AP Review - Special Senses

What are the five special senses?

Vision, hearing, proprioception (balance), olfaction (smell), gustation (taste)

Describe the structure and function of the cochlea in hearing

Spiral shaped organ in inner ear, contains hair cells that convert sound waves to neural signals

Rods

Detect light intensity, function in low light

Cones

Detect color, function in bright light

Explain how taste buds detect different flavors

Different taste receptors for sweet, salty, sour, bitter, and umami

What is the function of the semicircular canals in the inner ear?

Detect rotational movement of head, contribute to sense of balance

Describe the path of light through the eye to the retina

Cornea → Aqueous humor → Pupil → Lens → Vitreous humor → Retina

How do olfactory receptors detect odors?

Bind to odor molecules, generate neural signals sent to olfactory bulb

What is the role of the auditory ossicles in hearing?

Amplify and transmit sound waves from eardrum to inner ear

Explain the function of the lens in the eye

Focuses light onto retina, changes shape to accommodate for near or far vision

How does the vestibular system contribute to balance?

Detects head position and movement, integrates information with visual and proprioceptive inputs

What is the blind spot in the eye, and why does it occur?

Area where optic nerve exits retina, lacks photoreceptors, creating a small blind area in visual field

Describe the process of sound wave transmission in the ear

Outer ear sends sound vibrations through ear canal→ Eardrum vibrates and sends vibrations → Middle ear (ossicles: incus, malleus and stapes) vibrates by these tiny bones touching or “conducting” vibrations through round window → Inner ear (cochlea) sensory hairs move and send action potential through auditory nerve to the brain and into the limbic system/ temporal lobe

How do photoreceptors in the retina convert light into neural signals?

Light causes chemical changes in photopigments, leads to changes in membrane potential and neurotransmitter release

What is the function of the Eustachian tube?

Equalizes air pressure between middle ear and environment

Explain how nearsightedness works and what corrective lens is needed for it

Also called myopia, the eyeball is too long or the cornea is too curved, causing light entering the eye to focus in front of the retina instead of directly on it, this means close objects appear clear, but distant objects look blurry, concave lenses (also called diverging lenses) can be used to correct, lenses spread out light rays before they enter the eye, moving the focal point back onto the retina so that distant objects can be seen clearly.

What are the basic taste sensations detected by taste buds?

Sweet, salty, sour, bitter, and umami

Describe the structure and function of the middle ear

Contains ossicles (malleus, incus, stapes), amplifies and transmits sound waves

How does the pupil regulate the amount of light entering the eye?

Constricts in bright light, dilates in dim light

What is the role of the olfactory bulb in smell?

Receives signals from olfactory receptors, processes and relays information to brain

Explain how the brain interprets visual information from both eyes

Combines input from both eyes, processes information to create a single, coherent image