Dergam Al-Tarawneh. - Saleem khresha. 1 P a g e

Transcription

1 Dergam Al-Tarawneh - - Saleem khresha 1 P a g e

2 This will be an exact replica of what Dr. Saleem said because weʼve already experienced that even if the science says something you should always consider his info correct. The doctor started with some true or false questions and they are : First : donor blood is usually collected into warfarin/heparin which acts as an anticoagulant (True or False)? FALSE and the correction is : The donor blood is collected into ACD ( Acid Citrate Dextrose ) this is the best anticoagulant to use for the survival of RBCs. Sometimes it s written as CPD ( citrate phosphate dextrose ). In the previous lecture we ve mentioned that one of the complications that might occur during blood transfusion is citrate toxicity how is that? What happens is that when the blood transfusion is done in a fast manner that citrate wonʼt have the time to be converted into bicarbonate so the patient dies from the lack of ionized calcium ( CITRATE TOXICITY ). Second : most antibodies of incompatible blood transfusions are due to failure to check identical (True or False)? True. ( the doctor didn t give any extra info, he just said it s true ) Third : The sera of blood group O babies usually absence from antibodies ( True or False)? True : newborns with O blood group there is an absence of antibodies for almost the first two months and sometimes they are not formed at all. 2 P a g e

3 Now, The doctor started talking about an example of phenotypic Recognition of the newborn blood characteristics : Fatherʼs phenotype ANNRh Motherʼs phenotype BMNrh Child phenotype Which test is best used to exclude incompatibility? CROSS MATCH TEST : to exclude any incompatibility. The results excludes paternity (the father says that the child isn t his ) How can we make sure? To give our results we will now see the genotype probabilities for the father and the mother : Father : AANN AONN AANN AONN Mother : BBMN BOMN BBMN BOMN The child genotype OONN Now and that we ve concluded that the child gamete is OO NN RhRh,We know that an ONRh gene is present in the father gamete and the mothers gamete as well So ultimately the paternity could not be excluded and the child is the manʼs son. 3 P a g e

4 Note : in the previous example we ve seen that MN & NN were not changed and that is because they are DOMINANT TRAITS, that cannot be changed. Fourth: after blood had been stored for about three weeks at least 70% of transfused RBCs will be retained in the circulation after 24 hours after transfusion ( True or False)? True : there is no 100% 13 so the answer is approximately true. Note : we usually use blood after two weeks its very rare to use it after three weeks, in two weeks old blood 80% of the RBCs are retained. So in normal conditions 1 to 2 weeks old blood is usually used but the 3 to 4 weeks old blood is used in extreme conditions such as wars only, taking in consideration that hyperkalaemia might occur leading to an increase in potassium ion in blood leading to arrhythmias and eventually cardiac arrest and death in worst case scenario. The lymphatics of the digestive system : Itʼs associated with the process of fat absorption but the question here is why fat? Itʼs because that fat molecule are large in size so they canʼt pass through capillaries so instead they pass through the gap in the Lymphatic capillaries. Now how does substances go in and out of capillaries and vessels in the arterial and venous ends? - In the arterial end the blood pressure is 32 and the colloidal osmotic pressure is 28 so filtration happens ( movement of substances out of the vessels to the tissues) - At the Venous end the blood pressure decreases to 16 and colloidal pressure doesn t change so osmosis occurs ( the substance return from the interstitial spaces to the vessels by osmosis) After osmosis little of plasma and proteins remain in the tissue these remaining go into lymphatics ( the lymphatic system clears the interstitial space ) 4 P a g e

5 Note : lymph fluid that enters the lymphatic vessels drains venous blood via thoracic and right lymphatic duct. Now we know that the plasma clots so lymph also clots since lymph is also plasma (so it contains clotting factors) but this clotting depends on the protein content of the plasma that differ by location (highest in the liver) so the tissue with the highest concentration of proteins may be susceptible to lymphatic clotting. We have already mentioned that water insoluble fats are absorbed in intestines to the bloodstream (the doctor kept repeating this piece of info over and over ) lymphocytes in circulation comes from lymphatic tissue and vessels so in the thoracic duct there is an appreciable amount of lymphocytes. No lets talk about the components of the lymphatic system : As we know they are : Lymphatic organs Lymphatic vessels Lymph nodes Lymphatic ducts Now the doctor started to describe what is called Typical Lymphatic Pathway which is : Lymphatic system drains the interstitial spaces cleaning them then The substances cleared moves as lymph in lymphatic capillaries that merge with other capillaries to form afferent lymph vessels then it goes to lymph nodes where the lymph is filtered then moves through efferent lymphatic vessels to meet up with multiple other vessels to from the lymphatic trunk that merge with other trunks and joins the collecting duct then subclavian vein to enter the blood. 5 P a g e

6 The doctor started talking a bit about histology mentioning lymphatic related organs such as : Spleen tonsils and thymus. The doctor said that these organs aren t related to Lymphatic system in a 100% way. And he mentioned some of the tissues that lack lymphatic vessels such as : CNS cornea of the eye bone marrow epidermis portion of the spleen and a avascular tissues Flow of lymph: ( doctor Saleem said that the following informations are very very important so pay good attention ) Lymph, like venous blood, is under relatively low pressure and may not flow readily through the lymphatic vessels without the aid of outside forces. These forces include: Contraction of skeletal muscles Pressure changes due to the action of breathing muscles Contraction of smooth muscles in the wall of larger lymphatic vessel 6 P a g e

7 The most important functions of the lymphatic system: Return of excess filtered fluid, normally capillary infiltration exceeds reabsorption by about 3 liters per day (20L filtered, 17L reabsorbed). Defense against disease, the lymph percolates through lymph nodes located on rout within the lymphatic system. Bacteria from interstitial fluid are destroyed by phagocytic cells in lymph nodes. Transport of absorbed fat from the digestive tract Return of filtered protein, most capillaries permit leakage of some plasma proteins during filtration, These proteins cannot readily be reabsorbed back into the blood capillaries but they can easily gain access to the lymphatic capillaries. Edema is a condition caused by accumulation of fluid (as well as proteins) in the interstitial compartment. Probable causes of edema 1. High capillary pressure Higher than normal amount of fluid is filtered Not the whole filtered blood will return back to the capillary 2. Low blood protein (low protein pressure) The low protein pressure causes less than normal amounts of fluid to return back by osmosis from the interstitial spaces 3. Lymphatic blockage Some parasites can block lymphatics and thus prevent fluid from returning back to the circulation. 4. Increased capillary porosity (Increase in the diameter of capillary pores) Same consequences as in the first cause Sorry for any mistakes Thank you 7 P a g e