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
Coagulation pathway
why does circulating blood not clot
The cells that line the blood vessels (endothelial cells) are smooth, preventing contact activation of factor XII, which leads to coagulation via the intrinsic pathway
antithrombin-heparin cofactor blocks the effects of thrombin on fibrinogen
Heparin, secreted by mast cells in the connective tissues of the blood capillaries, diffuses into the blood, and prevents blood coagulation
Thrombocytopenia
decreased numbers of platelets may be due to bone marrow damage (drugs or toxins), or due an autoimmune reaction against platelets.
Hemoglobin
a protein made of four heme groups and a globin. Each of the four heme groups contains an iron atom.
Carboxyhemoglobin
Carbon monoxide (CMO) occupies sites normally occupied by oxygen. CMO binds to hemoglobin with a much higher affinity (250x) than oxygen.
Oxyhemoglobin
Iron of the heme is in the ferrous state (Fe2+) and can carry oxygen
Methemoglobin
iron of the heme is oxidized to ferric form (Fe3+) and cannot carry oxygen
Carbaminohemoglobin
Carbon dioxide binds to other sites (amino groups) on hemoglobin, lowering its affinity for oxygen.
Myoglobin
Hemoglobin in muscle, which has only one heme group.
erythrocyte desctruction
When old RBCs become fragile, they are removed by the cells of the mononuclear phagocytic system (MPS), the macrophages, in the liver, spleen, and bone marrow
hemolysis
rupture of red blood cells
Processing of old red blood cells by macrophages
Macrophages arise from monocytes (a large white blood cell) that leaves the blood to the tissues and become necrophages. Macrophages are important phagocytic cells. They take in dead cells or bacteria and digest them using the enzymes in their lysosomes.
why are ions important in the blood
Ions serve a wide variety of important functions both inside the cell and out, and thus strict regulation of their concentrations is vital to ensure homeostasis
icterus
jaundice
What happens to the hemoglobin in the macrophages?
The components are recycled or disposed of as follows:
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Globin is degraded to amino acids, which are released in the blood so that the body can reuse it to form other proteins.
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Iron is released from the heme and circulated in the plasma carried by transferrin and is taken to the bone marrow, where it is used for synthesis of new hemoglobin, and the liver for storage as ferritin.
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The rest heme is converted to bilirubin, which is transported by albumin to the liver which then secretes it with bile. In the intestines, bilirubin is reduced to urobilinogen and excreted in the feces.
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Urobilinogen gives the feces its characteristic color. Some urobilinogen is reabsorbed into the blood and excreted as urobilin, the normal pigment of the urine.
hypertonic
solution contains more solutes (particles) in the medium than in the cells.
As a result, fluid in the cells moves into the solution to balance the difference in solute concentration.
Placing a cell in a hypertonic solution causes fluid from the cells to move into the surrounding medium by osmosis.
The decreased volume of fluid in the cells causes them to shrink (crenate).
Hypotonic
solution contains fewer solutes (particles) in the medium than in the cells
fluid in the solution moves into the cells to balance the difference in solute concentration.
Placing a cell in a hypotonic solution causes fluid to move inside the cell by osmosis.
The increased volume of fluid in the cell causes the cell to swell and ultimately rupture.
isotonic
solution contains an equal amount of solutes (particles) in the medium and the cells.
Fluid does not move by osmosis because an equilibrium of solutes has already been reached.
The cell size does not change
causes of anemia
Blood loss
Destruction of RBCs (hemolysis)
Decreased production of red blood cells in the bone marrow
Polycythemia
abnormal increase in the number of circulating red blood cells
signs of anemia
Pale mucous membranes
Increased heart rate
Muscle weakness
polycythemia vera
Results from excessive proliferation of erythroblasts (RBC progenitors) in the bone marrow.
As a result, there is increased blood volume and viscosity and spleen enlargement.
secondary polycythemia
Results as a compensation mechanism because of insufficient oxygenation.
Seen in animals raised at high altitudes, trained for racing, or affected by cardiac and pulmonary disease.
Relative polycythemia
Results from a reduction in the fluid (plasma) component of blood.
The concentration of RBCs is increased relative to the unit volume of blood.
This is the most common type of polycythemia in domestic animals; it is frequently caused by dehydration
what are the different types of leukocytes
granulocytes (neutrophils, eosinophils, and basophils) and agranulocytes (monocytes and lymphocytes).
Immunity
defense of the body through the activities of white blood cells, which include phagocytosis, cellular destruction, and antibody production.
Leukocytosis
An increase in the number of white blood cells. In bacterial infections, the number of leukocytes (especially neutrophils) increases.
Leukemia
uncontrolled (cancerous) proliferation of abnormal leukocytes and their precursors.
Neutrophil
stain a light, grayish-pink color, and are the most numerous leukocyte in the horse, pig, cat, and dog.
Leukopenia
A decrease in the number of leukocytes. Viral infection may reduce the number of white blood cells circulating in the blood. A reduction in WBC count may also be caused by toxemia and septicemia
Granulocytes
formed in the bone marrow. These cells have granules in their cytoplasm and curved, coiled, or segmented nuclei.
subdivided into neutrophils, eosinophils, and basophils, according to the staining characteristics of the granules.
Agranulocytosis
Inability of the bone marrow to produce WBCs due to drug poisoning or irradiation. During agranulocytosis, the body is left unprotected from invasion by disease-causing agents.
Eosinophils
large cells with large red or reddish-orange granules. Basophils have blue or purple-staining granules. They comprise less than 1% of the total leukocyte count
contain several enzymes, (including histaminases), that terminate local inflammatory conditions
Antibodies
immunoglobulin (Ig) molecules (i.e. IgE, IgA, IgG, IgD, or IgM), produced by B lymphocytes, that bind with high specificity to antigens (foreign particles).
Macrophages
numerous in places where foreign agents tend to invade the body (lungs, gut, lymph nodes, bone marrow, spleen, and under the skin)
are “large eaters.” They can ingest many bacteria and dead neutrophils via phagocytosis.
Macrophages are an important first line of defense. Together, monocytes and macrophages make up the mononuclear phagocytic system (MPS).
Basophils
have substances that initiate inflammatory reactions (histamine, serotonin, or bradykinin) and increase blood flow to injured tissues. They are related to tissue mast cells, which are frequently found near capillaries.
Agranulocytes
do not have granules in their cytoplasm. There are two types of agranulocytes: monocytes and lymphocytes.
monocytes
develop in the bone marrow before they enter the blood. They are motile, phagocytic, and capable of destroying bacteria.
important third line of defense. Their numbers increase in chronic inflammatory conditions. They are relatively large cells that migrate from the blood into tissues, where they differentiate into macrophages
Lymphocytes
subdivided into two major types: the B-lymphocytes and T-lymphocyte which are involved in protection of the body bacteria, viruses, toxins, etc
most abundant leukocyte in ruminants and chickens (60%), but are only 30% of the total WBCs in dogs, cats, horses, and pigs
specific immunity
protection of the body against specific foreign agents
involves the actions of B and T lymphocytes produced to defend against a particular antigen
B-lymphocytes
form antibodies (immunoglobulins), which destroy, neutralize, or immobilize invading agents.
T-lymphocytes: cytotoxic (or killer) T cells, and helper T-cells.
Cytotoxic T-cells attach to invading agents and destroy them.
Helper T-cells regulate the immune response of both T-cells and B-cells.
differential white blood cell count
total amount of neutrophils, monocytes, basophils, lymphocytes, and eosinophils in a cubic millimeter of blood
neutrophilia
in acute bacterial infections, the number of neutrophils significantly increase
Cell mediated immunity
mediated by T lymphocytes
Humoral immunity
involves B-lymphocytes and the antibodies they produce against the target antigen.
Phagocytosis
the ingestion of particulate matter, such as antigens and cell debris.
Both non-specific and specific immunity use the process of phagocytosis to protect the body. Neutrophils, monocytes, and macrophages are highly phagocytic white blood cells.
inflammation.
injured area becomes red and hot because of increased blood flow to the injured area. Following this, there will be swelling and pain
diapedesis.
amoeboid movement (like movement of an amoeba) of white blood cells through walls of the capillaries
chemotaxis
The attraction and movement of leukocytes (neutrophils and monocytes) to the inflamed area
Lymphogenous leukemia
excessive production of lymphocytes
myelogenous leukemia
excessive production of WBCs other than lymphocytes
