13 Alterations in Oxygen Transport Flashcards
Erythrocyte/RBC
count: 4.2-6.2 million cells/mm3
- buffers blood pH: carbonic anhydrase
hematopoiesis
stem cells> reticulocytes/erythroblast> mature RBC/erythrocytes
erythropoietin/EPO
made in kidney (adult)
- fetus + newborn made in liver + kidney
- renal disease causes anemia
nutritional requirements for erythropoiesis
-requires adequate amounts of iron, protein, vitamins, + minerals
folate + B12 deficiencies lead to…
impaired DNA synth in erythroid cells bs vitamins are coenzymes of key rxns in cell metab
absorption of B12 in sm intestines require…
intrinsic factor
-produced by parietal cells of stomach
Bilirubin
- rbc destruction
- porphyn is reduced to bilirubin in liver + excreted in bile
- intestinal bacteria convert bilirubin into URObilirubin which is excreted mostly in stool but also in urine
- too much bilirubin=jaundice
Anemia
deficit of RBC
-lox O-carrying capacity leads to hypoxia
Polycythemia
excess of RBC
- primary or acquired
- incr in blood viscosity + volume
general effects anemia
- reduction in O-carrying capacity (tissue hypoxia)
- compensatory mechanism to restore tissue oxygenation
- –SNS: incr heart rate, CO, circ rate, flow to vital organs
aplastic anemia
- stem cell disorder characterized by reductin of hematopoietic tissue, fatty marrow transplant, + pancytopenia
- disease of young or old (15-25; 60+)
pancytopenia
low RBC, WBC, + platelets
aplastic anemia
cause + diagnosis
- caused by toxic, radiant, immunologic injury to the bone marrow stem cells
- diagnosed w bone marrow biopsy
aplastic anemia
treatment
- bone marrow transplantation
- administer immunosuppressive therapy or stim hematopoiesis + bone marrow regeneration
anemia of chronic renal failure
failure of renal endocrine function impairs ERYTHROPOIETIN PRODUCTION + bone marrow compensation
anemia of chronic renal failure
treatment
-dialysis
-administer erythropoietin
(only used until Hgb is 12g/dl)
-replacement of iron, folate, + B12
95% respond to erythropoietin therapy
cobalamin
B12
anemia related to B12 or folate deficiency
-disrupt DNA synth of blast cells produces megaloblast
macrocytic
type of anemia related to B12 deficiency
-more overly large RBC (megaloblasts) than normal RBC
pernicious anemia
type of anemia related to B12 deficiency
-due to lack of intrinsic factor
folate deficiencies are usually from…
dietary deficiencies, alcoholism, cirrhosis, pregnancy, or infancy
pernicious anemia
clinical manifestations
- decreased RBC, WBC, + platelet counts
- increased MCV, megaloblastic dysplasia
- peripheral nerve degeneration
- shillings test indicates low B12
- gastric analysis reveals achlordydria
- megoblastic madness
achlordydria
absence of hydrochloric acid in gastric secretions
- a manifestation of pernicious anemia
Iron Deficiency Anemia
- insufficient iron for hemoglobin synth
- hypochromic, microcytic RBC, low MCV, MCH, + MCHC
- dec in serum ferritin level, serum iron level
- incr in total iron binding capacity
most common nutritional deficiency in the world
iron deficiency anemia
microcytic
smaller than normal RBC
MCV, MCH, MCHC
MCV: mean corpuscular vol
MCH: mean corpuscular hemoglobin
MCHC: mean corpuscular hemoglobin concentration
Iron Deficiency Anemia
manifestations
- PICA
- koilonychias (spoon-shaped nails)
- blue sclerae
Pica
cravings for nonfood substances like dirt, clay, ice, cardboard, hair
Iron Deficiency Anemia
treatment + prognosis
- oral administration of FERROUS SULFATE or IV FERRIC GLUCONATE (only in severe cases)
- -cont for 4-6 months
- treat underlying cause
-prognosis is excellent
Thalassemia
- incr hemolysis
- hypochromic, microcytic RBC
- autosomal recessive
- classifies by polypeptide chains w deficient synth (a or b-thalassemia
- low MCV, MHC, MCHC
- erythroblastic hyperplasia
hemolysis
RBC destruction
autosomal recessive
assoc. w mutant genes that suppress the rate of globin chain synth
most clinically severe form of thalassemia
thalassemia MAJOR
Sickle Cell Anemia
- genetically determined defect of hemoglobin synth
- results w hemoglobin instability + insolubility
- sickled cell causes vascular occlusion
sickle cell anemia is found exclusively in which population
black race
Sickle Cell Anemia
treatment + prognosis
- crisis: major medical event
- treatment of choice is stem cell transplant
prognosis is death if no/unsuccessful transplant
hemolytic disease of newborn
- fetal RBCs cross placenta, stim production of MATERNAL ANTIBODIES AGAINST Rh+ antigen on fetal RBC
- –not inherited fr mother; mother is Rh-
- maternal antibodies cross into fetal circulation causing destruction of fetal cells
- –ABO compatibility is most common
- —Rh incompatibility more clinically relevant
hemolytic disease of newborn
treatment + prognosis
- standard dose of anti Rh- immune globulin [RhoGAM] is given to mother before or after delivery
- severe cases, in utero blood transfusion + early delivery
prognosis: death, possible retardation, barely perceptible hemolytic process
RhoGAM
anti-Rh immune globulin
-given to mother before or after delivery when Rh incompatible
vocab checklist:
1 polycythemia 2 pancytopenia 3 macrocytic 4 megaloblast 5 pernicious A. 6 aplastic A. 7 achlordydria 8 pica 9 thalassemia 10 hemolysis
1 excess RBC (opp of "anemia") 2 low RBC, WBC, platelet 3 B12 related anemia 4 large RBC 5 B12 related anemia due to lack of intrinsic factor 6 stem cell disorder 7 absence of HCl acid in gastric secretion (due to pernicious A) 8 craving of nonfood 9 incr hemolysis 10 destruction of RBC
