Tactile and Special Sensory Organs - Module 18 Flashcards
Tactile and Special Sensory Organs
These are sensory receptors that responds to mechanical pressure or distortion
Mechanoreceptors
4 main types of Mechanoreceptors in Glabrous skin
- Pacinian Corpuscle
- Meissner’s Corpuscles
- Merkel’s Discs
- Ruffini Endings
Type of mechanoreceptor that responds to light touch, and adapts rapidly to changes in texture
Tactile Corpuscles (Meissner)
Type of Mechanoreceptor that detects tension deep in the skin and fascia
Bulbous Corpuscles (Ruffini)
This type of mechanoreceptor detects sustained pressure
Merkel Nerve Endings
This type of mechanoreceptor detects rapid vibrations
Lamellar Corpuscles (Pacinian)
Receptors of the ear that transduce sound for the brain
Hair cells in Cochlea
Provides senses of touch, pressure, and vibration
Cutaneous Mechanoreceptor
Slow adapting receptors:
Merkel’s disc and Ruffini corpuscle
Intermediate adapting
Free nerve endings
Rapidly adapting receptors
Meissner’s corpuscle and Pacinian corpuscle
The afferent neurons transmits messages through synapses in the
Dorsal Column nuclei
Where the second order neurons send signals to
Thalamus
Third order of neurons are in the
Ventrobasal complex
Third order neurons send signals to the ____________________
Somatosensory Complex
2 pathways of nerve impulses
- Medial lemniscal Pathway (Proprioreception & touch perception)
- Spinothalamic Pathway (Temperature & Pain)
Light touch is sensed by _________ of hair follicle receptors
Meissner’s Corpuscle
Pain is sensed by ___________ of hair follicle receptors
Nociceptors
Temperature is sensed by ____________ of hair follicle receptors
Thermoreceptors/Nociceptors
Strong pressure is sensed by ____________ of hair follicle receptors
Merkel’s disk
This corpuscle/receptor lies deep in the dermis and subcutaneous tissue
Pacinian Corpuscle
Receptors located at fingertips, tongue, soles, and genitals
Meissner’s corpuscles
Are elongated and ovoid mechanoreceptors
Meissner’s corpuscles
Merkel cell nerve complexes are known as:
Touch domes, Hederiform endings
Iggo’s capsule, Pinbus corpuscles, Haarschibe
Mechanoreceptor sensitive to skin stretching and contributes to fine motor control
Ruffini ending
Most widespread sensory receptor
Free nerve endings
Rapidly adapting receptors that detects touch, temperature, pain, and itch
Penicillate Fibers
These are particularly receptive to Cold sensation
Papillary Fibers
Example of Special Sensory Organs
Olfactory mucosa, Gustatory cells, Retina, Internal Ear
Responsible for the sense of smell
Olfactory receptors
Location of Olfactory receptors
Roof of Nasal Cavity
Receptor organ for Hearing
Organ of Corti
True or False, Organ of Corti is composed of two rows of outer hair cells and one row of inner hair cells
False, there are 3 rows of outer hair cells and 1 row of inner hair cells
5 Layers of Cornea
- Outer Corneal Epithelium
- Bowman’s Membrane
- Substantia Propria
- Descemet’s Membrane
- Inner Endothelium