In the early 1990’s there was a classic ad aired on Irish TV that featured a skeleton man proclaiming the virtues of drinking cow’s milk for the calcium benefit for our bones. Let’s jump in the time machine and check this one out for a sec…
I am studying my 2nd module of Year 3 right now and the focus is on Bones & Joints. It is relatively straightforward, at least compared to some of the other systems.
I am starting to see the connections between all the body’s systems now. For example, within bones we have red and yellow bone marrow. Red bone marrow contains pluripotent hematopoietic stem cells (some mouthful eh). These stem cells are the parent cells to all red and white blood cells, platelets and osteoclasts (bone remodelling).
- Red blood cells carry oxygen around the body and CO2 to the lungs for exhalation, in this way they are heavily linked to the Circulatory system.
- There are up to 10 different white blood cells all of which work within our Immune system. All 10 immune cells are created from these parent stem cells in red bone marrow.
- Platelets are involved in blood clotting so critical to healing and repair.
Bone health is also related to the Endocrine system in that PTH, a hormone released by the parathyroid gland is the primary mechanism for regulating calcium levels in the body. If calcium levels drop too low (<2.15 nmols), PTH is released which in turn:
- Stimulates the kidneys to reabsorb more calcium thus reducing the amount lost in urine (links to Renal system)
- Triggers the activation of Vitamin D (conversion of Cholecalciferol – inactive vitamin D – stored in the liver – to activated Calciferol in the kidneys) which increases the amount of calcium absorbed from food in the gut (links to Digestive system)
- Stimulates production of osteoblast bone cells which remove minerals like calcium from the bone matrix which increases calcium levels in the blood.
With all of these connections and stimuli affecting other systems and overall homeostasis within the body, bone health is really a key foundational aspect to overall good health.
There are many disorders when it comes to dysfunctioning bones and joints but some of the main ones are osteoarthritis, rheumatoid arthritis and osteoporosis.
My mum suffers from Rheumatoid Arthritis (RA) a bit which is outlined below. Her case is not that severe yet but it does get worse over time.


Yours in health and happiness,
JP