Special senses 2

1. What is blindness in dim light called?

Nyctalopia / Night blindness

2. What is the normal visibility or sensitivity range of wavelength of visible light?

400 – 750 nm

3. What is the pH of the aqueous humour?

pH 7.1 – 7.3

4. Which fluid rich in  K ion is present in the scala media part of the ear?

Endolymph

5. The cell bodies of which sensory cranial nerve is contained in the spiral ganglion?

Auditory / Vill cranial nerve

 

6. In the organ of Corti, bending of the cilia causes changes in the conductance of which ion of the hair cell membrane?

Potassium ion

7. What is the loss of sense of smell called?

Anosmia

8. What is the loss of sense of taste called?

Ageusia

9. During horizontal acceleration which part of thr vestibular apparatus is stimulated?

The maculae of Utricles

10. During vertical acceleration which part of the vestibular apparatus is stimulated?

The maculae of Saccules

11. Which receptors are stimulated during angular acceleration?

The semicircular canals

12. What is recording of the visual field of each eye called?

Perimetry

13. What is used to test the visual acuity for distant vision of each eye?

Snellen’s chart

14. What is used to test the colour vision pf the eyes?

Ischihara colour test chart

15. What is the advantage of a few cone receptors synapsing on a single bipolar cell?

High acuity and low sensitivity

16. Who explained the place theory / traveling wave theory of pitch discrimination?

von Bekesy

17. By how many times is the sound intensity increased before it reaches the inner ear?

22 times

18. Name the muscles in the ear that contract when a loud sound is made?

Tensor tympani and the Stapedius

19. What is the normal audible range of sound?

20 – 30 dB

20. What is the primary receptor for hearing?

The organ of Corti

21. What is the function of the ear ossicles?

To magnify intensity of sound

22. What is clouding of the eye lens with old age  called?

Cataract

23. What is the effect of lesion of the geniculocalcarine tract on the visual field of the eye?

Homonymous hemianopsia with macular sparing.

 ( UMS, 2008 )