Science

Skin Lesion and it’s types

Skin Lesions are the anomalies or findings that are not normally seen in a normal individual and indicates towards some sort of underlying disease or pathology.  Skin leasions can be found over the epidermis , dermis or mucosal surfaces anywhere in the whole body surface present in direct contact to external environment.  These lesions can be divided into three categories :- 1. Primary Skin Lesions  2. Secondary Skin Lesions 3. Special Lesions   1. PRIMARY SKIN LESIONS :-  These are the initial or non-modified lesions. These lesions can be furthur classified into –  a) Flat , Non Palpable lesions ; when size is less than 1 cm then it’s called Macule if larger then it’s a patch.  b) Circumscribed  , solid , raised lesions ; when size is less than 1 cm then it’s called Papules , when larger than 1 cm it’s reffered as plaques , if the lesion also have depth in it then it’s named as a Nodule.  c) Clear fluid filled lesion ; when size lesser than 1 cm it’s called as Vesicles and if larger then it’s called Bulla. d) Pus filled lesion ; when smaller called as Pustule , if larger and deeper then called An Abscess.  e) RBC extravasation over (Skin or Membrane). If less than 2 mm called as Petechiae , if between 2 mm to 1 cm named as Purpura , if larger then named as Echymoses .  f) Wheal ; is the term given to itchy , erythematous ,Transient evanescent plaque .  2. SECONDARY SKIN LESIONS :- When the primary lesion gets modified either by Treatment , Scratching or evolution of diseases.   a) Scale ; visible exfoliation of stratum corneum b) Crust ; Dried exudate such as Pus / Blood / Serum on skin surface   c) Erosion ; Focal or Complete loss of epidermis.  d) Ulcer ; Loss of epidermis alongside partial or total loss of dermis and Molecular Death of the involved layers.  e) Fissure ; Linear deep clefts or Cracks on the skin.  3. SPECIAL SKIN LESIONS :-  These are lesion seen only in certain kind of disease or disorders .  a) Target Lesion – seen in case of Erythema Multiforme .  b) Burrows – these are seen in individuals infected by Scabies as the parasite creates these burrows and serpigenous tunnels as their habitat over the skin.

Skin – largest sensory organs

Skin being the largest sense organ of the body among the 5 sense organs namely Vision , Hearing , Taste , smell and Touch.It weighs about 4-5 kg and comprises of about 16% of the body weight.Outlines the whole outer body by covering an area of around 1.7 m² (approx). Skin can be divided into 3 layers namely Epidermis , Dermis , Hypodermis. FUNCTIONS :- 1) It acts as a barrier in function by stopping all the external agents such as Bacteria , Viruses and other antigens present in the environment from directly entering in the body and disturbing the internal Homeostasis. 2) It also functions to provide the colour that every human holds via its EMU (epidermal Melanin Units) present in epidermis.One EMU consists of one melanocyte supplementing melanin to 36 keratinocytes.The number of EMU are same in all individuals around the world. It is the activity of the units which decides the skin colour of an individual. 3) It also functions as a sensory organ in the body with the help of some specialised cells and bodies . The sensory modalities percieved by the skin are Touch , Pressure , Vibration , Pain , Heat and Cold respectively. a) Touch – percieved by the Meissner Corpuscles.b) Thermal Sensation – percieved by Ruffini’s Corpusclesc) Pressure and Vibration – percieved by Pacinian Corpusclesd) Pain – percieved by free nerve endings.

Maths – Language of science

If we look around there will be 7 out of 10 students who might be fearful of their Maths exams in their schools the most. My question would be why? Because we don’t know what is the use of that math we are studying. Because we can’t picture the science this math shows us. Let’s see if I can help you in connecting to this weirdly fantastic subject. We know language is a tool to communicate expressions and emotions. And when we read words or a sentence we build a picture in the back of our mind. Because that’s how it works. The brain remembers pictures, scents and sounds but not words. So reading a book will create an image like a scene playing with characters moving around. Well, that’s how math helps us create the picture of science. The language of science is math. The rotation of a ball, the flying of birds, the falling of rain, etc. We can see them. But science finds its expression only in terms of math. I know, my words might bounce off your head. But hey, I’ve got an example for you. The phenomena of seeing the world with our eyes. The science of light and refraction and all that conversion to let us see the world as it is. For the thousands of shades and names of colors, the farthest of the distances, and the smallest of the details; all made possible by two small balls that sit in our head. Wanna know how? Eye, what we see as a part of our body, according to science is an optical instrument, or a camera in simple language. The eyelids can be compared to the shutter of the camera, and the cornea and crystalline lens to the lens of the camera. It’s the apparatus that focuses on the image we are trying to capture. And well the refractory system of our eye is far far advanced than the best iPhone’s camera. Almost fifty times more efficient. Woooww, that’s surprising!! The overall size of our eyeball is just 2.5 cm. And for images to fall on the retina (that is the screen or the reel inside the camera), and for us to see, there should be a great level of refraction of light. So you know, refraction is the bending of light due to a change in medium. And the eye is a cocktail of changing mediums! With math we tend to simplify the whole eyeball with a single convex lens. And to know the adjustments that lead us to see clearly we need to understand the lens maker formula. 1/f = 1/v + 1/u Where, f is the focal length of eye lens             u is the distance of object we want to see             v is the distance of image formed by the lens In the case of the eye, the image always needs to be formed on the retina, i.e. 17 mm from the lens. Thereby the focus of our lens changes with the help of the muscles in our eye, to let us see from the nearest to farthest objects. And this ability to adjust, if defected or lost, we take help of lens (i.e. glasses) to bring out the perfect combination of lenses with just the right focal length of our natural eye. Also, Power of lens = 1/f             Where distances are kept in meter Therefore, natural power of lens(P) = 100(1/1.7 + 1/u) So, power of the lens for far point of eye, that is infinite, is:             P = 100(1/1.7 + 0)             P = 58.82 Dioptre Similarly, power of lens for near point of eye, that is 25 cm, is:             P = 100(1/1.7 +1/25)             P = 62.82 Dioptre So can we picture a system of lenses adjusting in and out in a camera, to focus at objects of different distances. As when we focus on the farthest of the sky, the near objects get blurred. And isn’t it so beautiful to read these math equations and picture these beautiful eye clicking pictures of great moments? Does it make math a fearful subject? Or do we now know why math exists. Not just to shuffle with numbers and variables. It is for us to understand science. Hope I got this point well for you. Enjoy math!!

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