TEST 5 2026 COMPLETE QUESTIONS AND
ANSWERS GRADED A+
●● Bone marrow. 4%.
Answer: What is one of the largest organs in the body? What % does it
comprise of body weight?
●● Posterior superior iliac crest. Sternum, but is more dangerous
because it is thinner and can be punctured easier. Top of tibia below the
knee..
Answer: What is the most common site for bone marrow sampling in
adults? What is the site used when this cannot be reached? Site for
infants and kids?
●● All bones in infants, only flat bones in adults..
Answer: Where is bone marrow in infants and adults?
●● Main artery enters and branches to the periphery to form vascular
sinuses. Sinuses combine to form veins to reenter to circulation. Just
outside the sinuses are hematopoietic cords containing cells..
Answer: What is the structure of the bone marrow?
,●● Through fenestrations in the lining cells of the sinus, which are
basically adjustable holes between epithelial cells..
Answer: After maturation, how do cells enter the sinus?
●● Macrophages bring iron to the RBCs..
Answer: RBCs are inside a sinus, around a macrophage. Why?
●● Stromal cells. Reticulum that extends into the marrow cords, fat,
histiocytes, and endothelial cells..
Answer: What forms the formation and support network inside the
bone? What is it comprised of?
●● Osteoblasts. Osteoclasts. Core biopsy..
Answer: Which cells are bone forming? Bone destroying? Where can
both of these be seen?
●● Around a spicule.
Answer: Where should a differential be done on a bone marrow slide?
●● It supplies mature cells for circulation in a steady state or for
increased demand. Maintained by pluripotent stem cells. Cells
proliferate according to the stimulus they receive..
Answer: What is the function of bone marrow? What is bone marrow
self renewal maintained by? How do cells what to proliferate into?
,●● RBCs - 120 days. WBCs - 5-20 days..
Answer: What is the lifespan of RBCs and WBCs?
●● Only when it is necessary to diagnose them or treat them..
Answer: When should you aspirate a patient?
●● Anemia, polycythemia, leukopenia, and thrombocytosis..
Answer: Which diseases affect bone marrow composition?
●● Metastasizing tumors that have spread to the bone marrow such as
Hodgkin's lymphoma. Causes a spot of BM to not be able to produce
and will prevent a sample being taken from that area. A fever of
unknown origin will also affect BM production. Hereditary diseases
such as Gaucher (a storage pool disease) will also affect..
Answer: What diseases would affect the production of bone marrow?
●● Try to match the site by going to other side. Only aspirate sternum if
absolutely necessary..
Answer: If a tumor is present on the posterior superior iliac crest, what
should you try to do when trying to obtain an aspirate?
●● Aspirate represents the red marrow and is only used for the
differential. The biopsy represents the actual structure of the bone
, marrow by bringing cell to fat ratio into contemplation. A differential
cannot be performed on a biopsy..
Answer: What does the aspirate represent? What does the biopsy
represent?
●● Make sure it is actually BM by looking for a spicule, find a good
area, avoid bare nuclei, look for megakaryocytes and any abnormal
cells..
Answer: When examining BM under low power, what should be looked
for?
●● 80% during childhood. 50% age 30-70. If over the age of 70,
reduced cellularity will have to be calculated. For a 70 year old, 100-
70=30%. 30% plus or minus 10% = 20-40%/.
Answer: What percentage of cellularity should BM have during
childhood? Age 30-70? Age above 70? How do you calculate reduced
cellularity?
●● 500-1000, both RBCs and WBCs. Myeloid to erythrocyte ratio,
normal is 3:1. Lymphocytes, monocytes, and plasma cells are not
included. There are more myeloid cells in the ratio due to their shorter
lifespan, they require replacement more often..
Answer: When examining BM under oil power, how many cells should
be counted? Which cells? What ratio should be determined and what is
normal? What is NOT included in the ration count? How is this ratio
determined?