Question

Chapter 16:

What is adaptation?

What is the conjunctiva? What is the lacrimal apparatus?

What is the aqueous humor? Where is it located? What is vitreous humor?

What does the iris do? How does it work (include relevant associated structures/muscles)?

What are the muscles that regulate the iris & pupil size? How do they work?

What are the following: optic disc? Fovea centralis?

What is refraction? What structures in the eye refract light?

What is accomodation?

What are the names of the photoreceptors & photoreceptor cells? What types of vision does each mediate? What is retinal? Why is it important?

What are the steps in the visual cycle?

What are the steps for visual signaling in the photoreceptor cells? What happens during the dark & what changes with light? How do the visual cycle & visual cell signaling fit together—how do they relate to each other?

How are visual signals transmitted from photoreceptor cells to the brain (what is the path)?

What forms the optic nerve? What is the optic chiasm? Optic tract? Optic radiations?

What is the tympanic membrane? What are the auditory ossicles? What are their names & how are they connected?

What are the names of the 3 canals in the cochlea? How are they organized & connected to each other? What are the vestibular, basilar, & tectorial membranes? What is the spiral organ?

What is the structure of hair cells for hearing? What are tiplinks?

How is information transmitted from sound waves to activation of hair cells? How is the basilar membrane organized to transmit sound information?

What are the components of the vestibule? What are the Otolithic membrane & Otoliths?

How are the semicircular canals organized? What are the ampulla, crista & cupula?

What aspect of equilibrium/balance do static & dynamic equilibrium sense. How do they work?

What is the structure in the nose responsible for olfaction (smell)?

How many olfactory receptors are in each olfactory receptor neuron? What is a glomerulus?

What is different about transmission of olfaction to the cortex (different from other sensory input)?

What are the 5 primary tastes?

What are papillae? What are the 3 different types & where are they located? What are taste buds? How are they organized?

Answer 1

1)It is the process in which eye gets adjusted to increasing and decreasing light intensity by closing and opening of the pupil and iris of the eye.

2)Conjunctiva--It is a layer of cells inside the eye which consists of keratinized epithelial cells and goblet shaped cells.

Lacrimal apparatus--It is the apparatus which consists of tear glands and secretes watery tears with lysozyme.

3)Aqueous humor-It is a fluid that maintains the fluidity inside the eye and avoids friction.It is present in the spaces inside the eye.

Vitreous humor-It is also a fluid present between the retina and the lens of the ball present inside the eye.

4)Iris--it is made up of muscle fibres which control the amount of light entering the eye.

5)Smooth muscle fibres control the opening and closing of aperture or hole in the eye called as pupil along with the iris controlling the amount of light entering the eye.

6)optic disc--it is point present near the starting of optic nerves which does not contain cones and rods.

fovea centralis--It is the region which contains the network of nerves near the retina in the eye.

7)refraction--it is the bending of light thus creating an angle when light passes from one medium to another where both the mediums have different refractive index and density. Cornea and lens in the eye refract light from aqueous humor to vitreous humor.

8)accomodation of eye--it is a adjustment of the eye after seeing an object to visualise the object clearly with a proper distance and focus.

9)names of photoreceptors and photoreceptor cells--These consist of rods and cones which help in the formation of image on the retina with proper nerve stimulation.Rods get stimulated at night and cones during the day. The retinal pigment is present which undergoes isomerisation from cis-to -trans when it receives light stimulus along with activation of retinal G-protein receptors.

10)steps is visual cycle--1)activation of cis-retinal to trans-retinal 2)saturation, bleaching of the retinal pigment to retinol pigment 3)recycling of the retinal pigment in dark phase adaptation.

11)signals are transmitted from the photoreceptor cells to the brain with the help of optic nerves.

12)optic nerve--it is a nerve which transmits the information from the retina to brain.optic chaisma--it is point on the network of nerves where the nerves cross each other near the eye.optic tracts--these are the nerve bunches which are formed together after the crossing over point. optic radiations--it is the axons and neurons in the nucleus of the eye and the primary visual cortex.

13)Tympanic membrane--it is small tissue present inside the ear.auditory ossicles--it is the small ear bones present in the ear forming the hammer, anvil and stapes.

14)3 canals in the cochlea--it is the scala tympani,scala vestibule, and the scala vestibule. vestibular,tectorial and basilar membrane are the membranes present in the inner ear. They help in vibrations in the cochlea. spiral organ--they are the structures present on the inner surface of basilar membrane with hair cells and help in the transmission of sound in the ear.Structure for hearing in the ear is called as sterocilia.Tiplinks are the filaments that connect the stereocilia to each other in the ear.

15)Hair cells in the organ of corti respond to sound and help in the transmission of sound waves in the cochlea. Basilar membrane is the structure that separates the scale tympani and scala media in the ear. The sound wave causes the basilar membrane to move apart and thus the sound wave increases in amplitude and frequency as it passes to the cochlea.

16)components of vestibule--vestibule is the bony part of the ear which is present behind the cochlea.otolith membrane--it is a mmebrane present in the vestibule of the ear.otolith--it is the calcium carbonate structure present in the ear.

17)semicircular canals--they are long connected pipe or tube like structures which consist of three components like horizontal,posterior and superior semicircular canals.They are concerned with movements of the head and sensing in the ear.ampula is a space filled with air inside the ear ,crista consists of capping of cells and cupula consists of hairy cells.

18)Various organs of the ear which maintain balance and posture are the labyrinth,saccule, utricle and the semicircular canals. they sense the sound waves coming to the ear and send to the cochlea.

19)Structure pesent in the nose for sensing the smell or olfaction is the nasal cavity which contain olfactory receptors.

20)Humans have 10 million olfactory nerve receptor neurons.Glomerulus --it is a network of olfactory nerve bulbs present in the brain which connect neurons connected to other organs.

21)The area and the region of the brain where the odor chemical nerve stimulus is transferred is different for olfactory conduction in the cortex as compared to other regions of the brain.

22)5 taste-salt,sour,sweet, bitter and umami.

23)papillae are protruberances present at the sides and tips of tongue which have taste buds for different tastes. 3 types-1)fungiform papillae 2)filiform papillae 3)foliate papillae 4)circumvallate present on the tongue. taste buds--they are the taste cells present on the tongue.They are organized on the tongue along with the TASR receptors for sensing the taste of various chemicals.