Lecture 5: Hemolymphatic system I Flashcards
Erythroid and myeloid precursors form what
erythroid: RBC
Myeloid: all other WBC
megakaryocytes form what
platelets
___cells are one precursor cell in bone marrow that gives rise to many different cell types
pluripotent hematopoietic stem cells
what is the role of erythropoietin
produce more RBC. It is produced by kidney and senses low blood volume or hypoxia and increases RBC
what does thrombopoitein do
increase platelet volume
which bone marrow is indicative of young vs old animal
red marrow- young
Yellow/fat marrow- old
what is extramedullary hematopoiesis
hematopoiesis occurring outside of the bone marrow
when does extramedullary hematopoiesis occur
during stress or disease states
What organ is responsible for filtering the blood
spleen
what is the red pulp
monocyte-macrophage system cells, vascular spaces, stromal cells, hematopoiesis
what is the white pulp
primary site for B and T cell interactions
what is the function of the trabecular smooth muscle in spleen
allows it to contract
what tissue is this and identify 1-2
spleen
1. White pulp
2. Red pulp
what is the structure and function of lymph node cortex
outer and inner, B and T cell follicles, respectively.
Important site for B/T cell interactions
what cells make up medulla of LN
cords of macrophages, lymphocytes, plasma cells and sinuses
lymph nodes ___specific areas of the body that allow for surveillance for ___within blood/lymph
drain, antigens
lymph h node- identify 1-6 (2, 4, and 6- what cells present)
- Outer cortex
- B cell follicles
- Inner cortex
- T cell follicles
- Medulla
- Macrophages, lymphocytes, plasma cells
where is the thymus located
cranial mediastinum
what is the purpose of the lymphoid portion of thymus
T lymphocyte development
what is function of epithelial portion of thymus and what does it contain
“scaffold for thymus”, Hassalls corpuscles
what type of tissue is this and identify 1-2
thymus
1. Lymphoid portion- t lymphocytes
2. Epithelial portion- hassall’s corpuscles
what is this structure in a young animal
thymus
what is the function of the thymus
differentiation and maturation of T lymphocytes, positive and negative selection
what is positive selection in thymus
survival of T lymphocytes because they appropriately recognize MHC and dont react to self antigens
what is negative selection in thymus
results in apoptosis/ death of T lymphocytes that recognize host cell/ self antigens
what are some causes of hyperplasia in bone marrow
hypoxemia, tissue inflammation, hemorrhage, hemolysis, idiopathic
bone marrow of older patient. What response to injury occurred
Hyperplasia- diffusely red marrow- increased hematopoietic tissue
What is happening here and describe the pathogenesis
- Chronic interstitial pneumonia
- Longstanding hypoxemia
- Increased renal erythropoietin production
- Bone marrow erythroid hyperplasia
What is an example of a syndrome that can cause dysplasia
myelodysplastic syndrome- abnormal/immature hematopoietic cells
what is the normal ratio of fat to hematopoietic cells in normal bone marrow
50/50
what happens to fat: hematopoietic cell ratio in a hypoplastic bone marrow
increase ratio of fat
which of the following is normal vs abnormal and what is wrong
left: normal
Right: abnormal- hypoplasia of bone marrow
what is aplasia in bone marrow
failure of hematopoietic cell development- ALL hematopoietic lineages in bone marrow
what is the result of aplasia of bone marrow
aplastic anemia- cytopenias of all cell lines- aplastic pancytopenia
what are some causes of asplasia leading to aplastic anemia
- Chemical- antimicrobial, chemotherapy, phenylbutazone, bracken fern
- Infectious- ehrlichia, parvo, FIV, FeLV
- Idiopathic
pancytopenia including thrombocytopenia increases risk for __ and __
infections and hemorrhages
what is myelophthisis
replacement of hematopoietic tissue
what are some causes of myelophthisis
- Neoplasia- leukemia, lymphoma
- Myelofibrosis- fibrosis as sequels of necrosis
- Inflammation
What wrong and what is pathogenesis
- Chronic negative energy balance
- Excessive marrow fat use and atrophy
- Serous atrophy of fat
normal bone marrow in a young animal will have greater amounts of hematopoietic tissue or fat
hematopoietic tissue
systemic inflammation/infection would be expected to cause: bone marrow hypoplasia or hyperplasia
hyperplasia
aplastic anemia is an example of bone marrow __that results in cytopenias of __ cell lines
aplasia, all
what are some clinical signs of anemia
Pale MM, lethargy, weakness, exercise intolerance, increase liver enzymes, cardiac murmurs
suspect anemia, perform a blood smear, what sign would be seen for regenerative anemia
reticulocytes
anemic patient, perform blood smear, what are these and what does it tell you
Reticulocytes—> regenerative anemia
what species do not release reticulocytes into circulation and require bone marrow examination or sequential CBC to determine regenerative anemia
horses
what are some causes of regenerative anemia due to hemorrhage/loss
trauma, von Willie brand dz, neoplasia, GI ulceration, parasites
what are some causes of regenerative anemia due to hemolysis
- Immune mediated
- Infections-hemoparasites
- Toxins- oxidizing, clostridial
- Mechanical fragmentation
- Incompatible blood transfusions
what is hemolytic anemia
increased rate of erythrocyte destruction
where does extravascular hemolytic anemia occur
hemolysis at level of spleen
where does intravascular hemolytic anemia occur
Within blood vessels
what are 2 common findings for both intravascular and extravascular hemolytic anemia
- Prophetic hyperbilirubinemia causing icterus
- Splenomegaly
what type of hemolytic anemia caused this
both intra and extravascular
which is more common: intra or extravascular hemolytic anemia
extravascular
what gross lesions are associated with extravascular hemolytic anemia
- Meaty splenomegaly- no blood on cut section
what causes splenomegaly in extravascular hemolysis
destruction of RBC’s by hyperplastic macrophages (increased # of macrophages)
what are some common causes of extravascular hemolysis
- IMHA
- Mechanical fragmentation
- Hemoparasites
what type of hemolytic anemia caused this
extravascular hemolytic anemia
what are the causes of IMHA
- Primary- idiopathic
- Secondary- neoplasia/infection
what type of hemolytic anemia is present with IMHA
extravascular hemolytic anemia
what is the target and pathogenesis for IMHA
- Erythrocytes
- Enhanced destruction by splenic macrophages
- Marked regenerative response and activation of thrombosis
what are some postmortem findings of IMHA
- Icterus
- Splenomegaly
- Thromboembolic disease and/ or hypoxia—> ischemic necrosis of liver, kidney, lung, heart, spleen (infarcts)
What is neonatal iseoerythrolysis
type of IMHA in horses that occurs when newborn receives colostrum derived maternal antibodies which react against its own erythrocytes= extravascular lysis
what is the pathogenesis of neonatal isoerythrolysis
immunosensitization of the mare from exposure to an incompatible blood type inherited from a stallion (especially Aa and Qa)
Foal necropsy shows these signs, blood work also shows anemia, what is wrong
Neonatal isoerythrolysis
what are two signs of intravascular hemolysis
- Hemoglobinemia: serum is pink following centrifugation
- Hemoglobinuria
what are some causes of intravascular hemolysis
- Toxins- clostridial
- Oxidants- copper, onion, acetaminophen, red maple leaf
- Hemoparasites- Babesia
what is the pathogensis of bacillary hemoglobinuria
- Patient with C. Hemolyticum or C. Novyi dormant in liver
- Flukes migrate through liver causing necrosis
- Produce anaerobic environment
- Spores germinate into vegetative form
- Produce toxins that directly damage RBC membrane
- Intravascular hemolysis/ hemolytic anemia
what are some differentials for wine port colored urine in ruminants
- Copper toxicity
- Babesiosis
- Bacillary hemoglobinuria
- Leptospirosis
what is the result of an oxidative injury
conversion of hemoglobin to methemoglobin which can’T bind oxygen, blood is a brown color
Take blood and its a chocolate color- what is wrong
exposed to oxidant—> methomeglobinemia—> intravascular hemolytic anemia
what are some common oxidants
copper poisoning, nitrate poisoning, brassica toxicity (kale and turnip), red maple leaf, acetaminophen, naphthalene, propofol, zinc
why should you never feed red maple leaves to a horse and what are some signs of toxicity
- Oxidative injury to RBC’s
- Intravascular hemolysis
Signs: icterus, hemoglobinuric nephrosis with hemoglobinuria
perform a blood smear on anemic patient and there are no reticulocytes- what does that tell you and what are two origins of disease
- Non regenerative anemia
Diseases
1. Primary bone marrow disease
2. Extra marrow disease
9 month old cat presents to you in respiratory distress and you take chest rad and discover a mass within cranial mediastinum. Cat is known to be FeLV positive.
What structure is likely affected?
What relevance does FeLV have
- Thymus likely affected
- Retroviruses like FeLV like to induce neoplasia—> lymphoma
What organ specific cell type is involved in extravascular hemolysis
splenic macrophages
on a blood smear in an anemic patient, seeing __indicates regenerative anemia
reticulocytes
What are some causes of extravascular hemolytic anemia
Immune mediate (IMHA, neonatal isoerythrolysis), mechanical fragmentation (DIC), hemoparasites
immune mediated disease primarily causes what type of hemolysis
extravascular
oxidizing agents and bacterial toxins typically cause what type of hemolysis
Intravascular hemolysis
