GENERAL RECEPTORS
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Transcript of GENERAL RECEPTORS
GENERAL RECEPTORS
SPECIAL RECEPTORS-- On the Retina
2. CONES -- color
RECEPTORSRECEPTORS
•Mechanoreceptors1. Hearing -- located in the Cochlea of the inner ear2. Baroreceptors -- monitoring of Blood Pressure --located in the arch of the Aorta & in the carotid sinuses
--for Hearing, Position, & Balance
•Photoreceptors for Vision (sight)
•Located throughout the body•Found in the Dermis layer of the skin
•Receptors for touch, pressure, pain & temperature
-- pain receptors also called NOCICEPTORS
1. RODS -- dim light & motion
3. Proprioceptors --Located in muscles, tendons, joints
& the semicircular canals of the inner ear--Provide information on position, balance
& movement of limbs•Osmoreceptors 1. Located in the digestive tract & in
the hypothalamus2. Monitor for changes in the concentration
of body fluids (Electrolytes)
1. Taste --taste buds located on the tongue fissures--4 types (Bitter, Sour, Salty, & Sweet)
2. Smell --olfactory cells located in roof of the nasal cavity
3. Receptors for O2 & CO2 located in arch of theAorta & carotid sinuses
•Chemoreceptors -- for Taste, Smell, O2 & CO2 levels
DEFINITIONSADAPTATION-- Receptors adjust themselves so that they no
longer respond to the stimulus as they did in the beginning.
REFERRED PAIN
Gallbladder pain maybe felt in in the shoulder
Kidney pain may be feltin the lumbar (flank)region
-- Some neuron connect impulses from the skin &the viscera to send to the brain
-- The brain cannot differentiate,so assign pain to the skin
EYEEYE
Cornea
Aqueoushumor
Ciliarybody
Suspensoryligament
Lens
Clear, transparent, anteriorcoat of the eye
Part that is replaced in acorneal transplant
Watery fluid & helpsmaintain curve of cornea
& carries nutrientsto the cornea & lens
thickness is adjustedto focus light
-- lens thins or flattens out for distance
-- lens thickens orrounds up for near vision-- hold Lens in place &
help it to change shape
Refraction -- the change of direction of a light ray as it passes from one medium to another (bending)
Accommodation -- coordinated eye changesto enable us to focus on
on objects
RetinaChoroid
Sclera
Vitreoushumor
Jelly-like substance that give the eye shape & aids in refraction
If lost cannot be replaced causing blindness as retina falls forward
Removal of the eyeball iscalled Enucleation
opaque back portion ofthe Cornea
Cornea
absorbs stray lightrays & nourishesthe retina
Rods
-- functions in dim light & senses motionCones-- functions in bright light & is sensitive to
3 colors Red Green Light blue
Foveacentralis
Opticnerve
Retinalartery & vein
Opticdisc
-- Cranial Nerve II carries visual impulses from the rods& cones to the Occipital Lobe
(Blind Spot) -- area in which there is no rods or conesArea where the vascular bed can be directly examined
--swelling & inflammation of the optic nerve
Papilledema
-- area that contains a large amount of cones, so it isthe point of most acute vision
Lens
Pupil
Iris
Muscles of the EyeIntrinsic muscles -- inside the eye
Colored portion of the eye
-- regulates amount of lightentering the eye
-- rounds up or flattens to view objects
Myopia -- nearsightedness
Hyperopia -- far-sightedness
Presbyopia -- old-sightedness
Astigmatism -- distortion of thecurvature of the cornea
Extrinsic Muscles
6 muscles attach to the skull bones & the sclera to allow for coordinated movementNerves for the Extrinsic Muscles
-- supplies one extrinsic muscle eachTrochlear Abducens&
Oculomotor-- supplies 4 extrinsic muscles
Protection of the Eye-- Skull bones-- Eyelid & eyelashes
--eyelashes sense particles-- sebaceous glands help lubricate the eye
(Sty -- inflammation of one of these glands)
Lines the eyelid & corneaDestroys pathogens
ConjunctivaLacrimal gland
Lacrimalducts
Produces tears
Tears film across the eyein the direction of the nose
Keeps the eyeball moist
EAREARExternal Structures
Pinna
ExternalAuditoryCanal
TympanicMembrane
Also called the Auricle
Helps collect sound wavesNot necessary for hearing
Made of cartilage
which captures foreign material & protects the earSound vibrations are first picked up here
In small children, it is chiefly made of cartilage
EustachianTube
Malleus
Incus
Stapes
Middle EarIt’s a cavity filled with air& containing OssiclesConnects middle ear to the throatEqualizes pressureEasy route for infection
Lies between the tympanic membrane & IncusShaped like a hammer
Shaped like an anvil & lies between the Malleus & StapesAttaches to the Oval window, which is the dividing line between Middle & Inner earThese bones are joined in such a way that sound waves are amplified 20x by the time they reach the oval window
Vestibule
Semicircularcanal
Osseous Labyrinth
Cochlea
Functions in hearingContains Organ of Corti,the site for the sensory receptor cells (Hair Cells)
Vestibulocochlearnerve
Impulses are picked up here and sent to the 8th Cranial nerve Vestibulocochlear
Base of the canal contains 2 sacs with hair cells that deal with head position & equilibrium
Inner Ear
-- vibrations enter herethrough the Oval window
Within the Bony Labyrinth is a Membranous Labyrinth
MembranousLabyrinth
The inner ear contain fluid
Between the Bony labyrinth and the Membranous labyrinth is a fluid called: Perilymph
Endolymph -- is the fluid inside the MembranousLabyrinth
bonemembrane
perilymphendolymph
Balance & Equilibrium
Senses eye movement & head position
Also send impulses to Vestibulocochlear nerve & then to the Cerebellum
Organ of CortiOrgan of Corti
Hair CellsBasilar
Membrane
TectorialMembrane
Endolymph
Impulse sent tothe Temporal Lobeof the CerebralCortex
Electrical Stimuluspicked up by theVestibulocochlearNerve
Bending of Hairs ofReceptor Cells ofOrgan of Corti startsthe ElectricalStimuli
Vibration of theBasilar Membrane
Fluid Movementwithin Cochlea
Sound Waves
Vibration of theTympanic Membrane
Vibrationof OvalWindow
Dissipationof Energy
Vibration ofRound Window
Middle Ear bonesVibration of
HEARING LOSS
Conductive Deficit
--Causes:
Cerumen (ear wax)
Foreign bodies
Perforation of the tympanic membrane
Otitis Media -- inflammation or infection of themiddle ear
Otosclerosis -- immobility of an ossicleusually the stapesTreatment is a Stapendectomy
Treat underlying cause
Nerve Deficit-- Damage to the 8th Cranial Nerve
--Causes:
Prolonged exposure to loud noises
Drugs like Streptomycin; Neomycin
Cochlear atrophy
German measles in the first trimester
Mumps
Cilia (hair cells) on the receptors have worn awayis the most frequent cause of nerve deafness