Constituents of Blood Flashcards
Blood Overview
Blood is a type of connective tissue made up of
- watery ECM
- cellular elements
Bloods Cellular Elements
- RBC - gas transport
- WBC - immune function
- Platelets - clotting/hemostasis
Blood Components by Centrifuge
Top layer - 58% plasma volume
Middle layer - <1% WBC
Lower layer - 42% RBC volume
Hematopoeisis
synthesis of blood cells
- occurs in the bone marrow of the pelvis/spine/ribs/cranium/long bones
Pluripotent hematopoietic stem cells
partially but not permenently differentiated stem cells
Erythrocytes
are RBC’s
Megakaryocyte’s
give rise to plateletss
Types of WBC’s
- neutrophil
- monocyte
- basophil
- eosinophil
- lymphocyte
Erythropoietin (EPO)
sensed and produced at the kidney cells, acts on cells in bone marrow to grow more RBC
Thrombopoietin (TPO)
sensed and produced at the liver, acts on cells in bone marrow to grow more megakaryocytes (which give rise to platelets)
Hemoglobin
- contains 4 heme groups
- each heme group contains a porphryin ring with an iron atom in the center, allows for 4 Oxygens to cooperatively bind
Anemia
low RBC count due to
1. accelerated RBC loss
2. decreased RBC production
Accelerated RBC loss causes
- blood loss
- hemolytic anemia (RBC desctruction) which can be genetic (sickle cell) or acquired (malaria)
Decreased RBC production
- aplastic anemia (drugs/radiation)
- dietary insufficiencies (iron/b12/folic acid deficiency)
Hemostasis & Tissue Repair Steps
- vasoconstriction
- platelet plug formation
- coagulation
- dissolution of clot
Intrinsic Pathway
exposure of collagen starts the pathway, activating a series of factors as a checking process to prevent uneeded occlusions, ultimately we activate FACTOR 10
- prothrombin converted into thrombin
- thrombin activates fibrinogen which turns into fibrin
- fibrin becomes cross linked through RBC collection
- clot breakdown through plasmin
Extrinsic Pathway
- Tissue factor leaks into the vessel from the ruptured wall
- activates a number of factors, ultimately FACTOR 10
- prothrombin converted into thrombin
- thrombin activates fibrinogen which turns into fibrin
- fibrin becomes cross linked through RBC collection
- clot breakdown through plasmin
Fibrinolysis
clot dissolves due to the actions of enzyme plasmin
Blood Types: O
does not have any antigens, but produces A & B antibodies
- universal donor
- only recieves O
Blood Type A
has A antigens, but produces B antibodies
- can be given to A and AB because they dont have A-antibodies
- recieves O and A
Blood Type B
has B antigens, but produces A antibodies
- can be given to B and AB because they dont produce B-antibodies
- recieves O and B
Blood Type AB
has A & B antigens, but does not produce any antibodies
- can only be given to AB
- universal recipient
Rhesus (Rh)
+ means you carry the Rh antigen
- means you dont carry the Rh antigen
