Bone Marrow | The University Of Western Ontario

University:
The University Of Western Ontario
Course:
ANAT 2200B | Systemic Anatomy of the Human Body
Academic year:

2022
Views:

379

Pages:

3
Author:

Kyuwon J.

Bone marrow ● Specialised vascular connective tissues in medullary cavity on long bones and interabecular spaces in cancellous bones ○ Primarily on hematopoiesis after birth ○ Red blood cells production ○ White blood cells production ○ Platelets productions ● Maturation of immune cell happens here ● Storage for hematopoietic stem cells ● Fat storage ○ Yellow marrow ● Resirovroir for iron and other growth factors ○ TGF-B ■ Important stored growth factors ■ Typically stored in bone matrix ■ Released when osteoclastic bone resorption has been triggered ○ BMPs ■ BMP-2 ■ BMP-4 ■ BMP-7 ● Osteogenesis inducements ● Cause of mesenchymal stemcells ○ Triggering osteoblasts ● Fracture healing = essential use ○ FGF ■ Present in marrow stroma ■ Stimulation of proliferation ■ Regulation of angiogenesis ○ PDGF ■ Released on injury + fracture ● Cehmotaxis ● Enhancement of fracture repair ○ VEGF ■ Locally stored in marrow ■ Angiogenesis triggering ■ Blood vessel growth through osteogenesis ● Responsible on bone remodeling ○ Marrow bone signaling Red bone marrow ● Hematopoietic ● Active production of blood cells ○ Flat bones ■ Sternum ■ Ribs ■ Vertebrae ■ Skull ■ Pelvis ○ Proximal epiphyses ■ Femur ■ Humerus ● Cellular (in high level) ● Rich with sinusoidal blood supply ● Containment of hematopoietic cords Yellow bone marrow ● Dominated through adipocytes ● Hematopoietically inactive when in normal conditions ○ Medullary cavity ■ Long bone diaphysis ● Femur ● Tibia ● Humerus ● Reversible ○ Revertable to red marrow in certain cases ■ Severe anemia ■ Chronic hypoxia ■ Hematologic stress Age related changes of Bone Marrow ● Newborns ○ Entire skeletons ○ Red marrow ● Childhood ○ Gradual replacements through yellow marrow ● Adult ○ Red marrow limited ○ Tends to be found in axial skeletons ● Elders ○ Further fatty replacement Marrow conversion happens from distal to proximal and appendicular to axial