Exam 2 - Lecture 19 (Sensory Receptors) Flashcards
What are sensory receptors?
Receptors that detect changes in thermal, mechanical, or chemical stimuli applied to the surface or interior of the body.
Where are 3 places where we can find somatic sensory receptors?
- Skin
- Muscles
- Tendon
Where in the CNS are sensory receptors located?
Dorsal horn/dorsal root ganglion
What is the classification of dorsal root ganglion neurons?
Unipolar
How does the CNS know the specific stimulus?
Sensory receptors
Sensory modalities are _____ to certain sensory receptors.
specific
On what part of the neuron are somatic sensory receptors found?
Terminal end of the primary sensory neurons
DRG neurons are _____ neurons
primary sensory
What are the 7 types of somatic sensory receptors?
- Free nerve ending
- Hair follicle terminal
- Merkel’s corpuscle
- Meissner’s corpuscle
- Pacinian corpuscle
- Golgi-tendon organ
- Muscle spindle
What is the modality for FNE?
pain, temperature
What is the modality for hair follicle terminals?
touch
What is the modality for Merkel’s corpuscle?
touch, pressure
What is the modality for Meissner’s corpuscle?
touch, vibration (<100 Hz)
What is the modality of Pacinian corpuscle?
Vibration (>100 Hz)
What is the modality of Golgi-tendon organ?
Muscle tension, proproception
What is the modality of muscle spindle?
Proprioception
What is the morphology of FNE?
free nerve ending (“naked”)
What is the morphology of hair follicle terminal?
free nerve ending (“naked”)
What is the morphology of Merkel’s corpuscle?
Merkel cell + axon terminal
What is the morphology of Meissner’s corpuscle?
Encapsulated by cells
What is the morphology of Pacinian corpuscle?
LARGE, encapsulated by many layers of cells
What is the morphology of muscle spindle?
Intrafusal muscle fibers, sensory fibers, c.t. capsules
What is the morphology of Golgi-tendon organ?
Collagen fibers, sensory axons, c.t. capsule
Where are FNEs located?
epidermis
Where are hair follicle terminals located?
skin (dermis near base of follicle)
Where are Merkel’s corpuscles located?
Skin (basal layer of epidermis)
Where are Meissner’s corpuscles located?
Skin (tip of dermal papillae)
Where are Pacinian corpuscles located?
Skin (deep in dermis of glabrous and nonglabrous skin)
Where are muscle spindles located?
skeletal muscle (perimysium)
Where are Golgi-tendon organs located?
Origins and insertions of skeletal muscle fibers into the tendons of skeletal muscle
What is the receptor for FNE (pain) called?
Nociceptor
What is the receptor for FNE (temp) called?
thermoreceptor
What is the receptor for hair follicle terminals (touch) called?
mechanoreceptor
What is the receptor for Merkel’s corpuscle (touch and pressure) called?
mechanoreceptor
What is the receptor for Meissner’s corpuscle (touch and vibration) called?
mechanoreceptor
What is the receptor for Pacinian corpuscles (vibration) called?
mechanoreceptor
What is the receptor for Muscle spindles (proprioception) called?
proprioceptor
What is the receptor for Golgi-tendon organ (muscle tension) called?
mechanoreceptor
What is the receptor for Golgi-tendon organ (proprioception) called?
proprioceptor
Sensory receptors are at terminal ends of _____.
Sensory axons
Sensory modality is _____.
Receptor specific
Sensory neurons carry signals to the _____.
CNS
What is another name for DRG neurons?
primary sensory neurons
What is the normal RMP on a mammalian axon?
-65 mV
