Ch. 13 Disorders of Red Blood Cells Flashcards
what is the purpose of RBC?
transportation of oxygen to the tissues
describe RBCs
- biconcave to provide more surface area for O2 diffusion
- thin to allow for rapid diffusion of O2
- most common type of blood cell in the body
Hemoglobin synthesis is dependent on..
iron
erythropoiesis
- making of RBCs
- takes place in the membranous bones of the vertebrae, sternum, ribs and pelvis
What role do the kidneys play in erythropoiesis?
kidneys release erythropoietin (which is a hormone that stimulates erythropoiesis) when they sense a decrease in O2
*why if a patient has kidney disease they could experience Low RBC
Where does erythropoiesis take place in children up to age 5?
in the bone marrow
how does one get the iron needed to make RBC?
- ingested in foods like spinach, kale, liver, meat
- iron is recycled in the spleen (damaged RBC get destroyed and iron gets put back in the blood)
Hemaglobin (Hgb)
How Much?
-measures the hemoglobin content of the blood
Hematocrit (Hct)
How functionable are the RBCs? How’s their size?
-measures the red cell mass in the plasma
anemia
abnormally low number of circulating RBC
S/S of anemia
Shortness of breath, fainting, chest pain, angina, heart attack, muscular weakness
Hemolytic Anemia
- premature destruction of RBCs
- bone marrow becomes hyperactive (too fast so they aren’t big and beefy)
causes of Hemolytic Anemia
- intrinsic factor defect (intrinsic factor is found in the GI tract and helps absorb iron)
- external cause like Dialysis ( RBC get damaged in the machine)
Blood Loss anemia
Hemorrhage or chronic blood loss
Hemorrhage : sudden loss of volume/RBCs. body isn’t profusing organs. patient can go into hemorrhagic shock
Chronic blood loss: volume is unchanged but iron stores are depleted. Examples: Colon cancer (bloody stools), Menopause/Menstruation(bleeding heavily)
Sickle Cell Anemia
- inherited/no cure
- erythrocytes (RBC) become rigid, change shapes, damage the cell membranes
- decreased O2 saturation can predispose a person w/SCD to have a sickling of the hemoglobin to occur(Crisis) ex: cold, stressed, physical exertion, dehydration
Iron Deficiency Anemia
dietary deficiency (low iron rich foods) or chronic blood loss (menstruation, hemorrhoids, polyps)
Pernicious Anemia
vitamin B12 (or could be due to foliate/folic acid deficiency) deficiency
- vitamin B12 is essential for DNA synthesis and nuclear maturation
- prevents abnormal fatty acids from being incorporated into neuronal lipids
- B vitamins are absorbed through gastric mucosa, intrinsic factors
- diminished ability to absorb vitamins B w/age
Aplastic Anemia
disorder of the bone marrow, effects production of RBC, WBC, and platelets.
- decreased RBC -Anemia
- decreased platelets - increased bleeding
- decreased WBC - increased susceptibility to infection
has had good success with stem cell treatment
polycythemia
too much bone marrow stimulation
-excess RBC, WBC, Platelets
could be primary or secondary
polycythemia vera
primary polycythemia
- high viscosity of blood-thick(treated w/fluids)
- prone to clots and bleeding due to platelet abnormalities
hypertension is common with these people
Secondary Polycythemia
-form an increase in erythropoietin (in kidneys)
Caused by….
-usually a chronic condition that causes a decrease in oxygen supply which will stimulate a polycythemia condition.
or
-long term smokers, COPD
-chronic hypoxia (need O2)
- kidneys cant determine cause of decreased O2 so even though patient has normal amount of RBCs, erythropoietin is still released, RBC get high count
treat with oxygen (normal environment is 21% oxygen in the atmosphere)
