Lecture 23 Flashcards
Constituents of Blood
How much blood in the human body?
its about 7% of the body weight
5L in a 70kg male
4L in a 58kg female
What is blood and what is it made up of?
a connective tissue
- 58% plasma (1/4 of body ECF) containing vitamins, proteins and ions
- 42% Cellular Elements red and white blood cells and transported round the body
- 1% platelets used in clotting and hemostasis
The layer of platelets is known as…
the Buffy layer
Hematopoeisis
the synthesis of blood in red bone marrow in flat bones and proximal ends of long bones
Lifespan of red and white blood cells
- 120 days for red blood cells (25% bone marrow production)
- 6-12 hours for white blood cells (75% of bone marrow production)
What is the name of the precursor cell for all white. red and platelets
pluripotent hematopoitetic stem cells
what are cytokines?
proteins that are released from a cell to signal another
Where are the cytokines released and what do they affect?
Erythropoietin (EPO) - released from the kidneys to increase red blood cell growth
Thrombopoietin (TPO) - productions of platelets signalled from liver
Interleukins - all types of cells prompted from fibrocytes in the bone marrow
Hypoxia
low O2 in the blood
hemoglobin
2 alpha and beta dimers forming a tertramer with binding cooperatvity
each heme have a porphyrin ring that contains Fe
Anemia
low RBC count by accelerated loss of blood or decreased production
examples of accelerated RBC loss
- blood loss
- hemolytic anemia
- genetic like sickle cell
- acquired like malaria
examples of decreased RBC production
- aplastic anemia from drugs or radiation
- dietary insuffciencies iron, folic acid and vitamin b12
Difference between Hemostasis and Hemapotesis
Hemostasis - keeping blood inside the blood
Hemapotesis - production of blood cells
the 4 stages of hemostasis
1) Vasoconstriction
2) Platelet Plug Formation
3) Coagulation (formation of clots)
4) Dissolution of the clot (fibrinolysis)
Explain Vasoconstriction
paracrine signal for a release of norepinephrine which will go to the alpha 1 receptors on the smooth muscles and cause ca2+ to be released allowing for constriction
Explain platelet plug formation
planets constantly flow in the blood, when a cut appears, they stick to the exposed collagen.
explain coagulation
the formation of a clot
- in the intrinsic pathway, coagulation factors lead to activation of factor 10
- in the extrinsic factor phospholipids and ca2+ are released
- factor 10 uses Ca2+ and the phosolipids to set of Active 10
- in the Common Pathway, Active 10 and Ca2+ turns prothrombin into thrombin
- Thrombin turns Fibrinogen into Fibrin and factor 13 into Active 13
- Active 13 and Ca2+ turns fibrin into cross linked fibrin
Explain Fibrinolysis
Once tissue is repaired, clot is dissolved by enzyme plasmin
Blood Type O
- has no antigens
- creates antibodies A and B
Blood Type A
- has antigen A
- makes antibodies B
Blood Type B
- has antigen B
- makes antibodies A
Blood Type AB
- has both antigens
- makes no antibodies
Why does blood typing occur?
if you make antibodies, you cant have blood with that antigen or your blood will clot
What makes the rhesus factor different?
Rh- people don’t make the rhesus factor unless they are exposed to Rh+
What’s the danger to new Rh- mothers
if the baby is Rh+, the mother will make antibodies for the Rh+ if their blood mixes. The second baby could then be affected?
What’s the solution to the Rh baby issue
inject with immune repressors so the mom won’t make the antibodies
