BLOOD Physiology 2024 PDF

DL 27 Liyan Khashan Rahma Almadany Eba’a Al Zayadneh  BLOOD ‫ مكوناته‬، ‫رح نحكي عن وظائف الدم‬ ‫و بعض خصائصه … بغض النظر‬...

DL 27 Liyan Khashan Rahma Almadany Eba’a Al Zayadneh  BLOOD ‫ مكوناته‬، ‫رح نحكي عن وظائف الدم‬ ‫و بعض خصائصه … بغض النظر‬ ‫عن عدد الساليدات لكن المحاضرة‬ )): ‫خفيفة ان شاء هللا‬ Functions of the Blood: 1. Transportation of elements: O2, CO2, nutreints, Wastes, and Hormones (endocrine). 2. Regulation of various things: ▪ pH levels: its very narrow range and has to be throughly controlled, buffers are usually used (Co2 and bi-crabonate are big players in pH regulation along with the lungs, kidneys and blood.) ▪ Temperature: surface level blood vessels normally vasodilate (expand) when faced with higher than normal body temperature (fever), this occurs in order to lose the extra heat. The opposite happens when the temperature drops lower than normal, the vessels constrict (shrink) so they reserve as much heat as they can. The blood’s fluidity and various other features make this possible. ▪ Blood Pressure: The blood volume is directly proportional/related to blood pressure, so a higher blood volume, means a higher Bp and vice versa. A low blood pressure is harmful, as it means there’s no enough driving force for the blood to reach its target vital organs. A higher Bp has its own share of negative effects, first, its harmful for the blood vessels, which includes raptures (leaking) and thromboses, secondly, this also causes trouble for the heart as there will be higher load on it as it will need to pump against a higher resistance when there’s a rather high Bp. This lead the  blood to work harder, which creates strain on the cardiac muscles, which is obviously harmful. ▪ Osmotic Pressure: blood is composed of lots of large proteins, in case of having these proteins unable to move from one compartment to another, this creates an osmotic (oncotic colloid) pressure. this pressure is very important for fluid homeostasis. So as things stand, the osmotic pressure should always remain in equilibrium, any change of it on either side, this will cause a shift in the fluids and a change in fluid volume within the compartments. This is especially important during the exchange between the capillaries and the Interstitial fluid, because if there’s no enough Osmotic pressure in the blood vessels, then theres no enough pressure for the fluids to go back to the circulation from the Interstitial fluid. Loss of protein from the blood causes a plummet in the osmotic pressure, normally the fluids that left the capillaries, should be re-absorbed back into circulation, but there wont be enough net- reabsorption force, so the fluids will accumulate in the Interstitial spaces, which causes diseases like ascites in the abdomen and edema. ‫ بينخفض الضغط األسموزي في األوعية‬، ‫ لما يفقد الدم البروتينات الخاصة فيه‬:: ‫توضيح‬ ‫الدموية هاد الضغط كان سبب لجذب السوائل من األنسجة المحيطة إلى األوعية الدموية لكن‬ ‫ ما رح تقدراألوعية الدموية من سحب السوائل بشكل كافي من‬، ‫لما انخفض هاد الضغط‬ )‫ و يسبب الوذمة (التورم‬،‫ و هاد يؤدي إلى تراكم السوائل في الفراغات بين الخاليا‬،‫األنسجة‬ )):‫يُطلق عليه اسم االستسقاء (مش مهم بالعربي‬،‫في حالة تراكم السوائل في التجويف البطني‬ ▪ Volume: blood is an important component of the extracellular fluid and thus it plays a big role in the total volume of bodily fluids. Kidney is the main site of volume regulation of blood. Blood volume is directly related to blood pressure.  : ‫نتابع وظائف الدم‬ 3. Protection: ▪ Clotting (coagulation): when there’s a cut in the body, certain components of the blood take action and close off this cut, preventing blood loss. Clotting also protects the body by stopping any foreign pathogens from entering the body through these cuts. ▪ Immune system: protects the body against the invading micro-organisms. ▪ Proteins: many proteins have protective roles, as some proteins protect the body against some harmful elements and ions, however these ions are needed by the body, however they’re needed in one place only and shouldn’t move around, these proteins keep these ions confided to where they are needed. An example of this is Iron, its very reactive and thus it should be bound to a transporter protein. Composition of blood If we have a sample of blood in a tube, and place this tube very quickly in a machine called centrifuge, and by centrifugation (a very fast shaking), the blood components will separate accordong to density. There will be three layers, the thickest and most dense one has a bright red color; it contains the Red Blood Cells. The second layer; called the Buffy layer (of white color) is composed of the White Blood Cells and Platelets. The top layer is a clear yellowish fluid called Plasma. If coagulation is done to the sample beforehand, the top layer)plasma) is called serum. 45% of volume and weight of the blood is RBCs. This % is called hematocrit or Packed Cell Volume (PCV). The top layer (plasma) shapes up around 55% of total blood volume. White Blood Cells and Platelets are less than 1% so they are normally included in the 45% when asked about the total % volume of blood cells in general. Fluids of our body shape up around 67% percent of our total body mass, out of these 67% the blood is only 8% and even out of these 8% plasma is 4-5% Plasma is mainly made of water, along with dissolved substances. The main protein dissolved in the plasma is called Albumin, it makes up around 54% of the total proteins in the plasma. Other proteins like globulins and fibrinogen are also dissolved in the plasma. Other solutes can be found dissloved in the plasma But in a much lower %, examples are Sodium Chloride, Glucose, fatty acids, hormones, O2 and CO2 as well as waste products like Urea and Ammonia.  FORMED ELEMENTS The formed elements are cells and cell fragments suspended in the plasma, theyre divided into three classes: 1. Red Blood Cells (Erythrocytes) In one microleter (10^-6, 1/50 of a singular drop) an approximate of 5 million RBCs can be found. This range is not set in stone as: gender, age, weight and diseases can all affect it, but we are talking approximation. Out of all 3 classes of formed elements, RBCs make up 99%. RBCs are bi-concave in shape 2. White Blood Cells. (Leukocytes) The remaining 1% is both WBC and Pltls combined. In one microleter around 5000-10,000 units of WBCs can be found. This range can also change in case of infections and inflammations. There are many types of White blood cells; Neutrophills are the major type in terms of numbers, 60-70% of WBCs are neutrophills. Neutrophills have multi lobules. Lymphocytes make up 20-25%, lymphpcytes have even further types: B-lymphocytes, T-lymphocytes, and Natural Killers. Monocytes (mature into microphages), are kidney shaped. Eosinophills. (reddish in color) Basophills. (blue colored)  3. Platelets (Thrombocytes) In one microleter around 150,000-400,000 units of each can be found. This range can also change in case of infections and inflammations. Platelets are not full cells, they're parts of cells, or rather fragments. PHYSICAL CHARACTERISTICS OF THE BLOOD 1. Normal temperature is 38°C 2. It’s viscous and sticky 3. It’s slightly alkaline, as the pH’s range is 7.35-7.45 4. The blood’s color depends on the Oxygen saturation, so the more saturated it is, the brighter the color red is. The less oxygen the darker the color is.  5. It’s 20% of ECF, 80%by weight. 6. Blood volume: 5-6 in males , 4-5 in females / Body size. 7. Hormonal regulation : RAAS , ANP , ADH. Q: Are all blood sample tubes the same ? And procedures ? Ans : There are different tubes that differ in color for each sample of blood, that segregation depends on the bloody type or the specific test it will undergo. For an instance, a test might require a blood that shouldn’t coagulate, so we simply add an anti-coagulant. If we need the sample to coagulate, we simply do nothing because once a sample is left alone It will start coagulating on its own, just like an injury. This is done when we need the serum rather than the plasma. Serum is simply plasma without fibrinogen and coagulation factor. :: ‫توضيح للكالم في األعلى‬ ‫يتم وضع الدم في أنابيب بألوان مختلفة حسب نوع االختبار المطلوب‬ ‫ ليش ؟؟؟‬، ‫ ف ما بنضيف أي شيء‬، ‫ أما إذا كان بده دم يتجلط‬. ‫ يتم إضافة مادة مضادة للتجلط‬،‫مثلا إذا كان االختبار بده دم ما يتجلط‬ ‫ هذا يحدث عندما نحتاج إلى المصل‬، ‫ألنه بمجرد ترك العينة لحاله الدم ببلش يتجلط تلقائيًا زي اللي بصير باإلصابات لما تنجرح مثلا‬.) ‫بدالا من البلزما ( يعني لما بدنا نحصل على مصل بنخليه يتجلط ف بينفصل المصل عن الخثرة المتجلطة‬ ‫ طيب ليش بدون الفيبروجين ؟؟؟ ألنه الفيبروجين تم استهلكه في عملية تكوين‬. ‫المصل هو البلزما بدون الفيبروجين وعوامل التجلط‬ )): ‫الخثرة (يساهم في عملية التجلط مع عوامل التجلط أكيد‬  Methods of extracting blood: 1. Venipuncture: penetration of a vein with a needle. 2. Finger or heel stick: pricking the finger tip. 3. Arteriole stick: can be done to measures gases in artries. Blood is considred to be a liquid connective tissue. The interstitial fluid has a feature that allows it to constantly renew, this renewal happens when the exchange between it and the blood vessels occur. The body cannot possibly rely on the dissloved O2 in the plasma, and this is exactly where the RBCs (erythrocytes) come into play, their main function is to transport oxygen throughout the body, as it has a special mechanism and component that allow this to happen, name the Hemoglobin (it’s an excellent acid-base buffer( So RBCs ( carry hemoglobin, bearing O2 to the tissue) Also, RBCs have an enzyme called carbonic anhydrase, this enzyme facilitates (catalyzed) the reaction between CO2 and H2O to give us carbonic acid (H2CO3). Without this enzyme this reaction is impossible to happen. CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻ The carbonic acid will then dissociate into H+ and bicarbonate (HCO3-), this allows large amounts of CO2 to be carried in solution as (HCO3- ). This increases the efficiency of transporting CO2. ‫هذه العملية تساعد‬ ‫في ذوبان ثاني أكسيد‬ ‫تمت كتابة هذا الشيت عن روح والدة الزميل عمرو رائد من دفعة تيجان‬ ‫الكربون بكميات أكبر‬ ‫اللهم ارحمها و اغفرلها ووسع ُمدخلها‬ ‫ مما يسهل‬،‫في الدم‬ ‫نقله إلى الرئتين‬ ‫للتخلص منه‬