Thursday, May 26, 2011

Tongue


Tongue is a muscular organ of the digestive system that is responsible for the sense of taste. It is located on the floor of the mouth with papillae located on it's surface. Taste buds contain taste receptors and are able to recognize salty, sweet, sour, bitter and umami (savour) tastes. An average human tongue contains about 8000 taste buds. The human tongue includes eight muscles which aid with chewing food. These muscles allow the tongue to move in different directions. The human tongue is approximately 4 inches long. The human tongue is attached to the floor of the mouth by the frenulum and hyoid bone in the throat. Tongue's primary function is mastication (chewing) and its secondary function is speech, kissing, etc.

Wednesday, May 25, 2011

Auditory Processing Disorder


Auditory processing disorder affects a person's ability to hear and/or comprehend sound. It is related to how the auditory section of the brain processes the sound. A person with this disorder can have normal hearing ability since this particular disorder does not mean inner ear impairment which is responsible for hearing sounds only. People who are affected by this condition cannot comprehend verbal words clearly and have  a difficult time distinguishing between different sounds. Some signs of this condition are: more time to process what is said, difficulty listening, having trouble paying attention to details, need the speaker to speak slowly. An Auditory Trainer can be used to help a person with this disorder.

Sunday, May 8, 2011

Human Faeces


Feces are the waste product of human digestive tract. The faecal matter is formed in the large intestine where it solidifies. The faeces contain food residue, water, bacterias, and secretions from the small intestine and the liver such as bile, etc. The food that is eaten is absorbed through the small intestine and then the unabsorbed parts of the food accumulates, moves and stores in the large intestine. In large intestine the water and ions are absorbed through it's muscular walls, therefore the materials turn solid. The solid materials move out of the body through anus, by means of the muscles in large intestine and rectum contracting and moving the solid wastes forward. when blood cells die their colour change to brown/yellow and the bile coming from the liver causes the faeces to have a brownish colour. The smell of the faeces is the result of bacterias in the faeces, therefore giving it a bad smell.

Saturday, May 7, 2011

Angioplasty


Angioplasty is the reconstruction of blood vessels that were damaged by cholesterol deposit, disease or injury. In this technique, a ballon catheter is inserted to the narrowed blood vessel and then inflated. The inflation causes the fatty deposits to disappear. After the ballon successfully widened the vessel, it is deflated and withdrawn. Another method to widen the blocked blood vessels is to use a stent. In this procedure a stent is placed around a balloon and inserted inside the vessel with a catheter. After the balloon is positioned properly, the balloon inflates and stent is left around the vessel's wall. The stent remain in the blood vessel permanently in this procedure. Radioactive colours are used to determine the site of damaged blood vessels before Angioplasty is done.

Friday, May 6, 2011

Tinnitus


Tinnitus is a subjective ringing/buzzing noise sensation in one or both ears that does not have an external source. Tinnitus is considered to be a symptom of an underlying condition such as otosclerosis or accumulation of ear wax. Listening to loud music with a headphone could cause the ringing sound in one or both ears. Tinnitus can last for a few minutes to many years and it can have negative effects a person's ability to sleep. Some of the treatments available for tinnitus are: cleaning the ear canal (if the condition is caused by ear wax accumulation) and cochlea implant (auditory part of the ear responsible to transfer vibrations to never fibbers) . Cochlea implant is surgically inserted inside the ear and allows the person to hear external voices.

Thursday, May 5, 2011

How Do We Hear?


Sound waves first enter through the flap of the ear. The ear drum vibrates and causes three small bones (malleus, incus and stapes) to vibrate also afterwards.  As the stapes (one of the small bones) moves, it touches the oval window which separates inner and middle ear. At this stage, the oval window fluctuations causes the sound waves to be transferred to what is called the cochlea. There are two auditory liquids inside cochlea, perilymph and endolymph. In the organ of corti (auditory receptor area) small hair  cells receive vibrations from the auditory liquids and then the sound waves are sent to auditory nerve fibres where the sounds are heard.

Monday, May 2, 2011

Testosterone & It's Function In The Body


Testosterone is a male hormone (androgen) that is responsible for men's secondary sexual characteristics such as beard, deep voice and muscle mass. Testosterone is secreted from testes and adrenal glands(glands located on top of the kidneys that produce hormones and release them to the body) in males. Females body produces small amounts of testosterone in the adrenal glands which is necessary for healthy sexual drive and also prevents bone loss. According to a study the male body produces ten times more the amount of testosterone produced in females. It should also be mentioned that as the result of this, females are more sensitive to testosterone molecule. Some effects of testosterone on the body are: sperm production, causes enlargement of body organs such as brain, heart and liver, attention, spatial ability.

Sunday, May 1, 2011

How do we see?


Light rays enter the cornea first which is a transparent layer on top of the pupil. Cornea focuses the light rays properly so that a clear vision is created. The function of the iris or the coloured portion of the eye is to contract and dilate the eyes during dark and bright times. The ciliary body produce flatting and thickening of the lenses for distant and close vision. After light rays have reached Retina (light sensitive layer of the eye), the electric impulses travel through the optic nerve and reaches the brain where an image is created. The part of the brain that is responsible for vision is called the cerebral cortex and located at the back of the brain.
An interesting fact about our eyes is that the images are upside down when they reach the retina but the brain corrects the image so we see it as an upright image.