TRANSPORTATION IN HUMAN BEING NCERT

              WE HAVE STUDIED THAT BLOOD IS A FLUID CONNECTIVE TISSUE.BLOOD HAVE OF FLUID MEDIUM CALLED PLASMA IN WHICH THE CELLS ARE SUSPENDED.PLASMA TRANSPORT FOOD ,NITROGENEOUS WASTE AND CO2 IS DISSOLVED FORM ,OXYGEN IS TRANSPORTED BY THE R.B.C. MANY OTHER SUBSTANCES LIKE SALT ALSO CARRIED BY THE BLOOD .HENCE WE NEED A PUMPING ORGAN TO PUSH BLOOD AROUND THE WHOLE BODY AND NETWORK OF TUBES TO REACH ALL THE TISSUE AND A SYSTEM IN PLACE TO ENSURE THAT THIS NETWORK IS NOT HARMED.

HEART- HEART IS A MUSCULAR ORGAN THAT PUMPS BLOOD BY CIRCULATORY SYSTEM BECAUSE BOTH OXYGEN AND CARBON DIOXIDE HAVE TO BE TRANSPORTED BY HEART,THE HEART HAS DIFFERENT CHAMBERS TO PREVENT THE OXYGEN .SUCH BLOOD FROM MIXING WITH THE BLOOD CONTAINING CO2. THE CO2 SUCH BLOOD HAS TO REACH THE LUNGS FOR THE CO2 TO BE REMOVED.AND THE OXYGENATED BLOOD FROM THE LUNGS HAS TO BE BROUGHT BACK TO THE HEART.THIS O2 RICH BLOOD IS THEN PUMPED TO THE REST OF THE BODY.

               OXYGEN RICH BLOOD FROM THE LUNGS COME TO THE THIN WALLED .UPPER CHAMBER OF THE HEART ON THE LEFT ,THE LEFT ARTIUM RELAXES WHEN IT IS COLLECTED THUS BLOOD .IF THEN CONTRACTS WHILE THE NEXT CHAMBER THE LEFT VENTRICLE EXPENSE SO GET THE BLOOD IS TRANSVERED IT.WHEN THE MUSCULAR LEFT VENTRICLE CONTRACT IN ITS TURNS..THE BLOOD IS PUMPED OUT TO THE BODY THE DEOXYGENATED UPPER CHAMBER ON THE RIGHT ARTIUM AS IT EXPENDS.

                     AS THE RIGHT ARTIUM CONTRACTS THE CORRESPONDING LOWER CHAMBER .THE RIGHT VENTRICLE DILATES .THIS TRANSFER BLOOD TO THE RIGHT VENTRICLES.WHICH IS TURN PUMPS IT TO THE LUNGS FOR OXYGENATION.SINCE VENTRICALS HAVE TWO PUMP BLOOD INTO VARIOUS ORGAN .THEY HAVE THICKERS MUSCLES HOLES THEN THE ATRIA DO VALVES ENSURE THAT BLOOD DOES NOT FLOW BACKWARDS. WHEN THEARTRIA AND VENTRICAL CONTRACTS.

BLOOD VESSELS- ARTERIS ARE THE VESSELS WHICH TRANSFER BLOOD AWAY FROM THE HEART TO DIFFERNT ORGAN OF THE BODY.  ON REACHING A TISSUE OR ORGAN THE ARTRY DIVIDES INTO SMALLER AND SMALLER VESSEL TO CARRY THE BLOOD TO ALL THE INDIVIDUAL CELLS.THE SMALLEST VESSELS CONTAINS WALLS WHICH ARE ONE CELL THICK AND ARE KNOWN AS CAPALLERIES. EXCHANGE OF MATERIAL BETWEEN THE BLOOD AND THE SURROUNDING CELLS OCCUR ACROSS THIS THIN WALL. THE CAPALLERIES THAN JOIN TOGETHER TO MAKE VEINS THAT TRANSPORT THE BLOOD AWAY FROM THE TISSUE OR ORGAN.

MAINTAINANCE BY PLATELETS- IN THE SITUATIONS WHEN WE ARE INJURED AND START BLEEDING NATURALLY THE LOSS OF BLOOD FROM THE SYSTEM HAS TO BE REDUCED.IN ADDITION LEAKAGE WOULD CAUSE LOSS OF PRESSURE WHICH WOU;LD MINIMIZE THE EFFICIENCY OF THE PUMPING SYSTEM.THE BLOOD HAS PLATELET CELLS TO AVOID THIS WHICH CIRCULATE AROUND THE BODY AND PLUG THESE LEAKS BY HELPING TO CLOT THE BLOOD AT INJURY.