Anatomy and Physiology Ch 17: Blood

Red Blood Cells Breakdown

* life span of a red blood cell is 100 -120 days because they do not have dan so can't repair themselves - red blood cells are anuclete so can not synthesis new proteins or grow and divide -ols red blood cells become fragile and the hemoglobin been to degenerate -can get trapped in smaller circulatory channels especially in the spleen because they can not change shape anymore -macrophages in the spleen engulf and breakdown during red blood cells. - when the red blood cells is broken down the heme, iron and globing are separated. the iron binds to ferritin or hemosiderin and is stored for used.. the heme is degraded to yellow pigment bilirubin. the liver secretes bilirubin in the bile into the intestines where it degraded again into urobilinogen and then it transformed into a brown pigment stercobilin that leaves body in feces.. the globing is metabolized into amino acids and released into circulation.

steps in becoming an arganulocyte

- monocytes are derived from a myeloid line, it goes from mono blast to promonocyte before lean the bone marrow and becoming a monocytes. they share a common presecutor with neutrophils can they can live for several months. - lympoctyes - are derived from lymphoid line. T lymphocytes precursors give a rise to immature T lymphocytes that leave the bone marrow to mature in the thymus. B lymphocyte precursors give rise to immature B lymphocytes that mature in the bone marrow, Lymphocytes live from a few hours to decades. many hematopietic hormones (EPO and CSFs are clinically used. they can stimulate the bone marrow of cancer patients that are receiving chemotherapy and stem cell transplant to make more formed elements. this is also used to increase the protective innune system in AIDs patients.

Production of Erythrocytes

-Hematopoiesis is the formational of all blood cells - red blood cell formation occurs in the red bone marrow; which is composed of reticular connective tissue which borders a wide blood capillaries called the blood sinusoids. the red bone marrow is found in axial skeleton, girdles and the proximal epiphyses; pf humerous and femur. with in this network are immature blood cells, macrophages, fat cells amd reticular cells which secrete connective tissue fibers. -hematopietic stem cells are known as hemocytoblasts. the stem cells give rise to all formed elements. the hormones and growth factors such the cell towards a specific pathway of blood cell development. tonce the immature blood cell is committed to a certain blood cell development they can not change.which is why the growth cell and hormones such the cells towards its specialization. the new blood cell than enters the blood sinusoids

Erythrocyte Disorders

-Most erythrocyte disorders are classified as either anemia ( to little red blood cells) or polycythemia ( to many red blood cells. 1) Anemia iron deficiency anemia pernicious anemia renal anemia aplastic anemia thalassemais sickle cells anemia 2) polycythemia

Blood Transfusions

-cardiovascular system minimizes effects of blood loss by: 1) reducing volume of affected blood vessels (constrict blood vessels) 2) stepping up production of red blood cells. ( erythropoiesis) the blood can compensate for only so much blood loss. loss if 15 - 30 % of blood causes pallor and weakness. Loss of more than 30% of blood results in potential fatal severe shock ( not enoug blood left pump around body) RESTORING BLOOD VOLUME - the blood volume needs to be replaced immediately to restore adequate circulation when blood levels are low. Fundamentally, blood consists of proteins and cells sus- pended in a salt solution. Replacing lost blood volume essen- tially consists of replacing that isotonic salt solution. Normal saline or a rnultiple electrolyte solution that mimics the electro- lyte composition of plasma (for example, Ringer's solution) are the preferred choices. Volume replacement restores adequate circulation but can- not, of course, replace the oxygen-carrying capacity of the lost red blood cells. To date, only transfusion of red blood cells can do that (see below), but research on ways to replace that capa- bility by using artificial blood substitutes is ongoing. TRANSFUSING RED BLOOD CELLS - whole blood cell transfusions are used only when blood loss is rapid and substantial. infusions of packed red blood cells or PRBCs ( plasma and WBCs removed) are preferred to restore oxygen carrying capacity. blood banks usually separate donated blood into comments and the shelf life of blood is 35 days. . The usual blood bank procedure involves collecting blood from a donor and mixing it with an anticoagulant that prevents clotting by binding calcium ions Human blood groups of donated blood must be determined because transfusion reaction can be fatal. blood typing determines gross. Because blood is such a valuable com,nodity, it is rnost often separated into its component parts so that each cornponent can be used when and where it is needed. human blood groups - red blood cells bear different antigens. antigens are anything perceived as foreign that can generate an immune response. red blood cell wntigen are referred to as aggluatonogens because promote agglutination. mismatched transfused blood is perceived as foriegn and may be destroyed. it is also potentially fatal. humans have at least 30 naturally occurring Red blood cell antigens. the presence or absence of each antigen is used to classify blood cells into different groups. Some blood groups (MNS, Duffy, kell, and lewis) are only weak angulation it is not usually types unless patient will need several transfusions. antigens of ABO and Rh blood groups cause most vigorous transfusion reactions; therefore, they are major groups typed. ABO blood groups are based on the presence or absence of two agglutinogens (A and B) on the surface of the red blood cells. Type A has only A agglutinogens. Type B had only B agglutinins. Type AB has both A and B agglutinogen and Type O has neither A nor B agglutinogens. blood may contain preformed anti A or anti B antibodies which are called agglutinins and they act against transfused red blood cells with ABO antigens not present on the recipients red blood cell so if you put B in an A antigen then the agglutinins attack the B antigen necause you have B antibodies. so if you are AB you do not make antibodies. anti A or Anti A form in blood aboutt 2 months of age and they reach adult level by 8 to 10 years old O is most common AB is least common is US RH blood groups- there are 52 named RH agglutinogens which are known as Rh factors. C,D and E are the most common types of Rh factors. Rh+ indicates the presence go D antigens and 85% of Americans are Rh+. 15 % are Rh- which means they do not carry D antigen. Anti-Rh antibodies are in Rh- individuals and not RH+ individuals, but you don't have to because if you aren't expose to red blood cells with a RH+. Anti-Rh antibodies are formed if an Rh- individuals receive Rh+ blood or if RH- mom is caring and Rh+ fetus. Second exposure to Rh+ will result in typical transfusions reactions not the first time because body takes time to react and start making antibodies. Transfusion reactions - occur if mismatched blood is infused. the donor cells are attacked by the recipients plasma agglutinin. the agglutation of foreign red blood cells clog small vessels. after a few hours cells begin to rupture and relaease hemoglobin into the bloodstream. that results in dinminshes oxygen carrying capacity, decreased blood flow beyond blocked vessel and hemoglobin that is not confined in a cell is toxic to the kidney tubules can lead to renal failure. some symptoms of a transfusion reaction includes fever chills low blood pressure rapid heartbeat nausea and vomiting. treatment is preventing kidney damage with fluids and diuretics to washout hemoglobin. Type O is the universal donor and it has no A and B antigens and Types AB is the universal recipients with no anti A or anti B antibodies, this is sometimes misleading because other agglutinogens that cause transfusion reactions must be considered, Autologous transfusions are when patient predates own blood that is stored for when they need it

steps of becoming a granulocyte

1) myeloblast - they arise from myeloid stem cells 2) promyelocytes: accumulate lysosomes 3) myelocytes - accumulate granules 4) band cells nuclei form a curved arc. 5) mature granulocytes nuclei become segemented before being releases in the blood Just before granulocytes leave the marrow and enter the circulation, their nuclei constrict, beginning the process of nuclear segmentation. 10x more are stored in the one marrow than in the blood 3x more white blood cells are formed than red blood cells because white blood cells have a shorter life because it is cut short by fighting microbes.

Polycythemia

An abnormal excess of red blood cells which increase blood velocity and causes sluggish blood flow. -polycythemia vera: Bone marrow cancer leading to excess red blood cells. hematocrit may go up to as high as 80%. blood volume may double causing the vascular system to become engorged with blood and severely impairing circulation. treatment includes thearuputic phlebotomy ( which . people with polycythemia also complain of dizziness. -secoundary polycythemia is caused by low oxygen levels an example of low oxygen levels if high altitudes. It is seen in people that live in high altitudes because it is a physiological response to the reduced atmospheric pressure and lower oxygen content of the air in such areas. RBC counts of 6-8 million/μ! are common in such people. another cause of secondary polycythemia is increased EPO production. -blood doping -is practiced by athletes competing in aerobic events it artificially induces polycythemia. it is when red blood cells are removed from the athletes body which makes more red blood cells to be made and then stored. after that the red blood cells and reinfuse red blood cells back into the blood. before an event to increase oxygen levels for stamina. Since red blood cells carry oxygen, the additional infusion should translate into increased oxygen-carrying capacity due to a higher hematocrit, and greater endurance and speed should result. Other than the risk of stroke and heart failure due to high hernatocrit and high blood viscosity, blood doping seems to work

The Composition of Blood

Blood is the only fluid in the body and it is a type of connective tissue. blood is a which homogenous liquid. blood also has cellular and liquid components. The blood has a matrix which is known as the plasma. The cells found living in the blood that are known as blood cells are called formed elements. the formed cells are found in the plasma. blood lacks collagen and elastic fibers typical of other connective tissues, but dissolved fibrous proteins become visible as fibrin stands during blood clotting. when we spin blood in the centrifuge more mass goes to the bottom and lighter things go to the top. reb blood cells are found at the bottom go the tube they transport oxygen. this is the most dense and it made up of erthrocytes ir accounts for 45% of the total volume of blood in a sample. the Buffy coat is next and it is made up of leukocytes and platelets it accounts for less than 1% of whole blood in the sample. white blood cells act in various ways to protect the body and platelets are cell fragments that stop the bleeding. the plasma is at the top and it is least dense it accounts for 55% of whole blood in the sample. cellular water and proteins are found in this section. the hemacrit is the percentage of the sample in the blood sample. The formed elements includes erythrocytes which are red blood cells. leukocytes which are white blood cells platelets

Blood Plasma

Blood plasma is straw colored sticky fluid it is made up of 90% water. this water is useful because it is a solvent and a lot of things need to be dissolved in the water. the water also helps dissolve heat it contains nonprotein nitrogenous substances which are by products of cellular metabolism such as urea, ureic acidd, creationine and ammonium salts. it containes over 100 dissolved solutes like nutrients, gases, hormones, waste, ( nucleic and amino acid breakdown products, carbon dioxide) proteins( around 150) , inorganic ions.( sodium poutasim, chloride, calcium magensium and iron these are electrolytes) Electrolytes vastly out number the other solutes. helps maintain normal blood ph and osmotic pressure. electrolytes have cations and anions cations include potassium calcium and magnesium anions include chloride phosphate sulfate and bicarbonate plasma proteins are most abundant solutes they remain in the blood and are not taken up by cells. the protiens are mostly produced by the liver except for hormones and gamma globulins. . plasma proteins account for about 8% of plasma weight. Plasma proteins have a lot of functions. they are used as fuel or metabolic nutrients as or other organic solutes, such as glucose, fatty acids and amino acidd Albumin is a types of plasma protein It makes up 60% of plasma proteins. The functions is a carrier of other molecules so it has hypnophobic areas that help transport fatty acids to move things out and into the cell , as a blood buffer of the Ph ( For example, when blood protein levels drop undesirably, the liver makes more proteins. When the blood starts to become too acidic (acidosis), both the lungs and the kidneys are called into action to restore plas,na's normal, slightly alkaline pH.) and the main contributor to plasmic osmosis pressure contributes to plasma osmotic perssure by drawing water in the blood globulins - 36% of plasma pressure proteins consist of alpha and beta and gamma . alpha and beta are produced by the liver and most are transport proteins that bind to lips, metal ions and fat soluble vitamins gama are antibodies released by the plasma cells during an immune respons. antibodies found in gamma fibrinogen is 4% of plasma proteins it is produced by the liver and it forms fibrin threads of blood clot

blood typing

Donor blood is mixed with antibodies against common agglutinogens. If the agglutinogen is present that clumping of red blood cells will occur. Blood is typed for ABO and Rh factor in the same miner. Cross matching is typing between specific donor and specific recipient. so you mix the recipients serum with the donor red blood cells and you mix the recipients red blood cells with the donors serum to make sure that they won't agglutinate.

Stages of Erythropoiesis *but still the production of erythrocytes*

Erythropoiesis is a process of the formation of red blood cells that takes around 15 days. the stages of the transformations begins when the 1) hemotopoieitic stem cells transforms into myeloid stem cells 2) the myeloid steam cells transforms into proerythrobllast 3) proeryblast divides many times transforming into basophilic erythroblast 4) basophilic erythroblast synthesize many ribosomes, which stain blue 5) then the cell becomes a Poluchromatic erythroblast and that synthesize large amounts od red- hued hemoglobin; cells now shows both pink and blue areas. 6) Then cell becomes Orthochromatic erythroblast which contain mostly hemoglobin so it appears pink and ejects most of the organelles the nuclei degrades causing the concave shape 7) then cell becomes reticulocytes and still contains a small amount of ribosomes 8)mature into a erythrocytes in 2days the ribosomes degrades transforming it into a mature red blood cell the reticulocyte count indicates the rate of red blood cell transformation do not need to know what comes first what need to know - stem cell is a large cell that has organelles with no hemoglobin. then it becomes small ell with little to no organelles and a lot of hemoglobin large number of ribosomes to make proteins which makes the cell blue and it makes a lot of hemoglobin which makes cell pink and blue then it ejects the nucleus which makes the cell blue then the ribosomes are removed to become a red blood cell

types of white blood cells

Granulocytes- there are three types: neutrophils, eosinophils and basophils. - they are larger and shorter-lived than red blood cells. they are sperhical in shape. their nuclei is lobed rather than circular. the cytoplasmic granules are stained with quite specifically Wright's stain. and they are all phagocytic ( take in waste ) to some degree. Nuetrophils- it is called that because they are neutral due to acid or basic. are the most numerous white blood cell. they account for 50 to 60 % of white blood cells and is about twice of the size of red blood cells. the granules are stained with both acid( red) and basic ( blue )dyes which makes a lilac color. granules that are larger contain wither hydrolyticc enzymes( which are regarded as lysosomes) or the smaller ones contain antibacterial proteins called defenses. they can also be called polymorphononuclear leukocytes ( PMNs or polys) the cell can have anywhere from three to six lobes in the nucleus because the nucleus is lobular. They are very phagocytic and are referred to as bacteria slayers. there numbers increase in an acute bacterial infection like menegiites or appendities. they are chemically attracted to areas with inflammation, they include bacteria in an vesicle called phagosome. they kill microbes by a process called respiratory burst. respiratory bust is when the cell uses oxygen to synthesize potent oxidizing substances ( bleach or hydrogen peroxide) defense granules merge with phagosomes and from spears that price holes in the membrane of the ingested microbe, Eosinophils - they account for about 2 to 3 % of all leukocytes. there nucleus has two lobes that are connected by a broad band that resembles earmuffs. granules are stained red. the granules ar elymsomes like and filled with digestive enzymes. however unlike other lysosomes they lack enzymes that specially digest bacteria. the most important thing eosinophils do is that they release enzymes on large parasitic worms ( like flatworms and round worms) that are too large to be phagocytized and they digest the surface of the worm (These worms are ingested in food (especially ra\v fish) or invade the body via the skin and then typically burrow into the intestinal or respiratory mucosae. Eosinophils reside in the loose connective tissues at the same body sites, and when they encounter a parasitic worm "prey," they gather around and release the enzymes from their cyto- plasmic granules onto the parasite's surface, digesting it away.) they also play a role in allergies and asthma as well as immune response modulators in the immune system. Basophils - are the rarest forms of white blood cells the account for 0.5 to 1 % of white blood cells. the nucleus is deep purple that is shaped like a S or U with one to two constrictions. the large purplish black granules contain histamine. Histamine is an inflammatory chemical that acts as a vasodilator ( which makes the blood vessels dilate bigger) and attracts white blood cells to inflamed sites. Antihisamies counter this affect. the function of basophils are similar to mast cells because once a basophil gets into the tissues it is known as a mast cell. Although mast cell nuclei tend to be more oval than lobed, the cells are similar microscopically, and both cell types bind to a particular antibody (irnrnunoglobu- lin E) that causes the cells to release histamine. However, mast cells and basophils arise from different cell lines. Arganulocytes - lack os visible cytoplasmic granules. both have spherical ( lymphocytes ) or kidney shaped nuclei( monocytes) , there are two types lymphocytes and monocyte. even though they look similar. they have different functions and unrelated cells types. lymphocytes - are the second most numerous white blood cells and it accountss for about 25%, it is a large dark purple and circular/ spherical nuclei with a thin rim of blue cytoplasm. it is mostly found in lymphoid tissue ( an example would be lymph nodes and the spleen)., but a few circulate in the blood. they are crucial to immunity. there are two types of lymphocytes.: T lymphocytes ( Tcells) and B lymphocytes ( B cells). T cells act against virus infected cells and tumor cells. B cells give rise to plasma cells which produce antibodies. T cells and B cells can not be told the difference because they look alike but have different functions. Monocytes - is the largest of the white blood cells and account for 3 to 8 % of all white blood cells. they have a lot of pale blue cytoplasm. they also have dark purple tanning and U kidney shaped nuclei. they leave circulation and enter the tissues and differentiate into macrophages. macrophages are actively phagocytic cells that are crucial against the fight of virus, intracellular bacterial parasite and chronic infections. macrophages also eat red blood cells that are dying. macrophages activate lymphocytes to mount an immune response

General Structure and Functional Characteristics

Leukocytes or white blood cells are the only formed elements that are complete cells with a nuclei and organelles. they make up for less than 1% of the total blood volume which is abound 4,800-10,800 per ul of blood. the main function of the white blood cell is to fight against disease. unlike red blood cells which are confined int the bloodstream and carry out their functions in the blood stream. they can leave through capillaries by diapedesis (leaping across) . They can also more through tissues by amoeboid motion and they follow a positive chemotaxis.( they are responding to a sort of chemical) a white blood cell over the count of 11,000 per ul is known as leukocytosis. this condition is a normal response to an infection in the body. white blood cells are grouped together in two major categories: granulocytes and arganulocytes. granulocytes contain visible cytoplasmic granules (secrete vessels ) - neutrophils - eosinophils - basophils arganulocytes do not contain visible cytoplasmic granules -lympoctyes -basophils when students are asked to list the white blood cells in order from most to least adunbant. they should remember ( never let monkeys eat bannas) neutrophils, lymphocytes, monocytes, eosinophils and basophils. *do not need to work about.

Function of Erythrocytes

RBC are dedicated to respiratory gas transport hemoglobin binds reversibily with oxygen which means in the lungs the red blood cells needs to pick up the oxygen and than brings the oxygen to the tissues when he oxygen reaches the tissues the oxygen has to leave the hemoglobin and red blood cells and get into the tissue. so the oxygen needs to be able to leave and enter the cell. that the it is the protein that a makes red blood cells red. most of the oxygen carried in the blood is bound to hemoglobins. normal values of hemoglobins is 13-18g/100 ml for makes and 12016/100ml for females hemoglobin consist of red heme pigment bound to the protein globing globin is composed of four polypeptide chain which are two alpha and two beta, each globing is is bounded to a heme pigment A heme/ group pigment is bonded to each globin chain and it gives the blood the red color and each heme's central iron atoms binds to one oxygen. the iron is found in the center of the heme group. and it is the heme group with the iron in the middle is what allows the irevrisbilty go the oxygen and cos in the hemoglobin each hemoglobin molecule can transport four oxygens because each iron atom can combine reversibly with one molecule of oxygen. each red blood cell contains 250 million hemoglobin molecules. so each of the red blood cells can scoop up 1 billion molecules of oxygen the fact that hemoglobins are contained in the red blood cell instead of the plasma prevents it from leaking out of the blood stream ( through porous capillary walls) and clogging up the kidneys. Large amounts of free hemoglobin in the blood \vould also make blood more viscous and would draw water from the tissues into the bloodstream by osmosis. oxygen is loaded on the hemoglobin from the lungs and it produces oxyhemoglobin ( Rudy red). it produces oxyhemoglobin because the iron is partially oxide by the oxygen. the oxyhemoglobin is a three dimensional shape. so hemoglobin turns into oxyhemoglobin. oxygen diffuses from the air sacs of the lungs into the blood and then into the red blood cells where it binds the iron in the hemoglobin. oxygen is unloaded into the tissue which produced deoxyhemoglobin or reduced hemoglobin (dark red) Oxygen detaches from the iron, hemoglobin regains its former shape resulting in it being deoxyhemoglobin. then the oxygen diffuses from the blood into the tissue fluid than into the tissue cells. the carbon dioxide is loading on the hemoglobin from the tissues. 20% of carbon dioxide in the blood but it binds to the globing amino acids rather than the heme group which is called carbaminohemoglobi. carbaminohemoglobin occurs much better when the hemoglobin is already in its reduced or deoxyhemglobin state ( which means dissaociated from oxygen. carbon dioxide occurs from tissue to lungs *does not examplian how like the others.

Disorders of Hemostasis or If blood does not clot correctly

There are two major types of disorders. Thromboembolic disorders result in undesirable clot formation. and Bleeding Disorder which is abnormalities that prevent normal clot formation. Disseminated intravascular coagulation (DIC) involves both types of disorders which is a wide spread clotting and serve beeding. THROMBOEMBOLIC DISORDERS - thrombi and emboli. the thrombi is a clot that developed and persist in unbroken blood vessel it may blood circulation which can lead to tissue death. Embolus is a thrombus th breaks away from the bloodstreamat is moving freely in the blood stream and Embolism is when an emblus is obstructing a vessel EX pulmonary emboli. risk factors include atherosclerosis, inflammation cause thromboembolic disease by allowing platelets to gain a foothold, slowly flowing blood or blood stasis from immobility particularly in bedridden patients and those taking a long flight without moving around. In this case, clotting factors are not washed away as usual andaccumulate, allowing clots to form. Anticoagulant drugs that can prevent thombombolic conditions or undesirable clotting include aspirin which is an antidepressant that inhibits thromboxane A2. Heparin which is an anticoagulant used clinically for pre and postoperative cardiac care. warfarin ( Coumadin) which is used for people irone to atrial fibrillation and it interferes with action of vitamin K Because treatment with warfarin is difficult to manage, the introduction of direct oral anticoagulants using other mechanisms has been welcomed. Dabigatran directly inhibits thrombin. BLEEDING DISORDERS - thrombocytopenia is a dfienct number of circulating platelets. in severe cases petechiae which are purplish sptsappears as a result of spontaneous, widespread hoemorage. thrombocytopenia can happen due due to suppression or destruction of red bone marrow ( example radiation, maliginary or drugs) planet count is less than 50,00 ul. treatment usually involves transfusion of concentrated platelets. impaired liver function is another bleeding disorder there is an inability to synthesize procoagulants ( clotting factors ) and it causes include a vitamin K deficiency, hepatitis or cirrhosis. liver disease can also prevent liver from producing bile which is needed to absorb fat and vitamin K. Hemophilia is another factor of a bleeding disorder which incluedes several similar hereditary bleeding disorders: hemophilia A is the most common type and is 77% of all causes it is due to a factor VIII deficiency. Hemophillia B is a IX deficeny. Hemophillia C is a factor XI defeincy it is much milder than both cases and it is seen in both cases. Symptoms of these include prolonged bleeding especially in joint cavities. Commonly, the person's joints become seriously disabled and painful because of repeated bleeding into the joint cavities after exercise or trauma.Treatments include injection of genetically engienneered factors which has eliminated need for plasma transfusion and risk of contracting hepatitis and HIV. DISSEMINATED INTRAVASCULAR COAGULATION (DIC) - this involves both a widespread clotting and severe bleeding. the widespread clotting occurs in intact blood vessels blocking blood flow.. severe bleeding flows because residual blood is unable to clot because the clotting factors are being depleted. this can occur in septicemia ( bacterial infection in the blood ) , incompatible blood transfusion and complications in pregnancy.

Erythropoiesis Regulation

balance of making red blood cells is important because -too few Red blood cells lead to tissue hypoxia -two many red blood cells increase blood viscosity to ensure that the number of red blood cells remain in the homestattic range more than 2 million red blood cells are made per second balance between red blood cell production and destruction depends on hormonal control and dietary requirements ( like iron, amino acid and certain B vitamins) Hormonal Control - the main hormones that stimulates the formation of red blood cells is Erythropoietin (EPO).it is a glycoprotein hormones there is always a small amount of EPO in the blood to maintain basal rate. it is released by the kidney ( and some from the liver) in response of hypoxia. So, when the levels of oxygen are low oxygen sensitive enzymes in the kidney cells can not degrade or breakdown hypoxia - inducible factor (HIF). HIF can accumulate which triggers the synthesis of EPO So the kidney will release EPO and it would get transferred around in the blood then it goes to the red bone marrow the EPO will tick some of the hemocytoblast. then it will decide to become a red blood cell. so that will cause more oxygen in the blood which will help wit the hypoxia.Notice that hypoxia does not activate the bone marrow directly. Instead it stimulates the kid- neys, which in turn provide the horrnonal stimulus that activates the bone marrow. What is the cause of hypoxia. -decreased red blood cell numbers due to hemorrhage or increased destruction -insufficient hemoglobin per red blood cell ( example iron deficiency) -reduced availability of oxygen ( examples high altitudes or lung problems such a pneumonia When there is too many RED BLOOD CELLS -too many re dblood cells or high oxygen levels in the blood that inhibit EPO production - the amount red blood cells in the blood does not control the rate of ertyropoiesies it is based on the ability to transport enough oxygen to meet tissue demands -EPO causes erythrocytes to mature faster testosterone enhances EPO production males which accounts for the higher red blood cell count in males . Some athletes abouse EPO. the use of EPO increase hemocrit which allows athletes to increase stamina and performance it has dangerous consequences like EPO can increase democrat from 45% up to even 65% with dehydration concentrating blood even more. It can also cause blood to become like sludge ( harder for blood to be pumped around.) and can cause clotting stroke or heart failure Dietary Requirements you need amino acids ( to make alpha and beta chain )lipids and carbohydrates.(to fuel) iron is available from the diet. 65% of iron is found in the hemoglobin which the rest in the liver spleen and bone marrow. the spleen is the major part where red blood cells get broken down so you need iron. free iron ions are toxic sp iron is bound with proteins so they are stored in cells as ferritin and hemosiderin. to move iron transferrin is used. It is transported in blood bound protein transferrin. Vitamin B12 and folic acidsd are nesicary for DNA synthesis for rapidly diving cells such as developing red blood cells iron is lost each day in feces urine and perspiration. women loss an average of more iron a day because of menstrual cycle

Physical characteristics and volume

blood is a sticky, opaque fluid with metallic taste due to iron associated with hemoglobin color varies with due to amount of oxygen found present. -high oxygen levels how a bright scalet red -low oxygen levels show a dark red color. the ph of the blood is around 7.35 - 7.45. It should vary. the blood makes about 8% of the body weight. the average volume of blood in women 4-5L liters and in men 5-6L of blood volume differences are due to size of men and women due to testosterone. women also tend to have a lower red blood cell count Thant than men ( women 4.2-5.4 million cells per microliter and men 4.7-6.1 million). if the number of red blood cells increase beyond normal range, blood becomes more viscous and flows more rapidly. blod is more dense that water due to the formed elements, but more specifically due to red blood cells.

clot retraction and fibrinolysis

clot must be stabilized and removed when damage has been repaired, clot retraction occurs when the actin and myosin in platelets contract within 30 - 60 minutes. the contraction pulls on the Brin strands squeezing the serum from the clot. the serum is plasma minus the clotting proteins. that draws ruptured blood vessel edges closer togethe. the vessel is still healing even as the clot retraction occurs. Platelet - derived growth factor ( PDGF) is released by platelets and it stimulates division of smooth muscle cells and fibroblast to rebuild the blood vessel walls as fibroblasts form a connective tissue patch in the injured area, endothelial cells, the vascular endothelial growth factor ( VEGF) stimulates endothelial cells to multiply and restore the endothelial lining Fibrinolysis is a process whereby clots are removed after repair is completed and it begins within 2 days and continues for several days until clot is dissolved. Plasminogen, is a plasma protein that is trapped in the clot and is converted into plasmin which is a fibrin digesting enzyme. the tissue plasminogen activator (tPA) also known as factor XII and thrombin play a role in the conversion process ( so converting plasminogen into plasma).

Structural Characteristics of the Erythrocytes

erthrocytes are small - diameter ( 7.5 um) cells that contribute to gas transportation and they are bound by the plasma membrane. the cell has biconcave disc shape with a depressed center, is enucleate and essentially has no organelles because the red blood cell do not have mitachondria and generate ATP by aerobic mechanisms, they do not consume any of the oxygen they carry making them efficient oxygen transporters. filled with hemoglobin (Hb) for transport. discounting the water pressure the erthrocytes iv over 97% hemoglobin. other proteins are present like antioxidant enzymes that help get rid of harmful oxygen radicals. Reb blood cells are longer than some capillaries contains plasma membranes protein spectrum and other rprotiens spectrum provides the flexibility to change the shape. which is why it can spring back to shape Surperb example of complementarity of structure and function three features make it efficientt for gas transport -biconcave shape offers huge area relative to volume for gas exchange -hemoglobin makes up 97% of cell volume not counting the water which is good because that is the molecule that bunds and transport gases - red blood cells have no mitochondria - they need amp but use glycolysis because it does not use oxygen to do so. atp production is anaerobic, so they do not consume any of the oxygen they transport

Diagnostic Blood test

examination of blood can yield information on a persons health for examples low democrat seen in cases of anemia. blood glucose test check for diabetes and leukocytosis can help signal infection. A high fat content (lipidernia) gives blood plasma a yellowish hue and forecasts problems in those with heart disease.Microscopeic examination of blood can reveal any variations in size or shape of red blood cells like abnormal size shape or color could indicate anemia. A differential white blood cell count looks at relative proportions of each white blood cells increases in specific white blood cell can help with the diagnosis. Prothrombin time (to assess the ability of blood to clot,) and platelets count (when thrombocytopenia is suspected.) assess hemostasis. CMP ( comprehensive medical panel) blood chemistry profile that checks various blood chemicals levels. abnormal levels can indicate liver or kidney disorders. Complete blood count checks formed elements democrat and hemoglobin.

Developmental Aspects of Blood

fetal blood cells form in fetal yolk sac, liver and spleen. the by seventh month red bone marrow is primarily hemopoietic area by seventh month. blood cells develop from mesenchymal cells called blood islands. The fetus forms hemoglobin F which has a higher affinity for oxygen then hemoglobin A formed after birth. Blood diseases of aging includes chronic leukemias, anemias, clotting disorders, and usually precipitated by disorders of the heart, blood vessels or immune system.

Formed Elements

formed elements are RBC, WBC, and platelets red blood cells are disc shaped white blood cells look like gaudily stained spherical platelets look like debris that is scattered around red blood cells out number every other formed element only white blood cells are complete cells which means that nuclei and all other organ eels because red blood cells do not have a nuclei and other organelles and platelets are cell fragments most formed elements only survivee in the bloodstream only few days most blood cells originate in bone marrow and do not divide

Platlets clotting

hemostasis is a fast series of reactions for stoppage of bleeding. when a bleed happens clotting factors and substances released by and injured tissues are required there are three steps involved: Step 1 vascular spasm Step 2: Platlet plug formation Step 3: Coagulation ( blood clotting) Step 1 VASCULAR SPASM - we break a blood vessel and the smooth muscle associated with the blood vessel constrict and causes the diameter of the blood vessel smaller which decrease the amount of blood leaving the body. so what happens as that the vessel will respond to injury with vascontrction. vascular spasm are triggered by 1) direct injury to vascular smooth muscle, 2) chemical released by endothelial cells and platelets, 3) pain reflexes. this is the most effective in smaller blood vessels. it can also significantly release blood floe until the other mechanisms kick in. STEP 2: PLATELET PLUG FORMATION - platelets will activate and bind to one anther and form a plug to stop the blood. the platelets stick to collagen fibers that are exposed when vessel is damaged. the platelets do not stick to vessels that intact because the collagen is not exposed. also prostacyclin s and nitric oxide secreted by the endotheliul cells act to prevent platelet sticking to each other and undaunted areas the von willebrand factor helps stabile platelet - collagen adhesion by forming a bridge between collagen and platelets. when the platelets activate they become well and spiked and stick and release chemical messengers ADP and serotonin and thromboxane A2. ADP causes more platelets ro stick and release their content. serotonin and thromboxane A2 enhance vascular spasm and platelet agreetmon. this is a positive feedback cycle which means the more platelets that stick the more chemicals that are releases. platelet plugs can be fine for small vessel tears, but larger breaks in vessels need an additional step. Step 3: COAGULATION ( BLOOD CLOTTING) - we turn blood into a gel by proteins to block the blood from leaking out. Coagulation reinforces platelet plug with fibrin threads. bloods clots are more effective in sealing larger vessel breaks. blood is transformed form liquid to gel when dissolved blood proteins assemble into fibrin threads. usually synthesized by the liver. A series of reactions use clotting factors ( procoagulants) mostly in plasma proteins. it is numbered I to XIII in order of discovery. vitamins K is not directly involved in coagulation, but is needed in order to synthesize four factors. Coagulation occurs in three phases: PHASE 1: TWO PATHWAYS TO PROTHROMBIN ACTIVATOR- this imitated by intrinsic or extrinsic pathways (usually both). a tissue damaging events then involves a series of procoagulants and each pathway cascades towards and ends with the activation of factor X. Factor X then complexes with Ca2+, PF3 ( platelets factor 3), and factor V to form prothrombin activator. In the transit factor it is called intrinsicc because clotting factors are present within the blood and it is triggered by nrgatively charged surfaces such as activated platelets, collagen, or even glass of a test tube. in a extrinsic pathway it called an extrinsic factor because factors needed for clotting are located outside the blood. it is triggered by exposure to tissue factor also cast called factor lll. this factor bypasses several steps of the intrinsics factor which makes the extrinsic pathway faster in an extreme can form clot in 15 seconds. PHASE 2: COMMON PATHWAY TO THROMBIN-prothrombin activator (INACTIVE)r catalyzes transformation of prothrombin to active thrombin PHASE 3: COMMON PATHWAY TO THE FIBRIN MESH - thrombin converts soluble fibrinogen into fibrin. the fibrin strands form structural basis of clot. the fibrin causes the plasma to become a gel like trap catching formed elements. thrombin ( along with CA2+) activate factor X1111 (bibrin stabilizing factor which crosslink fibrin (Cross-linking further strengthens and stabilizes the clot, effec- tively sealing the hole until the blood vessel can be pennanently repaired.and strengthens and stabilizing clot. Anticoagulants - factor that normally dominante in blood to inhibit coagulation. they inhibit clotting. Clot fomration usually is complete within 3 to 6 minuets.

production of white blood cells

leukopoiesis is the production of white blood cells. they are stimulated by two different types of chemical messengers from the red bone marrow and mature white blood cells which are: internuerns and colony- stimulating factors ( CSFs). interleukins are numbered ( example: IL-3 and IL-5). colony - stimulating factors (CSFs) are named for white blood cells they stimulate ( example granulocyte CSF stimulated granulocytes). Hematopoietic factors, released by support- ing cells of the red bone marrow and mature WBCs, not only prompt the \vhite blood cell precursors to divide and mature, but also enhance the protective potency of mature leukocytes. all white blood cells originate from hemocytoblast cell that branches into two pathways: hymphoid stem cells and myeloid cells. Lymphoid stem cells produce lymphocytes. myeloid stem cells produce all other forms of white blood cells.

Platelets

platelets are not cells but they are fragments of larger cells called megakarocyte. they contain several chemical that are involved in the clotting process. examples include serotonin, calcium,, enzymes, ADP, platelet derived growth factor. the main function of the platelets is to form temporary platelet plug that helps seal breaks in the blood vessels. platelets age quickly and degenerate in 10 days. circulating platelets are kept inactive and mobile by nitric oxide(NO) and prostacyclin ( keep them from activating) and secreted bu endothelial cells lining blood vessels. the formation go platelets are regulated by thrombopoitetin. it is formed in the myeloid line from megakaryoblast ( stage 1 megakarocyte). mists occurs but there is no cytokinesis which causes large stage IV cells with multi lobed nucleus that are known as Stage IV megakarocytes. after it is formed the stage IV megakaryocytic presses against a sinusoid (the specialized type of capillary in the red marro\v) and sends the cytoplasmic projection into the lumen of the capillary. which causes the projections to break off into platelets fragments. These extensions rupture, releasing platelets like leaves blowing offa tree, seeding the blood with platelets. The plasma membranes associated with each fragment quickly seal around the cytoplasm to form the grainy, roughly disc-shaped platelets Platelets age quickly and degenerate in about 10 days.

Blood Functions

several different functions include: transport - moves nutrients and waster products around the body ( ex blood cells and hormones) Examples of transport -delievering oxygen, carbon dioxide and nutrients to the blood cells - transfers metabolic waste like carbon dioxide to the lungs and waste like nitrougous waste to the kidneys to be recreated from the body by urine -transports hormones from the endocrine organs to target organs Regulation - if something happens how will the blood fix it like if a blood vessel gets broken how does the body stop it. helps in temperature is body gets cold the body will withdrawl blood from the skin to prevent warmth from being radiated out. If warm the blood will be rushed back into the skin because it warm and you do not want to be overheated Examples of regulation - the blood helps control body temperatures by absorbing and distributing heat. - maintaining normal pH in the body which is 7.4. many blood proteins and other blood borne solutes acts as buffers to prevent excessive or abrupt changes in the blood pH that could jeopardize normal cell activities. the blood also acts as a reservoir for the body' s " alkaline reserve" of bicarbonate ions. - maintaining adequate fluid volume in circulatory system blood proteins prevent excessive fluid loss from the bloodstream into tissue spaces. As a result the fluid volume in the blood vessels remain ample to support efficient blood circulation to all parts of the body. Protection - white blood cells (lycrocytes) protiens are found in the blood which are related to the immune system Examples of Protection - preventing blood loss by Palma proteins and platelets in blood to initiate clot formation. so when a blood vessel is damaged, platelets and plasma proteins initiate clot formation to halt blood loss - preventing infection agents of immunity are carried in blood like antibodies, complement proteins and white blood cells. The blood contains antibodies, complement proteins and leukocytes also known as white blood cells and they all help defend the body against foreign invaders such as bacteria and viruses.

Leukocytes disorders

the overproduction of abnormal white blood cells cause leukemia sand infectious mononucleosiss. An abnormal low white blood cell count is called leukopenia. it could be drug induced and particularly by anticancer drugs or glucocorticoids ( suppress immune system. -luekemias are cancerous conditions that involve th overproduction os white blood cells. they usually involve voles of single andonormal cell.(descendants of a single cell) that remain unspecialized and proliferate out of control, impairing normal red bone marrow function named according to abnormal white blood cell clone involved. example isMyeloid leukemia involves myeloblast descendants. another example id lymphocytic leukemis involve lymphocytes. Acute leukernia is quickly advancing because it derives fromstem cells which primarily affects children. Chronic leukernia is slowly advancing because it involves proliferation of later cell stages is more prevalent in older people. without treatment all leukemia are fetal. the immature and non functional white bed cella are just floating around in the blood.Other symptoms include fever, weight loss, and bone pain. Although tremendous nurnbers of leukocytes are produced, they are nonfunctional and cannot defend the body in the usual way. cancerous cells fill red bone marrow which crowds out other cell lines which leads to anemia and bleeding. when people die of leukemia it is due to internal hemorrhage to overwhelming infections. Treatment includes radiation antiluekemic drugs ( they destroy rapidly growing cells and induce remission) and stem cell transplant ( used in selected individuals when donors are present. - infectious Mononucleosis - it is highly contagious viral disease and it is knows as the kissing disease it is usually seen in young adults and it is caused by the Epstein Barr virus. this results in a high number of typical arganulocytes( lymoocytes) which causes involved lymphocytes to become enlarged and scientist thought that cells were monocytes so the disease is names mononucleosis. symptoms include being tired achy, chronic sore throat and low fevers. it usually last 4-6 weeks , but there is no cure.

Factors limiting normal cell growth

there are two mechanisms that limit the size of a clot 1) swift removal and dilution of clotting factors 2) inhibition of activated clotting factors. the limited amount if thrombin is restricted to clot by fibrin threads and prevents clot from getting too big into the blood stream . Antithrombin III inactivates any unbound thrombin from the fibrin that escapes into the bloodstrea protein C, another protein produced in the liver, also inhibit the activity of other intrinsic pathway clotting factors.. heparin that is found in basophil and mast cells inhibits thrombin by enhancing antithrombin III. factors preventing undesirable clotting facts preventing platelets adhesion includes : 1) smooth endotheilialium of blood vessels prevents platelets from clinging. 2)Endothelial cells secrete antithrombin substances such as metric oxide and prostacyclin. 3) Vitamin E quinoa, formed when vitamin E reacts with oxygen it is a potent antiguaulant