biol 121 chp 19: the cardiovascular system - the blood
DESCRIPTION
This is a lecture presentation for my BIOL 121 Anatomy and Physiology I students on Chapter 19: The Cardiovascular System: The Blood (Principles of Anatomy and Physiology, 14th Ed. by Tortora and Derrickson). Rob Swatski, Associate Professor of Biology, Harrisburg Area Community College - York Campus, York, PA. Email: [email protected] Please visit my website for more anatomy and biology learning resources: http://robswatski.virb.com/TRANSCRIPT
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The Cardiovascular System: Blood
BIOL 121: A&P I Chapter 19
Rob Swatski Associate Professor of Biology HACC – York Campus Te
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Internal Fluid Environment of
the Body
Blood plasma (in blood vessels)
IntersLLal fluid (b/w cells)
FuncLons of Blood
Transport: O2, CO2, wastes, nutrients, heat,
hormones
RegulaLon: pH,
temperature, osmoregula*on
Immunity: white blood
cells (leukocytes)
CloNng: prevent blood
loss (hemorrhage)
3
9
What is Blood?
Blood plasma & formed elements
pH = 7.4 (7.35-‐7.45)
Volume = 4-‐6 liters
High viscosity – benefits?
14
Albumins
Most abundant
plasma protein
Made in the liver
Maintains blood osmoLc
pressure
Transports hormones
18
Formed Elements
Erythrocytes (Red blood
cells)
Leukocytes (White blood
cells)
Thrombocytes (Platelets)
21
Hematocrit
Blood plasma (55% volume)
Formed elements (45%
volume)
Anemia: low RBCs
Polycythemia: high RBCs
22
Hemopoiesis
ConWnual replacement of blood cells
Embryo: yolk sac, liver, spleen, thymus, lymph nodes, red bone
marrow
AVer Birth & Adult: red bone marrow only
HemopoieLc Growth Factors (regulate differenWaWon & proliferaWon of blood cells)
ErythropoieLn (EPO, kidneys): increases RBCs
ThrombopoieLn (TPO, liver):
sWmulates platelet formaWon
Cytokines (bone marrow,
WBCs, fibroblasts, endothelial cells): sWmulate hemopoiesis;
increases WBCs; colony-‐sWmulaWng
factors & interleukins
27
28
Flexible, biconcave disk High SA-‐V raWo
No nucleus or organelles
Contain hemoglobin
Do not divide 5.4 million per uL (men); 4.8 million per uL (women)
Erythrocytes
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Hemoglobin (Hgb)
4 polypepWde chains (quaternary)
1 heme (Fe+2) per chain
Each heme combines reversibly with 1 O2
32
Gas Transport by
Hemoglobin
1 Hgb (4 hemes) can carry up to 4
O2
Globin carries CO2 to lungs
Also transports nitric oxide
(NO): vasodilator
35
RBC Life Cycle
120-‐day life span
Constant wear-‐and-‐tear
No repair possible: why not?
Dead RBCs removed by macrophages in liver, spleen, marrow
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Hemoglobin Recycling
Globin à amino acids
Heme à Fe+3 & biliverdin
Transferrin: transfers iron to liver or bone
marrow
Biliverdin à bilirubin à bile
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Erythropoiesis
RBC producWon in red bone marrow
SWmulated by hypoxia
CFU-‐E à Proerythroblasts
ReLculocytes à eject nucleus, then organelles
Become mature erythrocytes
42
Leukocytes
No hemoglobin
Larger cells with nucleus
Less abundant than RBCs & platelets
Unique MHC-‐anWgens
Granular or Agranular
44
WBC Physiology
Only 2% in circulaWon
Most in lymph, skin, lung, nodes,
spleen
Leukocytosis
Leukopenia
50
Neutrophils
Polymorphonuclear leukocytes (“polys”)
60-‐70% of WBCs
Numerous, Wny granules
MulW-‐lobed nucleus
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Lymphocytes
20-‐25% of WBCs
Agranulocytes
B cells, T cells, NK cells
Large, round, darkly stained
nucleus
Sky blue cytoplasm
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Monocytes
3-‐8% of WBCs
Agranulocytes
Larger cell: 12-‐20 μm
Kidney or horseshoe-‐
shaped nucleus
Foamy blue-‐gray cytoplasm
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EmigraLon of WBC’s
EmigraLon = Exit out of blood capillary
SelecLns: on BV endothelium
Integrins: on WBC membrane
Roll à SWck à Squeeze
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Chemotaxis
Cellular movement toward
chemicals
Kinins: released from injured
Wssues
Toxins from microbes
Phagocytosis: neutrophils, monocytes, macrophages
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Neutrophil FuncLons Fastest response & emigraWon to
bacteria
Phagocytosis
Secrete lysozymes
Contain strong oxidants: O2
-‐, H2O2, OCl-‐
Contain defensins
63
Eosinophil FuncLons
Emigrate into Wssue fluid
Secrete histaminase
(“an*histamine”)
Reduce inflammaWon from allergic reacWons
PhagocyWze anLgen-‐anLbody
complexes
Arack parasiWc worms
65
Basophil FuncLons Emigrate into CT as mast cells
Secrete histamine, serotonin, & heparin
Intensify inflammaLon
Trigger hypersensiLvity
reacLons (allergies)
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Monocyte FuncLons Emigrate in large
numbers
PhagocyWze microbes
Remove dead Wssue post-‐infecWon
DifferenWate into
macrophages
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Macrophages
Fixed
Alveolar cells (lungs)
Kupffer cells (liver)
Wandering
Emigrate to site of injury/infecWon
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Lymphocyte FuncLons B cells: destroy bacteria
& toxins
B cells à Plasma cells (secrete anLbodies)
T cells: destroy viruses, fungi, organ transplants,
cancer cells, some bacteria
Natural Killer (NK) cells: destroy variety of infecWous microbes &
tumor cells
DifferenLal WBC Count
Neutrophils: bacterial infecWon,
burns, stress, inflammaWon
Lymphocytes: viral infecWon, some leukemias,
infecWous mononucleosis
Monocytes: fungal/viral infecWon, some
leukemias, TB, other chronic
diseases
Eosinophils: allergic
reacWons or parasites,
autoimmune disease
Basophils: allergic
reacWons, leukemias, cancers,
hypothyroid-‐ism
76
77
Platelets (Thrombocytes)
150,000-‐400,000 platelets/uL
5-‐9 day lifespan
Removed by macrophages in liver & spleen
FuncWon in hemostasis,
including blood cloNng
79
Platelet Anatomy
Cell fragments
No nucleus; Contain many vesicles (granules)
Granules store cloNng factors & accessory clotng
chemicals
84
Clotng (CoagulaWon)
Factors ADP ATP
Calcium ions Serotonin Thromboxane A2
Fibrin-‐Stabilizing-‐Factor
Platelet-‐Derived Growth Factor
(PDGF)
Platelet Chemicals
Red blood cell
Platelet
Collagen fibers and damaged endothelium
1 Platelet adhesion Collagen fibers
Liberated ADP, serotonin, and
thromboxane A2
2 Platelet release reaction Collagen fibers
PLATELET PLUG
3 Platelet aggregation
90
CloNng (CoagulaLon)
Serum
Clot = insoluble fibrin
Traps blood cells
CloNng factors in plasma & platelets
Tissue factor
91
Calcium ions (Ca+2) Clotng Factors
Tissue Factor (TF) or
ThromboplasWn
CloNng (CoagulaLon) Factors
98
HemostaLc Control
Prostacyclin
From BV endothelium & WBCs
Prevents platelet
adhesion & release reacWon
AnLcoagulants
AnLthrombin, Heparin, and AcLvated
Protein C (APC)
FibrinolyLc System
Fibrinolysis
Plasminogen (inac*ve) à Plasmin (ac*ve) à digests fibrin
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Intravascular CloNng
(Thrombosis) Thrombus:
inappropriate clot
Stasis
AccumulaWon of clotng factors à coagulaWon
Embolus (Pulmonary embolism)
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AnLcoagulants Aspirin: blocks thromboxane A2
Heparin: used during hemodialysis & surgery
Coumadin (Warfarin): vitamin K antagonist
Citrate phosphate dextrose (CPD) or EDTA:
removes Ca+2
ThrombolyLc agents: streptokinase à dissolves
clots
103
Blood Types
Glycoproteins & glycolipids on
RBC membranes
AggluLnogens = A anLgen & B
anLgen
AnL-‐A and AnL-‐B anLbodies in
plasma
ABO blood group
105
ABO Blood Group
A anWgen only = Type A
B anWgen only = Type B
Both A and B anWgens = Type AB
Neither A or B anWgens = Type O
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AnLbodies (AggluLnins)
Plasma contains anWbodies to the anWgens not found
in your blood
AnL-‐A anLbody: reacts with A anWgen
AnL-‐B anLbody: reacts with B anWgen
107
Rh Blood Group
AnWgen discovered on RBCs of Rhesus
monkeys
Rh+: anWgen present
Rh-‐: anWgen absent
AnL-‐Rh anLbody develops only in Rh-‐ plasma a9er
exposure
109
Blood Transfusions
Transfer of whole blood, cells, or plasma
Treat anemia or severe blood
loss
IncompaLble transfusions: agglu*na*on
RBCs burst, Hgb results in kidney
damage
110
DonaLng & Receiving Blood
Type O = Universal donor
No A or B anWgens on RBCs
Type AB = Universal recipient
No anW-‐A or anW-‐B anWbodies in
plasma
111
Blood Typing
Detects ABO and Rh groups
Mix blood sample with serums (anLsera) containing
anWbodies to each anWgen
Cross-‐matching: determines compaWbility
114
Anemia
Low RBC count
Reduced O2-‐carrying capacity
of blood
Not enough O2 to produce ATP
& heat
FaWgue, cold intolerance, skin
pallor
119
Sickle-‐Cell Anemia GeneWc mutaWon in Hgb synthesis
Deforms RBCs à easily rupture &
clot
Found in malaria belt regions
Carriers have increased malaria
resistance
RBCs leak K+ à kills parasite