General and Special Senses Flashcards
Special Senses
Located in one specific area only.
(Sight, taste, hearing, smell)
General Senses
Located throughout the body.
(Touch)
5 Types of general Receptors
Mechanoreceptors
Chemoreceptors
Photoreceptors
Thermoreceptors
Nociceptors
Mechanoreceptors
Respond to physical stimulus.
Chemoreceptors
Respond to chemical stimulus
Photoreceptors
Respond to light stimulus
Thermoreceptors
Respond to change in temp
Between 54-117 F
Nociceptors
Respond to Pain
Free Nerve Endings
Mostly Nociception
- Pain
- Temperature
- Itch
- Movement
Enclosed Receptors
Merkels Disks
- light touch and superficial pressure
Hair Follicle Receptors
- non discriminative light touch
Meissners Corpuscles
- Discriminative Light touch
- Located in superficial dermis
Ruffini’s End Organs
- Continuous Touch
Pacinian Corpuscles
- Deep pressure, vibration, proprioception
- located in deep dermis
Reffered Pain
Feeling pain in an area other than wehre the pain originated from
Caused by converging neural tracts
Brain must make sense, and projects it to most likely area
Phantom Pain
Feeling pain in an area of the body that no longer exists
Region Still exists in the brain and can fire
Gate Control Theory
Brain can only process so much information at one time
Must be selective in processing the stimuli that are coming into the brain and ignore everything else
Can be used to ignore pain
Regions Of taste on the tounge
DRAW
Retina Layers
And Direction that light passes throuhg
DRAW
Three Tunics of the Eye
Fibrous Tunic - Sclera and Cornea
Vascular Tunic - Choroid, cilliary body, iris
Nervous Tunic - Retina
Rods vs. Cones
Rods
- B+W
- low visual acuity
- high sensitivity
- concentrated on periphery
Cones
- RGB
- High visual acuity
- Low sensitivity
- Concentrated in center
Different Kinds of Sight
Myopia - Near sighted
Hyperopia - Far sighted
Emmatropia - Normal Vision
Pathway of light
Outside Air → cornea → aqueous humor of anterior cavity → pupil → lens → Vitreous Humor of posterior cavity → photoreceptors → Bipolar cells → RGCs → RGC axons → optic disc → Optic Head → Optic Nerve → Optic Chiasm → Optic Tract → Superior colliculi → Lateral Geniculate Nucleas of the thalamus → Primary Visual cortex of the occipital lobe of the brain
Positive vs Negative afterimage
Positive - Seeing a light after a strong stimulus has been removed (PRs continue to fire)
Negative - The lack of sight after being exposed to a strong stimulus for a prolonged period (PRs are exhausted and must reload)
Cochlear Duct
DRAW
Pathway of sound
Outside air → pinna → external acoutstic canal → tympanic membrane → malleus → incus → stapes → oval window → perilymph of vestibular duct → vestibular membrane → endolymph of cochlear duct → tectorial membrane → hairs bend → cochlear nerve → vestibulocochlear nerve → inferior colliculi → primary auditory cortex of the temporal lobe of the brain
