en.wikipedia.org/wiki/Bone
3 corrections found
Every day, over 2.5 billion red blood cells and platelets, and 50–100 billion granulocytes are produced in this way.
The red-blood-cell and platelet numbers here are far too low. Normal adult marrow produces about 200 billion red blood cells per day and about 100 billion platelets per day.
Full reasoning
This sentence understates normal blood-cell production by large margins.
- A recent NIH-indexed review states: "Under normal conditions, the bone marrow generates ∼200 billion new RBCs per day".
- A platelet biogenesis review states: "This multi-step biogenesis yields approximately 100 billion platelets each day in an adult human".
So the article's figure of 2.5 billion for red blood cells is off by roughly 80-fold, and the same 2.5 billion figure for platelets is off by about 40-fold. Even without resolving the granulocyte number, the combined claim is incorrect because the red-blood-cell and platelet counts are demonstrably wrong.
2 sources
- Iron-Deficiency Anemia in CKD: A Narrative Review for the Kidney Care Team - PMC
Under normal conditions, the bone marrow generates ∼200 billion new RBCs per day to match the number of old (senescent) RBCs removed from the circulation.
- Post-Transcriptional Expression Control in Platelet Biogenesis and Function - PMC
This multi-step biogenesis yields approximately 100 billion platelets each day in an adult human, but these rates can increase by a factor of 10 or more when the demand increases.
In the upper limbs, only the diaphyses of the long bones and scapula are ossified. The epiphyses, carpal bones, coracoid process, medial border of the scapula, and acromion are still cartilaginous.
This is incorrect for skeletal maturity. By and after puberty, the carpal bones and the hand bones are ossified and their growth plates are closed, not still cartilaginous.
Full reasoning
The claim contradicts standard descriptions of skeletal maturation.
Two reviews of bone-age assessment state that carpal bones ossify during childhood and that after puberty the hand bones are fully developed:
- One review says: "After puberty, all carpals, metacarpals, and phalanges are completely developed, their physes are closed".
- Another explains that the carpal bones are not ossified at birth, but their ossification centers appear progressively through childhood.
So a statement that at skeletal maturity the upper limb has only ossified diaphyses and that the carpal bones and epiphyses are still cartilaginous is false. This looks like a misplaced developmental-stage statement rather than a correct description of mature human anatomy.
2 sources
- Evaluation of Bone Age in Children: A Mini-Review - PMC
After puberty, all carpals, metacarpals, and phalanges are completely developed, their physes are closed, and the assessment of skeletal maturity is based on the degree of epiphyseal fusion of the ulna and radius.
- Hand X-ray in pediatric endocrinology: Skeletal age assessment and beyond - PMC
The carpal bones are not ossified at birth, and they ossify solely via their primary ossification centers. Capitate and uncinate bones are the first to show ossification centers (2nd to 4th month) while the pisiform is the last (9-12th year).
Osteoporosis is defined in women by the World Health Organization as a bone mineral density of 2.5 standard deviations below peak bone mass, relative to the age and sex-matched average.
This mixes up T-scores and Z-scores. The WHO osteoporosis threshold is based on a T-score relative to a healthy young-adult reference population, not an age-matched average.
Full reasoning
The sentence confuses two different comparison standards used in bone-density reporting.
- NIAMS explains that a T-score compares a person's bone mineral density with that of a healthy young adult, and that a T-score of -2.5 or lower indicates osteoporosis.
- The same NIAMS page explains that a Z-score is the comparison to healthy people of the same age, ethnicity, and sex.
- A review summarizing the WHO criteria likewise states that osteoporosis is 2.5 SD or more below the mean level for a young adult reference population.
So the article is wrong to say the WHO definition is relative to the age- and sex-matched average. That describes a Z-score-style comparison, not the WHO diagnostic threshold for osteoporosis.
2 sources
- Bone Mineral Density Tests: What the Numbers Mean | NIAMS
A T-score is the difference between your bone mineral density and 0, which is the bone mineral density of a healthy young adult... If your T-score is -2.5 or lower, you might have osteoporosis... The Z-score is the difference between your bone mineral density and the average bone mineral density for healthy people of your age, ethnicity, and sex.
- An overview and management of osteoporosis - PMC
WHO definitions of osteoporosis based on BMD... Osteoporosis: 2.5 or more below that of the mean level for a young adult reference population | T score at or below -2.5.