Idiopathic Thrombocytopenia Purpura Flashcards
What portion of the blood = Plasma?
55%
13
What portion of the blood is the Hematocrit?
45%
(about 5 million mm3 + or - 1/2 million)
(14)
What makes up the “Buffy Coat” in a centrifuged vile of blood?
Leukocytes and Platelets
13-14
What is a decreased hematocrit indicative of?
Anemia
(below 4 million)
(14)
What is an increased hematocrit indicative of?
Polycythemia
(above 6 million)
(14)
About how many molecules of hemoglobin does 1 RBC carry?
250 million
14
How many molecules of Oxygen does 1 RBC carry?
About 1 billion
(250 million hemoglobin)
(14)
What hormone is in charge of RBC production?
Erythropoietin
*released from the kidneys then forms new RBCs through the process erythropoiesis in the bone marrow
(example of negative feedback)
(15)
What are 2 examples of non-regulatory factors that affect RBC synthesis (their absence will alter production)?
Iron and Amino Acids for hemoglobin synthesis
Vitamin B12 and Folic Acid for DNA synthesis
(15)
What is Pernicious Anemia caused by?
What is the result?
Caused by malabsorption of vitamin B12
Result = slowing of erythropoiesis produces large RBCs (macrocytes) that are fragile and easily destroyed
(15)
When is the Erythrocyte Sedimentation Rate increased?
Elevated during infection, arthritis, and other inflammatory diseases
*During infections, tissues release “acute phase reactant proteins” which stick to RBCs and allow them to clump together = increase rate that they fall out of solution
(16)
What are the 3 broad groups of plasma proteins?
Albumins (smallest and most common) Globulins Fibrinogen (largest and least common) *all made in liver except y-globulins (from lymphatic tissue) (16)
What does plasma colloidal osmotic pressure do?
Which plasma protein is the main contributor to plasma colloidal osmotic pressure?
Prevents excessive fluid filtration
Albumin = main contributor
(16)
What will a lack of Albumin cause?
Hypoproteinemia
Decr. plasma protein = decr. plasma colloidal osmotic pressure = incr. loss of fluid from capillaries == Edema
(16)
What is the general function of: a-globulin, b-globulin, y-globulin?
a-globulin = carrier proteins and clotting factors
b-globulin = carrier proteins i.e. transferrin, apo-protein B, b1, b2
y-globulin = antibodies
(17)
What is the main precursor to a clot?
Fibrinogen
(fibrinogen = precursor for fibrin; fibrin forms insoluble mesh a.k.a coagulation/clotting)
(17)
What is the term for the ability of blood to maintain its volume?
What are the 3 key mechanisms that make this possible?
Homeostasis 1) vascular constriction 2) platelet plugs 3) clot formation (17)
Describe the vascular constriction step of blood homeostasis
Trauma to vessel wall induces vasoconstriction
- nervous stimulation causes endothelin-1 (vasoconstrictive factor) to release from smaller vessels
- platelets release thromboxane A2 and serotonin = vasoconstriction
(17)
During the platelet plug step of blood homeostasis, what 2 things promote platelet aggregation?
Thromboxane (from tissues) and Thrombin
17
Define homeostasis
Dynamically balanced state of self-regulation
(always changing but always staying the same)
(8)
What are the clinical features of idiopathic thrombocytopenia purpura?
*Disorder of decreased platelet numbers* Easy bleeding w/ increased bleeding time Micro-bleeds at capillaries (purple spots on skin) Easy bruising Nosebleeds (12)
What is specific gravity and what is blood’s specific gravity?
Specific Gravity = measure of the density of a solution relative to water.
Blood’s specific gravity = 1.050 g/ml
(13)
What is the pH of blood?
What is the temperature of blood?
Is blood more or less viscous than water?
pH = 7.4
temp = 98.6 F or 37 degrees C
blood = 3-5 times more viscous than water
(13)
True or False: Erythropoiesis is a fast-acting form of negative feedback?
False;
Erythropoiesis (forming new RBC) is a slow-acting example of negative feedback
(15)
