HEMA W3:2 Flashcards
Hematopoietic tissue is in bone marrow or lymphoid tissue continuing blood production
DEFINITIVE HEMATOPOIESIS
Lymphoid tissue
DEFINITIVE HEMATOPOIESIS
Found in bone marrow and thymus
B cells and T cells are derived
Primary lymphoid tissue
Found outside bone marrow
Mucosa associated lymphoid tissue (MALT)
Gut associated lymphoid tissue (GALT)
Secondary lymphoid tissue
Normal bone marrow contains two major components
Red and yellow marrow
haematopoietically active marrow and has an ability to produce blood
Red marrow
haematopoietically inactive marrow, it has a fats
yellow marrow
Age dependent production
Infancy or early childhood:
5-7 year of age:
Adulthood: 40% are red marrow found in sternum, vertebrae, scapulae, pelvis, ribs, skull, and proximal portion of long bones
80-90% involvement of red marrow
Infancy or early childhood
60% involvement of red marrow
5-7 year of age
40% are red marrow found in sternum, vertebrae, scapulae, pelvis, ribs, skull,
and proximal portion of long bones
Adulthood
refers to the process which red marrow is replaced by yellow marrow that is made up of adipocytes
Retrogression
It is performed to define the ratio of red marrow to yellow marrow that
usually decreases with age
Marrow cellularity
marrow has 30-70% hematopoietic cells
Normocellular
marrow has <30% hematopoietic cells
Hypocellular
