Some interesting things about Synapses

A synapse is a functional membrane-to-membrane contact of the nerve cell with another nerve cell, an effector (muscle, gland) cell, or a sensory receptor cell.
The term "synapse" was coined by Charles Scott Sherrington in 1897.
The distance separating two neurons at a synapse is 20-40 nanometers.
There are basically 2 types of symapses.
1. Chemical synapse
2. Electrical synapse.

Loss of taste

Most of us know that loss of vision is called blindness and loss of hearing is called deafness.

Some may also know that loss of smell is called anosmia.

Many doesn't know what loss of taste is called.

A decrease in ability to taste is called HYPOGEUSIA, and a total loss of taste is termed AGEUSIA.

what is the fifth taste?

Every one knows that there are five primary taste sensations.

1. Sweet

2. sour

3.Bitter 

4. Salt

Did you ever thought what could be the fifth taste

The 5th primary taste sensation is called "umami."

It is a taste taste that occurs when foods with glutamate are eaten.

The red eye of Photography

Do you know what causes "red eye" when you take a flash photograph?

The choroid is a layer of tissue at the back of the eye that contains a large number of blood vessels. Red eye usually happens when a flash photograph is taken in dim light. In dim light, the pupil of the eye is dilated and allows plenty of light to enter the eye. Red eye is caused when the choroid reflects the light of the flash. The pupil does not constrict fast enough to reduce the amount of light that enters the eye. Therefore, the flash of light reflects back out of the eye and is recorded on film. Some cameras use red eye reduction methods that send out a short burst of light before the film is exposed. The brief burst of light allows the pupil to constrict and thus reduces red eye.

Medicine logo

A staff or wand with either one or two snakes wound around it is often used as a symbol of medicine. The single snake staff is attributed to the ancient Greek God Asclepius (Aesculapius or Asklepios); the two snake wand, called a caduceus, is attributed to the mythological character Hermes (Mercury). 

Some more interesting facts

The optic nerve is the thickest of the cranial nerves and is made of about 1,200,000 fibres. Approximately it  carry 38% of all nerve fibers that enter or leave the brain. Where as the abducens nerve is the thinnest and comprises of about only 3,700 fibres.

Some thing interesting

Hi friends I have found some thing interesting

You have probably experienced "deja vu" -- the feeling that something is familiar to you. Did you know that some people experience the feeling that something is unfamiliar? This is call "jamais vu."

Other feelings that sometime occur:

deja entendu = already heard
deja eprouve = already experienced
deja fait = already done
deja pense = already thought
deja raconte = already recounted
deja senti = already felt, smelt
deja su = already known (intellectually)
deja trouve = already found or met
deja vecu = already lived
deja voulu = already desired

Hi Good Morning

Hi friends a very good morning to all.

KRRISH

The cool cloud

The Brain Game

Everyone wants to stay in shape, and now you can keep your brain in shape as well with the Brain Trainer. The Brain Trainer is a fun, hand-held game that allows you to compete against yourself in order to keep yourself mentally fit. This little gadget performs tests that stimulate your brain by working the frontal cortex. This is the part of your brain that controls creativity, memory, and communication.

So if you find yourself forgetting things or losing your train of thought easily, you may just need to exercise your brain. The Brain Trainer was invented by a neuroscientist in Japan. It is designed to take you through a series of programs that quickly stimulate your frontal cortex in order to enhance mental agility. The programs include tests in which you add, subtract or multiply as fast as possible, count as quickly as you can, or add a series of numbers sequentially. There are also tests for memorization and recalling as many numbers as possible.

When you are feeling like you need a mental boost just pull out your handy Brain Trainer. As you progress through the programs the device also keeps track of you score and time for each session so you can always compete against yourself and try to increase your brain power each time you play. The Brain Trainer runs on 2 AAA batteries.

Start increasing your mental capacity and get your Brain Trainer

The cattle of Munnar

Answers

1. Answer: ACDE

DISCUSSION: Many skulls from the Neolithic period have been found, some of which contain cranial defects with evidence of bone healing, indicating that these individuals underwent trepanation during life and survived the operation. The earliest known writing dealing with surgical topics is the Edwin Smith papyrus. In the works of Hippocrates is the first written account of trepanation. During the second half of the nineteenth century, general anesthesia was introduced and the principles of asepsis were developed. These steps were important for all areas of surgery, including neurosurgery. In addition, it became recognized that certain areas of the nervous system were especially important for certain neurologic functions and that intracranial and intraspinal abnormalities might be localized by the history and neurologic examination findings, thus providing a more specific target for neurosurgical exploration through the small bony openings to which surgeons were restricted at the time. Victor Horsley of London was the first surgeon to prepare himself specifically for surgery of the nervous system and to concentrate his efforts in that area.

2. Answer: C

DISCUSSION: Harvey Cushing (1869–1939) laid the groundwork for much of what is done in neurosurgery. For example, he standardized operative procedures and introduced many techniques and instruments that are still in use. He also made careful and detailed studies of intracranial tumors and established their classification. By his own multifaceted career and through his many students from around the world he influenced the development of neurosurgery to a degree not equaled before or since.


3. Answer: BDE

DISCUSSION: MRI has proved to be a better modality than CT for evaluation of disease of the central nervous system (CNS), such as diseases at the base of the skull (particularly the sellar and cerebellopontine angle cistern regions) and for most tumors, white matter disease (e.g., multiple sclerosis), early stroke, congenital abnormalities, vascular malformations, and spinal disease. New techniques of MRI such as fast spin echo (FSE) pulse sequence have been developed to detect mesial temporal sclerosis, which is the most common cause of intractable complex partial seizure. Differentiating pure compression fracture from metastatic disease of the vertebral bodies in a patient with known primary cancer is also possible by new MRI technique; however, for patients with certain types of metal (pacemaker, surgical clip, or foreign body, which may move in the magnetic field and cause injury to the patient or significant artifacts) within the bodies, MRI is contraindicated.

4. Answer: ACDE

DISCUSSION: Diffusion-weighted MR is a new development in MR applications and is sensitive to microscopic motion of water protons (Brownian motion). Initial applications have involved imaging of early stroke and neoplasia. Early evidence also suggests that diffusion-weighted imaging can differentiate tumoral edema from tumor and identify the nonenhancing part of the tumor. Doppler sonography, MRA, and CT angiography (CTA) are all useful for evaluating the stenotic condition of carotid bifurcation noninvasively. However, sonography is very operator dependent, and MRA commonly overestimates the degree of carotid stenosis resulting from the turbulence, dephasing at points of stenosis or irregularity. CTA obtained by spiral or helical CT has a good correlation rate with carotid angiography (92%). Conventional carotid angiography remains the most accurate imaging modality for evaluation of the stenosis of carotid bifurcation. Although CT and MRI have taken the place of myelography in evaluating neurologic diseases, it is still useful in detecting diffuse subarachnoid seeding, which may be difficult to identify on MRI. The bone detail and calcification are poorly identified on MR, so in a patient with facial trauma, CT is a better modality than MR. With MRS, metabolites within a selected region of interest (ROI) can be investigated, and spectral peaks that reflect the concentrations of the metabolite within the ROI can be obtained. The metabolites include lactate, neuronal marker (NAA), phosphorus metabolites, creatine, and choline. Reduction in the NAA level and elevation in lactate level could be noted in acute stroke.


5. Answer: ABCD



DISCUSSION: In children, brain tumors are more commonly situated below the tentorium than above it. In adults, the reverse is true. Cytologic examination of CSF may provide critical diagnostic information in a patient with meningeal carcinomatosis or subarachnoid spread of a primary brain tumor such as a medulloblastoma, but in most instances CSF examination is not of significant value. Furthermore, in a patient with a brain tumor lumbar puncture may be dangerous; it may promote brain herniation. If there has not been a surgical breach of the dura mater, primary brain tumors seldom spread to areas outside the intracranial and intraspinal compartments. Most gliomas, including astrocytomas, cannot be cured by surgical resection. The pilocytic astrocytoma of the cerebellum and the optic nerve glioma are exceptions to that rule. Neoplasms of astrocytic, oligodendroglial, or ependymal origin vary histologically along a spectrum from benign to malignant, with no sharp dividing line. Furthermore, even the most benign-looking ones tend to recur after surgical resection.

Hi friends

Hi friends. Good aftenoon.
Its a busy day to me. Lots of work. By evening i will publish the answers to the yesterdays questions.
Bye.

6th June 2008

1. Which of the following are true about the history of neurosurgery?
A. The history of trepanation dates back to the Neolithic period.
B. The earliest known writing dealing with surgical topics is the Ebers papyrus.
c. The writings of Hippocrates contain the first recorded descriptions of trepanation.
D. The three key developments that were necessary to permit successful intracranial and      intraspinal surgery were anesthesia, asepsis, and the concept of localization
     of different functions  in different areas of the nervous system.   
E.Victor Horsely of London was the first surgeon to specialize in neurosurgery.

2. The neurosurgeon who has had the most profound influence on the development
     of neurosurgery is/are
A. Fedor Krause of Germany.
B. William Macewen of Scotland.
C. Harvey Cushing of the United States.
D. Egas Moniz of Portugal.
E. Goeffrey Jefferson of England.

3.Which of the following conditions can be evaluated by magnetic resonance imaging (MRI)?
A. Stroke is suspected in a patient with a cardiac pacemaker.
B. Computed tomography (CT) shows a skull base tumor.
C. A coma patient with CT-demonstrated subarachnoid hemorrhage and an aneurysmal clip.
D. A patient with intractable complex partial seizure.
E. A lung cancer patient whose plain film of the lumbar spine shows a compression fracture of      the L2 vertebral body.

4.Which of the following statements about neuroradiologic imaging modalities is/are correct?
A.Diffusion-weighted MRI can differentiate tumor from edema and identify the nonenhancing     part of the tumor.
B. For evaluating the stenosis of the carotid bifurcation, MR angiography (MRA) is the most      accurate imaging modality.
C. Myelography is still useful in detecting some diffuse spinal disease such as cerebrospinal fluid     (CSF) seeding.
D. For evaluating the bony detail of patients with facial trauma, CT is a better imaging modality      than MRI.
E. Decreased amount of N-acetyl aspartate (NAA) and increased amount of lactate can be shown      in the MR spectroscopy (MRS) of a patient with acute stroke.

5.Which of the following are true about intracranial tumors?
A. The most common location of brain tumors of childhood is the posterior cranial fossa.
B. With few exceptions, examination of the CSF is of no value in the diagnosis of an intracranial      tumor.
C. Even the most malignant of primary brain tumors seldom spread outside the confines of the      central nervous system (CNS).
D. The majority of astrocytomas can be cured surgically.
E. Primary neoplasms of astrocytic, oligodendroglial, or ependymal origin represent gradations      of a spectrum from slowly growing to rapidly growing neoplasms.







    

MCQ's in Neurosurgery

Hi.
Dear friends from today I will post some important MCQ's in Neurosurgery every day.
I wll try to give the answers next day. Interested can answer and comment. Discussions are welcome.

My first blog

Hi Every one.
This is my first blog.
I have to know a lot more about blogging.
I would like to keep this open to discussions on Neurosciences as I am very much interested on Neurosciences.