Anemia, Fever and Temp regulation Flashcards
What is hemoglobin a measure of?
gm/dl; blood HB concentration
What is MCV?
average volume of red cells, mean corpuscular volume, volume of blood x HCT / #RBC
What is MCHC?
mean corpuscular hemoglobin concentration, HB/HCT,
What is reticulocyte count?
number of reticulocytes/total RBC;
What is hematocrit?
MCV x RBC, volume percent of RBC
What is mean corpuscular hemoglobin?
MCH, HB/RBC, concentration of hemoglobin packed in RBC
What is RDW?
red cell distribution width, measure variation in cell size, increased in sickle cell and nutritional deficiencies
What is anisocytosis?
RBC unequal size
What is poikilocytosis?
abnormally shaped
What is polychromasia?
abnormal increase in # of RBC premature in blood
what is hypochromia? How is this determined?
hypopigmentation; pale area more than 1/3 of RBC
What is microcytic? macrocytic? What cell is used for size comparison?
small RBC; large RBC; compare size to WBC
What is microcytic anemia?
Hb is decreased below normal and the MCV less than 80fl, MCHC may or may not be decreased if so hypochromic
What are the three general causes of microcytic anemia?
abnormality in iron metabolism, globin metabolism, and porphyrin metabolism
What are the causes of iron metabolism?
inadequate iron intake, chronic blood loss, and anemia of chronic disease
What are the causes of inadequate iron intake in microcytic anemia?
pediatric age, pregnant moms (iron uptake by fetus, suboptimal stores before pregnancy), otherwise inadequate iron intake in adults rare cause of microcytic anemia
What are the causes of chronic blood loss in microcytic anemia?
most common is GI; GI- ulcer, colon or gastric carcinoma, hiatal hernia, esophageal varices, ulcerative colitis, crohn disease, leiomyoma, salicylate, meckel diverticulum, hookworm, angiodysplasia; Female gential- dysfunctional uterine bleed, endometrial hyperplasia/carcinoma, excessive menses; Pulmonary- carcinoma, chronic infection; Urinary- bladder cancer, chronic infection
What are the causes of anemia of chronic disease? what amount are microcytic? normocytic?
rheumatoid arthiritis and other autoimmune disorders, cancer, chronic infection, severe tissue injury; 30% micro, 70% normo
What are the reasons for anemia of chronic disease?
impaired Fe flow into RBC- hepcidin triggers degrade. iron exporter (ferroportin) thus limiting egress from enterocytes and macrophages (limits Fe for microorganisms), may lead to anemia- infection, malignancy, and inflammation; decreased RBC survival, insufficient erythropoietin to stimulate RBC production
What are the types of thalassemia’s?
inherited, heterogeneous group, alpha and beta chain most common, in minor not anemia but have microcytosis, major= severe anemia
What are the features of Hemeglobin E?
SE Asia, most common globin abnormality, HgbS, beta chain abnormality, homo (marked hypochromia, microcytosis with little or no anemia) and heterozygous
What us serum ferritin? Decreased means? What can falsely increase?
principle storage form of iron; decrease in iron stores; chronic disease, when acute phase reactant increases (surgery, febrile illness, liver cell necrosis), oral or parenteral iron administration
What is iron-binding capacity?
IBC is a reflection of transferrin levels, although transferrin can be directly measured
What are causes of normocytic anemia?
chronic disease (most common), acute blood loss, marrow replacement (myeloplastic anemia), aplastic anemia, renal failure, hemolytic anemia
What are the causes of increased reticulocyte count in normocytic anemia? normal or decreased reticulocyte count?
acute blood loss, hemolytic anemia; anemia of chronic disease, renal failure, aplastic anemia, myelophthisic anemia (marrow replacement by infiltrative disease such as cancer and histoplasmosis)
What are the features of folate or B12 deficiency causing megaloblastic anemia?
maturation pattern in bone marrow, nuclear:cytoplasmic dyssynchrony, especially in RBC series, lab assessmentbegins with folate and B12 levels depending on hist and PE, schilling test- abnormal in B12 deficiency
what are the causes of drug-induced perturbed DNA synthesis?
antineoplastics, immunosuppressive, and antiretroviral
What are the causes of non-megaloblastic macrocytic anemia?
liver disease, hypothyroidism, bone marrow regeneration following blood loss or hemolysis with increased reticulocyte counts, myelophthisic anemia, myeloproliferative disease, multiple myeoloma, some causes of sideroblastic anemia
what neural structures are involved in thermoregulation? Which is the “thermostat”?
hypothalamus and limbic -> <- spinal cord and sympathetic ganglia; hypothalamus (esp. preoptic region, thermosensitive neurons)
What are mechanisms of heat production in the body?
mitochondrial oxidative phosphorylation (ADP->ATP, >50%), skeletal muscles during exercise ~25%, shivering in adult humans, and brown adipose tissue
where is brown adipose tissue located? characteristics? physiological role?
esp. near neck and scapulae; brown, profuse vasculature, numerous mitochondria (uncoupling protein 1, UCP1), thermoregulation in newborns and small mammals, possibly energy metabolism in adults (BAT activity inversely related to BMI)
What is the function of UCP1 in brown fat?
leaky inner membrane, energy released as heat, not stored as ATP, regulated by T3 locally
How is brown fat activated?
adrenergic neuron to B3 adrenergic receptor-> cAMP-> nucleus-> increase UCP1 production-> increase in heat
Where is heat lost? percent for each site?
skin 80-90%, 10% from lung