Special Senses Flashcards
8 receptor types
- Taste
- Smell
- Pressure
- Proprioceptor
- Audio
- Photo
- Thermo
- Pain
Taste receptor
Chemical detection with taste buds
Smell receptor
Chemical detection by olfactory cells
Pressure
Movement of the skin
Proprioceptor
Spatial awareness, limbs
Audio receptor
Detect sound waves
Photo receptor
Detect wavelengths of light
Thermo receptor
Detect heat changes
Pain receptor
Protect us from environment
sensory adaptation
Occurs when receptors become a custom to the stimulus. the neuron ceases to fire and receptors become less sensitive
What is stimulus
A form of energy receptors convert outside energy into nerve action potentials
Sclera (white part)
Supports and protects the internal eye
Cornea
Reflects light towards the pupil also acts as protective covering
Conjuctiva
Transparent layer around the sclera… Protection
Aqueous humour
A liquid that supplies the cornea with nutrients and refracts light
Choroid (layer)
Contains pigments that prevent scattering of light in the eye. contains blood vessels that feed the different structures
Iris
Regulates the amount of light entering the eye
Vitreous body(humour)
Maintains the shape of the eyeball and permits light transmission to the retina… Irreplaceable
Lens
Focus is the image on the retina
Pupil
Functions as a hole in the iris… Controls the amount of light that enters as well
Retina
Thin layer of the eye containing the photo receptors (rods and cones)
Rods
Detects shades(black and white)
- motion
- shares neurons
- have 125 million
- all over retina
Cones
- Detects colour
- each has own neuron
- you have 7 million
- concentrated in fovea centralis
Fovea centralis
Most sensitive area of the retina that contains only cones. Use for fine reading
Blind spot
the optic nerve attaches to the retina there are no cons or rods
Positive after image
After you look at a bright light and close your eyes and the image of the light you can still see
Negative after image
After you look at bright colours they will reverse and colour when you look away
Refraction
When light waves go through different mediums and they slow or bend
Muscles and ligaments control…
The shape of the lens, allowing us to focus
Accommodation
The adjustment of the lens to objects near and far
When we see close our muscles…
Flex, and the lens is oval
When we see far our muscles…
Relax, and our lens is round
Three different types of cones
Each sensitive to one of the three primary colours of source light, Blue red and green
Glaucoma
Caused by buildup of aqueous humor. Ducts are unable to drain excess fluid and the pressure may cause blood vessels to rupture which could lead to starvation of cells. (becomes misshapen)
Cataract
Occurs when the lens or cornea becomes cloudy… Replacement surgery can be done
Astigmatism
Is caused by an abnormal curvature of the lens or cornea… Would lead to poor focusing ability
Nearsightedness (myopia)
Eyeball is too long so focal points it in front of right now concave lens can correct this problem
Farsightedness (hyperopia)
Is caused by eyeball that is too short so focal points behind right now convex lens can correct this
Two functions of ear
- hearing
2. equilibrium
Three general areas of the ear
- External ear
- Middle ear
- Inner ear
Auricle (pinna)
Outer part of external ear, amplifies sound by funnelling it from large area into narrow auditory canal
Auditory canal
Carrie sound waves to the Tympanic membrane
Ceruminous gland
Secretes a waxy substance for protection
Tympanic membrane
The eardrum, convert soundwaves into mechanical vibrations
Ossicles
Bones that amplify and carry sound in the middle ear, three bones involved
Oval window
Receive sound waves from the ossicles
Round window
At the end of the cochlea to absorb fluid waves preventing echos
Eustachian tube
Airfield tube that equalize his air pressure in the external ear
Vestibule
A chamber at the base of a semi circle canals, concerned with static equilibrium
Semi circle canals
Fluid filled structures that provide information concerning dynamic equilibrium
Cochlea
A coil tube within the inner ear that identifies sound waves and convert them into nerve impulses
Cochlear fluid
Bathes the cochlear membranes and hairs of the organ Corti also carries vibrations
Organ of Corti
Changes the mechanical vibrations to nerve impulses
Two main components of Equilibrium
Static equilibrium, dynamic equilibrium
Static equilibrium
Involves movement along one plane
Dynamic equilibrium
Provides information during movement
