H3 Flashcards
What are the 2 types of bone marrow? (and where are they found)
- Red bone marrow (found in flat and long bones e.g. hip bones, skull, ribs, and vertebrae)
- Yellow bone marrow (found in hollow regions of compact bones of axial skeleton)
What does red bone marrow contain?
Stem cells that differentiate into red blood cells, white blood cells and platelets (specifically multipotent stem cells)
What does yellow bone marrow contain?
Fat and stem cells that can become cartilage, fat, or bone cells
Define differentiation
The process in which a cell changes from one cell type to another
What are the stages of the cell cycle?
G1: cell growth
S: synthesis: DNA doubles and chromosomes duplicate
G2: growth and preparation for mitosis
M: mitosis
Define apoptosis
Programmed cell death without the release of harmful substances
What is neoplasia?
Uncontrolled, abnormal growth of cells or tissues
What are the functions of the spleen?
Control of red cell integrity
Immune response
Sequestration
How does the spleen control red blood cell integrity?
- removes Howell-jolly bodies
- traps and engulfs aged or abnormal red blood cells
How does the spleen assist with the immune response?
- contains macrophages and dendritic cells
- initiates immune response
- presents antigen to B and T cells
- adaptive immune response
What is the normal anatomy and position of the spleen?
- wedge-shaped encapsulated organ
- upper left abdomen behind 9th and 11th ribs
What are the causes of splenomegaly (spleen enlargement)?
- liver disease
- haematologic malignancies
- infections
- congestion/inflammation
- primary splenic disease
When are bone marrow aspirates indicated?
Used to look for malignancies and pyrexia-inducing organisms
(pyrexia=constant fever)
What are the 2 main haematological malignancies?
Leukaemia: bone marrow cancer
Lymphoma: cancer of lymph nodes
What is splenic sequestration?
The trapping of old blood cells to be phagocytosed. Can be physiological or pathological (e.g. complication of sickle cell anaemia)
