Introduction to Hematology Flashcards
Blood centrifugation

Major types of “formed elements”
Erythrocytes, leukocytes, platelets
Erythrocyte lifespan
120 days
Thrombocyte lifespan
7-10 days
Methods for measuring formed elements
- Electrical impedence: The change in resistance produced when a cell or cell fragment passes through an electric current conducted across a small aperture
- Flow cytometry
Obtaining blood counts

Normal red cell indices

Most important plasma proteins
Proteins of the coagulation cascade, certain coagulation cascade regulatory factors, von Willebrand factor, and proteins that promote the lysis of clots, such as plasmin.
By adulthood, hematopoiesis is normally confined to . . .
. . . the axial skeleton, the proximal long bones, and the skull.
Organization of bone marrow

Decrease in all myeloid cells
Pancytopenia
Increase in all myeloid cells
Pancytosis
When the marrow is examined, in most instances . . .
. . . both an aspirate and biopsy are taken, usually from the posterior iliac crest.

Megakaryocyte

Reticulocyte

Orthochromic normoblast

basophilic (black arrow) and polychromatophilic (red arrow) normoblasts

Erythroblast

Metamyelocyte

Myelocyte

Promyelocyte

Myeloblast
Thymus on H and E

Splenic “slits”
The splenic arteries eventually give rise to small, arborizing arterioles, which empty into the splenic red pulp, an interstitial space separated from the venous sinuses of the spleen by a basement membrane with slit-like openings. Red cells that have normal deformability are able to push through the slits and return to the circulation, but cells that are rigid are retained and removed by resident macrophages.









