chapter 23 Flashcards
functions of blood
Transport medium for specialized defense cells Distribution of nutrients, oxygen and hormones Transport medium for metabolic wastes
function of erythrocyte
Carry Oxygen with the Help of Hemoglobin
Hemoglobin Binds CO2 (carbon dioxide) and
returns to lungs
Hemoglobin must have…
Iron
APPROX 65% OF IRON IS IN FORM OF
HEMOGLOBIN
approx 30+% stored in liver as Ferritin
Hemoglobin
Complex protein; Composed of Heme (the iron & biliverdin portion) + Globin (the amino acid portion) 2 alpha + 2 Beta chains Carries O2 from lungs to tissues and CO2 from tissues to lungs
Erythropoietin is produced in
the Kidneys
Stimulated by Hypoxia
Synthetic Erythropoietin Available
some causes of decreased erythropoiesis are
Kidney Failure
Chemotherapy or Medications
Erythropoiesis
Erythrocyte Production/Stimulation
Required Dietary Factors for RBC
production
Vitamin B12 (cobalamin) - required for DNA
synthesis
intrinsic factor necessary for absorption of
B12
Folic acid - (folate) required for DNA synthesis
Iron - required for hemoglobin synthesis
Vitamin C - increases absorption of iron
RBCS last about
120 days
RBCs are destroyed in
spleen or liver
RBC destruction
Hemoglobin is broken down
Biliverdin is converted to bilirubin and
excreted in bile via the gallbladder.
Iron (heme element) is carried on transferrin
to the liver were it is stored as ferritin or back
to the bone marrow to be reused
Globin/amino acid portion is recycled
red blood cell count measures
the total number of red blood cells in
1 mm3 of blood
average RBC count for male and female
Male: 4.35-5.65 trillion cells/L* (4.32-5.72 million cells/mcL**)
Female: 3.92-5.13 trillion cells/L (3.90-5.03 million cells/mcL
Percentage of reticulocytes
(normally
approximately 1%)
Provides an index of the rate of red cell
production
Hemoglobin Lab test
measured in grams per
100 mL of blood)
Measures the hemoglobin content of the blood
hematocrit
Measures the volume of red cell mass in 100
mL of plasma volume
things you might see in anemia
- Hypoxia Fatigue weakness dyspnea Pallor Tachycardia
adapting to anemia
heart rate increases, respiratory rate increases. this occurs at rest or with small exertion
microcytic
small RBC
normocytic
normal size RBC
macrocytic
large RBC
normochromic
Normal amount of Hemoglobin
hypochromic
Low amount of Hemoglobin (pale)
hyperchromic
Elevated amount/weight of
Hemoglobin (bright red)
pathophysiologic anemia
Increased destruction
Decreased production
Blood loss and sequestration; inherited (congenital) or acquired
internal blood loss anemia
joints, tauma, hematoma
external blood loss anemia
GI, renal, menses, bleeding disorder
blood loss anemia symptoms
mainly secondary to
hypovolemia
May be hard to recognize if chronic
Will eventually lead to iron loss anemia
sickle cell anemia (hemolytic)
Mutation in beta chains of hemoglobin •When hemoglobin is deoxygenated, beta chains link together Forming long protein rods that make the cell “sickle”
sickle cell triggers
Conditions which are associated with
low oxygen levels, increased acidity, or
low volume (dehydration) of the blood.
(Cold, stress, infection, physical exertion)
These conditions can occur as a result
of injury to the body’s tissues,
dehydrating states, or anesthesia.
sickled cells block____. this causes____
capillaries; acute pain, Infarctions cause chronic damage to liver,
spleen, heart, kidneys, eyes, bones
Pulmonary infarction
Cerebral infarction ->stroke
jaundice
r/t increased heme destruction
exceeding liver’s ability to conjugate and excrete
bilirubin
iron-deficiency anemia (IDA)
often caused by chronic blood loss, most common anemia worldwide, malabsorption, small pale RBCs, no Iron=no color, blood loss causes decrease in hemoglobin and hematocrit, hemolysis (destruction), increased demands
megaloblastic anemias
large RBCs, think nutrition, large deformed RBCs, can’t carry HgB
chronic disease anemias
Ex. Chronic Renal Failure; Normal size/color,
just not enough of them
pernicious anemia
No intrinsic factor-> vitamin B12 cannot be absorbed-> alteration in DNA synthesis needed for cell division-> delayed cellular division, altered nuclear pattern, megaloblastic anemia-> ineffective erythropoiesis: increased serum bilirubin and urobilinogen excretion
mild to moderate anemia is seen in:
AIDS, RA, SLE, HEP, renal failure, malig
pathologic mechanisms in anemia of chronic disease/inflammation
Decreased erythrocyte life span
Erythropoietin- Not making enough
- May be r/t renal pt and/or hemodialysis
Altered iron metabolism
polycythemia
increase in circulating blood cells in the blood due to bone marrow overgrowth
Classified as chronic myeloproliferative
disorder (making too many myelocytes)
forms of polycythemia
- polycythemia vera (primary)
- secondary polycythemia
polycythemia vera
increase in RBC, increase in WBC, increase in platelets. r/t increases in cell counts, treat with phlebotomy
secondary polycythemia
A possible complication of COPD, secondary polycythemia is a rare disorder that causes too many red blood cells in the blood. When too many red blood cells are produced, the blood becomes thick, hindering its passage through the smaller blood vessels
