Peripheral Nerve Flashcards
create myolien in the PNS
Schwann Cells
Peripheral Nerves contains ______but no _______
axons, dendrites
A nerve is usually made up from a variety of fascicles . Each fascicle is encased by ________.
perineurium
Inside the fascicle are a group of axons bathed in __________
endoneurial fluid
Each axon has an insulating lining of _____
myelin
Between the fascicles is a fatty material called the________
interfascicular epineurium
binds several fascicles into a nerve trunk
epineurium
A peripheral nerve contains:
- axons
- Schwann cells (produce myelin)
- Support cells (produce fibrocollagenous tissue; spindle-shaped
- blood vessels
Surrounds individual axons, Schwann cells and blood vessels
Endoneurium
The endoneurium is composed mainly of reticular fibers (RF) synthesized by ___________
Schwann cells
myelinated processes
white matter
nerve cell bodies, dendrites, axon terminals, bundles of unmyelinated axons and neuroglia
Gray matter
In the spinal cord = gray matter forms
an H-shaped inner core surrounded by white matter
In the brain - a thin outer shell of _______ covers the surface & is found in clusters called nuclei inside the CNS
gray matter
myleinate axons in the CNS
oligodendrocyte
Types of receptors
- Mechanoreceptor
- Thermoreceptors
- Nociceptors
- Proprioceptors
(muscle spindles)
Muscle Spindle
- encapsulated sensory receptor
- specialized stretch receptor
non-encapsulated sensory receptors in the skin
- Epidermal free ending
- Merkel ending
encapsulated sensory receptors in the skin
- Pacinian corpuscle
- Krause end bulb
- Meissner’s corpuscle
- Ruffini corpuscle
Receptors for ATP, histamine, and bradykinin mediate painful sensations
pain-sensitive endings
stimulates heat-sensitive Ca+ channels in these endings
Capsaicin
Vanilloid receptor, VR1 =
Transient receptor potential,
TRPV1
Merkel’s Discs and Mechanoreception are found in which layer of the epithelium?
basal layer
touch receptors
stimulates cold-sensitive Ca+ channels (Vanilloid receptors)
MENTHOL
Vanilloid receptor,
Transient receptor
potential,
TRPM8
pressure receptors fast conducting bulb shaped receptors located deep in the dermis in the skin and also in various internal organs
pacinian corpuscle
sensitive to vibration
Voluntary motor and sensory components
Somatic nervous system
Involuntary control of viscera
Sympathetic system
“fight-or-flight; thoraco-lumbar
Parasympathetic system
“steady-state”; cranio-sacral
Autonomic nervous system
Located in the border between dermis and epidermis, “cotton candy-like” structure surrounded by fibroblast and Schwann cells
Meissner’s Corpuscles
touch receptor
Contains autonomic ganglion for contraction of smooth or cardiac muscle, stimulation or inhibition of glandular secretion
Autonomic motor neuron
Nerves release angiogenic factors such as
VEGF (Vascular Endothelial Growth Factor)
