HEMA LEC: PLATELETS

MITOSIS

The pluripotential stem cell produces CFU–Meg, which can undergo________

ENDOMITOSIS

Eventually the CFU-Meg stops mitosis and enters _____

4-5 DAYS

MEGAKARYOCYTE MATURATION IN THE BONE MARROW

8N 16N

MOST MATURE MEGAKARYOCYTE ARE

PROLIFERATION

PHASE WHERE PROCESS OF ENDOMITOSIS TAKES PLACE

MATURATION

PHASE OF DEVELOPMENT OF CYTOPLASMIC GRANULES AND FORMATION OF DMS

CIRCULATION

PHASE WHERE MEGAKARYOCYTE RELEASE PROPLATELETS INTO THE BLOOD STREAM

ROUND

NUCLEUS OF MK-I MEGAKARYOBLAST

INDENTED

NUCLEUS OF MK-II PROMEGAKARYOCYTE

MULTILOBED

NUCLEUS OF MK-III MEGAKARYOCYTE

3:1

N/C RATIO OF MK-I

1:2

N/C RATIO OF MK-II

1:4

N/C RATIO OF MK-III

MEGAKARYOBLAST

NUCLEUS:

ROUND, OVAL, OR KIDNEY-SHAPED

FINE CHROMATIN PATTERN

BLUE STAINING MULTIPLE NUCLEOLI

DEMARCATING MEMBRANE SYSTEM

Series of membrane lined channels that invade from the plasma membrane and grow inward to subdivide the entire cytoplasm that becomes the future site of platelet fragmentation

CHROMOMERE

HYALOMERE

2 PARTS OF PLATELET

THROMBOPOIETIN

primary regulator of thrombopoiesis ; stimulates differentiation and maturation of megakaryocyte; produced by the liver and kidneys

INTERLEUKIN-6

Stimulates thrombopoietin production

STEM CELL FACTOR

Acts primarily on primitive cells of the hematopoietic cell lineages

FLT-3 LIGAND

for proliferation of megakaryocytic progenitor cells.

TGFs AND INTERFERON-A

Inhibitors of hematopoiesis

THROMBOCYTE

PLATELETS IS ALSO KNOWN AS

NO NUCLEUS

“The platelet is a portion of the megakaryocyte cytoplasm and, as such, contains _______”

1-4 um

SIZE OF PLATELETS

CIRCULAR TO ELLIPSOIDAL

SHAPE OF PLATELETS

6-7 fL

VOLUME OF PLATELET

8%

CHO, MINERALS, H2O, NUCLEOTIDES

60%

PROTEIN

30%

LIPID

LIGHT BLUE TO PURPLE

CYTOPLASM OF PLATELETS

THROMBUS CYTO

THROMBOCYTE CAME FROM A Greek word:

PERIPHERAL ZONE MEMBRANE

Responsible for platelet adhesion and aggregation

SOL-GEL STRUCTURAL ZONE

Lies beneath the platelet membrane.

PLASMA MEMBRANE

GLYCOCALYX

PERIPHERAL ZONE

MICROTUBULES

MICROFILAMENTS

SOL-GEL OR STRUCTURAL ZONE

VON WILLEBRAND DISEASE

deficiency in VWF

BERNARD-SOULIER SYNDROME

deficiency in GP Ib/IX/V

PLATELET ADHESION

Platelets roll and attach to non-platelet surface. REVERSIBLE

PLATELET AGGREGATION

Attachment of platelets to each other

○ Platelet plug forms

○ Platelet contents are secreted

IRREVERSIBLE