Exam 1 – Dr. Thomason Lecture 1 Flashcards
What do RBCs contain?
Hemoglobin (Hgb)
What does Hgb allow for?
Oxygen to be transported from the lungs to the tissues
Do mammalian RBCs have a nucleus? Reptiles, birds, and amphibians?
No
Yes
What is the shape of RBCs like for most species? Camelids?
Round
Ellipsoidal
How do RBCs work?
Higher concentration of oxygen in lungs allows for it to pass to deoxygenated blood through simple diffusion
How is O2 transported?
By binding to Hgb
What gives RBCs the red color?
Heme
Ferrous iron
What do heme molecules combine with?
A polypeptide chain (globin)
How many chains make up hemoglobin?
4
How many O2 molecules are there per hemoglobin chain?
1, so there are 4 O2 molecules per hemoglobin
What is the O2 concentration like for Hgb?
Almost always at maximum concentration
How much of the iron in the body is in Hgb? Liver and marrow?
65%
25%
What is iron absorbed from?
Small intestine
What does iron bind to? What does it form?
Apotransferrin
Transferrin
What is iron transported in?
Plasma
What is iron transported as?
Transferrin
What does transferrin strongly bind to?
Erythroblasts
What are erythroblasts?
The precursors to erythrocytes
What is iron stored in cells as?
Ferritin
Why is there a minimum amount of apoferritin?
It is an insoluble form of iron
What is bilirubin?
The break down of hemoglobin
Which has a higher affinity for O2, fetal Hgb or adult Hgb?
Fetal Hgb
What minimizes acidosis?
Bicarbonate
What is the average life span of RBCs?
Months
What are aged RBCs removed by?
Spleen
What happens to iron when Hgb is broken down?
It is reused-transported as transferring
What happens to globulin chains as Hgb is broken down?
It is reused
What happens to remaining heme as Hgb is broken down?
It is eliminated as bilirubin
Why is having too few RBCs a problem?
Oxygen cannot be distributed
What is the most essential regulator for erythrocyte production?
tissue oxygenation
What are factors associated with poor tissue oxygenation?
Low blood volume Anemia Low hemoglobin Poor blood flow Pulmonary disease
How can the body improve tissue oxygenation?
By increasing the number of RBCs
What tissue/organ is essential for increased production of RBCs?
Kidney
What is erythropoietin?
The principal stimulus for erythrocyte production
Where is 90% of erythropoietin produced?
Kidney
When does erythropoietin production start?
Within hours of hypoxia
2-5 days for maximum effect
When does erythropoietin production stop?
When hypoxia is not present
What happens if erythropoietin is not produced?
RBCs will not be produced
What happens with pathogenesis?
Decreased erythropoietin secretion by kidneys
Decreased bone marrow response
Reduced erythrocyte lifespan
Where are RBCs primarily produced?
Bone marrow
Where are RBCs produced in a fetus?
Spleen
Liver
Bone marrow
What helps during severe RBC loss?
Liver and spleen
Extramedullary hematopoiesis
What happens during RBC differentiation?
Cells and nuclei become smaller
Nucleus is extruded at the metarubricyte phase
What are reticulocytes like?
No nucleus but contains remnants of the golgi and mitochondria
What are reticulocytes released from?
The bone marrow into circulation for final maturation
What are reticulocytes?
The last stage before a fully mature erythrocyte
What are essential vitamins for RBC maturation?
Vitamin B12 and folic acid
What is anemia?
Reduced red blood cell mass
Decreased oxygen carrying capacity
What is regenerative anemia?
Producing erythrocytes, bone marrow is not a problem
What is non-regenerative anemia?
Not producing erythrocytes, bone marrow is a problem
What can regenerative anemia lead to?
Hemorrhage
Hemolysis
What is hemorrhage?
Had blood and lost it
What is hemolysis?
Had blood and it got destroyed
What happens during hemorrhage?
Lose all components of blood (RBCs and fluids)
What can cause hemorrhage?
Trauma Coagulopathy GI hemorrhage External parasites Hematuria Neoplastic rupture
What can hemolysis cause?
An animal to have a yellow color
What can cause zinc toxicity?
Pennies minted in 1983 to present
Zinc nuts
Zinc oxide ointment
How can zinc toxicity be treated?
Remove zinc source
What happens with babesiosis?
Ticks and blood transfusion
What 3 mechanisms cause anemia?
Hemorrhage
Hemolysis
Non-regenerative
What can non-regenerative anemia cause?
Systemic disorders and primary marrow disorders
What is polycythemia?
Increased number of RBCs
What does polycythemia do?
Increases blood viscosity causing sluggish blood flow through the peripheral blood vessels
What does cardiac failure lead to? Why?
Hypoxia
The lack of blood leads to poor oxygenation to the tissues
Is primary or secondary polycythemia more common?
Secondary
What is an example of primary polycythemia?
Polycythemia vera
Kidney tumors
What can cause polythemia vera?
It is genetic
What is an examples of secondary polycythemia?
Tissue hypoxia
What can cause tissue hypoxia?
High altitude
Cardiac failure
Significant pulmonary disease
What can be used to treat polycythemia?
Blood-letting
Leeches