Lecture 21 Blood and Immune Flashcards
Large blood vessels have
High volume/ low flow
Small vessels
Low volume/ high flow
2 things that blood pressure ensures
Even and efficient flow through the small capillaries, and low enough blood pressure to prevent capillary leakage, and high enough to avoid coagulation.
Leukocytes are responsible for:
Immune defence
Platelets are responsible for:
Coagulation and tissue repair
Plasma contains ____
fibrinogen, which is removed with coagulation.
2 major blood proteins:
Albumin and Globulin
Albumin:
50% of total blood protein. Maintains colloidal osmotic pressure. Binds and transports many small molecules, hormones.
Fibrinogen:
7% of total blood protein. Activated through the coagulation cascade to form cross-linked fibrin.
Immunoglobins: role and produced by ____
Antibodies, rpoduced by B lymphocytes.
Complement:
9 proteins that coat bacteria targeting them for phagocytosis.
What is the major complement component?
C3
What is opsonization?
Immune process where particles such as bacteria are targeted for destruction by an immune cell known as a phagocyte . The process of opsonization is a means of identifying the invading particle to the phagocyte.
Coagulation factors:
13 proteins cleaved in ordered cascade resulting in fibrinogen -> fibrin. Ca++ is essential to coagulation. haemopilia’s result from a missing component.
What is the most common form of haemophilia.
Factor VIII deficiency is the commonest form of hemophilia.
Blood pH is very tightly maintained at ___
7.4
What is the role of CD34?
It is a surface antigen marker on HSCs.
Adaptive immunity blood cells:
Small lymphocyte, T lymphocyte, B lymphocyte, Plasma cell
Innate immunity blood cells:
Basophil, Neurophil, Eosiniphil, Monocyte, Macrophage
Three important factors that drive haematopoiesis:
GM-CSF, EPO, G-CSF
GM-CSF
Granulocyte macrophage colony-stimulating factor.
Produced by macrophages, T cells, endothelial cells and fibroblasts.
Stimulates production of neutrophils, eosinophils, basophils and monocytes.
EPO:
Erythropoetin
Drives production of erythrocytes
Produced mainly by kidney during adulthood and liver in perinatal.
G-CSF
Granulocyte colony-stimulating factor.
- Produced mainly by different cells.
- Stimulates production of granulocytes but also acts to mature neutrophils.
O2 readily associates and dissociates in the __
associates in the lungs, and dissociates in the tissues.
Complement is essential for ___
innate immunity
___ is the most abundant complement in the serum
C3
3 pathways for complement:
Classical, Lectin, Alternative
The classical pathway for complement is mediated by ____
IgM or IgG binding to a microbe surface which is then bound by complement C1.
Deposited complexes are called ___
convertases.
Cleavage of C3, C4 and C5 produce small fragments called ___
anaphylatoxins
Anaphylatoxins are ____
Chemoattractants that attract and activate neutrophils.
Virulence factors:
Inhibit the complement cascade
The end stage of complement:
C5 onwards forms a lytic pore that cause some bacteria to lyse. This is the membrane attack complex or MAC.
Two pathways for coagulation:
Intrinsic, surface, and Extrinsic, tissue damage.
Which factor is common to both pathways in coagulation
10/X
What happens if calcium is removed from the coagulation pathway?
Blood will not clot
What is thrombin?
An enzyme that cleaves fibrinogen to fibrin which cross-links.
Plasminogen is converted to
plasma
What is TPA?
Tissue Plasminogen Activator;
Arterial pressure is matinained by:
Elastic vessel walls that contain an abundance of smooth muscle.
Venous pressure is:
lower because veins are not elastic
Each haemoglobin contains :
4 haem molecules each containg 1 iron atom in the ferrous ofmr (Fe2+).
In centrifugation:
Packed red cells 40%, buffy coat contains white cells 10%, plasma 50% contains soluble proteins, lipids, platelets.
CD34+ HSC gives rise to two multipotent stem cells
myeloid or lymphoid progenitors
Myeloid progenitors gives rise to:
eythrocytes
Lymphoid progenitor gives rise to:
B lymphocytes or T lymphocytes
Immature T lymphocyte differentiates into
CD4 or CD8
Erythrocytes are used solely for:
Oxygen transport
Myeloid cells provide you with:
innate immunity and phagocytosis is a key mechanism.
Lectins:
Carb binding proteins in blood that bind to unusual carbohydrates found only on microbes.
Phagocytic cells:
Neutrophils and macrophages have complement receptors that bind complement and initiate phagocytosis.
In the intrinsic pathway, which factors lead to the cleavage of factor X
12, 11, 9 and 8
Whivh factor activates thrombin
X
Anti coagulants:
Heparin and warfarin, block thrombin
