Chapter 19 - Blood Flashcards

Question

Hemoglobin (Hb or Hgb)

Answer 1

- Responsible for RBC's ability to transport oxygen and CO2 - Have a Quaternary structure: 2 a and b chains (4 Hb chains total) - Each Hb chain carries one heme, which has one iron ion (total of 4 in one hemoglobin molecule) - These iron ions can attach to oxygen, forming oxyhemoglobin (responsible for bright red color of arterial blood) - A hemoglobin molecule whose iron is not bound to oxygen is called deoxyhemoglobin. Blood containing RBCs filled with deoxyhemoglobin is dark red (in venous blood). - Fetal hemoglobin more readily attaches to oxygen than adult hemoglobin - When hemoglobin bound to CO2, carbaminohemoglobin results.

Answer 2

- Process of RBC production; in adults, this only takes place in red bone marrow 1) First, cells called hemocytoblasts (HSC's) in red bone marrow must divide into either myeloid cells (producing all red blood cells and some white blood cells) or lymphoid cells (producing lymphocytes, one of five types of white blood cells)

Answer 3

Day 1: proerythroblast Day 2+3: erythroblast Day 4: normoblast (still an erythroblast) Day 5: reticulocyte (with ejection of nucleus; stays in red bone marrow for a few more days to synthesize hemoglobin, then does one final day in circulation) Day 6: mature red blood cell

Answer 4

- glycoprotein produced in kidney and liver - released into plasma when O2 levels are low - once in bloodstream, EPO travels to red bone marrow, where it stimulates RBC production

Answer 5

1) during anemia 2) when blood flow to kidneys decline (stimulates RBC production via erythropoietin hormone) 3) when O2 content in air/lungs decline 4) when lung surfaces are damaged

Answer 6

- Macrophages of the spleen, liver, and red bone marrow play a central role in recycling red blood cell components. These phagocytes engulf aged red blood cells and also detect and remove Hb molecules from hemolyzed, or ruptured, RBCs (Figure 19–5). Hemoglobin remains intact only inside RBCs. If the Hb released by hemolysis is not phagocytized, its components will not be recycled. - Once a phagocytic cell has engulfed and broken down an RBC, each part of the Hb molecule has a different fate (see Figure 19–5). The alpha and beta chains of Hb are filtered by the kidneys and eliminated in urine. The globular proteins are broken apart into their component amino acids, which are then either metabolized by the cell or released into the bloodstream for use by other cells. Only the iron of each heme unit is recycled. The remaining portion is processed separately - When abnormally large numbers of RBCs break down in the bloodstream, urine may turn red or brown. This condition is called hemoglobinuria. The presence of intact RBCs in urine—a sign called hematuria (hē-mah-TYŪ-rē-uh)—occurs only after kidney damage or damage to vessels along the urinary tract

Answer 7

Substances that can trigger a protective defense mechanism called an immune response

Answer 8

Integral membrane glycoproteins. Substances that your immune system recognizes as “normal,” or “self.” In other words, your immune system ignores these substances rather than attacking them as “foreign"; these play huge role in determining blood type ******-most important three are A, B, and Rh (D)

Answer 9

- If you are Type A, you have surface antigen A only, and you have anti-B antibodies which will attack B surface antigens -If Type A surface antigen RBC's come into contact with Anti-A antibodies, the cells will clump together and then hemolyze/rupture (agglutination; cross-reaction)

Answer 10

Based on either presence of absence of Rh surface antigen/factor: - Rh positive (Rh+): presence of Rh factor - Rh negative (Rh-): absence of Rh factor ------------ *Ant-A and Anti-B antibodies are present throughout life, regardless of whether the individual has ever been exposed to foreign RBCs. In contrast, the plasma of an Rh-negative individual does not contain anti-Rh antibodies. These antibodies are present only if the individual has been sensitized by previous exposure to Rh+ RBCs. Such exposure can occur accidentally during a transfusion, but it can also accompany a seemingly normal pregnancy involving an Rh− mother and an Rh+ fetus.

Answer 11

O+ (neither A nor B surface antigens, both anti-A and B antibodies, and PRESENCE of Rh factor)

Answer 12

A: Type AB blood B: Type O blood

Answer 13

Type O- (lacks A and B surface antigens, and lacks Rh factor)

Answer 14

Doesn't involve a transfusion; rather, it involves Rh incompatibility between a mother and the fetus. - (See Slide) A Rh- mother's first Rh+ fetus is typically unaffected. However, future Eh+ fetuses may be affected (due to sensitization from mother developing anti-Rh antibodies from labor hemorrhaging)

Answer 15

Only another Type O can safely be transfused to a person with Type O blood.

Answer 16

If a person with type A blood receives a transfusion of type B blood, which contains anti-A antibodies, the red blood cells will agglutinate (clump), potentially blocking blood flow to various organs and tissues.

Answer 17

-AB+ is universal recipient for this reason -O- is universal donor for this reason

Answer 18

- Unlike RBC's, they have nuclei and other organelles, and lack hemoglobin - They help defend the body against pathogens, and help to remove wastes, toxins, and damaged/abnormal cells - At any given moment, most of the WBC's in the body are in connective tissue proper or in organs of the lymphatic system (circulating WBC's only comprise a small proportion)

Answer 19

- WBCs don't circulate as often as RBC's, and use vessels to get to sites if they need - Circulating WBCs can detect chemical changes - indicative of abnormalities - and leave the bloodstream to transport to those sites -*They can migrate out of the bloodstream: can attach to vessel walls (margination) and squeeze through endothelial cells to get to target site (emigration) -*Capable of amoeboid movement (which can allow WBC to move through the endothelial lining of vessels and enter target tissues/organs) -*All WBCs are attracted to specific chemical stimuli (positive chemotaxis): allows WBCs to be guided to pathogens/places of abnormality -**SOME WBCs are capable of phagocytosis

Answer 20

1) Granular leukocytes (neutrophils, esinophils, basophils) 2) Agranular leukocytes (monocytes, lymphocytes,)

Answer 21

- Neutrophils, Esinophils, Basophils, Monocytes - a variety of stimuli activate these leukocytes, regardless of the threat

Answer 22

Lymphocytes: respond to specific stimuli

Answer 23

- comprise 50-70% of circulating WBCs (and are the most Numerous of the WBCs) -round, nucleus-lobed - produced in red bone marrow - highly mobile; usually the first of the WBCs to arrive at an injury site - phagocytic; can kill bacteria by releasing hydrogen peroxide and superoxide anions - have short life span; most neutrophils in blood stream survive up to only 10 hours - after engulfing about 1-two dozen pathogens/bacteria, neutrophils may die - releasing chemicals that attract other neutrophils to the site - a mixture of dead neutrophils and other wastes form the "pus" that is associated with many injury/infection sites

Answer 24

- comprise 2-4% of circulating WBCs - round, nucleus-bilobed (2) - produced in red bone marrow - granules stain bright red with "eosin" dye - phagocytic; attack objects that are covered in antibodies (use exocytosis against multicellular pathogens/parasites) - reduce inflammation produced by mast cells and neutrophils - numbers of esinophils increase dramatically in allergic and parasitic situations -

Answer 25

- comprise <1% of circulating WBCs - round cell; nucleus is hard to see through its numerous dense granules (stain darkly with dye) - produced in red bone marrow - migrate to and enter injury sites and cross the capillary endothelium to accumulate in damaged tissue - once there, they release histamine (dilates blood vessels), heparin (prevents blood clotting), and other chemicals that promote/enhance the inflammation caused by mast cells - can release chemicals that attract eosinophils and other basophils to sites

Answer 26

- comprise 2-8% of circulating WBCs - very large, round, kidney-bean shaped nucleus (rather than lobed), abundant cytoplasm - produced primarily in red bone marrow - individual monocytes travel in bloodstream for only about 24 hours before entering tissues to become macrophages - aggressively phagocytic: and engulf pathogens and release chemicals that activate/stimulate other neutrophils and monocytes - can attract fibroblasts, which contribute to forming scar tissue in injured areas

Answer 27

- comprise 20-40% of circulating WBCs - generally round cell with round nucleus, very little cytoplasm - SPECIFIC: provide defense against specific pathogens - produced in red bone marrow and lymphatic tissues - at any given moment, most lymphocytes are in connective tissue or lymphatic system organs - Three classes: T cells (cell-mediated immunity, "offense" against foreign cells), B cells (humoral immunity, "defense" in creating antibodies that can attack antigens from anywhere in the body), NK cells (immune surveillance, detect and destroy abnormal cells that could otherwise become cancer) *******The T cells responsible for cellular immunity must migrate to their targets, but the antibodies produced by plasma (B) cells in one location can destroy antigens almost anywhere in the body

Answer 28

Inadequate amount of WBCs

Answer 29

Excessive numbers of WBCs (modest is okay during infection, but extreme can be indicative of leukemia)

Answer 30

Process of WBC production -**Stem cells that produce WBCs originate in the red bone marrow, with the divisions of hemocytoblasts (Figure 19–10). As we have noted, hemocytoblast divisions produce myeloid stem cells and lymphoid stem cells. Myeloid stem cells divide to create progenitor cells, which give rise to all the formed elements except lymphocytes. One type of progenitor cell produces daughter cells that mature into RBCs. A second type produces cells that manufacture platelets. A third type produces daughter cells that develop into neutrophils, eosinophils, basophils, and monocytes.

Answer 31

Myeloid stem cells are one of the two types of stem cells formed via the division of hemocytoblasts. Myeloid stem cells lead to creation of all the formed elements EXCEPT for lymphocytes. Myeloid stem cells divide to make three types of "progenitor" cells 1) One of which makes cells that mature into RBCs 2) Another of which makes cells that make platelets 3) Another of which makes cells that develop into all the WBCs excluding lymphocytes

Answer 32

Myeloid stem cell -> myeloblast -> myelocyte -> band cell -> mature WBCs (neutrophil, esinophil, basophil)

Answer 33

Hormones that are involved in regulating WBC populations. Four CSFs have been identified. Each stimulates the formation of WBCs or both WBCs and RBCs. The designation for each factor indicates its target. 1) Multi-CSF accelerates the production of granulocytes, monocytes, platelets, and RBCs. 2) GM-CSF stimulates the production of both granulocytes and monocytes. 3) G-CSF stimulates the production of granulocytes (neutrophils, eosinophils, and basophils) 4) M-CSF stimulates the production of monocytes. **Active macrophages release chemicals that make lymphocytes more sensitive to antigens and also accelerate the development of specific immunity. In turn, active lymphocytes release multi-CSF and GM-CSF, reinforcing nonspecific defenses.

Answer 34

Process of lymphocyte production -****Some lymphocytes are derived from lymphoid stem cells that remain in red bone marrow. These lymphocytes differentiate into either B cells or natural killer cells. Many of the lymphoid stem cells that produce lymphocytes migrate from the red bone marrow to peripheral lymphatic tissues, including the thymus, spleen, and lymph nodes. As a result, lymphocytes are produced in these organs as well as in the red bone marrow. Lymphoid stem cells migrating to the thymus mature into T cells.

Answer 35

An infected cut would contain a large number of neutrophils, because these phagocytic white blood cells are the first to arrive at the site of an injury.

Answer 36

The blood of a person fighting a viral infection would contain elevated numbers of lymphocytes, because B cells (B lymphocytes) produce circulating antibodies.

Answer 37

Basophils respond to an injury by releasing a variety of chemicals, including histamine and heparin. Histamine dilates blood vessels and heparin prevents blood clotting. Basophils also release other chemicals that attract eosinophils and other basophils to the injured area.

Answer 38

Play a major role in the clotting process alongside plasma (fibrinogens) -Disc shaped cytoplasmic fragment that contains actin and myosin (which can contract to reduce breaks in cell wall during clotting process), and has no nucleus. -They circulate for 9-12 days before being removed by phagocytes -About one-third of the platelets in the body at any moment are in the spleen and other vascular organs, rather than in the bloodstream. These reserves are mobilized during a circulatory crisis, such as severe bleeding (spleen is highly vascular)

Answer 39

1) Release chemicals important to clotting process 2) Temporarily patch the walls of damaged vessels - can form "platelet plug" that slows bleeding while clotting takes place 3) Can reduce size of break in vessel walls (via actin and myosin contractions)

Answer 40

Process of platelet (thrombocyte) production - Takes place in red bone marrow -Platelet production, or thrombocytopoiesis (throm-bō-sī- tō-POY-eh-sis), takes place in the red bone marrow. Normal red bone marrow contains megakaryocytes (meg-ah-KAR- ē-ō-sīts; mega-, big + karyon, nucleus + -cyte, cell), enormous cells (up to 160 μm in diameter) with large nuclei (see Figure 19–10). During their development and growth, megakaryocytes manufacture structural proteins, enzymes, and membranes. They then begin shedding cytoplasm in small membrane-enclosed packets. These packets are the platelets that enter the bloodstream. A mature megakaryocyte gradually loses all of its cytoplasm, producing about 4000 platelets before phagocytes engulf its nucleus for breakdown and recycling. Three substances influence the rate of megakaryocyte activity and platelet formation. They are (1) thrombopoietin (TPO), or thrombocyte-stimulating factor, a peptide hormone produced in the kidneys (and perhaps other sites) that accelerates platelet formation and stimulates the production of megakaryocytes; (2) interleukin-6 (IL-6), a hormone that stimulates platelet formation (during clotting); and (3) multi-CSF, which stimulates platelet production by promoting megakaryocyte formation and growth

Answer 41

The process of blood clotting to stop blood loss. At the same time, it establishes a framework for tissue repair. Three phases: 1) Vascular Phase 2) Platelet Phase 3) Coagulation Phase End of process is "clot retraction"

Answer 42

- last for 30 minutes following injury - endothelial cells of vessels contract and release endothelins, stimulating contraction and endothelial division - the endothelial cells become sticky and attach to platelets and each other

Answer 43

- platelets attach to endothelial cells, the basement membrane, exposed collagen fibers, and to each other - they release chemicals which promote aggregation, clotting, and repair -***As platelets aggregate and become activated, they release chemicals: These compounds include (1) adenosine diphosphate (ADP), which stimulates platelet aggregation and secretion; (2) thromboxane A2 and serotonin, which stimulate vascular spasms; (3) clotting factors, proteins that play a role in blood clotting; (4) platelet-derived growth factor (PDGF), a peptide that promotes vessel repair; and (5) calcium ions, which are required for platelet aggregation and in several steps in the clotting process. (positive feedback loop) -***Several key factors limit the growth of the platelet plug: (1) prostacyclin, a prostaglandin that inhibits platelet aggregation and is released by endothelial cells; (2) inhibitory compounds released by WBCs entering the area; (3) circulating plasma enzymes that break down ADP near the plug; (4) compounds that, when abundant, inhibit plug formation (for example, serotonin, which at a high concentration blocks the action of ADP); and (5) the development of a blood clot, which reinforces the platelet plug but isolates it from the general circulation.

Answer 44

- coagulation, or blood clotting, involves a sequence of steps leading to the conversion of soluble plasma protein fibrinogen into insoluble fibrin - as the fibrin network grows, blood cells and platelets become trapped in the fibrous tangle, forming a blood clot that seals off the damaged portion of the vessel

Answer 45

- once the fibrin meshwork and blood clot have formed, the platelets contract - and the entire clot undergoes retraction (about 30-60 minutes)

Answer 46

As the repairs proceed, the clot gradually dissolves in a process called fibrinolysis (fī-brih-NOL-uh-sis). The process begins when two enzymes activate the proenzyme plasminogen (plaz-MIN-ō-jen). These enzymes are thrombin, produced by the common pathway, and tissue plasminogen activator (t-PA), released by damaged tissues at the site of injury. The activation of plasminogen produces the enzyme plasmin, which begins digesting the fibrin strands and eroding the clot. To perform its vital functions, blood must be kept in motion. On average, an RBC completes two circuits around the cardiovascular system each minute. Blood begins to circulate in the third week of embryonic development and continues throughout life. If the blood supply is cut off, dependent tissues may die in a matter of minutes. In Chapter 20, we examine the structure and function of the heart—the pump that maintains this vital blood flow.

Answer 47

A decreased number of megakaryocytes would interfere with the blood’s ability to clot properly, because fewer megakaryocytes would produce fewer platelets.

Answer 48

Vitamin K is necessary for blood clotting, and fats are required for vitamin K absorption. So, if a person did not eat foods containing fat, this would lead to a vitamin K deficiency, which would, in turn, result in a decreased production of several clotting factors—most notably, prothrombin. As a result, clotting time would increase.

Answer 49

The activation of Factor XII initiates the intrinsic pathway.

Chapter 19 - Blood Flashcards

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