Module 2 Flashcards
Erythrocytes
red blood cells, or RBCs
he most abundant cells in the body. Their major function is to carry oxygen, loosely attached to hemoglobin, to the tissues.
do not have nuclei
thrombocytes
platelets
important for blood coagulation, which helps in prevention of blood loss (hemostasis)
lack nuclei in most species. They are essentially fragments of their larger progenitor cell, the megakaryocyte, and are specialized to aid in clotting
leukocytes
white blood cells, or WBCs
nucleated and are capable of independent movement. They protect the body against invading microorganisms (defense against disease).
pH of blood
7.4
2 parts of blood
cellular elements and plasma
what does plasma contain
water, salts, proteins, lipids, carbohydrates, and gases
organic substances in plasma
glucose, lipids, enzymes, amino acids, cholesterol, carbonate, hormones, non-protein nitrogen (NPN), and clotting factors.
the function of blood
aids in the distribution of heat, water, and solids, which contributes to homeostasis (constant conditions of ECF). It transports nutrients, hormones, waste production, and gases
what proteins are in plasma
albumin, fibrinogen, and globulins.
Hematocrit
the percent of packed cells (packed cell volume)
The major non-protein nitrogen (NPN)
urea, uric acid, creatine, creatinine, ammonium salts, and amino acids.
The major electrolytes in plasma
calcium, inorganic phosphorus, magnesium, sodium, potassium, chloride, and bicarbonate.
PCV
hematocrit-packed cell volume (relative proportion of red blood cells to plasma
erythropoiesis
formation of red blood cells
where are RBC formed before birth and in newborns
from undifferentiated stem cells in the liver, spleen, and bone marrow of long bones
buffy coat.
thin white layer located between the PCV and plasma
how is PCV determined
using a microhematocrit
where are RBC made in adults
red bone marrow of the sternum and occasionally in the vertebral column and pelvis
Erythropoietin
a hormone secreted by the kidneys that increases the production of red blood cells when oxygen levels are low in the tissues.
Reticulocytes
immature erythrocytes in the blood
reticulocytosis
The number of reticulocytes may increase above normal
Mean Corpuscular Hemoglobin (MCH)
hemoglobin weight per red blood cell; the amount of hemoglobin present in the average red cell.
MCH calculation
divide total hemoglobin by RBC count then multiply by ten
MCV calculation
divide PVC by RBC count and multiply by ten
Mean Corpuscular Volume (MCV)
represents size of the average red cell in femtoliters
How Are RBC Indices Used Clinically?
o classify anemias and to give an indication of the nature of the anemias
Macrocytic normochromic
pernicious anemia and folic acid deficiency
Normocytic normochromic
(MCV, MCH, MCHC: normal values). Included in this category are conditions as acute blood loss anemia, hemolytic anemia, aplastic anemia, Hodgkin’s disease, and leukemia
Microcytic normochromic
subacute and chronic inflammatory diseases, neoplasias, and idiopathic microcytic anemia.
Microcytic hypochromic
(MCH and MCHC: reduced). The disorders included in this category are iron deficiency, thalassemia, and lead poisoning
Extrinsic clotting pathway
(tissue damage)->activated when blood comes in contact with extravascular tissue because of injury to the tissues.
The extrinsic pathway provides direct activation of factor X and produces thrombin and fibrin quickly.
Hemostasis
the prevention or restriction of the loss of blood from vessel
where do platelets originate
megakaryocytes in bone marrow
steps of hemostasis
1)vasoconstriction (narrowing of blood vessels) caused by vascular spasms due to smooth muscle contractions resulting from sympathetic nervous system stimulation and serotonin action
2)platelet formation and aggregation. platelets in blood swell and become sticky in contact with exposed collagen of damaged tissue and release ADP and thromboxane A2 to facilitate aggregation. Platelets form a plug (small holes). large holes require a clot and a plug
Intrinsic clotting pathway
damage to blood ->ctivated when blood comes in contact with disrupted vascular epithelium because of injury to the blood vessels