Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/8/12.
Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.
-
Upload
daniella-higgins -
Category
Documents
-
view
214 -
download
0
Transcript of Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.
![Page 1: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/1.jpg)
Blood
Ch 19 Blood and Hemostasis
Muse Lecture #1 Bio 24405/7/13
![Page 2: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/2.jpg)
Introduction to the Cardiovascular System
A circulating transport system
A pump (the heart)
A conducting system (blood vessels)
A fluid medium (blood)
Is specialized fluid of connective tissue
Contains cells suspended in a fluid matrix
![Page 3: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/3.jpg)
Introduction to the Cardiovascular System
To transport materials to and from cells
Oxygen and carbon dioxide
Nutrients
Hormones
Immune system components
Waste products
![Page 4: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/4.jpg)
Functions of Blood
Transport of dissolved substances
Regulation of pH and ions
Restriction of fluid losses at injury sites
Defense against toxins and pathogens
Stabilization of body temperature
![Page 5: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/5.jpg)
Physical Characteristics of Blood
Whole Blood
Plasma
Fluid consisting of:
– water– dissolved plasma proteins (albumins and globulins)– other solutes (salt, dissolved gasses)
Formed elements
All cells and solids
![Page 6: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/6.jpg)
Physical Characteristics of Blood
Figure 19–1 The Composition of Whole Blood
![Page 7: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/7.jpg)
Physical Characteristics of Blood
Figure 19–1b The Composition of a Typical Sample of Plasma
![Page 8: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/8.jpg)
Physical Characteristics of Blood
Figure 19–1c The Composition of Formed Elements of Blood
![Page 9: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/9.jpg)
Physical Characteristics of Blood
Three Types of Formed Elements
Red blood cells (RBCs) or erythrocytes
Transport oxygen - red because of hemoglobin
White blood cells (WBCs) or leukocytes
Part of the immune system
Platelets
Cell fragments involved in clotting
![Page 10: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/10.jpg)
Physical Characteristics of Blood
Hemopoiesis
Process of producing formed elements
By myeloid and lymphoid stem cells
Fractionation
Process of separating whole blood for clinical analysis
Into plasma and formed elements
centrifugation or filtering
![Page 11: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/11.jpg)
Physical Characteristics of Blood
Three General Characteristics of Blood
38°C (100.4°F) is normal temperature
High viscosity
Slightly alkaline pH (7.35–7.45)
![Page 12: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/12.jpg)
Physical Characteristics of Blood
Blood volume (liters) = 7% of body weight
(kilograms)
Adult male: 5 to 6 liters
Adult female: 4 to 5 liters
![Page 13: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/13.jpg)
Plasma
Makes up 50–60% of blood volume
More than 90% of plasma is water
Extracellular fluids
Interstitial fluid (IF) and plasma
Materials plasma and IF exchange across capillary
walls
Water
Ions
Small solutes
![Page 14: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/14.jpg)
Plasma
Differences between Plasma and IF
Levels of O2 and CO2
Concentrations and types of dissolved
proteins
Plasma proteins do not pass through capillary
walls
![Page 15: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/15.jpg)
Plasma
Plasma Proteins Albumins (60%)
Transport substances such as fatty acids, thyroid hormones, and steroid hormones. HSA- Human Serum Albumin is also a redox buffer to protect proteins from oxidation.
Globulins (35%) Antibodies, also called immunoglobulins
Transport globulins (small molecules): hormone-binding proteins, metalloproteins, apolipoproteins (lipoproteins), and steroid-binding proteins
Fibrinogen (4%) Molecules that form clots and produce long, insoluble strands
of fibrin
![Page 16: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/16.jpg)
Plasma
Serum
Liquid part of a blood sample
In which dissolved fibrinogen has converted to solid fibrin
Other Plasma Proteins
1% of plasma
Changing quantities of specialized plasma proteins
Enzymes, hormones, and prohormones
![Page 17: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/17.jpg)
Plasma
Origins of Plasma Proteins
90% + made in liver
Antibodies made by plasma cells (WBCs(B-cells)
Peptide hormones made by endocrine organs
![Page 18: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/18.jpg)
Red Blood Cells
Red blood cells (RBCs) make up 99.9% of
blood’s formed elements
Hemoglobin
The red pigment that gives whole blood its color
Binds and transports both oxygen and carbon dioxide
![Page 19: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/19.jpg)
Red Blood Cells
Abundance of RBCs
Red blood cell count: the number of RBCs in 1
microliter of whole blood
Male: 4.5–6.3 million
Female: 4.2–5.5 million
Hematocrit (packed cell volume, PCV): percentage of
RBCs in centrifuged whole blood
Male: 40–54
Female: 37–47
![Page 20: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/20.jpg)
Red Blood Cells
Structure of RBCs - anucleate in mammals Small and highly specialized discs
Thin in middle and thicker at edge
Importance of RBC Shape and Size High surface-to-volume ratio
Quickly absorbs and releases oxygen
Discs form stacks called rouleaux Smooth the flow through narrow blood vessels
Discs bend and flex entering small capillaries: 7.8 µm RBC passes through 4 µm capillary
Figure 19–2d
![Page 21: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/21.jpg)
Red Blood Cells
Figure 19–2a–c The Anatomy of Red Blood Cells
![Page 22: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/22.jpg)
Red Blood Cells
Figure 19–2d The Anatomy of Red Blood Cells
![Page 23: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/23.jpg)
Red Blood Cells
Lifespan of RBCs
Lack nuclei, mitochondria, and ribosomes
Means no repair and anaerobic metabolism
Live about 120 days
![Page 24: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/24.jpg)
Red Blood Cells
Hemoglobin (Hb)
Protein molecule, that transports respiratory gases
Normal hemoglobin (adult male)
14–18 g/dL whole blood
Normal hemoglobin (adult female)
12–16 g/dL, whole blood
![Page 25: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/25.jpg)
Red Blood Cells
Figure 19–3 The Structure of Hemoglobin
![Page 26: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/26.jpg)
Red Blood Cells
Figure 19–4 ”Sickling” in Red Blood Cells
B-globin D6V
![Page 27: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/27.jpg)
Red Blood Cells
RBC Formation and Turnover
1% of circulating RBCs wear out per day
About 3 million RBCs per second
Macrophages of liver, spleen, and bone marrow
Monitor RBCs
Engulf RBCs before membranes rupture (hemolyze)
![Page 28: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/28.jpg)
Figure 17.5
Stem cell
Hemocytoblast
Proerythro-blast
Earlyerythroblast
Lateerythroblast Normoblast
Phase 1Ribosomesynthesis
Phase 2Hemoglobinaccumulation
Phase 3Ejection ofnucleus
Reticulo-cyte
Erythro-cyte
Committedcell
Developmental pathway
Enters bloodstream
![Page 29: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/29.jpg)
Red Blood Cells
Regulation of Erythropoiesis
Building red blood cells requires
Amino acids
Iron
Vitamins B12, B6, and folic acid:
– pernicious anemia
» low RBC production
» due to unavailability of vitamin B12
![Page 30: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/30.jpg)
Figure 17.6
Kidney (and liver toa smaller extent)releaseserythropoietin.
Erythropoietinstimulates redbone marrow.
Enhancederythropoiesisincreases RBCcount.
O2- carryingability of bloodincreases.
Homeostasis: Normal blood oxygen levels
Stimulus:Hypoxia (low bloodO2- carrying ability)
due to• Decreased
RBC count• Decreased amount
of hemoglobin• Decreased
availability of O2
1
2
3
4
5
IMBALANCE
IMBALANCE
This is why athletes train in low altitude
![Page 31: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/31.jpg)
White Blood Cells
Figure 19–11 The Origins and Differentiation of Formed Elements
![Page 32: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/32.jpg)
Platelets
Cell fragments involved in human clotting
system
Nonmammalian vertebrates have thrombocytes
(nucleated cells)
Circulate for 9–12 days
Are removed by spleen
2/3 are reserved for emergencies
![Page 33: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/33.jpg)
Platelet
![Page 34: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/34.jpg)
Platelets
Platelet Counts
150,000 to 500,000 per microliter
Thrombocytopenia
Abnormally low platelet count
Thrombocytosis
Abnormally high platelet count
![Page 35: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/35.jpg)
Platelets
Three Functions of Platelets:
1. Release important clotting chemicals
2. Temporarily patch damaged vessel walls
3. Actively contract tissue after clot formation
![Page 36: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/36.jpg)
Platelets
Platelet Production
Also called thrombocytopoiesis
Occurs in bone marrow
Megakaryocytes
Giant cells in bone marrow
Manufacture platelets from cytoplasm
![Page 37: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/37.jpg)
Platelets
Platelet Production
Hormonal controls
Thrombopoietin (TPO)
Interleukin-6 (IL-6)
Multi-CSF
![Page 38: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/38.jpg)
Hemostasis
Hemostasis is the cessation of bleeding
Consists of three phases
Vascular phase
Platelet phase
Coagulation phase
![Page 39: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/39.jpg)
Hemostasis
The Vascular Phase A cut triggers vascular spasm that lasts 30 minutes
Three steps of the vascular phase Endothelial cells contract:
– expose basal lamina to bloodstream
Endothelial cells release:
– chemical factors: ADP, tissue factor, and prostacyclin
– local hormones: endothelins
– stimulate smooth muscle contraction and cell division
Endothelial plasma membranes become “sticky”:
– seal off blood flow
![Page 40: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/40.jpg)
Hemostasis
The Platelet Phase
Begins within 15 seconds after injury
Platelet adhesion (attachment)
To sticky endothelial surfaces
To basal laminae
To exposed collagen fibers
Platelet aggregation (stick together)
Forms platelet plug
Closes small breaks
Figure 19–11b
![Page 41: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/41.jpg)
Hemostasis
Platelet Phase
Activated platelets release clotting compounds
Adenosine diphosphate (ADP)
Thromboxane A2 and serotonin
Clotting factors
Platelet-derived growth factor (PDGF)
Calcium ions
![Page 42: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/42.jpg)
Hemostasis
Factors that limit the growth of the platelet plug
Prostacyclin, released by endothelial cells, inhibits
platelet aggregation
Inhibitory compounds released by other white blood
cells
Circulating enzymes break down ADP
Negative (inhibitory) feedback: from serotonin
Development of blood clot isolates area
![Page 43: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/43.jpg)
Hemostasis
Figure 19–12 The Vascular and Platelet Phases of Hemostasis.
![Page 44: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/44.jpg)
1
Red blood cell
Platelet
Collagen fibersand damagedendothelium
Platelet adhesion11
2
Red blood cell
Platelet
Collagen fibersand damagedendothelium
Liberated ADP,serotonin, andthromboxane A2
Platelet adhesion1
Platelet release reaction2
1
2
3
Red blood cell
Platelet
Collagen fibersand damagedendothelium
Liberated ADP,serotonin, andthromboxane A2
Platelet plug
Platelet adhesion1
Platelet release reaction2
Platelet aggregation3
![Page 45: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/45.jpg)
Hemostasis
The Coagulation Phase
Begins 30 seconds or more after the injury
Blood clotting (coagulation)
Cascade reactions:
– chain reactions of enzymes and proenzymes
– form three pathways
– convert circulating fibrinogen into insoluble fibrin
Figure 19–12a
![Page 46: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/46.jpg)
Blood Clotting
Blood clotting Serum is blood plasma
minus clotting proteins Clotting – series of
chemical reactions culminating in formation of fibrin threads
Clotting (coagulation) factors – Ca2+, several inactive enzymes, various molecules associated with platelets or released by damaged tissues
![Page 47: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/47.jpg)
Hemostasis
Clotting Factors
Also called procoagulants
Proteins or ions in plasma
Required for normal clotting
![Page 48: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/48.jpg)
Hemostasis
Hemophelia is a loss of any one of these
![Page 49: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/49.jpg)
Hemostasis
Three Coagulation Pathways
Extrinsic pathway
Begins in the vessel wall
Outside bloodstream
Intrinsic pathway
Begins with circulating proenzymes
Within bloodstream
Common pathway
Where intrinsic and extrinsic pathways converge
![Page 50: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/50.jpg)
Hemostasis
The Extrinsic Pathway
Damaged cells release tissue factor (TF)
TF + other compounds = enzyme complex
Activates Factor X
![Page 51: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/51.jpg)
Hemostasis
The Intrinsic Pathway
Activation of enzymes by collagen
Platelets release factors (e.g., PF–3)
Series of reactions activates Factor X
![Page 52: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/52.jpg)
Figure 17.14 (1 of 2)
Vessel endothelium ruptures,exposing underlying tissues(e.g., collagen)
PF3
released byaggregated
platelets
XII
XI
IX
XIIa
Ca2+
Ca2+
XIa
IXa
Intrinsic pathwayPhase 1
Tissue cell traumaexposes blood to
Platelets cling and theirsurfaces provide sites formobilization of factors
Extrinsic pathway
Tissue factor (TF)
VII
VIIa
VIII
VIIIa
Ca2+
X
Xa
Prothrombinactivator
PF3
TF/VIIa complexIXa/VIIIa complex
V
Va
![Page 53: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/53.jpg)
Hemostasis
The Common Pathway
Forms enzyme prothrombinase
Converts prothrombin to thrombin
Thrombin converts fibrinogen to fibrin
![Page 54: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/54.jpg)
Hemostasis
Stimulates formation of tissue factor
Stimulates release of PF-3
Forms positive feedback loop (intrinsic and
extrinsic)
Accelerates clotting
![Page 55: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/55.jpg)
Hemostasis
Figure 19–13a The Coagulation Phase of Hemostasis
![Page 56: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/56.jpg)
Hemostasis
Figure 19–13b The Coagulation Phase of Hemostasis
![Page 57: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/57.jpg)
![Page 58: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/58.jpg)
3 Stages of Clotting
Extrinsic or intrinsic pathways lead to formation of prothrombinase
Prothrombinase converts prothrombin into thrombin
Thrombin converts fibrinogen (soluble) into fibrin (insoluble) forming the threads of the clot
![Page 59: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/59.jpg)
Hemostasis
Clotting: Area Restriction
Anticoagulants (plasma proteins)
Antithrombin-III
Alpha-2-macroglobulin
Heparin
Protein C (activated by thrombomodulin)
Prostacyclin
hirudin (leech protein)
EDTA
![Page 60: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/60.jpg)
Hemostasis
Calcium Ions, Vitamin K, and Blood
Clotting
Calcium ions (Ca2+) and vitamin K are both
essential to the clotting process
![Page 61: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/61.jpg)
Hemostasis
Clot Retraction
After clot has formed
Platelets contract and pull torn area together
Takes 30–60 minutes
![Page 62: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/62.jpg)
Hemostasis
Fibrinolysis
Slow process of dissolving clot
Thrombin and tissue plasminogen activator (t-PA):
– activate plasminogen
Plasminogen produces plasmin
Digests fibrin strands
TPA to treat strokes
![Page 63: Blood Ch 19 Blood and Hemostasis Muse Lecture #1 Bio 2440 5/7/13.](https://reader036.fdocuments.in/reader036/viewer/2022062517/56649ead5503460f94bb4e74/html5/thumbnails/63.jpg)
I shuued haf studied harder for myA & P exam