General Sensory Mechanisms Flashcards
Mechanoreceptor for Equilibrium
VESTIBULAR Receptors
Encapsulated endings of Skin Tactile sensibilities
- Meissner’s Corpuscles
- Kraus’ Corpuscles
Type C Nerve Fibers
- SMALL Unmyelinated fibers
- Conduct @ LOW Velocity
Exteroreceptive sensations
From the SURFACE of the Body
EM Receptors
- Rods and Cones
- For Vision
Discharge Zone of the Neuronal Pool
Includes ALL the Output fibers stimulated by incoming fibers
In terms of potential, Axons can elicit _____ while Dendrites can elicit _____.
- AP
- Local Potential
Somatic senses
Collect sensory info from ALL over the BODY
What sensations do Type C fibers usually carry?
- Pain
- Itch
- Temp
- Crude Touch
Labeled Line Principle
The Specificity of NERVE fibers for transmitting only ONE modality of sensation
Expanded tip endings of Skin Tactile sensibilities
Merkel’s Disc
Adaptation Receptor Characteristics
- All sensory receptors adapt either Partially or Completely to any constant stimulus after a period of time
- Some to a far greater extent than others
Nociceptors
- FREE nerve endings
- Responding to PAIN
Chemoreceptors
- Taste
- Smell
- Osm
- Blood CO2
- Arterial O2
Temporal Summation
- Increasing strength by increasing FREQUENCY of nerve impulses
- Deals with TIME
Type A Nerve Fibers
- Further subdivided in alpha, beta, gamma and delta
- LARGE and Medium sized MYELINATED fibers of SPINAL Nerves
Thermoreceptor
- Cold Receptors
- Warm Receptors
Mechanisms of Stimulation for Receptors
- Mechanical Deformation
(Pressing on a receptor) - Chemical Application
- Temp Change
- EM Radiation
What are the 5 Basic types of Sensory Receptors?
- Mechanoreceptor
- Electromagnetic
- Nociceptor
- Thermoreceptor
- Chemoreceptor
“MEN TC”
Modality
- Refers to each of the Principle types of SENSATION
- Used as a term in relationship to the types of sensation
Mechanoreceptor for Hearing
Sound receptors in the COCHLEA
Deep sensations
- Deep pressure
- Pain
- Vibrations
What is the Amplitude of a receptor potential to the Mechanical Stimulus ?
Direct Relationship
Mechanoreceptor for Arterial Pressure
Baroreceptors
Types of somatic senses
- Mechanoreceptive
- Thermoreceptive
- Pain
Special Senses
Refer to
- Vision
- Hearing
- Smell
- Taste
- Equillibrium
Diverging Neuronal Pathways
- May result in AMPLIFICATION of Initial signal
- May allow transmission of Original signal to SEPARATE Areas
Type of SENSES
- Somatic
2. Special senses
Types of Tonic Receptors
- Muscle spindles
- Macula
- Vestibule
- Baroreceptor
- Chemoreceptors
- Golgi Tendon organs
Facilitated/Inhibition Zones
- Neurons FURTHER from discharge zone that are Facilitated but NOT Excited
- May be INHIBITORY or EXCITATORY depending on the Input Fiber
What type of Nerve fivers make up more than HALF of ALL Sensory fibers in ALL Post-ganglionic autonomic fibers?
Type C
Encapsulated Endings for DEEP Tissue sensibilities
Pacinian Corpuscles
What type of Nerve fivers make up more than HALF of ALL Sensory fibers in most peripheral nerves?
Type C
Converging Pathways
- Multiple INPUT fibers Converge onto a Single OUTPUT Neuron
- Input fibers may be from a single source OR from Mult Separate sources
Phasic Receptors
- Adapt “to Extinction” w/in a SECOND or Less
- NOT transmit a Continuous signal
- Stimulated only when stimulus CHANGES
Spatial summation
- Increasing signal strength is transmitted by using progressively Greater # of Fibers
- Endings is Large in CENTER but reduces in Periphery
- Nerve endings OVERLAP fields
Types of Sensations
- Exteroreceptive sensations
- Proprioceptive Sensations
- Deep Sensations
Tonic Receptors
- SLOW adapting receptors
- Can transmit Information for many hours or days
- Transmit impulses as long as stimulus is present
T/F; Merkel discs connect to a SINGLE un-myelinated fiber.
False
They connect to a Single MYELINATED fiber
Reverberatory Circuits
AKA Oscillatory Circuits
- Cause by Pos Feedback w/in Neuronal circuit
- Once Stimulated, may discharge repetitively for a long time
Spray Endings for DEEP Tissue sensibilities
Ruffini’s Corpuscle
Differential Sensitivity
- Each Receptor is HIGHLY sensitive to one type of stimulus
- Almost non-responsive to others
Proprioceptive Sensations
Refer to PHYSICAL state of body
- Position
- Muscle sensation
- Pressure
- Equilibrium
