Odds and Ends: Ribs

Ribs!  Humans have 12 sets.  When you examine a disarticulated skeleton, you get a bag of 12 ribs. You just have to try to make heads or tails (literally) of them.  Students often do not realize that each rib has a teeny tiny engraved number. This number indicates to which pair of ribs the rib belongs. Because ribs come in pairs, students will find a left rib. They will also find a right rib for each of the 12 pairs.

The ribcage is an inverted cone. Imagine a wizard’s hat. At the top of the hat is the smallest pair of ribs, the first ribs. At the bottom of the inverted cone, there is an increase in the number of squishy organs. The cone also has a larger diameter needed for support. In factA statement based on direct observation that is repeatedly confirmed., the last two pairs of ribs, the 11th and 12th, are just kinda floating with no anteriorThe front of the body or toward the front when standing in the anatomical position. attachment. True ribs have their own cartilageA flexible connective tissue found in joints, the ear, nose, and rib cage. Cartilage can be of three. This cartilage attaches right to the sternumFlat bone forming the center of the chest; anchor for ribs and clavicles. Appears as a vertical dagg. It is shared by no other rib.  Rib pairs 1 through 7 do this. False ribs all have cartilage, but the cartilage comes together before attaching to the sternum. We call that an indirect attachment.  Rib pairs 8 through 10 do this. Some have no attachment, just cartilage going nowhere.  Floating ribs are tiny and have no attachment at all.

The anterior end of a rib articulates somehow with the sternum (direct, indirect, not at all). The end of the bone is oval shaped and is concave like a shallow bowl. The posterior end of a rib is called the headRounded proximal end that fits into the acetabulum of the hip bone.. This is similar to the proximalCloser to the point of attachment or origin. ends of all the long and stick bones. This is the end of the rib that articulates with vertebra. Have you ever hurt your back so badly that it hurts to breathe? This is why. As you inhale, your inverted-cone of a rib cage expands upward and outward. Your ribs allow this movementA fundamental property of life involving motion of the body or its parts. by pivoting against your vertebra, especially your chunky lumbar (lower back) vertebrae. I have often hurt my lower back. Each time, I think to myself, “Did I break a rib too?!?”

Students usually confuse a rib with the clavicleS-shaped collarbone; connects sternum to scapula; helps brace the shoulder., hyoidU-shaped bone in the neck below the mandible; does not articulate with other bones; supports tongue, or a stick bone, the fibulaSlender lateral leg bone; stabilizes ankle but bears little weight. being the most common. If you’ve ever eaten ribs of a beast, you might have noticed that the bone is c-shaped and flat.  Students are sometimes surprised by how this flatness makes the first rib look. I just feel like students can usually spot rib 6 or 7. However, they struggle to recognize ribs at either end of the collection. This tiny rib here is the first rib.  You didn’t expect a rib to look like that, right?  I don’t care what your instincts tell you when you get a C-shaped stick-looking bone. It’s a rib. Final answer.