HIST BLOCK II BLOOD

A large lymphocyte and several erythrocytes. The nucleus of this cell is round, and the cytoplasm is devoid of specific granules.

Giemsa stain. High magnification.

Monocyte

• Monocyte.
• This cell type has a kidney-shaped nucleus with delicately stained chromatin. The cytoplasm is slightly basophilic. Giemsa
• stain. High magnification.
• There are also azurphillic granules

• TEM: A human monocyte.
• the Golgi complex (G), the
• mitochondria (M), and the lysosomes or azurophilic granules (A).
• Rough endoplasmic reticulum is poorly
• developed.
• There are some free ribosomes (R).
• x22,000.

Monocyte

Monocyte

overview

• thrombocytes/platelets
• MEGAKARYOCYTES

• thrombocytes/platelets
• MEGAKARYOCYTES
• PLATELET DEMARCATION CHANNELS

• Platelet demarcation channel membranes are invaginations of the plasma  membrane
• PLATELETS therefore form from  segmentation of parts of the megakaryocyte 
• cytoplasm

• Thrombocytes/Platelets
• portion of megakaryocyte with platelet demarcation channels the channels are continuous with
• the extracellular space

• Platelet/Thombocyte
• platelet demarcation channels, lobes of the nucleus, mitochondria

• Platelet/Thombocytes
• Platelets may be divided into 4 zones
• Peripheral zone
• -cell membrane covered by thick glycocalyx
• -glycocalyx contains glycoproteins, gycosaminoglycans and coagulation factors

• Platelets/Thrombocytes ZONES
• Structural zone
•    -  microtubules, actin, myosin, actin-binding proteins
• -circumferentially arranged
• -responsible for cell shape

• Platelet/Thrombocytes ZONES
• Organelle zone
• -centrally located
• -mitochondria, peroxisomes, glycogen particles, granules.

• Platelets/Thrombocytes ZONES
• Membrane zone
• 2  types of membrane channels
• -  open canalicular system (OCS) (remnant of the platelet demarcation channel )
• -  dense tubular system (DTS)  (storage site for calcium)

• Thrombocyte/Platelets
• Platelet between RBC on left  and endothelial cell on the right

RBCs adjacent to a platelet

Overview of Platelet ZONES

• Platelet/Thrombocytes
• Platelets are involved with blood clot formation
• Fibrinogen is converted to fibrin
• Red blood cells trapped in fibrin forming a hemostatic plug

thrombi/ throboemboli

lymphocyte, monocyte, basophil, eosinophil, band neutrophil (stab), mature neutrophil, platelet, erythrocytes.

platelets, large lymphocyte, neutrophil, RBCs

band neutrophil, mature segmented neutrophil, platelets.

eosinophil,  neutrophil, platelets