X is the hardest letter in the alphabet for body parts. In fact, there is really only one well-known structure that starts with X: the xiphoid process, a small piece of bone at the bottom of your breastbone. A few related terms are useful to know too.
Here is the honest, complete list, with a clear explanation of each.
Quick List: Body Parts That Start With X
| Xiphoid process | Xiphisternal joint |
| X chromosome |
Chest
Xiphoid process: The small, pointed piece at the lower tip of the breastbone (sternum). It is made of cartilage at birth and slowly turns to bone, usually by about age 40. Several abdominal muscles and the diaphragm attach to it. During CPR, rescuers place their hands above it, because pressing on the xiphoid itself can injure organs underneath.
Xiphisternal joint: The joint where the xiphoid process meets the main body of the sternum. It is a useful landmark for doctors because it lies roughly level with the bottom of the heart.
Cells and Genetics
X chromosome: One of the two sex chromosomes found in almost every cell. Females usually have two X chromosomes and males usually have one X and one Y. The X chromosome carries hundreds of genes, including some linked to colour vision and blood clotting.
Where Does “Xiphoid” Come From?
The word comes from the Greek xiphos, meaning “sword.” The breastbone was compared to a short sword, with the xiphoid process as its tip.
Frequently Asked Questions
Is there an organ that starts with X?
No. No organ in the human body starts with X. The xiphoid process is the only common anatomical structure beginning with this letter.
Can you feel your xiphoid process?
Often, yes. Run your finger down the centre of your chest to the bottom of the breastbone, just above the upper abdomen. In some people it is easy to feel; in others it is hidden under muscle and fat.
What X word can kids learn for the body?
Xiphoid. It is a fun, unusual word, and children can try to find the tip of their breastbone.
Conclusion
X may have the shortest list in anatomy, but the xiphoid process is a real and useful landmark, especially in first aid. It makes a memorable entry in any A-to-Z of the human body.
Continue the series with body parts that start with W and body parts that start with Z.
This article is for general education only and is not medical advice. If you have a health concern, please talk to a doctor.
