Hemopoietic System It consists of 3 organs: 1-Lymph nodes
Lymph nodes Lymphadenitis:
inflammation of lymph node (L.n.).
I-Classification of lymphadenitis according to Duration: 1-Acute lymphadenitis
II-Classification of lymphadenitis according to Exudate and Lesions: 1-Serous Hemorrhagic
Acute Lymphadenitis: Macroscopic Picture:
1-The affected L.n. is enlarged. 2-The affected L.n. is congested. 3-Soft and moist
-Pus on cut surface in
-Hemorrhagic (dark red)
-Black wit bad odor in
-Friable cheesy material
Microscopic Picture: 1-Active hyperemia.
3-Hyperplasia of lymphocytes and REC.
4-Edema (Albumin) in
-Neutrophils and pus in
-Loss of cellular details and tissue architecture in Necrotic Lymphadenitis. -Gas bubbles and M.O. in Gangrenous Lymphadenitis.
-Follow the acute type -T.B., Johneâ€™s disease, Glanders, Actinobacillosis Macroscopic Picture: 1-L.n. is enlarged 4-Pink in color.
Microscopic Picture: 1-Fibrous connective tissue proliferation. 2-Hyperplasia of the lymphocytes and REC. 3-Caseation and calcification (TB). 4-Macrophages, epithelioid cells and giant cells infiltration.
Spleen Splenitis: Inflammation of spleen. I-Classification of Splenitis according to Duration: 1-Acute Splenitis (focal or diffuse) 2-Chronic Splenitis II-Classification of Splenitis according to Exudate and Lesions: 3-Suppurative: pyogenic M.O. (pyemia). 4-Hemorrhagic: Septicemic D. (anthrax) or trauma 5-Necrotic: S. necropherous, TB, Brucella 6-Gangrenous: Foreign body with saprophytic M.O.
Splenomegaly: Enlargement of spleen as in case of chronic anemia.
Bone Marrow In Young Animals: the bone marrow present in the shaft of all long bones. In Old Animals:
Red bone marrow present in epiphyses of long bones. Yellow bone marrow present in the shaft.
Gelatinous degeneration of B.M. Causes:
1-Bacterial toxins 2-Chronic debilitating diseases.
Lesions: The yellow and red bone marrow become gelatinous (Jellylike structure).
Decrease the number of RBCs.
Increase the number of RBCs.
Increase the number of leukocytes.
Increase the number of neutrophils.
Increase the number of eosinophils.
Increase the number of lymphocytes.
Increase the number of Monocytes.
Decrease the number of leukocytes.
Leukemia Definition: It is abnormal increase in the number of leukocytes especially with immature cells. Types of Leukemia: 1-Lymphocytic Leukemia. 2-Myelocytic or Granulocytic Leukemia.
Differences between Lymphocytic and Granulocytic Leukemia
Increase lymphocytes lymphoblasts
Increase granulocytes myelocytes myeloblasts
Enlarged or not
Enlarged with dark red color and ruptured
Enlarged with grayish red color
Yellowish and grayish (not pinkish)
grayish or pinkish
Liver, kidneys, Lesser affected than lungs the granulocytic
Focal or diffuse neoplastic swelling, greenish in color, fatty changes in liver