PSIO202 Exam 1 Lecture 8-9 Flashcards
What fluids serve the body’s cells?
ISF and blood
What is the study of blood and blood disorders?
hematology
What are the general percentages of the composition of blood?
plasma - 55%
formed elements - 45% (almost all erythrocytes)
What is the composition (%) of plasma?
91.5% water and 8.5% solutes
All formed elements come from what type of cell?
pluripotent stem cell
What are the 3 types of progenitor cells?
CFU-E (colony forming unit erythrocyte)
CFU-Meg (colony forming unit megakaryocyte)
CFU-GM (colony forming unit granulocyte macrophage)
What percent of plasma is proteins? Where are the plasma proteins created?
under 10%
liver
What plasma proteins are confined to the bloodstream? What do they do?
albumin - maintain blood osmotic pressure (BCOP)
immunoglobulins - antibodies that bind antigens
form antigen - antibody complexes
What else is in the plasma? (1 more protein and other solutes)
fibrinogen - clotting
electrolytes, nutrients, hormones, gases, waste products
What is a hematocrit? What is normal for men and women?
percent of blood occupied by cells
women - 38-46% avg 42
men- 40-54% avg 46
What are anemia and polycythemia? Causes of polycythemia? What issues are caused by polycythemia?
anemia - insufficient erythrocytes or not enough hemoglobin
polycythemia - too many erythrocytes (more than 65%) caused by dehydration, hypoxia, or blood doping. This can impede the flow of blood (too thick)
What does hemoglobin do? What is the structure? Where does it get the oxygen? Does it carry anything else?
carry oxygen
4 protein chains, 2 alpha and 2 beta, and each has a heme group. Heme is a porphyrin ring with an iron in the middle. Iron can bind an oxygen. Therefore, 4 O2 carried in a Hb.
Oxygen is picked up in the lung capillaries, and it can also transport CO2 which combines with the amino acids in the globin part of Hb
What is the Hb concentration in a healthy woman/man?
woman: 14 gm/100 ml
man: 16 gm/100 ml
Explain erythropoiesis.
occurs in red bone marrow
pluripotent stem cell > myeloid stem cell > colony forming unit erythrocyte with EPO (erythropoietin) >
proerythroblasts > reticulocyte > nucleus ejected and mature erythrocte forms, Hb forms
What is the main regulator of differentiation/proliferation of erythrocytes? Where is it produced? What happens if it is absent?
erythropoietin (EPO) produced by the kidneys, increase RBC precursors and without it the cells go through apoptosis
What can be done for people with reduced kidney function who do not have enough EPO?
recombinant DNA technology, recombinant EPO
When a red blood cell dies, what happens to it?
engulfed by a macrophage in the spleen or liver
broken down into globin and heme
Globin: broken down into amino acids, which are reused for protein synthesis
Heme: broken into biliverdin and iron
biliverdin > bilirubin > secreted by the liver into the bile > stercobilin into the feces and urobilin into the urine
iron transported in the blood by transferrin, stored in the liver/muscle/spleen, than attached to ferritin to transfer to the bone marrow > joins with all the other stuff to make more red blood cells > RBC enter bloodstream through sinusoidal capillaries
How long do RBC’s live? Why can’t they just repair themselves?
about 120 days, they do not have a nucleus so they can’t make repairs but breakdown products are reused
Where are pluripotent stem cells located? Where is that substance located?
in the red bone marrow, which is located in the pectoral and pelvic girdles of the axial skeleton
How are thrombocytes formed? Start with the pluripotent stem cell. Include what happens to the formed platelets.
pluripotent stem cell > myeloid stem cell > CFU-Meg + thrombopoietin > megakaryoblast > megakaryocyte > fragment into thrombocytes/platelets > 2/3 circulate and 1/3 stored in the spleen
Where is thrombopoietin released from? Where is erythropoietin released from?
liver, kidney
How many thrombocytes are fragmented from one megakaryocyte? What are the diameters of these two?
2000-3000 thrombocytes from 1 megakaryocyte, 160 um vs 2-4 um.
What is a thrombosis, thrombis, and embolus?
thrombosis - formation of a clot
thrombis - clot
embolus - circulating clot
What is the formation of thrombocytes called? What is the formation of erythrocytes called?
thrombocytopoiesis
erythropoiesis
What is hemorrhage?
severe uncontrolled bleeding
What is hemostasis, and how does it occur?
reactions designed to stop bleeding
vascular spasm, platelet plug, and coagulation
What occurs in phase 1 of hemostasis?
vascular spasm:
reduces vessel diameter, presses the endothelial surfaces together, stops flow instantly
Where does vascular spasm occur, and where is it effective?
only occurs where there is smooth muscle (not capillaries) and only effective in small vessels or precapillary sphincters (not high pressure vessels or veins)
What occurs in phase 2 of hemostasis?
platelet plug:
exposed collagen avtivates platelets, they stick to each other
activated platelets activate thromboxane A2, serotonin and ADP which attract more platelets
ADP makes platelets sticky
thromboxane A2 and serotonin cause vasoconstriction
What occurs in phase 3 of hemostasis?
Coagulation:
intrinsic and extrinsic pathway, instrinsic takes more time
Explain the extrinsic pathway of coagulation.
tissue trauma released tissue factor (TF) > activated X + V > prothrombinase
> prothrombin (II) converts to thrombin > more factor V, fibrinogen (I) and XIII which create fibrin threads and strengthen them
Explain the intrinsic pathway of coagulation.
damaged endothelial expose collagen > platelets and XII are activated >
XII > activated X
platelets > platelet phospholipids > activated X
activated X > prothrombinase > prothrombin (II) converts to thrombin > more factor V, more platelet phospholipids, and fibrinogen and XIII which create and strengthen the fibrin threads
What are the main functions of thrombin?
convert fibrinogen into fibrin (soluble to insoluble mesh)
and
avtivate factor XIII which stabilizes the mesh
What does prothrombinase directly cause?
converts prothrombin to thrombin
What factors is Vitamin K needed to synthesize?
2, 7, 9, 10 (II, VII, IX, X)
Regarding coagulation, what is synthesized in the liver?
prothrombin, fibrinogen, and factors V, VII, IX, and X
What is a hemophiliac?
lack of factor VIII
What is fibrinolysis?
dissolution of a clot
What is involved in fibrinolysis?
tissue plasminogen activator, thrombin, and plasminogen react to form plasmin which digests the fibrin strands
