Life Processes
* The circulatory system consists of the heart and blood vessels.
* Plasma contains suspended red blood cells, white blood cells and Platelets.
* Red blood cells contain a pigment called haemoglobin.
* In newborn babies, 17 to 22 gm/dl of haemoglobin should be present in the blood. For children, the normal range is between 11 and 13gm/dl and for adults it is between 12 and 18gm/dl.
* Arteries carry blood away from the heart.
* Veins carry blood to the heart.
* Lymph is a colourless fluid. It contains less protein that plasma.
* Fishes have two chambered hearts.
* Amphibians and reptiles have three chambered hearts.
* Birds and mammals have four chambered hearts.
* In birds and mammals, blood flows from the body to the heart, from the heart to the lungs and again back to the heart.
* In a fish, blood flows from the gills to the body to the heart.
* The force exerted by blood against the walls of blood vessels is blood pressure.
* Sphygmomanometer measures blood pressure.
Transportation in Human and Plants – Transportation in Humans
* The transportation of substances in the body is done by the circulatory system.
* The circulatory system, also known as the cardiovascular system, consists of the blood, blood vessels and the heart.
* Blood transports food, water and oxygen to the various parts of the body.
* The fluid part of blood is known as plasma.
* In the plasma there are three main types of cells- Red Blood Cells, White Blood Cells and platelets.
* The Red Blood Cells, also referred to as RBCs, transport oxygen from the lungs to the rest of the body.
* The White Blood Cells or WBCs defend our body against infections.
*The loss of blood from cut is prevented by the platelets.
* The blood vessels are mainly of two types- Arteries and Veins.
* Arteries transport blood from the heart to the other parts of the body.
* When an artery enters an organ it divide and re- divides to form capillaries.
* The capillaries join together to form veins and the veins transport blood back to the heart.
* The heart acts like a pump and pumps blood to all parts of the body.
* The rhythmic contraction and relaxation of the heart is known as the heart- beat.
* A device used to hear the heart- beat of a person is called a stethoscope.
* The removal of harmful wastes and excess water is performed by the excretory system.
* The excretory system consists of the kidneys, ureters, urinary bladder and urethra.
* Due to an infection or injury to the kidney, it may cease to function. This is known as kidney failure.
Body Fluids
* Blood liquid connective tissue that consists of 55% liquid plasma and 45% formed elements called blood cells.
* Major proteins is plasma include albumins, globulins and fibrinogens.
* Formed elements include erythrocytes, leucocytes and platelets.
* Erthrocytes or Red Blood Cells (RBCs) are involved in the transport of respiratory gases.
* Leucocytes or White Blood Cells (WBCs) include neutrophils, eosinophils, basophils, lymphocytes and monocytes.
* Clotting or coagulation is a preotective mechanism that takes place at an injured site to prevent loss of blood.
* Interstitial fluid or tissue fluid is formed when some quantity of water and water- soluble substances squeeze out from the blood capillaries into the intercellular spaces.
* Lymph is a colourless fluid that contains lymphocytes, nutrients, hormones and proteins.
Blood Groups
* The presence or absence of ‘A’ and ‘B’ antigens on the surface of RBCs determines ABO blood groups.
* The presence or absence of the ‘Rh’ antigen on the surface of the RBCs determines Rh blood groups.
* Antibodies are present in the blood plasma.
* Specific antigen and antibody reactions result in the clumping or agglutination of RCBs.
* Individuals with blood group ‘O’ are called universal donors
* Individuals with blood group ‘AB’ are called universal recipients.
* Rh incompatibility in an Rh negative woman carrying an Rh positive foetus results in erthroblastosis.
Cardiac Cycle
* Double circulation involves pulmonary and systematic circulation.
* Pulmonary circulation refers to the circulation of blood between the heart and the lungs.
* Systemic circulation refers to the circulation of blood between the heart and the tissues of the body.
* A heartbeat is caused by the systole or contraction and diastole or relaxation of the chambers during the circulation of blood.
* The sequence of events that includes systole and diastole forms a cardiac cycle.
* The cardiac cycle is driven by the action potential generated by the SAN and distributed through the ventricles by the Bundle of His.
* Cardiac output equals the product of the stroke volume and the number of beats/minute.
