Tag: disorders of nervous system

The epithelium of cornea, lens, and conjunctiva are of ectodermal origin. It is made up of the surface ectoderm. It is absent in the central part of the cornea. Conjunctiva is supplied with blood vessels. It is highly vasculated in the form of fine capillaries. The sclera is the opaque part of the fibrous coat which covers the posterior part of the eyeball. The conjunctiva covers the sclera. The sclera is visible through the transparent bulbar conjunctiva. 

The canal of Schlemm is a channel in the eye that collects aqueous humor from the eye and moves it into the bloodstream. If the canal is blocked, the pressure in the eye can increase, resulting in glaucoma. Glaucoma is a condition that causes damage to the eye's optic nerve. It is associated with a buildup of pressure inside the eye. The increased pressure, called as intraocular pressure, can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma will cause permanent loss of vision. Thus, the correct answer is option D.

Cataract is due to clouding of the lens. Due to this, the lenses become opaque and the vision is impaired. In this condition, an operation is needed. Cataract is very common in old age.

Medicines which are used to enlarge or dilate the pupil for the eye examination is called as dilating drops such as atropine, cocaine and scopolamine. These chemicals are derived from belladonna. Atropine works by blocking muscarinic receptors, that are found in the muscles of the eye. These receptors are involved in controlling the size of the pupil and the shape of the lens. Thus, the correct answer is option D.

• The Nemeth Braille Code for Mathematics is a Braille code for encoding mathematical and scientific notation linearly using standard six-dot Braille cells for tactile reading by the visually impaired.
•  The code was developed by Abraham Nemeth. The Nemeth Code was first written up in 1952. Different languages have different types of braille code like example :
• Unified English Braille (UEB) Code
• European Braille Code (EBU)
• Cyprus Braille Code. Hence, Unified English Braille (UEB) Code, European Braille Code (EBU), Cyprus Braille Code are Braille codes.

• Louis Braille was born in Coupvray, a small town about twenty miles east of Paris, on 4 January 1809.
• He and his three elder siblings – Monique Catherine (b. 1793), Louis-Simon (b. 1795), and Marie Céline (b. 1797)– lived with their parents, Simon-René and Monique, on three hectares of land and vineyards in the countryside.  Hence,    Louis Braille was born in Coupvray.

Sign language is represent by making gestures without speaking. This language cannot be written or spoken. Normally this language is used for people who cannot speak or listen.

• A cell is made up of six dots that fit under the fingertips, arranged in two columns of three dots each. 
• Each cell represents a letter, a word, a combination of letters, a numeral or a punctuation mark. 
• The first ten letters of the alphabet are formed using the top four dots (1, 2, 4, 5). This results in 2*2*2*2*2*2=2^6=64 different patterns of raised/unraised dots. 
• But, according to the Braille description, we must eliminate one of these 64 possible patterns, because at least one dot must be raised. Therefore, there are 63 possible raised-dot patterns.

• Braille is a system of reading and writing by touch used by the blind. The basic Braille symbol, called the Braille cell, consists of six dots arranged in the formation of a rectangle, three dots high and two across. 
• Other symbols consist of only some of these six dots. It consists of arrangements of dots which make up letters of the alphabet, numbers, and punctuation marks. 
• The basic Braille symbol, called the Braille cell, consists of six dots arranged in the formation of a rectangle, three dots high and two across. There are no different symbols for capital letters in Braille. Hence, Capital letter does not have separate symbols in Braille Script