Cutaneous Sensation and Psychodermatology (including diseases and medications) Flashcards
Where is the itch sensation limited to?
Skin, mucosa, and cornea
Describe Merkel cells
Light touch
Slow-adapting Aβ sensory fiber
Located along the stratum basale between keratinocytes
Also can be associated with hair
Meissner’s corpuscle
Describe Messiner’s corpuscle
Touch (dynamic skin deformation)
Rapidly-adapting Aβ sensory fiber
Merklel cell
Describe Ruffini corpuscle
Stretch
Slow-adapting Aβ sensory fiber
Pacinian corpuscle
Pacinian corpuscle
Describe Pacinian corpuscles
High pressure, vibration
Rapidly-adapting Aβ sensory fiber
Single non-myelinated nerve fiber enclosed by a multi-layer connective tissue capsule
Describe the sensation of hair follicles
Light touch, low-frequency vibration
All types of sensory fibers
What are the three intercommunicating plexuses of arteries and veins?
1) Deep plexus (interface of dermis and subcutis - some branches supply lower hair follicle and epitrichial sweat glands)
2) Middle plexus (level of the sebaceous gland and supplies arrector pili, middle hair follicle, and sebaceous glands)
3) Superficial plexus (capillary loops just below the epidermis - supplies upper hair follicle and epidermis)
Describe arterioles
endothelial cells surrounded by smooth muscle cells, most likely function as part of the resistance vessels in skin
If you wanted to stain Merkel cells on histopathology, what stain would you use?
CK20 (green)
IHC NSE (brown)
Ruffini corpusle
Potential new somatosensory organ in dogs
Non-encapsulated free nerve endings
What is one sentence that can describe how Merkel’s discs, Meissner’s corpuscles, Ruffini endings, and Pancinian corpuscles experience a finger moving over braille?
Each receptor sensors the same stimuli differently
Which type of nerve fibers typically respond to innocuous touch?
C fibers
Which type of nerve fibers typically respond to nociceptive touch?
Aδ fibers
C fibers
What is a dermatome?
An area of the skin supplied by one spinal nerve
What supplies the nerves of the skin of the head?
Cranial nerves
What supplies the nerves of the skin of the trunk and forelimbs?
Thoracic spinal nerves
What supplies the nerves of the hind limbs?
Pelvic spinal nerves
What are tylotrich hairs?
Large primary follicle surrounded by a ring of neurovascular tissue
Aδ fibers
Rapid
Associated with a tylotrich pad
What are the rapid adapting mechanoreceptors?
Pancinian corpuscle
Meissner corpuscle
Guard and down hairs
Tylotrich hairs