Sensory Flashcards
Extroceptors
External surface
Introceptors
In vessels or tissues of organs
Proprioceptors
In muscles joints and inner ear
By stimulus
Mechanorecptors
Mechanical energy
Thermoreceptors
Temp energy
Nociceptors
Damage to tissue
Photoreceptors
Light energy
Chemoreptors
Chemical energy
Osmoreceptors
Osmotic pressure of body fluids
Light modality
Photoreceptors of retina
To the ganglion cell then to brain
Sound modality
Air pressure
Cochlea where the receptive organs can sense it
Taste modality receptor cells in taste buds
Particular tats in single medullary nucleus
Temperature modality
Through cold and hot temp.
Cutaneous somatosensory system
Pressure modality
Gives infor regarding cuntaneous stimuli
Smell modality
Called olfaction
Synapse at the olfactory cranial nerves
Adaption in sensory Receptors
Descremases in sensitivity of Receptors during a maintained constant stimulus
Impulses decrease
Perception or sensation may fade
Receptors vary on how quickly adapt
Rapid adapting when signal ch ages in a stimulus
Slow adapting is continuing to monitor pain body position and chemical composition of blood
Somatic sensation
Arise from stimulation of sensory Receptors in skin, certain muscles membranes, muscles, tendons joints and inter ear
Tactile sensations
Activation of encapsulated mechanoreptors for touch pressure and vibration
Activation of free nerve ending for itch and tickle
Thermal sensation
Activation of thermoreptor free nerve ending that adapt rapidly but generate impulses at lower frequency for prolonged stimulus
Stimulate nocipetors instead, producing painful sensation when temps are above or below
Pain sensations
Activation of nociceptor free nerve endings
Localization of pain sensations
Somatic fast pain
Very precisely localized to simulated area
Somatic slow pain
More diffuse appears to come from larger area of skin
Referred pain
Involves visceral nociceptors
Pains appears to come from area of skin served by the same segment of spinal cord
Can be overlying stimulated organ or far away but precisely mapped based on shared neutral pathway
Two point discrimination
Ability to discern that two nearby objects touching the skin are truly two distinct points, not one.
Proprioception sensations
Activation of proprioception for awareness of movements and position of head and limbs
Monitor degree of muscle contraction and many of tension on tendons
In ear. Relative to gravity
Muscle spindles
Detect muscle length(stretch reflex)
Tendon organs
Detect tendon tension
Somatic sensory pathways
Relay info from somatic sensory Receptors to the primary somatosensory area in the cerebral cortex and cerebellum
Acending pathways is set of 3 neurons
First order impulse from somatic to CNS
Second order decussate in spinal cord or brain stem then Cary to thalamus
Third order- impulse from thalamus to postcentral gurus on same side
P
Spinothalamic
If you step on thumbtack
You realize something sharp on foot
Your spinothalamic intralaminar projections and spinoreticular tract chase you to feel ouch
And spinomesenspjalic tracy leads to pain modulation
Allowing us to think we feel better
Basal nuclei
Receive input from sensory, associating and motor areas of cerebral cortex
Basal nuclei
Responds with feedback signals through thalamus
Synape with upper motor neurons that go to the motor cortex areas that initiate and terminate movements
Send impulses to thalamus and midbrain to suppress unwanted movements
Send impulses to brain stem to reduce muscle tone
Movement of cerebellum
Active in both learning and performing rapid coordinating highly skilled movements
Monitors intentions for movements
Received input though pins from cerebral cortex and basal nuclei
Monitors actual movemnts
revives input from proprioceptors
Compared intentions and actual movemnts
Sends out correcting feedback if any discrepancy
Analgesia
The inability to feel pain
Aspirin and ibuprofen
Considered anti- inflammatory
