Physiology lesson 2 Flashcards
What is sensation?
The Ascending pathway… awareness of stimulus/changes in internal and external environment
What are the subtopics of receptor classification by location?
1) exteroceptor
2)interoceptor
3)proprioceptor
Exteroceptors include?
skin and most receptors of the special sensce (vision, hearing, equilibirum, smell, taste)
Another name for interoceptor?
visceroceptors
What are proprioceptors?
Like interoceptors but location in skeletal muscle, joint, ligaments, CT
What gives information concerning movement and position of body
proprioceptor
Give examples of complex receptors?
Photorecpeotrs
Hair cells
Taste cells
Simple receptors are also known as?
General sensory receptors
General sensory receptors include what types of nerve endings
encapsulated or nonencapsultaed (free)
Give 3 examples of nonencapsulated
1) free nerve endings
2)Merkel cells (light pressure)
3)Hair follicle receptors(mosquto landing on your arm)
Free nonencapsulated nerve endings mostly respond to what?
Pain and tempreture abit of pressure and itch
Describe the type of fibers free nonencapsulated nerve endings are
sensory fibers are non mylenated, small diamete C-fiber
ALL encapsulated receptors are what?
-thermoreceptor
-photoreceptor
-Mechanoreceptors
-chemoreceptor
Mechanoreceptors
List the 6 types of encapsulated receptors
1) Tactile corpuscle(meisner)
2)Lamellar corpuscles (pacinian)
3)Bulbous corpuscle (Ruffini)
4)muscle spindle
5)Tendon organs
6)joint kinesthetic receptor
Where is Tactile corpuscle found?
beneath epidermis in dermal pappillae
Where is lamellar corpuscle found?
Scattered in dermis and subcutanous tissue
Where are bulbous corpuscles found?
dermis and subcutanous tissue.
Types of proprioceptors
1)muscle spindles
2)tendon organ
What are the 3 important criteria for a stimulus to excite a receptor and action potentials to reach
the CNS.
1)The stimulus energy must match the specificity of the receptor
2)The stimulus must be applied within a sensory receptor’s receptive field
3) The stimulus energy must be converted into the energy of a graded potential, a process called
transduction.
What are two types of graded potenial?
1)generator potential: generates AP in sensory neuron
2)receptor potenital: GP occurs in another cell
What is a nerve?
cordlike organ part of peripheral system
Each axon/nerve fiber is surrounded by what?
endoneurium
What is the connective tissue … binds groups
of axons into bundles called fascicles
perineurium
What surpressess CNS axon regeneration?
Oligodendrocytes they are studded with growth-inhibiting proteins + astrocytes at site of injury form scar tissue that blocks axon regrowth
