The Sensory Receptors Flashcards
Functions of the parts of eye
Sclera
Protects the eye and gives it its shape.
Choroid
Supplies nutrients to the eye through blood vessels.
Retina
Receives photons and converts them into a nerve impulse.
Iris
Controls the amount of light entering through the pupil.
Pupil
Allows light to enter the eye.
Rods
Detect contrasts (black and white) but not color.
Cones
Detect color.
Macula
Translates light entering the eye into the images we see.
The Control of the light entering the pupil
Light reflex
When a lot of light is entering the eye, the pupils constrict
When there’s less light entering the eye, the pupils dilate
Dilated vs Constricted pupil
Dilated: Open, allowing more light.
Constricted: Smaller, allowing less light.
Two types of of vision receptors
Rods: Black/white/contrasts.
Cones: Color.
Path of Light through the Eye and Neural Impulse
Cornea
Aqueous humor
Pupil
Lens
Vitreous humor
Retina
Optic Nerve
Nerve Carrying Neural Impulse to Visual Cortex
Optic Nerve
Functions of Structures: Cornea, Aqueous Humor, Lens, Vitreous Humor
They allow light rays to travel to the retina, where they converge.
Effects of Myopia, Hypermetropia, Presbyopia, and Astigmatism on Vision
Myopia: Nearsightedness, difficulty seeing distant objects caused by overly large eyeball or overly curved lens
Hypermetropia: Farsightedness, difficulty seeing close objects caused by smaller eyeball and insufficiently curved lens
Presbyopia: Farsightedness due to loss of lens flexibility.
Astigmatism: Blurred vision due to irregular cornea or lens curvature.
Corrective Lenses for Myopia, Hypermetropia, Presbyopia, and Astigmatism
Myopia: Concave lenses.
Hypermetropia: Biconvex lenses.
Presbyopia: Biconvex lenses.
Astigmatism: Cylindrical lenses (limit refraction and concentrate light rays).
Functions of the structures of the ear
Pinna: Captures sounds.
Auditory Canal: Carries sounds to the eardrum.
Eardrum & Ossicles: Amplify or tone down sound by transmitting vibrations to the inner ear.
Auditory Tube: Balances air on both sides of the eardrum.
Vestibule & Semicircular Canals: Provide information on the body’s position in space.
Cochlea: Transforms sound vibrations into nerve impulses.
Travel of Vibrations through the Ear and Neural Impulse
Sound vibrations are received by the pinna.
They are then sent to the auditory canal.
They strike the eardrum
The vibration travels to the ossicles (hammer, anvil, and stirrup)
Then reaches the vestibule
The cochlea and cilia create the nerve impulse and the auditory nerve sends the nerve impulse to the auditory area of the brain
Cerumen and Its Usefulness
Cerumen is earwax.
It protects the ear from infection and acts as a barrier to insects, water, and injury.
Common Names of the Three Ossicles
Hammer anvil and stirrup
What two structures are connected by the ossicles
The ossicles connect the eardrum and the cochlea
Location of Receptor Organ for Sound
The Cochlea (fluid-filled)
attached to cilia
Makeup of the Human Nose
Outer structures: cartilage
Inner structures: nostril and sinus and nasal cavity
Olfactory Epithelium
The olfactory epithelium is the processor for olfaction.
It interfaces with the olfactory cortex, located at the top.
Criteria for Detectable Odor
The substance must be an odorant.
It must be volatile, meaning it must be airborne.
The substance must be sufficiently concentrated to stimulate the olfactory cells.
It must come in contact with the cells of the olfactory epithelium without being blocked by nerves.
Describe the makeup of the human tongue
The tongue and the gustatory papillae or taste buds
What is a papilla? Where do we find taste buds?
Papilla is the receptor for taste, can be referred to as little nodes
Taste buds are all over the tongue, they are concentrated in the tips, sides and back surface
What does sapid mean?
Substance has a taste
What 4 criteria must be met in order for a substance to have a detectable flavour?
Must be sapid
Must be soluble
Must be sufficiently concentrated to stimulate the cells of the taste buds
Must come in contact with the taste buds of the gustatory papillae
The 3 stimuli for skin
Pain, temperature, and pressure
What are the two main layers of skin and what is beneath them?
The two main layers of skin are the epidermis and dermis. Beneath them is another layer called the hypodermis.
