Chapter 18 - General & Special Senses Flashcards
What are sensory receptors?
A specialized cell that sends sensations to CNS.
What are the types of sensory receptors?
Tonic and phasic.
What doe tonic receptors do?
Always sending signals to CNS.
What do phasic receptors do?
Becomes active only with changes in the conditions they monitor.
What are the types of receptors?
Chemoreceptors, nociceptors, thermoreceptors, mechanoreceptors, photoreceptors.
What is the function of chemoreceptors?
Taste and smell.
What is the function of nociceptors?
Cell damage (mechanical, electrical, thermal,).
What is the function of thermoreceptors?
Thermal.
What is the function of mechanorecepors?
Hearing, stretching, and body position.
What is the function of photoreceptors?
Light.
Receptor characteristics?
Receptive field and receptor specificity.
What are receptive fields?
Area monitored by a single receptor cell.
What is receptor specificity?
Each receptor responds to a specific stimulus (photoreceptor will not respond to a chemical stimulus).
What is sensation?
The sensory information arriving at the CNS.
What is perception?
Conscious awareness of sensation.
Perception characteristics?
All nerve impulses are identical, brain interprets impulses, and feeling that occurs when sensory impulses are interpreted.
Sensory adaptation characteristics?
Occurs when sensory receptors are subjected to continuous stimulation, results in a reduction of sensitivity, at some point along the pathway impulses are conducted at a decreased rate, there are several types.
What are the types of sensory adaptations?
Peripheral adaptation and central adaptation.
What is peripheral adaptation?
When sensory receptors decrease their level of activity.
What is central adaptation?
Sensory neurons are still active and CNS causes reduced perception.
What are sensory limitations?
Information from receptors is incomplete, do not have receptors for every stimulus, receptors have limited range, and stimulation requires a neural event that is interpreted.
What are some animals can detect that humans cannot?
Infrared, ultraviolet, ultrasonic, and magnetism.
What are general senses?
Do not have specialized receptor cells or sensory organs.
What are special senses?
Can have specialized receptor cells separate from the sensory neuron, structurally more complex, and receptors are localized in sense organs.
What are the major groups of general senses?
Exteroceptors, proprioceptors, and interoceptors.
What are exteroceptors?
Relay info about external environment.
What are proprioceptors?
Depict body position in space.
What are interoceptors?
Monitor the internal environment.
What are nociceptors?
Sense tissue damage, perceived as pain, and free nerve endings with large receptive field.
Nociceptor characteristics?
Found everywhere except brain, provide a protective function, and do not adapt well.
What are the types of pain?
Fast pain (prickling), slow pain (burning), and referred pain.
What is fast pain?
Quick, inducing a reflex usually end when stimulus ends.
What is slow pain?
Begin later, persist longer, ache.
What is referred pain?
Visceral pain that feels like it is coming from a more superficial region.
What causes referred pain?
Superficial structures being innervated by the same spinal nerves as the damaged viscera.
Example of referred pain?
Brain freeze.
Thermoreceptor characteristics?
Involve heat & cold, free nerve endings in skin, quick to adapt, and felt as pain.
When do thermoreceptors feel pain?
If temp goes above 45 C or if temp goes below 10 C.
Mechanoreceptor characteristics?
Sensitive to mechanical forces that cause tissues to be deformed.
Types of mechanoreceptors?
Tactile, baroreceptors, and proprioceptors.
What do tactile receptors sense?
Touch, pressure, and vibration.
What do baroreceotors detect?
Pressure changes in walls of vessels, etc.
What do proprioceptors sense?
Position of joints & muscles.
How many types of tactile receptors are there?
6.
How many categories of tactile receptors are there?
2.
What are the categories of tactile receptors?
Unencapsulated and encapsulated.
What are the unencapsulated tactile receptors?
Free nerve endings, root hair, and tactile disc.
Where are free nerve endings and what do they detect?
In papillary of dermis. General touch.
What do root hair receptors detect?
Monitor distortions & movement across body surfaces.
Where are tactile discs and what do they detect?
Expanded nerve terminal that synapses with merkel cell. Sensitive to fine touch.
What are the encapsulated tactile receptors?
Tactile (meissner’s) corpuscles, lamellated (pacinian) corpuscles, and ruffini corpuscles.
Where are tactile corpuscles found?
Where tactile sensitivities are very well developed.
What do lamellated corpuscles respond to?
Deep pressure.
Where are ruffini corpuscles and what do they detect?
In the dermis. Detect pressure with little adaption.
What is another name for baroreceptors?
Stretch receptors.
What do baroreceptors regulate?
Autonomic activities such as… Digestive tract, bladder, carotid sinus, lung, colon, and major arteries.
What are the types of proprioceptors.
Muscle spindles and golgi tendon organ.
What do muscle spindle proprioceptors detect?
length of muscle.
What do golgi tendon organ proprioceptors detect?
tension in a tendon during contraction.
what do chemoreceptors respond to?
Substances dissolved in surrounding fluids