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A&P 2 > Chapter 19 - Blood > Flashcards

Chapter 19 - Blood Flashcards

1
Q

What is serum?

A

Plasma with the clotting factors removed

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2
Q

Where are most plasma proteins produced?

A

Liver

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3
Q

Which of the plasma proteins function in blood clotting?

A

Fibrinogen

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4
Q

Least abundant type of plasma protein?

A

Hormones

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5
Q

What would be the effect on your body if for some reason your liver was damaged and stopped producing albumins?

A

Tissue swelling (albumins keep water inside vessels)

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6
Q

How is it that liver disorders can alter the composition and the functional properties of blood?

A

The liver is the primary source of plasma proteins.

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7
Q

What would happen if blood flow to kidneys was obstructed?

A

Hematocrit would increase; body would respond by increasing red blood cells in blood?

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8
Q

Which type of protein is responsible for transporting triglycerides in the blood?

A

Apolipoproteins

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9
Q

Functions of Blood:

A

1) Transports dissolved gases, nutrients, triglycerides, hormones, and metabolic wastes
2) Regulates pH and the ion composition of interstitial fluids
3) Restricting fluid losses at injury sites
4) Defends against toxins/pathogens
5) Stabilizes body temperature

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10
Q

Blood Characteristics

A
  • Temp of about 38 C, 100.4 F
  • Five times as viscous as water
  • Slightly alkaline, pH: 7.35-7.45
  • Liters in 7% of human’s body weight (Male has 5-6 liters, Female has 4-5 liters)
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11
Q

Whole blood (a fluid connective tissue)

A

Plasma and Formed Elements

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12
Q

Whole blood: Plasma

A
  • comprise 55% of whole blood
  • water/ions/small solutes of plasma are continuously exchanged with the interstitial fluid
    -***7% Plasma proteins, 1% other solutes, 92% water
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13
Q

Plasma: Plasma proteins

A
  • 7% of plasma
  • proteins are dissolved in plasma, usually remain within bloodstream “trapped”, 90% of proteins synthesized by liver
    -ALBUMINS, GLOBULINS, FIBRINOGENS
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14
Q

Plasma proteins: Albumins

A
  • constitute 60% of plasma proteins
  • major contributors to osmotic pressure of plasma
  • also important in transporting fatty acids, thyroid hormones, and steroid hormones
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15
Q

Plasma proteins: Globulins

A
  • constitute 35% of plasma proteins
  • *Antibodies “immunogoblins”: attack pathogens alongside white blood cells
  • *Transport globulins: bind small ions, hormones, and other compounds
  • also important in transporting fatty acids, thyroid hormones, and steroid hormones (thyroid binding globulin, metalloproteins - transferrin for iron, apolipoproteins, steroid-binding proteins - testosterone binding globulin)
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16
Q

Plasma proteins: Fibrinogens

A
  • constitute 4% of plasma proteins
  • Help in clotting: fibrinogens usually dissolve into plasma and are soluble. However, under certain conditions (a bleed/injury), fibrinogens become insoluble and form “fibrin”, which can form a strand and clot.
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17
Q

Whole blood: formed elements

A
  • comprise 45% of whole blood
  • Red blood cells (most abundant, 99.9%), white blood cells, platelets (cell fragments)
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18
Q

Hematocrit

A

Percentage of formed elements in a blood sample. Normal is Packed Cell Volume (PCV)- 46 in men, 42 in women (estrogen does not stimulate red blood cell production).

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19
Q

Hemopoiesis/Hematopoiesis

A

Process by which formed elements are produced. Two populations of stem cells - myeloid and lymphoid stem cells - are responsible for the production of formed elements.

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20
Q
  1. What would be the effects of a decrease in the amount of plasma proteins?
A

A decrease in the amount of plasma proteins in the blood (usually by liver disease/disorder) would lower plasma osmotic pressure, reduce the ability to fight infection, lower clotting ability, and decrease the transport and binding of some ions, hormones, and other molecules.

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21
Q

19.2

A
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22
Q

What can effect a hematocrit?

A
  • Decreased blood flow to kidneys: stimulates RBC production and increases hematocrit
  • Increases during dehydration, due to less water making up plasma
  • Increases upon stimulation of hormone “erythropoietin”
  • Decreases with bleeding
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23
Q

Characteristics of RBC’s? What does its biconcave shape and flexible plasma membrane allow for?

A
  • Gives RBC large surface area, allowing them to more easily and quickly exchange oxygen across its membrane (which is needed for gas exchange in lungs)
  • RBC’s can form “rouleaux” or stacks if needed, helpful in crossing narrow blood vessels
  • Can change shape in order to squeeze through very small capillaries
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24
Q

Mature RBC’s

A

When a developing red blood cell differentiates, it loses any organelle not directly associated with its primary function: the transport of respiratory gases. Mature RBCs are anucleate, without nuclei; they retain only the cytoskeleton. Without nuclei and ribosomes, circulating RBCs cannot divide or synthesize structural proteins or enzymes. As a result, the RBCs cannot repair themselves, so their life span is relatively short—normally less than 120 days. With few organelles and no ability to synthesize proteins, their energy demands are low. Without mitochondria, they obtain the energy they need through the anaerobic metabolism of glucose that is absorbed from the surrounding plasma. The lack of mitochondria ensures that absorbed oxygen will be carried to peripheral tissues, not “stolen” by mitochondria in the RBC.

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25
Q

Hemoglobin (Hb or Hgb)

A
  • 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.
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26
Q

Erythropoiesis

A
  • 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)
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27
Q

Stages of RBC Maturation

A

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

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28
Q

Erythropoietin

A
  • 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
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29
Q

Erythropoietin is released during:

A

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

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30
Q

Hemoglobin recycling (slide 14)

A
  • 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
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31
Q

19.3

A
32
Q

Antigen

A

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

33
Q

Surface antigens (agglutinogens)

A

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)

34
Q

Antibodies (agglutinins)

A
  • 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)
35
Q

Rh blood group

A

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.

36
Q

Most common blood type

A

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

37
Q

If an individual’s RBCs clump together when exposed to anti-A and to anti-B antibodies, the individual has: (A)
If no reaction occurs upon exposure, the individual has: (B)

A

A: Type AB blood
B: Type O blood

38
Q

In emergency situations where compatibility testing is not possible, which blood type is preferred for transfusions?

A

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

39
Q

Hemolytic disease of the newborn (HDN)

A

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)

40
Q
  1. Which blood type can be safely transfused into a person with type O blood?
A

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

41
Q
  1. Why can’t a person with type A blood safely receive blood from a person with type B blood?
A

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.

42
Q

When it comes to blood transfusions, the antibodies of the donor do NOT matter so much as their surface antigens

A

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

43
Q

19.4

A
44
Q

White blood cells (leukocytes): Intro

A
  • 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)
45
Q

WBC Characteristics and Function

A
  • 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
46
Q

Two General Groups of WBCs (Leukocytes) Based on Appearance:

A

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

47
Q

Nonspecific defenses

A
  • Neutrophils, Esinophils, Basophils, Monocytes
  • a variety of stimuli activate these leukocytes, regardless of the threat
48
Q

Specific defenses

A

Lymphocytes: respond to specific stimuli

49
Q

Neutrophil

A
  • 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
50
Q

Esinophils

A
  • 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
51
Q

Basophils

A
  • 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
52
Q

Monocytes

A
  • 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
53
Q

Lymphocytes

A
  • 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
54
Q

Leukopenia

A

Inadequate amount of WBCs

55
Q

Leukocytosis

A

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

56
Q

Leukopoiesis

A

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.

57
Q

Myeloid Stem Cells: How do they create the formed elements?

A

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

58
Q

LOOK AT SLIDE 26!!!

A
59
Q

Granulocyte development

A

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

60
Q

Colony-stimulating factors (CSFs)

A

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.

61
Q

Lymphocytopoiesis

A

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.

62
Q

Which type of white blood cell would you find in the greatest numbers in an infected cut?

A

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.

63
Q

Which type of cell would you find in elevated numbers in a person who is producing large amounts of circulating antibodies to combat a virus?

A

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

64
Q

How do basophils respond to an injury?

A

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.

65
Q

Platelets (thrombocytes)

A

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)

66
Q

Platelet functions

A

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)

67
Q

Thrombocytopoiesis

A

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

68
Q

19.6

A
69
Q

Hemostasis

A

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”

70
Q

Hemostasis: Vascular Phase

A
  • 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
71
Q

Hemostasis: Platelet Phase

A
  • 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.

72
Q

Hemostasis: Coagulation Phase

A
  • 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
73
Q

Hemostasis: Clot Retraction (End-Stage)

A
  • once the fibrin meshwork and blood clot have formed, the platelets contract - and the entire clot undergoes retraction (about 30-60 minutes)
74
Q

Fibrinolysis

A

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.

75
Q
  1. A decreased number of megakaryocytes would interfere with what body process?
A

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

76
Q

How could a fat-free diet affect blood clotting?

A

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.

77
Q

Unless chemically treated, whole blood will coagulate in a test tube. This clotting process begins when Factor XII becomes activated. Which clotting pathway is involved in this process?

A

The activation of Factor XII initiates the intrinsic pathway.

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