Histology of BloodHistology of Blood

dr. Zulham, M.Biomeddr. Alya Amila Fitrie, M.Kes

Department of HistologyMedical Faculty, University of North

Sumatera20092009

Blood

Specialized Specialized connective tissue

Consisting of cells & plasma

Buffy coat

Hematocrite

Components separated by centrifugation if blood is collected in the

presence of anticoagulants

Plasma

Th fl id t f th bl dThe fluid component of the blood

Contain salts & organic compound (amino acids, lipids, vitamins, proteins & hormones)

In the absence of anticoagulant, cellular element + plasma proteins → clot in the test tube

The fluid portion from above → serum, i ll fib i f lessentially fibrinogen-free plasma

Cellular Elements

ErythrocyteLeucocyte

GranulocyteNeutrophilNeutrophilEosinophilBasophil

A l tAgranulocyteLymphocyteMonocyte

Platelets : not a cell

Erythrocyte / Red Blood Cells (RBCs)

Non-nucleated, Biconcave-shaped cell, ∅ 7-8 μm, 4-, p , ∅ 7 8 μ , 46.106/mm3

Lack organelles Consist only of a plasma membrane its Lack organelles. Consist only of a plasma membrane, its underlying cytoskeleton (→flexible) , Hb & glycolytic

enzymes

Circulate for 120 days, senescent RBCs are removed by phagocytosis or destroyed by hemolysis in the spleen.

Clinical significance : Cytoskeletal & Hb abnormalities, Erythroblastosis foetalis

RBCs & Reticulocytes

RBCs are replaced in the RBCs are replaced in the circulation by reticulocytes

Reticulocytes complete their Hbsynthesis & maturation 1-2 days y y

after entering the circulation

Reticulcytes account for 1-2% of circulating RBCs

Leukocytes / White Blood Cells

6000-1000/mm3

Categorized as Granulocytes (primary & spesific cytoplasmic granules) & p y p g )

Agranulocytes (primary granules only)

Leukocytes leave the bloodstream (diapedesis) & enter connective tissue

Granulocytes

Neutrophil Eosinophil Basophil

Multilobed nucleus, ∅ 12-15 μm. Lifespan varies, can be distinguished by their cytoplasmic granulesg y y p g

Neutrophil

Have a lobulatednucleus, usually

2-5 lobules

60-70% of Lifespan 6-7 h li 60 70% of

circulating leukocytes

hours, may live > 4 days in the

connective tissuey connective tissue

Eosinophil

Bilobed nucleus Granules : large,

refractile, stain red Bilobed nucleus refractile, stain red in blood smear

2-4% of circulating leukocytes

May also leave the circulation →

First line of defense against parasites &

participate in b h lleukocytes connective tissue triggering bronchial

asthma

Basophil

Bilobed nucleus, that b d b l

Granules : large, metachromaticobscured by granules metachromatic

cytoplasmic granules

Only 1% of circulating l k

May also leave the circulation →

connective tissue Play role in

immediate & delayed hleukocytes connective tissue,

resemble mast cells hypersensitivity

Agranulocytes

Lymphocytes Monocyte

Round or indented nucleus, contain only lysosomal-type, primary granules.yp , p y g

Lymphocyte

24-44% of circulating Nucleus : round &

li htl i d t dcirculating leukocytes slightly indented

Cytoplasm: basophilic,

appearing as a thin d h

Large lymphocyte (3% of all

lymphocytes 9-12

Small lymphocyte ( 97% of all

lymphocytes 6-8 rim around the nucleus

lymphocytes, 9 12 μm)

lymphocytes, 6 8 μm)

Lymphocyte

Monocytes

Nucleus : kidney-h d l ∅ 9-12 μmshaped or oval ∅ 9 12 μm

Cytoplasmicgranules are small

Circulate in blood 12-100 hours, then

enter connective

Connective tissue → macrophage

granules are small enter connective tissue Bone → osteoclast

Platelet

S ll t l i f t d i d f th Small cytoplasmic fragment derived from the megakaryocyte

Megakaryocyte → develop cytoplasmic projection → proplatelets fragment into plateletsproplatelets→ fragment into platelets

Central region (granulomere) : mitochondria, RER, Golgi app., granules

Peripher region (hyalumere) : microtubulus & microfilament → regulate shape & movementmicrofilament → regulate shape & movement

Th k Thank you…