~Chapter 14 - Lecture Section 14.1 Flashcards
___ Perception is part of the broader category of Somatosensory processing.
Cutaneous
What is Cutaneous Perception?
Processing of touch and pain sensations from receptors in the skin
What is Proprioception?
“Body sense”, processing of input from skin, muscles, tendons, and vestibular systems to create a perception of the body, and where it is in the environment. Can be used for posture and movement
What is Kinesthesis?
A sense of movement of the body and limbs
What sense is one of the most ancient and important of all the senses?
Touch
All ___ are deaf, this includes ___, ___, and ___.
Cephalopods // Octopi // Squid // Cuttlefish
___ and ___ have poor hearing.
Snakes // Armadillos
In no group of animals is the sense of ___ optional, sense of ___ is well-developed across all different kinds of animals.
touch // touch
What are the Evolutionary 4 F’s?
Fighting, Fleeing, Feeding, and Fornicating
Why has Cutaneous Perception been difficult to study?
- Developing a precisely controllable stimulus
- There is a limitation in the Electrophysiological techniques. Its fairly hard to characterize the receptors themselves because of Touch Artifacts, where, when you’re recording from an area, if you move and wiggle the electrode it creates interference, and so the fact that you are touching the skin, even if the electrode is placed fairly far away from the site of recording, you get movement artifacts.
- Finding appropriate animal models to study touch info in. Humans are fairly unique mammals in that we have mostly hairless skin, and so there are specializations in humans that don’t exist in other mammals.
What is the heaviest organ in the body?
The Skin
Is the skin the largest organ in the body?
No. The Villi and Alveoli in the digestive and respiratory system have larger surface areas.
What is the function of the Epidermis and Dermis?
They work together to prevent bacteria, chemical agents and dirt from entering our bodies. They also preserve bodily fluids by decreasing evaporation.
What is the Epidermis composed of?
Dead cells
The Dermis is made up of ___.
Live cells
The Dermis houses specialized receptors for ___.
Cutaneous perception
The specialized receptors for touch are referred to as ___.
Mechanoreceptors
What are the 4 Mechanoreceptors?
Merkel Receptor, Meissner Corpuscle, Ruffini Cylinder, Pacinian Corpuscle
The names of the Mechanoreceptors are of ___ and ___ origin.
Italian // German
The Merkel Receptor is associated with ___ fibres.
SA1
The Meissner Corpuscle is associated with ___ fibres
RA1
The Ruffini Cylinder is associated with ___ fibres.
SA2
The Pacinian Corpuscle is associated with ___ fibres.
RA2
Mechanoreceptors have Mechanosensitive transducers which transform ___ into ___. Somewhat similar to the Mechanosensitive channels in the ___.
physical movement // neural activity // Cochlea
Transducers reside in the ___ of ___.
unmyelinated endings // afferent fibres
The unmyelinated ending of a Transducer is studded with ___.
Mechanosensitive ion channels
What does “SA” mean?
“Slowly adapting”. This means that, if you press on a Merkel Receptor, as long as the pressure is present, it will continuously fire action potentials until the stimulus is discontinued.
What is the frequency response of a Merkel Receptor?
0.3-3Hz
Where is the Merkel Receptor located?
Shallow location, on the Dermis/Epidermis border.
What is the order of depth of the Mechanoreceptors from most superficial to deepest?
Merkel Receptor → Meissner Corpuscle → Ruffini Cylinder → Pacinian Corpuscle