Activity 6 RED CELL FRAGILITY, BLOOD TYPING, BLEEDING TIME AND CLOTTING TIME AND HYPEREMIA
Introduction In clinical practice, hematological information accumulated from a series of blood tests conducted on a small volume of blood - even a single drop - can be of great diagnostic and prognostic value. There are certain molecules on the surfaces of all cells in the body that can be recognized as foreign by the immune system of another individual. These molecules are known as antigens. antigens. As part of the immune response, particular lymphocytes secrete a class of proteins called antibodies that antibodies that bind in a specific fashion with antigens. The specificity of antibodies for antigens is analogous to the specificity of enzymes for their substrates, and of receptor proteins for neurotransmitters and hormones. Matria!" and Mt#od" A. R! "## "## $RA%I#IT& $RA%I#IT& Ten '()* test tubes were prepared in serial dilution of +a"l solution in different concentrations with distilled water. A representative was asked to sterile his pointer finger with alcohol in gauze pad. sin sing g a lanc lancet et pen, pen, the the fing finger er was was pric pricke ked. d. Two drops drops of bloo blood d was was adde added d to each each test test tube tube concentration. ach test tube was covered with parafilm stretching up to the mouth. The blood with salt concentration was mied in a slow inverting manner of the tube using the middle and thumb finger. $inally $inally the () test tubes were all subected for centrifugation at (/))g for 0 minutes. 1. 1#22! T&3I+% 2btain a clean microscope slide. sing a glass-marking pencil, mark one end A and the other end 1. #ance your finger to obtain blood. "lean the palmar surface of the third or fourth finger with a sterile gauze pad soaked with 4)5 ethanol. 6ith a sterile lancet or needle, make a puncture on a fingertip. 6ipe off the first drop. 3lace one drop of blood on each of the marked slide. Add one drop of anti-A serum to the A side. Add Add one drop of anti-1 anti-1 serum to the 1 side. 6ith a toothpick, toothpick, using a differen differentt toothpick toothpick for each side. 7pread each miture over an area of about ).4/ in diameter. 2bserve the slide for any agglutination of red cells. ". 1#!I+% TI8 A+! "#2TTI+% TI8 7terilize the fingertip using rectified spirit and allow to dry. 8ake a sufficiently deep prick using a sterile lancet, so that blood comes out freely without s9ueezing. 8op the blood by touching the fingertip with a filter paper. This is repeated every (/ seconds, each time using a fresh portion of the filter paper, till bleeding stops. +ote the time. It is seen that the blood stains on the filter paper get smaller to disappear finally when bleeding stops. nder sterile precautions make a sufficiently deep prick in the fingertip. f ingertip. Touch Touch the blood drop at the fingertip using one end of the capillary tube kept tilted downwards. The tube gets easily easily filled filled by capillary capillary action. After After about two minutes start snapping off small lengths of the tube, at intervals of (/ seconds, each time noting whether the fibrin thread is formed between the snapped ends. +ote the time when the fibrin thread is first seen. !. :&3R8IA 6ind a rubber band in the chosen finger. 6ait for several minutes to note for difference in size and color of the finger. 3repare 3repare a /))-ml tap water in a beaker then put it in water bath set at ;/ degrees ". Immerse the finger in the beaker for a few minutes to note for sensations other than warmth that the finger was eposed to.
R"u!t" A$ Rd C!! Fra%i!ity Tu& Nu'&r ( 0 = ; / > 4 ? @ ()
Co!or o( )u*rnatant "lear "lear "lear "lear "lear Reddish Reddish Reddish Reddish Reddish
O&"rvation" Pr"nc o( RBC" at t# &otto' o( tu& < < < < < -
0. If a cell that is normally in osmotic e9uilibrium is transferred to a more dilute solution, water will enter the cell, the cell volume will increase, and the solute concentration of the cytoplasm will be reduced. =. If the cell is transferred to a more concentrated solution, water will leave the cell, the cell volume will decrease, and the solute concentration of the cytoplasm will increase. B$ B!ood ty*in%, &!din% ti' and c!ottin% ti' &our 7ample
Anti-A 7erum Agglutinate
1leeding time "lotting time
Anti-1 7erum Agglutinate
1lood Type A1
( minute ;/ sec
;. A12 typing If your blood cells stick together when mied with • • • •
Anti-A serum, you have type A blood Anti-1 serum, you have type 1 blood 1oth anti-A and anti-1 serums, you have type A1 blood If your blood cells do not stick together when anti-A and anti-1 are added, you have type 2 blood.
/. Assessing blood clotting and bleeding factor is very important if you are about to have a surgical procedure. 7urgery or an inury of any kind increases the risk of a blood clot. ThatBs because the clotting process is stimulated as your body attempts to stop the bleeding and close the surgical wound. A clot is normally formed by the blood cells and clotting factors working together to create a protective scab over a healing wound. The surgical procedure may stimulate clots to form in error in blood vessels, which then may block the normal flow of blood.
B$+ Cro""Matc#in% )ru' )a'*!
Rd C!! )u"*n"ion Agglutination !onor Type A1 Recipient Type A
>. "ross matching is a must before blood transfusion to determine if the donorBs blood is compatible with the blood of an intended recipient. Transfusion errors that result in such agglutination can lead to blockage of small blood vessels and cause hemolysis 'rupture of red blood cells*, which may damage the kidneys and other organs. C$ Hy*r'ia 2bservations 4.(
7ize swell "olor dark-purple color
1y winding the rubber band on the finger the oygen level decreases and swells due to blood vessel dilation.
4.0
7ize '<* crease, shrink "olor reddish
An increase metabolic rate re9uires a greater flow of blood thus the vessels dilate.
?. :yperemia :yperemia is when there is an increase in blood flow to the tissues and organs. Active or functional hyperemia is an increase in blood flow associated with increased metabolic activity. A greater blood flow is re9uired to increase oygen delivery and enhance the removal of carbon dioide andCor lactate from these metabolically active tissues. Reactive hyperemia on the other hand is an increase in blood flow to the tissues when they have been deprived of oygen.
Di"cu""ion "ell membranes are semipermeable barriers, and osmotic gradients are established between intracellular and etracellular fluids which can cause water to flow into and out of the cells. The amount of osmotic pressure depends upon the difference between the concentrations of non-diffusible ions on each side of the membrane. Osmotic fragility is a test to detect whether red blood cells are more likely to break down. The intracellular fluid of erythrocytes is a solution of salts, glucose, protein and hemoglobin. A ).@5 +a"l solution is said to be isotonic when blood cells reside in such a medium, the intracellular and etracellular fluids are in osmotic e9uilibrium across the cell membrane, and there is no net influ or efflu of water. In the performed eperiment, ).@5 +a"l wasnBt eactly used and instead a higher concentration of +a"l was given.
$igure ( 6hen subected to hypertonic media 'eperiment Tube (-/*, the cells lose their normal biconcave shape, undergoing collapse 'leading to crenation* due to the rapid osmotic efflu of water. 2n the other hand, in a hypotonic environment 'Tube 4-() with greater volume of distilled water*, an influ of water occurs the cells swell, the integrity of their membranes is disrupted, allowing the escape of their hemoglobin 'hemolysis* which dissolves in the eternal medium.
$igure 0. Crnatd "a'*! -Tube (-/*
$igure =. H'o!y.d "a'*! 'Tube >-()*
If as little as )./5 of the red blood cells are hemolyzed, the released hemoglobin will cause the serum or plasma to appear pale red or cherry red in color. +ote that the hemolyzed sample is transparent, because there are no cells to scatter light. 2n the other hand, the crenated sample after centrifugation formed a cell fractionation where the resulting supernatant is clear and the pellet visible at the bottom looks very pale.
The blood groups refer to the presence on human red blood cells of certain antigens, the blood group factors. 2ne very important group of factors present on the red blood cells is the A12 system. The A12 group of a person depends on whether hisCher red blood cells contain one, both, or neither of the 0 blood group antigens A and 1. There are, therefore, ; main A12 groups A, 1, A1 and 2. The presence or absence of agglutinations will determine the blood type found. This agglutination reaction, which is very important in determining the safety of transfusions is due to a mismatch of genetically determined blood types.
Antibodies 'agglutinins* for the antigens A and 1 eist in the plasma and these are termed anti-A and anti-1. The corresponding antigen and antibody are never found in the same individual since, when mied, they form antigen-antibody complees, effectively agglutinating the blood. Agglutination 'clumping* of red blood cells occurs when cells with A-type antigens are mied with anti-A antibodies and when cells with 1-type antigens are mied with anti-1 antibodies. +o agglutination would occur with type 2 blood. 3eople with type A blood have type A antigens on their red blood cells and antibodies in their plasma against the type 1 antigen. 3eople with type 1 blood have type 1 antigens on their red blood cells and antibodies in their plasma against the type A antigen. Therefore, if red blood cells from one blood type are mied with antibodies from the plasma of the other blood type, an agglutination reaction occurs. In this reaction, red blood cells stick together be cause of antigen-antibody binding. Hemostasis 'literally - blood halting* depends on three interrelated and overlapping sets of events •
• •
"onstriction of the blood formation of a platelet DplugD 1lood clotting "lot retraction
vessels
and
Bleeding time is the interval between the moment when bleeding starts and the moment when bleeding stops. +ormal bleeding time is to ; minutes. 8easures the time taken for blood vessel constriction and platelet plug formation to occur. +o clot is allowed to form, so that the arrest of bleeding depends eclusively on blood vessel constriction and platelet action. It is used to evaluate platelet function and is typically performed, along with a platelet count, in people with a personal or family history of bleeding disorders, or as a preoperative safety measure before a scheduled surgery.
Clotting time is the interval between the moment when bleeding starts and the moment when the fibrin thread is first seen. 1leeding time and clotting time are not the same. 1leeding time depends on the integrity of platelets and vessel walls, whereas clotting time depends on the availability of coagulation factors. In coagulation disorders like haemophilia, clotting time is prolonged but bleeding time remains normal. The normal range for clotting time is =-() mins. In order for blood to clot, the enzyme thrombin must be generated from the plasma precursor prothrombin. Thrombin then converts soluble fibrinogen into insoluble fibrin. %eneration of thrombin involves the se9uential activation of a number of other plasma clotting factor, this process is also being assisted by "a<< and by factors released by platelets and damaged tissues . The time taken for blood to clot mainly reflects the time re9uired for the generation of thrombin in this manner. If the plasma concentration of prothrombin or of some of the other factors is low 'or if the factor is absent, or functionally inactive*, clotting time will be prolonged. "lotting time is also prolonged in conditions like vitamin E deficiency, liver diseases, disseminated intravascular coagulation, overdosage of anticoagulants etc. Cross-matching blood, in transfusion medicine, refers to the comple testing that is performed prior to a blood transfusion, to determine if the donors blood is compatible with the blood of an intended recipient, or to identify matches for organ transplants. "ross matching is a must before blood transfusion to determine if the donorBs blood is compatible with the blood of an intended recipient
$igure ;. Cro""'atc#in%$ A type A1 donor mied with the blood of a type A recipient. 6hen transfusing blood, it is important to remember that the donorFs blood must not contain red blood cells that the recipientFs antibodies can agglutinate. Theoretically, then, individuals belonging to blood group 2 are universal donors, while those of blood group A1 are universal recipients. If the types do not match G if the donor is type A, for eample, and the recipient is type 1 G the recipientBs antibodies attach to the donorBs red blood cells and form bridges that cause the cells to clump together, or agglutinate. Transfusion errors that result in such agglutination can lead to blockage of small blood vessels and cause hemolysis 'rupture of red blood cells*, which may damage the kidneys and other organs. Hyperemia is when there is an increase in blood flow to the tissues and organs. 6hen blood flow is reduced temporarily, the skin becomes pale. If pressure is applied to the skin, the blood in the vessels of the skin stagnates. 2ygen in the hemoglobin is 9uickly used by the tissue in the area, and the hemoglobin becomes darker as a result of deoyhemoglobin formation. 6hen you obstruct blood flow by tying a rubber band around a finger, it swells and the color of the skin gives a bluish hue, termed cyanosis. 2nce removed, the skin turns fiery soon after the occlusion is removed. This is known as reactive hyperemia. Reactive hyperemia is an increase in blood flow to the tissues when they have been deprived of oygen. 6hen blood flow to an area is restricted, the arterioles in that area dilate as a result of the release of chemicals 'products of metabolism* by the oygen-deprived cells. 6hen blood flow is no longer restricted, blood rushes into the dilated blood vessels as the oygen level increase.
Active or functional hyperemia is an increase in blood flow associated with increased metabolic activity of an organ or tissue. !uring the immersion of one finger in a warm water there was an increased in the metabolic activity, where the skin dilated and turned red in color, showing an increase in the blood flow. A greater blood flow is re9uired to increase oygen delivery and enhance the removal of carbon dioide andCor lactate from these metabolically active tissues. After few minutes upon immersion a short painful sensation other than warmth was felt which later on adapted on the surrounding temperature. Another good eample of active hyperemia is the increase in blood flow that accompanies muscle contraction, which is also called eercise or functional hyperemia in skeletal muscle. 1lood flow increases because the increased oygen consumption of during muscle contraction stimulates the production of vasoactive substances that dilate the resistance vessels in the skeletal muscle.
Conc!u"ion The primary function of blood is to supply oygen and nutrients as well as constitutional elements to tissues and to remove waste products. 1lood also enables hormones and other substances to be transported between tissues and organs. 1lood is also involved in maintaining homeostasis problems with blood composition or circulation can lead to downstream tissue malfunction, thatBs why, assessing your blood can greatly prevent health problems.
Litratur citd 7dmesa. Hascular. Retrieved (= 7eptember 0)(/ from httpCCclassroom.sdmesa.eduCbbrothersC!ocs 50)0=/Cvascular.pdfa
Health communities. Blood clotting tests. Retrieved on 13 September 2015 from httpCCwww.healthcommunities.comCblood-testsCblood-clotting-tests.shtml 8c%ill. A12 7ystem. Retrieved on (= 7eptember 0)(/ from httpCCwww.medicine.mcgill.caCphysioCvlabCbloodlabA12n.htm 6ikipedia. :emolysis. Retrieved on (= 7eptember 0)(/ from httpsCCen.wikipedia.orgCwikiC:emolysisJ2utsidethebody ncyclopedia of Ayurvedic 8edical 3lants. 1leeding time K clotting time. Retrieved on (= 7eptember 0)(/ from httpCCwww.indianmedicinalplants.infoCarticlesC1#!I+%-TI8.html "H3hsyiology. 1lood $low. Retrieved on (0 7eptember 0)(/ from httpCCwww.cvphysiology.comC1lood 50)$lowC1$))/.htm
