Ch 16: Blood. Plasma and Cellular Elements of Blood Hematopoiesis RBC Physiology Coagulation. Blood = connective tissue. Extracellular matrix:. Specialized cells:. Fig 16-1. Plasma. Blood Components Overview. Blood. 20-40%. Total WBC: 4,000 - 11,000. 2-8%. Cellular Elements.
Plasma and Cellular Elements of Blood
Total WBC: 4,000 - 11,000
Compare to Fig 16-2
RBC bag of Hbfor carrying O2
lifespan ~ 120 days
source of ATP for RBC?
Porphyrin ring with Fe in center
How many O2 can 1Hb carry?
1st genetic illness traced to a specific mutation:
aa: glutamic acid valine (aa #6 of 146)
HbA HbS crystallizes under low oxygen conditions
= Opposite of hemorrhage stops bleeding
Too little hemostasis too much bleeding
Too much hemostasis thrombi / emboli
Three major steps:
Vessel damage exposes collagen fibers
Platelets adhere to collagen & release factors
local vasoconstriction & platelet aggregation
decreased blood flow platelet plug formation
+ feedback loop
Platelet activating factor (PAF)
Two coagulation pathways converge onto common pathway
“Cascade” is complicated network!
Numbering of coagulation factors according to time of discovery
Active factor X
reinforces platelet plug
Plasmin, trapped in clot,
will dissolve clot by fibrinolysis
Clot formation limited to area of injury: Intact endothelial cells release anticoagulants (heparin, antithrombin III, protein C).
SEM x 4625
Dissolve inappropriate clots
Examples:Urokinase, Streptokinase & t-PA
Prevent coagulation by blocking one or more steps in fibrin forming cascade
Inhibit platelet adhesion plug prevention