Untitled lesson

10. Glaucoma is an eye disease which affects vision caused by what?

-optic nerve damage

11. In which color ranges do the three pigments in the human retina have their

major sensitivities?

-S cones, M cones, L cones

12. Describe the pathway that sound travels from entering the ear to reach the organ

of Corti?

-Outer Ear: Sound waves enter the ear through the pinna (the outer part
of the ear) and travel down the ear canal to the eardrum (tympanic
membrane).

-Middle Ear: The eardrum vibrates from the sound waves, and these
vibrations are passed to the three tiny bones in the middle ear (the
ossicles: malleus, incus, and stapes). The stapes pushes against the oval
window, the entrance to the inner ear.

-Inner Ear (Cochlea): The movement of the stapes creates waves in the
fluid inside the cochlea, a spiral-shaped structure. This causes the
basilar membrane to move.

-Organ of Corti: Inside the cochlea, the organ of Corti has hair cells that
detect the movement of the basilar membrane. When the hair cells
move, they turn the vibrations into electrical signals.

-Auditory Nerve: The electrical signals are sent through the auditory
nerve to the brain.

-Brain: The brain processes these signals as sound, and we perceive what
we hear.

13. Describe the anatomical structures of the human ear.

1. Outer Ear:

●Pinna (Auricle): The visible part of the ear that catches sound waves.

●Ear Canal: A tube that carries sound from the pinna to the eardrum.

●Eardrum (Tympanic Membrane): A thin membrane that vibrates when sound
hits it.

2. Middle Ear:

●Ossicles: Three tiny bones that pass the vibrations from the eardrum to the
inner ear:

○Malleus (Hammer)

○Incus (Anvil)

○Stapes (Stirrup)

●Eustachian Tube: A tube that helps equalize pressure in the ear.

3. Inner Ear:

●Cochlea: A spiral, fluid-filled structure that turns sound vibrations into
electrical signals.

●Organ of Corti: Inside the cochlea, it has hair cells that detect sound vibrations
and convert them into signals.

●Oval Window: A membrane that connects the middle ear to the cochlea,
through which vibrations pass.

●Round Window: Helps release pressure in the cochlea.

●Semicircular Canals: Help with balance (not involved in hearing).

4. Auditory Nerve:

●The nerve that carries the electrical signals from the cochlea to the brain,
where they are interpreted as sound.

14. The ossicles of the ear pass on sound vibrations to the fluid in the inner ear. In

what structure is this fluid located?

-Cochlea

15. What is the function of the middle ear ossicles?

The middle ear ossicles (malleus, incus, and stapes) have the job of passing sound
vibrations from the eardrum to the inner ear.

●The malleus receives vibrations from the eardrum.

●The incus passes the vibrations to the stapes.

●The stapes then sends the vibrations to the oval window, which leads to the
inner ear.

Their main function is to amplify and transmit sound to the cochlea for further
processing.

16. What are the three small bones involved in hearing?

-Malleus (hammer)

-Incus (anvil)

-Staples (stirrup)

Perception study guide

1. To what, in the skin, does the term “nociceptors” refer?

-Pain receptors

2. What are the different sensory receptors in the skin?
-Meissner’s corpuscles: Fine touch, flutter.

-Merkel cells: Sustained pressure, texture.

-Pacinian corpuscles: Vibration, deep pressure.

-Ruffini endings: Stretch, continuous pressure.

-Thermoreceptors: Temperature changes.

-Nociceptors: Pain.

3. Which part of the retina has the greatest sensitivity to light?
-Fovea centralis

4. What is the place where the blood vessels and nerve fibers come together and

leave the posterior chamber of the eye called?

-Optic disc or blind spot

5.Accommodation refers to the eye’s ability to focus light from objects whatever
their distance from the eye. How is this achieved?

-The ciliary muscles contract, making the lens thicker and more curved
to bend light more.

-The ciliary muscles relax, making the lens thinner and flatter to bend
light less.

6. Which cells of the retina are responsible for detecting light in scotopic (i.e. low

light) conditions?

-Rod cells

7. What is the light sensitive cell in the retina that responds to color called?

-cones

8. What muscle dilates and constricts the pupil?
-Iris

9. Describe the lens of the human eye (anatomically and physiologically)

-Ana : It is made of layers of protein fibers and is held in place by the
suspensory ligaments, which connect it to the ciliary body. The lens is
clear and flexible, allowing it to change shape.

-Phy: The lens focuses light onto the retina at the back of the eye. It
changes shape to focus on objects at different distances:

17. For which condition is a hearing aid most successful at treating?

-sensorineural hearing loss (old age)

18. Which structure lies on the boundary between the middle and inner ear and has

the stapes bound to it?

-Oval window

19. What is the term for your sense of taste?

-Gustation

20. What is the term for your sense of smell?

-Olfaction