disease that destroys myelin sheaths, so impulse conduction slows and eventually ceases.
Identify
Ganglion
Identify
Glial cell
Identify
neurone
Identify
satellite cell
Identify
Node of ranvier
Identify
Glial
Identify 23 and what substance is found in b
Perineum
Epineurium
Identify
Astrocyte
Identify
Microglia
Identify
Ependymal cells
Axon
- Arises from axon hillock
- Transmits impulses away from cell body
- Neurofilaments + microtubules provide strength
Branches at end of axon called terminal boutons.
Astrocyte
- Recycle + absorb neurotransmitters
- Maintain BBB
- Regulate nutrient, ion and dissolved gas concentrations
- Provide structural support
- Form scar tissue
- ## line pia mater, forming glia limitans, which is an impermeable barrier.
Oligodendrocytes
- Form myelin sheaths around axons - which are an insulating layer to increase speed of action potential in CNS
Microglia
Microglia are small phagocytes
- Migrate towards injured neurons
Engulf invading organisms & dead neurons.
Ependymal cells
Ependymal cells: line cerebrospinal fluid-filled cavities - called ventricles.
Fluid is called cerebrospinal fluid, is constantly circulating. Cells have cilia to help movement of fluid.
Schwann cell
Schwann cells surround axons producing myelin in the peripheral nervous system.
Each Schwann cells surrounds one axon.
Identify
Nissl bodies
Identify
Neurone
Identify
Myelin sheath
Identify
dendrite
Identify
axon
Identify
Axon hilloc
Identify
Ganglion
Identify
Nissl bodies
Identify
Ependymal cell
Identify
Astrocyte