Blood Flashcards
What differentiates mammalian red blood cells from avian red blood cells?
Avian blood cells are nucleated
What allows cells to change direction?
Chemotaxis
What can changes in RBC morphology indictae?
blood loss, toxin exposure, involvement of specific organs
What can altered WBC morphology indicate?
Acute inflammation, keukemia
What is the structure of blood?
Highly cellular with a fluid extracellular matrix
What is the fluid makeup?
Plasma is made of 91% water, 7-8% proteins and 1-2% electrolytes
What is serum?
The fluid portion remaining after coagulation
What blood proteins are produced by the liver?
Fibrinogens for blood clotting, albumins, globulins
What proteins are produced by plasma cells and lymphocytes?
immunoglobulins (antibodies)
What is the normal level of plasma proteins?
5.7 - 7 g/dl
albumin: 2.4 - 3.6 g/dl
Globulins 2.1 - 4.6 g/dl
What is PCV?
Hematocrit: the % of blood occupied by red blood cells
This is related to the number and size of red blood cells
What is the normal PCV (Hematocrit)?
~45% of blood volume
Canines (37-55%)
Felins (24-45%)
Males are higher than females
What is the buffy coat?
The thin, superficial layer containing WBCs and platelets in the centrifuged blood sample
What are romanovsky stains?
Methylene blue and eosin
Nuclei stain more reddish
Where should you examine a blood smear?
Towards the end but before cells are clumped and torn
How large are red blood cells?
4-8 microm
No nucleus or organelles
What does a red blood cell consist of?
Cell membrane and hemoglobin
What does hemoglobin consist of?
Four polypeptide chains attached to iron-containing heme groups
How long do red blood cells circulate?
120 days then removed by spleen macrophages
How many RBCs die per hour?
100 million per hour per lb of body weight
If the spleen is removed, what removes RBCs?
Bone marrow
What is the volume of hemoglobin in canine erythrocytes?
12 - 18 g/dl
How many red blood cells does a dog have?
5.5 - 8.5 * 10^6 RBC/dl
What is the mean corpuscular volume of the canine?
60.6 - 77 fl
What is the mean corpuscular hemoglobin concentration?
32 - 36 g/dl
Do young animals have more or less hematocrit than mature animals?
Lower hematocrit due to rapidly expanding vascular space
Young animals also have high lymphocytecounts, more RBC anisocytosis, polychromasia and nucleated RBCs due to replacing fetal RBCs with adult RBCs
What blood changes occur during excited or vigorously exercised patients?
High lymphocyte counts
What is stress leukogram?
High WBC count can be due to stress or exercise
What is anemia?
Too little hemoglobin
Is anemia a disease?
No, it is a symptom of increased RBC loss or decreased/ineffective RBC production
What is poikilocytosis?
Variations in cell shapes
What is anisocytosis?
Variations in cell size
WHat 3 classifications exist for RBCs?
Normocytic, macrocytic or microcytic
What species is uniform microcytosis normal?
Akitas and goats
What species is macrocytosis or anisocytosis normal?
Neonates
What is polychromasia?
Reticulocytes
Variation in color
Usually describes the appearance of large, juvenile, blue staining, polychromatophilic macrocytes.
What are some inclusions in RBCs?
Basophilic stippling (aggregated ribosomes) Howell-Jolly bodies (nuclear remnants) Heinz bodies (oxidized hemoglobin)
Why are WBCs considered transient?
They function primarily outside the vascular system
WBCs become defensive cells when they enter connective, lymphatic or bone marrow tissue
Name the granulocytes
Neutrophils, eosinophils, basophils
Name the arganulocytes
Lymphocytes and monocytes
What are granulocytes?
Cells that have bi- or multi-lobed nuclei ,cytoplasmic specific and non-specific granules
Granules are secretory vesicles and lysosomes
What are cells named after?
How granules of the cell stain
Are all granulocytes are phagocytic?
Yes. Neutrophil is best phagocyte
What is a heterophil?
Birds form of neutrophil
Whats the % of WBC in blood?
Typically 60 - 70%
Describe neutrophil
Highly segmented (3-5 nuclei) Light granules that don't stain Phagocytose bacteria and substances
Describe the granules of the neutrophil
Specific granules: antibacterial agent
Azurophilic granules: Lysosomes
Where are neutrophils formed?
Bone marrow then circulate, marginate and migrate
What is the circulating pool?
PMNs that circulate transiently (6-8 hours), these cells are present in blood sample
What is the marginating pool?
PMNs that are stuck to vessel walls.
What is the ratio of marginated neutrophils to circulating neutrophils?
1:1
What cells are responsible for producing pus?
Neutrophils migrate to tissue, phagocytose stuff, and produce pus
Describe eosinophils
Rare. Circulate for minutes to a couple hours
Increase with parasitic and allergic conditions
Bi-lobed nucleus with specific pink granules
What are the functions of eosinophils?
Phagcytose, especially antigen-antibody complexes
Kill parasitic larvae by releasing granules containing hydrolytic enzymes
Counteract the action of histamine and inhibit mast cell degranulation (eosinophils are attracted by substances released from basophil and mast cells)
Describe basophils
Very rare except rabbits and fowl
Large cell with a lobed nucleus that is ribbon-like. Specific granules that stain blue-gray or purple with basic dyes
What are the functions of basophils?
Similar to mast cell
Hypersensitivity and anaphylaxis. IgE on surface causes the release of histamine and heparin granules after reacting with an antigen
How do basophils modulate inflammatory responses?
Basophils synthesize cytokines that initiate or modulate the response.
Histamine plays a role in hypersensitivity reactions like hives, anaphylaxis and acute allergy
What is the cause of basophilia?
Persistent basophil count of 200+/ul
Allergy and hypersensitivity (usually accompanied by increased eosinophils)
Parasites that have significant tissue contact
Basophilic leukemia (extremely rare) myeloproliferative neoplasm
What are mast cells?
Rare in peripheral blood
Round to oval central nucleus
Numerous purple granules that may obscure the nucleus
What are lymphocytes
12-30% of WBCs
lymphocytes decrease with age and increase with viral infection
Most abundant WBC in ruminant, pig, fowl
Describe characteristics of lymphocytes
Dark, round nucleus
Little to no basophilic cytoplasm
Small lymphocytes predominate circulation and large lymphocytes are activated B cells or natural killer cells
What is the main function of the lymphocyte?
Main cell of the immune system, antibodies
What is a monocyte?
3-10% WBCs
Largest WBC
Indented, tri-lobed or horseshoe nucleus
Precursor of mononuclear phagocyte system
Where are monocytes found?
In transit from bone marrow to body tissues
Monocytes remain in the blood for 3 days
What is a platelet?
Non-nucleated cytoplasmic fragment of megakaryocyte
What is the lifespan and size of a platelet?
Lifespan ~10 days
Size 2-3 microns
Often occur in clumps in blood smears and nucleated in birds
What is the function of platelets?
Plugs for vascular damaged, blood clotting, clot retraction, clot dissolution, factors for vascular repair
What does the platelet cytoplasm consist of?
Granules (lysosomes, peroxisomes, dense granules, alpha granules)
Most organelles that are found in other cells
What is the normal platelet count?
200-500 * 10^3 ul
Describe a clot
Aggregation of platelets, fibrin and entrapped blood cells
What is a thrombosis?
Clotting within a blood vessel
What is a embolus?
Piece of a blood clot
What are triggers for blood clots?
Endothelial damage, sluggish blood flow, changes in blood cells, systemic or metabolic disease
What are the characteristics of avian blood?
Oval, nucleated RBCs (same in amphibians, fish)
Heterophils (rod-shaped, acidophilic granules)
More common basophils
Thrombocytes are nucleated and small and may resemble lymphocytes
Characteristics of canine blood
Leptocytes (target cells, decreased volume so cell membrane has folds)
Eosinophils have granules that vary in size, number and staining intensity, vacuolated cytoplasm (especially in greyhounds)
Basophils have translucent cytoplasm
Characteristics of feline blood
Howell-Jolly bodies are normal in 1% of RBCs
Heinz bodies are normal in up to 10% of RBCs
May see nucleated RBCs in peripheral blood
Basophils stain light lavender or mauve
Characteristics of equine blood
Prominent rouleaux formation (stacking of RBCs)
Howell-Jolly bodies normal in 1% of RBCs
Eosinophils have extremely large granules
Characteristic of bovine blood
More lymphocytes than neutrophils
Neutrophils have acidophilic granules and one lobe connected to main nucleus
Eosinophils have C-shaped nucleus
Characteristics of porcine blood
Neutrophils are dark-staining with coiled nucleus and lobes connected by strictures
Eosinophils are heavily granulated and obscure the nucleus
Basophils have coccoid or dumbbell shaped granules
