9/24a Common Blood Disorders (Biomedical Sciences) Flashcards
what does the hematologic system consist of (big picture)?
Blood vessels throughout the entire body
involves multiple organs
Bone Marrow - for creation and maturation
thymus - WBCs and immune system so antigen presentation and antibody formation effect on formation of WBCs
Spleen is the filter of the hematologic system
composition of the blood
- plasma (water (91%) and proteins (7%) - clotting proteins, albumin for osmotic stability, globulins - immune proteins antibodies
- formed elements - blood cells
1. RBCs are the most common
2. WBC (leukocytes, monocytes, neutrophils, eosinophils, basophils)
3. Platelets
4. Plasma
primary function of hematologic system
- through red blood cells
- responsible for delivering oxygen to various tissues
- hemoglobin molecules have iron that help bind oxygen to transfer them to tissues in gas exchange
functions of the hematologic system
- delivery oxygen of substances for cellular function
- removal of wastes
- immune function
- injury repair
- maintain acid/base balance
how does waste get removed in the hematologic system?
: delivery of waste products to spleen, liver, and kidneys for excretion and filtration
what is the purpose of oxygen in the hematologic system?
delivery oxygen of substances for cellular function
immune function of hematologic system?
WBCs are infection fighting cells, leukocytes (neutrophils are the most common and respond to bacterial infections); Lymphocytes respond to viral infections
injury repair of hematologic system?
: hemostasis and appropriate inflammatory response, gets initiated by platelets
how does hematologic system maintain acid/base balance?
:CO2 is an acid and the exchange in respiratory and renal systems makes sure the pH balance is maintained
Hematopoesis
creation of blood cells
- occurs in bone marrow of adults
- embryonic yolk sac, fetal liver and spleen in the fetal development
process of hematopoesis
- starts with hematopoetic stem cells (pluripotent)
- reside in bone marrow
- differentiate in response to signals that come from other organs (thymus > bone marrow to produce lymphocytes > response to antigen presentation)
extramedullary hematopoesis
adult liver or adult spleen plays a role in the creation of blood cells in abnormalities/pathology
what does it mean to be pluripotent?
same stem cell differentiates into a variety of cell types
- Erythrocyte
- Megakaryocyte
- leukocyte
- -B&T Lymphocytes - thymus to bone marrow
- -Monocytes
- -Neutrophils
- -Eosinophils
- -Basophils
lymphoid cell vs myeloid cell
- Lymphoid cell matures into a BRT lymphocyte
- Myeloid cell becomes a red blood cell, a megakaryocyte, or any kind of white blood cell (in response to cytokine activity and antigens from foreign invaders)
Erythrocytes
Red Blood Cell
- hemoglobin and hematocrit are used to look at function of RBC
- principle function is to delvier oxygen
- can’t deliver oxygen if there is not a lot of hemoglobin
- bi-concave cell that has flexibility to get through small vessels without lysing open
- circulates for 90-120 days and travels to spleen to remove the iron from RBC
Hemoglobin and RBC relationship
RBc is the vehicle for hb to function in the delivery of oxygen.
RBC without hb does no good in a clinical perspective
Hb lies on the outside/periphery of the RBC
after the RBCs lifespan, what happens to it?
circulates for 90-120 days and travels to spleen to remove the iron from RBC
IRON is conserved and recycled - tightly by the spleen
Iron is contained within Hb and it acts to bind with the oxygen
Hb goes to the liver and gets excreted as bile into the GI tract
hemoglobin normal values
male - 14-18g/dL
female - 12-16 g/dL
newborn - 14-24 g/dL
CRITICAL VALUE - <8.0g/dL
RBCs normal values in the body
male - 4.7-6.1 million
female - 4.2-5.4 million
what does HB require for formation?
Iron
B-12
Folic Acid
what is hematocrit?
percentage of blood volume that is made of red blood cells (hemoglobin x 3)
lab parameter
~45% for most patients
if the value is not in normal range:
too high: RBCs are abnormally large
too low: More white blood cells/plasma than they should
if RBC, HGB, and HCT values are low, what is the issue?
anemia
Causes of anemia
- iron deficiency
- b12 and folate deficiency
- blood loss
- hemolysis
- bone marrow failure
- chronic disease
- dilution
- pregnancy
- genetic
pathways that cause anemia
- not forming blood cells properly
- either losing or destroying blood cells (after surgery, trauma, genetics)
High RBC, HGB, or HCT counts are caused by
Erythrocytosis/Polyceythemia
- hypoxic states
- lung disease
- smoking
- high altitudes
- dehydration
- polycythemia vera
Symptoms to watch for with anemic patients
- dyspnea, tachypnea (elevated RR)
- increased HR
- weakness
- fatigue
- palor
- low blood pressure
- syncope
- watch out for orthostatic blood pressure
- chest pain - biggest reason for transfusion
- light-headedness
- Unique symptoms = pica, craving for non-food items (ice or paint chips)
cause of anemia
- most common = iron deficiency
- -reason why in the US is because of GI blood loss
- -reason why world wide = dietary
- menstrual breathing
Treatment for anemia
- oral iron supplements
- intravenous iron infusion
- transfusion of RBCs
severe/acute anemia
transfuse RBCs
or intravenous iron formulation
Vitamin B12 and folate deficiencies
- due to lack of intake or absorption
- both absorbed in GI tract
- interfere with DNA synthesis of RBCs
causes of B12 and folate deficiencies
- B12 = malabsorption could be why because it is absorbed in the terminal ilium with intrinsic factor from parietal cells
- Malabsorption of folic acid is NOT common b/c it is absorbed everywhere in the GI tract
Unique Symptoms of B12 and folate deficiency
- neuropathy from B12 deficiency
- if it is not treated early on, the symptoms can become permanent
- balance, proprioception, neuropathy issues
Blood loss anemia
due to trauma, surgery or other blood loss
-bone marrow does try to keep up by generating increased numbers of immature red blood cells (reticulocytes) because of stem cells