CBSE Class 10 Science Bio Medical Technique Notes

BIO-MEDICAL TECHNIQUE

DIAGNOSTIC IMAGING TECHNIQUES :

(a) Radiography :

It is based on the ability of X-rays to pass through softer parts of body but not through hard parts of the body. It was discovered by W. Roentgen.

1. Working : An X-ray beam of short wavelength is passed which forms the shadow of denser parts of body on a photography plate to produce a radiograph.
2. Medical Application : To detect bone fractures and dislocations. To kill internally located tumors. To detect diseases like pneumonia, TB, etc.

(b) Angiography :

X-rays are coupled with certain image intensifiers like Bismuth compounds, iodine solution, etc.

1. Working : Hollow organs are filled with image intensifiers and then X-ray photography is done
2. Medical application : To detect the digestive tract.

Digital subtraction angiography (DSA) uses iodine solution as image intensifier and detects the blockage of blood vessels of heart, brain or kidney.

Computed Tomographic Scanning (CT - scane) :

It is a radiologic technique which combines the uses of X-rays with computer technology to produce clear two or three-dimensional cross sectioned images of deep internal structures. It is also called Computed Axial Tomography (CAT).

It provides more detailed information than X-rays; and tends to minimizes the amount of radiation exposure.

Medical application: excellent method for examination of brain, spinal cord, chest etc.

It gives three dimensional image of internal organs.

(d) Magnetic Resonance Imaging (MRI) :

It is also called Nuclear Magnetic Resonance (NMR) spectroscopy.

It is a diagnostic technique that provides high quality cross-section or three dimensional images of organs without using X-rays or other radiations.

Medical application : It help in examination of brain.

To detect cancerous growth in organs like liver, kidney.

To study blood flow.

(e) Ultrasound Imaging :

It is also called ultrasonography of echography. It invoves the use to high frequency (1 to 15  MHz)  ultrasonic sound waves to produce images of structures within the human body.

Medical application : Useful in diagnosing the diseases of kidney kidney stones, gall tones.

MONITORIG OF VITAL FUNTIONS OF BODY.  :

 (a)  Eectrocardography (ECG) :

It is technique of recoding the electrical change in the heat muscles during one heart beat.

Medical application :  To detect the abnormalitites o the heart like high blood pressures, coronary heart diseases .

 (b) Electroencephalography (EEG.)

It is the graphical representation of the electron activity of the brain cells which are picked up by the electrodes placed on seclp, while instrument to preprare an EEG  is called electroencephalograph.

The neurons of brain generate four types of waves in different of nervous activity.

 (i) Alpha waves             (b) Bate waves                         (iii)  Theta wave                       (iv) Delta waves

Medical application : It reflects the state of patients brain and his state of consciousness. It also

(c)  Polygraphy :

It involves the recording of qualitvative change in certain physiological parameters like pulse arte, blood pressure changes, respiration rates, etc. while the graphic representation is called polygraph    

DIAGONTIC TECHNIQUE OF BLOOD :   

(a) Haemoglobin Estiamtion :

Amount of heamolgobin per 100 ml of blood is called heamolgobin count and is measured by hamometer.  Normal

Normal Hb – amount of adult female – 12 + 2 gram %

Normal Hb  amount of adult male -14. 5 + 2 gram %  

(b) Determination of Total Leucocyte count (TLC) :

Total number of leucocytes per microliter or per cubic millimeter is called total leucoctyes count. Average WBC count is 7000 per mm³

(c) Determintion of Differential leucocyes of blood is called differential leucocte conut. Normal range of differential leucocytes count in adult :

Neutrophils 420 – 75 %

Monocytes 2 – 10 %

Basohils < 1%

Lymphocytes 20 – 40 %

Eosinpohile 1 – 6 % 

(d)  Erythrocyte sedimentation Rate :

The rate of sedimentation of RGC is in a given interval time is called ERS.

Medical application : It differentiates between functional disease and degenerative disease. It is an index of progress of diseases like rheumatoid arthmatoid arthritis and TB.

(e) Detection of Blood Glucose :

Normal values of glucose – 80 – 120 mg/100 ml of blood.

(f) Detection of Blood Urea :

Normal urea level 10 – 45 mg /dl of blood.

(g) Detection of Lipid profile in Blood :

Normal value of cholesterol 140 – 250 mg/dl

(h) Widal Test : 

Typhoid or Enteric fever is caused by a gram negative bacillus bacterium, salmonella widal test is based upon the antigen- antibody serological interactions

(i) Enzyme  Linked immnuosorvbent Assay :

ELISA technique is widely used for the detection of an antigen or antibody in a sample by antigen antibody interaction. It is to detect the infections diseases like tuberculosis typhoid AIDS etc.

OTHER DIANOSTIC TECHNIQES :

(a) Endoscopy :

It is technique to detect and operated some internal organs of body without surgery with the help of an instrument called endoscope.

Mecdical application : To detect the presence of cysts, ulcers of tumors on epithelial of internal organs.

 (b) LASER Microsurgery :

LASER is formed of high energy particles of light, amplified by emission or radiation so called Light Amplified by Stimulated Emission of Radiation.

(c) Haemodialysis : k

It is based on the principle of dialysis which involves separation  of nitrogenous wastes from the blood is case of acute renal failure.

Medical application : It helps in regulating the pH and electrolyte level of plasma,

(d) Prosthesis :

Prosthesis is the technique of implanting of an artificial body part within body to replace defective body part.

Artificial body parts include : Heart – Lung machine, Artificial cardiac pacemaker, Defibrillator etc.

(e) DNA Finger Printing : 

It is done by southern blotting technique using DNA fragments, ecdonclease enzyme. It was developed b Alec Jeffrys. Laboratory for DNA finger printing is situated is situated in Hyderabed at the Centre for Cell and molecular biology (CCMB)

Medical application : It is used for identification of criminals in case of murder or rape and paternity test in case of disputed parentage.

(f) Orgen Transplantation :

In involves the transfer of organs like kidney cornea etc. from one person, to another. It is governed by principle of Histocompatibility. It states that success of transplantation depend so the matching of HLA (Human leucocyte antigen) complex and MHC (Major histocompatibility complex) complex determined by genetic composition  

Type of transhlantation :

(i) Autograft : When transplanted tissues is taken from the same body.

(ii) Isograt : When transplanted tissue is taken from genetically identical persons like identical twins.

(iii) Allografts : When transplanted tissues is taken from individual of same species but having different MHC or HLA alleles. 

(iv) Xenografts : When transplanted tissues/ organ is taken from animal of different species.

Following measures are suggested :

(i) Organs should be taken from the members of sibing species (having similar genetic constitution.

(ii) In skin transplantion, autographing should be preferred.