Difference between revisions of "Bone"

Revision as of 02:17, 30 September 2010

Bone is a scaffold. Tumours occasionally arise in them; these are dealt with in the bone tumours article.

Normal

Normal bone has osteocytes.
- If the osteocytes are missing... the bone is dead.

Osteoblasts - make bone.
Osteoclasts - destroy bone.

Memory device: 'b' before 'c'.

Bone marrow

Fat content (%) ~= age (in years)^[1]
- e.g. 60 year old will have 60% fatty replacement.

Should see three cell lines.
- The cell lines:^[2]
  - Erythroid (red cells),
  - Myeloid (white blood cells),
  - Megakaryocytic (platelets).

Note: Lymphocytes are considered separately and typically spared in bone marrow failure.^[3]

Identifying the lines:^[4]

Megakaryocytes:
- Big cells ~ 3x the size of a RBC.
Normoblasts (RBC precursors):
- Hyperchromatic, i.e. blue, nucleus.
Myeloid line:
- Granules.
- Reniform nucleus, i.e. kidney bean shaped nucleus.

Images:

Myeloid line (WC).

Organization

Mature hematopoeitic cells at the centre (distant from bone).
Immature hematopoeitic cells adjacent to the bone.

Infectious

Osteomyelitis

General

Hematogenous - often in children.
Direct entry (skin defect) - adults with diabetes.

Microscopic

PMNs.

Chronic osteomyelitis

Plasma cells.
- May be sterile, i.e. no organisms.

Bone tumours

Main article: Bone tumours

This is a big topic. It is dealt with in a separate article.

References

[1] IAV. 26 Feb 2009.

[2] ttp://emedicine.medscape.com/article/199003-overview

[3] ttp://emedicine.medscape.com/article/199003-overview

[4] ttp://upload.wikimedia.org/wikipedia/commons/6/69/Hematopoiesis_%28human%29_diagram.png

[1]

[2]

[3]

[4]

@@ Line 1: / Line 1: @@
-#redirect [[bone tumours]]
+'''Bone''' is a scaffold.  Tumours occasionally arise in them; these are dealt with in the ''[[bone tumours]]'' article.
+==Normal==
+*Normal bone has osteocytes.
+**If the osteocytes are missing... the bone is dead.
+*Osteoblasts - make bone.
+*Osteoclasts - destroy bone.
+Memory device: 'b' before 'c'.
+===Bone marrow===
+*Fat content (%) ~= age (in years)<ref>IAV. 26 Feb 2009.</ref>
+**e.g. 60 year old will have 60% fatty replacement.
+*Should see three cell lines.
+**The cell lines:<ref>[http://emedicine.medscape.com/article/199003-overview http://emedicine.medscape.com/article/199003-overview]</ref>
+***Erythroid (red cells),
+***Myeloid (white blood cells),
+***Megakaryocytic (platelets).
+Note: Lymphocytes are considered separately and typically spared in bone marrow failure.<ref>[http://emedicine.medscape.com/article/199003-overview http://emedicine.medscape.com/article/199003-overview]</ref>
+Identifying the lines:<ref>[http://upload.wikimedia.org/wikipedia/commons/6/69/Hematopoiesis_%28human%29_diagram.png http://upload.wikimedia.org/wikipedia/commons/6/69/Hematopoiesis_%28human%29_diagram.png]</ref>
+#Megakaryocytes:
+#*Big cells ~ 3x the size of a RBC.
+#Normoblasts (RBC precursors):
+#*Hyperchromatic, i.e. blue, nucleus.
+#Myeloid line:
+#*Granules.
+#*Reniform nucleus, i.e. kidney bean shaped nucleus.
+Images:
+*[http://commons.wikimedia.org/wiki/File:Bone_marrow_WBC.JPG Myeloid line (WC)].
+====Organization====
+*Mature hematopoeitic cells at the centre (distant from bone).
+*Immature hematopoeitic cells adjacent to the bone.
+==Infectious==
+===Osteomyelitis===
+General
+*Hematogenous - often in children.
+*Direct entry (skin defect) - adults with diabetes.
+====Microscopic====
+*PMNs.
+===Chronic osteomyelitis===
+*Plasma cells.
+**May be sterile, i.e. no organisms.
+==Bone tumours==
+{{Main|Bone tumours}}
+This is a big topic.  It is dealt with in a separate article.
+==See also==
+*[[Hematopathology]].
+*[[Soft tissue lesions]].
+*[[Small round cell tumours]].
+==References==
+{{reflist|2}}
+[[Category:Weird stuff]]