Blood and Bone Marrow Flashcards
What are the general functions of blood?
-Carries oxygen, nutrients, hormones, etc
◦ Helps eliminate CO2 & wastes
◦ Immune system
-WBCS use it as a transport system
What is the peripheral blood volume?
~ 9% of body weight
blood is considered a connective tissue
What is Plasma and what is it made up of? (high molecular weight molecules and high molecular weight molecules)
*90% water; 10% other things
Low molecular weight molecules
◦ Glucose, electrolytes (salts), urea
High molecular weight molecules
◦ Albumin
◦ Clotting factors
◦ Immunoglobulins (antibodies)
◦ Enzymes
◦ Hormones
◦ Lipoproteins
Low molecular weight substances in Plasma are in equilibrium with____________
interstitial fluids
What is the function of Albumin? and what happens when albumin decreases?
◦Holds fluid in vascular space (maintains oncotic pressure)
◦ Decreased albumin results in low
oncotic pressure and edema/ascites
What are the differences between Serum and plasma?
-Serum is liquid remaining after blood
has clotted
◦ Lacks most clotting factors
◦ Lower total protein level than plasma
Plasma is liquid in
unclotted blood
◦ In blood vessels
◦ In tubes containing anticoagulant
*good to do cell count
What is Hematopoesis?
- Production of blood cells
-Primarily occurs in adult bone marrow
(medullary cavities of bones) - starts in spleen as baby
-Some extramedullary hematopoiesis in
spleen
◦ Esp. mouse, ferret, hedgehog
What is red Marrow?
Active bone marrow
What is the distribution of red marrow (active bone marrow)?
- Proximal ends of long bones (in spongy bone)
- Flat bones (e.g. vertebrae, sternum, ribs,
iliac wings)
◦ Medullary cavity in diaphysis usually
contains yellow marrow
There is an Increased ________ in young growing animals and at times of increased demand
red marrow
Which is red marrow and yellow marrow in the images? how did you identify this?
- Left-yellow marrow
- Right- Red )active) marrow
*Innactive marrow is mainly FAT!!! hence all the gaps
*
Which type of connective tissue is red marrow supported by ?
-Reticular connective tissue
What type of cells tart hematopoiesis?
-Pluripotential stem cells
- they have the capability of becoming any types of cells more of themselves
Where do b and T cells (precursors) originate?
- bone marrow
Not all lymphocytes finalize their growth in the bone marrow ( other lymphoid tissues:T cells-thymus, ileocecal prayers patch, spleen)
Hematopoiesis involves both ______ and ________ of cells
- amplification
-differentiation of cells
*Differentiation – developing
features specific for a given cell type
*Terms for production of each cell
type (LEARN THESE WORDS)
◦ RBC’s - Erythropoiesis
◦ WBC’s – Granulopoiesis
◦ Platelets by megakaryocytes –
Megakaryopoiesis (or Thrombopoiesis)
what is the name of the hematopoiesis process of RBC’s?
Erythropoiesis
what is the name of the hematopoiesis process of WBC’s?
granulopoeises
what is the name of the hematopoiesis process of platelets?
Megakaryopoiesis
What are the differences bone marrow aspirate and core biopsy?
Aspirate
* Superior cell detail
* Better for detection of small numbers of tumor
cells
* Difficult to assess cellularity
Core Biopsy
* Better estimate of cellularity & architecture
Individual cell ID harder
How can blood cells be examined?
-blood counts (using purple top tube to count individual cells- CBC)
- blood smears (air dried and stained with romanovsky stain)
What are erythrocytes? and what is their composition?
-RED BLOOD CELLS
-Most common cell type in blood
Histologic appearance
◦ Homogeneous orange to pink due to hemoglobin
Composition of hemoglobin
◦ Globin (2 alpha & 1 beta molecules)
◦ Heme (contains Fe - iron)
What is biconcave disk shape (observed in some species)?
-High surface area to volume
ratio
◦ Optimal gas exchange
- Allows for deformability (flexibility)
during circulation
Which erythrocytes (RBCs) do this belong to?
- dogs have biconcave disk shape
-birds, reptile, amphibians don get rid of their nucleus
what do RBCS outside of the blood vessel indicate?
-hemorrhage (in real/ not just incidental hemorrhage marcophages are present cleaning the area up)
What is polychromasia?
-presence of more immature red blood cells than what is considered normal
-Immature RBCs (polychromatophils)
Larger
*Cytoplasm has blue-grey tinge (ribosomes present)
-More easily visualized with New Methylene Blue or other vital dye
*Clumps ribosomes
*Cells called reticulocytes
What are senescent RBC’s, and what happens to them?
- process by which cell ages
RBC’s circulate for several months
-Worn out or damaged RBC’s are eliminated by macrophages in spleen & bone marrow
-Escaped RBCs (hemorrhage) are phagocytosed by macrophages
What are granulocytes in leukocytes (WBC’s) and what do each one of them look like?
-Neutrophils - “neutral” staining granules
*Indistinct and almost colorless
*Sometimes pale pink to pale lilac
Eosinophils – “eosinophilic” granules
*Orange to pink (similar to RBCs)
Basophils
*Granules are either dark purple or a pale lavender color (dogs & cats)
Which species do each of these neutrophils look like?
What is granulopoiesis?
As the nucleus becomes more lobular, with tight heterochromatin, these cells lose their ability to undergo mitosis.
Cells develop lineage specific secondary granules
What do neutrophils look like? what is their life span?
Usually the most numerous WBC
Duration in blood: 6-10 hrs
Lifespan in tissue: 1-2 days (few seen in healthy tissues)
Typical Appearance
*Multilobed (ribbon shaped or segmented) nucleus (segs)
*Tightly clumped chromatin
*2o granules usually indistinct or fine
What is the bactereiostatic function of neutrophils?
-Phagocytize and kill bacteria
-Myeloperoxidase (H2O2 to HOCl)
-Respiratory burst - free radical formation (deadly to whatever they ingest)
-Lysozyme – degrades cell walls
-Low pH in phagosomes
What is the role of neutrophils in inflammation?
-First responders to any inflammation rxn
-Synthesize and release immunoregulatory molecules (esp. 2o granules)
*Pro-inflammatory factors
*Anti-inflammatory factors
-Anaerobic metabolism: survive in necrotic tissues
-Release of degradative enzymes leads to tissue damage
what are the characteristics of eosinphils?
-Ribbon shaped nucleus
-distinguished by SUPER ORANGE granules
-Defense against parasites
*Not very phagocytic
*Granule contents (e.g. eosinophil peroxidase) dumped onto parasite
-Regulation of allergic reactions
-Survive several wks in tissues (after originating in blood)
eosinphil variations in different breeds
what is the least commonly found leukocyte, that is not easily found in tissue? and wha tis their
BASOPHILS
-Function – promote inflammation
*Heparin & histamine affect smooth muscle; make capillaries leaky
*Hypersensitivity reactions (e.g. allergic rx to wasp stings)
VERY granulated (cytoplasm looks purplish, ribbon snapper nucleus/ grey in cats)
typical appearance of basophils
What is the difference between basophils and Mast cells (don’t have to identify mast cells on exam) ?
-Similar metachromatic granules & functions
*Mast cell – round to oval nucleus (connective tissue cell) DARK PURPLE GRANULES-
*Basophil – bilobed to ribbon shaped nucleus (BLOOD)
Arise from different precursors in marrow.
*Basophil leaves marrow already mature
*Mast cell is a tissue cell
-Circulates in immature form; matures in tissue
-Important cause of allergic reactions
-If its in the blood, its more likely to be a basophil
-If its in the tissues, its more likely to be a mast cell
What are Agranulocytes, and what define them?
-Monocytes & Lymphocytes
-Have lysosomes, but lack the specific/secondary granules found in granulocytes
What are the characteristics of lymphocytes?
-MOST PREDOMINANT agranulocyte
-Predominant WBC in some species
-Precursors produced in marrow but then “seed” lymphoid tissue where new cells are produced
Thymus
Lymph node
Spleen, etc.
**CYTOPLASM IS OVER TO ONE SIDE
what are the functions of lymphocytes?
-Important for protection against microbes (esp viruses) and neoplasia
*Production of antibodies (B lymphocytes)- LONGEST LIVED CELLS
*Destruction of infected or neoplastic cells (T lymphocytes)
Variable life span; some live for years
Most time spent in the lymphoid tissues
Recirculate, moving from lymph node to lymph node via lymphatics and blood stream looking for “invaders”
Monocytes are in _______, macrophages are in ______ (macrophages are adult monocytes)
- blood
-tissues
*have blue grey cytoplasm, c shaped nucleus (sometimes has vacuoles)
What are the characteristics of monocytes?
-THEY ARE NOT GRANULATED
Precursors for long lived macrophages (live for months in tissue)
Variably sized-usually the largest WBC
Nucleus is round to lobulated with loose “stretched out”
chromatin
Cytoplasm
Grainy, blue to blue-grey
+/- vacuoles
what are the Monocyte/macrophage Function?
-Phagocytosis-large particulate debris
-Antigen processing
-Cytotoxicity
-Production of monokines
-Interleukins
-Tumor necrosis factor
-Factors that promote tissue repair & angiogenesis
Production of Tissue Factor procoagulant
-Link between inflammation and coagulation (accelerate clotting)
-induce inflammation
what do macrophages look like under the microscope?
H&E
-Large with abundant eosinophilic cytoplasm -Round to oval to bean shaped euchromatic nucleus
Romanovsky stained cytology smear
Large, round to oval
Basophilic cytoplasm, often with vacuoles
Macrophages (histiocytes)
light bean shaped nucleus
what do platelets look like in stain?
200,000-500,000/μl
Small cytoplasmic fragments
*Light stained periphery
*Central zone with granules
*NO nucleus
Survive 8-10 days
What do platelets do?
-they form blood clots (patches/stick to each other)
-Role in stimulation & regulation of inflammation
-Platelet derived growth factor stimulates proliferation of smooth muscle, fibroblasts, etc
-Platelets stick to bacteria – facilitate phagocytosis
