blood Flashcards

1
Q

Components of blood

-also , what kind of tissue is blood

A

–blood is CT

Plasma = extracellular matrix

Formed elements = living cells

  • Erythrocytes
  • Leukocytes
  • Platelets
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2
Q

how does oxygen affect blood color?

A

low O2 = dark red

high O2 = scarlet

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3
Q

Blood in centrifuge

A

Plasma on top 55%
Buffy layer = WBC and platelets <1%
Hematocrit = RBCs 45%
- 47% for men; 42% for femals

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4
Q

3 Func of blood

A

distributing substances
-O2, waste to lings and kidneys, hormones

regulating blood levels
-temp, pH (bicarbonate ion buffers), fluid volume

protection

  • no blood loss (clots)
  • no infection: antibodies, complement proteins, WBCs
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5
Q

Components of blood plasma

A
  • 90% water
  • a ton of dissolved solutes
  • most solutes are plasma proteins which are made by the liver and stay in the blood
  • 60% albumin; 36% globulins; 4% fibrinogen
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6
Q

Albumin

A
  • main contributor to osmotic pressure
  • substance carrier and blood buffer
  • made by liver
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7
Q

Where do most blood cells originate?
How long do they last in the blood?
Do they divide?

A
  • bone marrow
  • a few days
  • nah
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8
Q

What is the formation of blood cells called and how is it regulated?

A

hemopoiesis or hematopoiesis

regulated by negative feedback for RBC and as needed for WBCs

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9
Q

First two steps of hematopoiesis

A

!. Pluripotent stem cell

2. Myeloid cell or Lymphoid ell

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10
Q

-what helps push hematopoiesis in one way or another?
-can cells go backward in the process
-where do new blood cells enter the blood stream?
What is the exception to the no dividing rule?

A
  • hormones and growth factors
  • no
  • blood sinusoids
  • lymphocytes
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11
Q

Erythrocyte structure

A
  • biconcave disk
  • basically just a Hb filled sack
  • has plasma membrane protein Spectrin so that it’s flecible enough to fit through small capillaries
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12
Q

How do Erythrocyte’s structural features compliment their functional tasks?

A
  • biconcave shape = greater surface area for gas exchange

- no mitochondria = anaerobic atp production = no use of the O2 they’re carrying

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13
Q

Hemoglobin components and structure

how much hb per rbc?

A
  • Globin = 4 polypep chains : 2 alpha and 2 beta
  • Heme = red pigment bonded to each globin chain
  • Heme’s central iron atom binds one O2

250 mil

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14
Q

How do changes in gas content affect Hb?

A
  • O2 loading in lungs = oxyhemoglobin (ruby red)
  • O2 unloading in tissues = deoxyhemoglobin (dark red) (reduced)
  • CO2 loading in tissues = carbaminohemoglobin = 20% of CO2 in blood binds to Hb
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15
Q

Process of RBC production

A

-pluripotent stem cell –> myeloid stem cell ——–> reticulocytes enter blood stream –> 2 days later they’re RBCs

reticulocytes don’t have nuclei

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16
Q

Balance of Erythropoiesis

A
  • too few = hypoxia
  • too mmany = blood viscosity
  • balance depends on hormonal regulation and adequate supplies of iron, AAs and B vits
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17
Q

Hormone that controls Erythropoiesis

A
  • Erythropoietin (EPO)
  • direct stimulus
  • always some in blood to maintain basal rate of production
  • released in kidneys in response to hypoxia
  • triggers rapid maturation of COMMITTED marrow cells –> increases reticulocyte count in 1-2 days
  • enhanced by testosterone

RESPONSE TO O2 CARRYING CAPACITY– NOT NUMBER OF RBCs

18
Q

hypoxia causes

A
  • low RBC bc of hemorrhage or increased destruction
  • not enough Hb per RBC (e.g. iron deficiency)
  • reduced O2 availability (high altitude)
19
Q

Dietary requirements for erythropoiesis

Bonus: how and where is iron stored

A
  • AA, lipid, carbs
  • iron 65% in Hb, rest in liver spleen and bone marrow –> stored in cells as ferritin and hemosiderin–> transported in blood with prot transferrin
  • Vit B12 and folic aid for DNA synth for rapidly dividing baby RBCs
20
Q

Fate and destruction of Erythrocytes

A
  • 100-120 days
  • no prot synth, growth or division
  • become fragile and Hb degenerates
  • get trapped in small circulatory channels esp in spleen
  • macrophages eat them
  • heme and globin split and iron is saved
  • heme makes bilirubin in bile to intestins –> urobilinogen –> stercobilin in fees
  • globilin makes AA
21
Q

Anemia

A
  • low O2 carrying capacity
  • not a disease in and of itself
  • blood O2 levels can’t support normal metabolism
  • fatigue, pallorm short breath, chills

Caused by

  • blood loss
  • low RBC productio
  • high rbc destruction
22
Q
Hemorrhagic anemia
Chronic Hemorrhagic anemia
Iron deficiency anemia
Pernicious anemia
Renal anemia
Aplastic anemia
Hemolytic anemia
A
  • blood loss from stab wound
  • slight perisstant blood loss like ulcer
  • blood loss, low iron intake, or impaired absorption
  • automimmune – destroys stomach mucosa, so no intrinsic factor, so can’t absorb B12, so RBCs can’t divide (macrocytes)
  • lack of EPO often accompanies renal disease
  • destruction or inhibition or red marrow by drugs, chems, radiation, viruses
  • premature RBC lysis (weird Hb, bad transfusions, infections, large spleen)
23
Q

How do Leukocytes exit cappilaries

A
  • through diapedesis

- moe through tissue spaces by ameboid motion and positive chemotaxis

24
Q

Leukocytosis and Leukopenia

A
  • WBC over 11,000 (normal if infection)

- WBC less that 4000

25
Q

5 types of WBC in order of most numerous

A
Neutrophils
Lymphocytes (t and b)
Monocytes
Eosinophils
Basophils
26
Q

2 categories of lymphocytes

A

Granulocytes : neutrophils, eosinophils, and basophils

Aranulocytes = lymphocytes and monocytes

27
Q

Granulocytes

A
  • bigger than RBCs, but don’t live as long
  • lobed nuclei
  • all phagocytic to some degree
  • Wright’s stain
28
Q

Neutrophils

A

50-70% of WBCs

  • “Polymorphonuclear leukocytes”
  • Granules have hydrolytic enxymes/ defensins
  • 3-6 lobes in nucleas
  • 2x RBC size
  • VERY phagocytic “bacteria slayers”
29
Q

Eosinophils

A
  • bilobed nucleus
  • granules similar to lysozomes –> release enzymes to digest paracytic worms
  • alleries and asthma –> granular proteins promote inflamation
  • modulate immune response
30
Q

Basophils

A
  • Granules have histamine
  • Histamine = inflammatory chem that acts as vasodilator to attract WBC to inflamed sites
  • similar to mast cells
31
Q

Lymphocytes

A
  • mostly in lyphoid tissue (lymph nodes and spleen) –> few circulate in blood
  • crucial to immunity
  • T lymphocytes act against virus-infected cells and tumor cells
  • B lymphocytes give rise to plasma cells which make antibodies
  • Natural killer cells func in innate, non-specific immunity
32
Q

Monocytes

A
  • biggest leukocyte
  • leave circulation, entering tissues and differentiate into macrophages
  • Macrophages = actively phagocytic cells
  • Activate lymphocytes to mount an immune response
33
Q

Leukopoisis

  • where?
  • what stimulates it
  • what is the cellular CA
A
  • red bone marrow
  • interleikins and colony stimulating factors
  • hemocytoblasts
34
Q

Leukopoiesis

  • 2nd step
  • progression of granulocytes
  • where are granulocytes stored
  • which type of blood cell does the body make more of?
A
  • Lymphoid stem cell = lymphocytes; Myeloid stem cells = all the others
  • myeloblast–>promyelocyte–>myelocyte–>band–>mature cell
  • bone marrow
  • 3x more WBCs, but shorter life; die in battle
35
Q

progression of agranulocytes

A

Monocytes (last several months)

  • common precurser with neutrophils
  • monoblast–>promonocyte–>monocyte

Lymphocytes (few hours to decades)
-Lymphoid stem cell–>T lymph precurser (thymus) and B lymph precurser

36
Q

Platelets

  • what is it?
  • granular or agranular?
A

-cytoplasmic fragments of megakaryocytes
-granules with sratonin, Ca, enzymes, ADP, and platelet derived growth factors
150000-400000

37
Q

Main function of platelets

  • lifespan
  • hormone regulating their production
  • derive from
A
  • form plugs that help seal breaks in blood vessels
  • kept inactive in circulation by Nitric oxide and prostacyclin from endothelial cells
  • live 10 days
  • homrone = thrombopoietin from liver and kidney
  • from megakaryoblast
38
Q

Hemostasis

  • definition
  • required elements
  • steps
A
  • series of reactions to stop bleeding
  • need clotting factors and substances released by platelets/injured tissue
  1. vascular spasm
  2. platelet plug formation
  3. coagulation
39
Q

Hemostasis: vascular spasm

  • what is it?
  • what triggers it?
  • where is it most effective?
A

-vasoconstriction of damaged blood vessel

triggered by

  • direct injury to vascular smooth muscle
  • chems released by endothelial cells and platelets
  • pain reflexes

effective in small blood vessels

40
Q

Hemostasis: Platelet Plug Formation

  • feedback
  • process
  • chems
A
  • positive feedback
  • damaged skin exposes collagen fibers
  • platelets stick to collagen via plasma protein von Willebrand factor
  • Platelets swell, and get stick and release cham messengers
  • ADP makes moreplatelets stick and release chems
  • seratonin and thromboxane A2 enhance vascular spasm and platelet aggregation
41
Q

Hemostasis: Coagulation

A
  • Reinforces platelet plug with fibrin threads (fibrinogin)
  • blood turns to gel
  • series of rxns using clotting factors (procoagulants)
  • vit K needed to synthesize 4 of the 13 clotting factors
42
Q

3 stages of clotting

A
  1. Extrinsic or intrinsic pathways lead to formation of prothrombinase
  2. Prothrombinase converts prothrombin into thrombin
  3. Thrombin converts fibrinogen (soluble) into fibrin (insoluble) forming the threads of the clot