The adult human skeleton is made up of 206 bones. But the number of bones in the female body actually differs from males. This is due to some small anatomical differences between men and women.
Key Facts
- The adult male skeleton has 206 bones
- The adult female skeleton has 204 bones
- The key difference is that women have fewer ribs and smaller facial bones
Male vs Female Skeleton
Here is a breakdown of the key differences in the number of bones between male and female bodies:
Ribs
Males have 12 pairs of ribs while females have only 11 pairs of ribs. The 12th pair of ribs in men are known as ‘floating ribs’ and do not connect with the sternum. Women do not have these two floating ribs.
Facial Bones
Women tend to have smaller and less angular facial bones. In particular, the mandible (jaw bone) tends to be smaller and less robust in females.
Other Bones
All other bones are the same between men and women. The differences in ribs and facial bones account for the total 2 less bones found in women compared to men.
Developmental Differences
The developmental differences arise during puberty when testosterone leads to further growth of bones in males. Estrogen does not effect skeletal growth and bone size as much as testosterone.
Here are some of the key effects of testosterone:
- Promotes bone growth
- Increases bone density and strength
- Leads to broader shoulders and ribcage
The increased testosterone results in larger and denser bones throughout the male skeleton. This accounts for the extra 12th pair of ribs and the more robust male facial features.
Other Skeletal Differences
There are some other subtle differences between the male and female skeleton:
Pelvis Shape
The pelvis bones differ to allow childbearing in females. The female pelvis is flatter, wider and proportionally larger.
Skull Size
The average male skull size is larger than the average female skull. However, the number of skull bones is the same.
Hands and Feet
Males tend to have slightly thicker and longer bones in their hands and feet. The bone count is the same though.
Summary Table
| Skeletal Difference | Male | Female |
|---|---|---|
| Number of Ribs | 12 pairs (24 ribs) | 11 pairs (22 ribs) |
| Facial Bone Size | Larger | Smaller |
| Pelvis Shape | Narrower | Wider |
| Skull Size | Larger | Smaller |
| Hand/Foot Bones | Larger | Smaller |
| Total Bones | 206 | 204 |
Conclusion
In summary, the adult female skeletal system contains 204 bones, while the adult male skeleton contains 206 bones. The key differences are that females have one less pair of ribs and smaller facial bones due to developmental differences influenced by sex hormones.
While the bone count differs slightly, the female skeleton is perfectly adapted to support both the female body form and processes like childbearing. The skeleton allows females to live healthy and active lives.
Maintaining the health of your bones is important through adequate nutrition and weight-bearing exercise. Lifestyle factors like smoking, low calcium intake and sedentary behavior should also be avoided. Consult your doctor if concerned about bone health.
