Bontrager Chapter 10: Bony Thorax - Sternum and Ribs Anatomy

Name the bones that articulate DIRECTLY with the sternum

1. clavicles 2. the first 7 (true) ribs

Name the 2 POSTERIOR joints of the ribs

1. costotransverse joints 2. costovertebral joints

What are the three names for the uppermost border of the manubrium (palpable landmark)

1. jugular notch 2. suprasternal notch 2. manubrial notch.

Name the three divisions of the adult sternum

1. manubrium (superiorly; 2") 2. body (4") 3. xiphoid process (~1")

Name the three main components of the bony thorax

1. sternum (anteriorly) 2. thoracic vertebrae (posteriorly) 3. ribs (12 pairs)

Where is the only bony connection between the shoulder girdle and bony thorax?

At the sternoclavicular joints where each clavicle articulate with a lateral end of the manubrium at the clavicular notches *underneath each sternoclavicular joint is a facet for articulation with the cartilage of the first rib

Do the anterior ribs unite directly with the sternum?

NO. The true ribs articulate with the sternum via a short piece of costocartilage.

Do the ribs 11-12 connect anteriorly?

No. They are floating ribs.

costochondral union / junction

Ribs 1 - 10 form a unique union where the cartilage and bone are bound together by the periosteum of the bone itself. This permits NO Motion therefore a synarthroidal joint

Describe the shape and average length of the adult sternum

The adult sternum is thin, narrow and flat; averages about 7" in length

Where do the ribs 8-10 articulate anteriorly?

They also possess costocartilage but they connect to the costocartilage 7 which in turn connects to the sternum

Anatomy of a typical rib (from posterior to anterior)

Vertebral End 1. Head - articulates w/ 1-2 thoracic vertebral bodies 2. Flattened Neck 3. Elevated tubercle - allows articulation w/ transverse process of vertebra and allows attch of a ligament 4. angle - point of forward angulation 5. shaft (body) Sternal End

Describe the appearance of the 8th - 12th ribs

after the 7th ribs, they appear shorter and shorter through the 12th pair of ribs *The bony thorax is typically widest at the lateral margin of the 8th ribs

1st Sternocostal Joint

cartilage of the first rib attaches directly to the manubrium w/ no snovial capsule and allows no motion (synarthroidal) cartilaginous (synchondrosis), synarthroidal

At what disk level is the sternal angle?

disk space between T4 + T5

The part of the rib that is most superior is the _________ end, nearest the _________

posterior; vertebrae

Describe the appearance of the first pair of ribs

short, broad and most vertical of all of the ribs

2nd - 7th Sternocostal Joints

synovial joints allowing a plane (gliding) motion making them diarthroidal joints these bones facilitate the bony thorax movement during breathing mnemonic: Super Duper Pooper

costovertebral joints

synovial joints w/ articular capsules lined by synovial membrane, allowing a plane/gliding motion (therefore diarthroidal)

costotransverse joints

synovial joints w/ articular capsules lined by synovial membrane, allowing a plane/gliding motion (therefore diarthroidal) found on the 1st - 10th ribs

sternoclavicular joint

synovial joints w/ articular capsules permitting a plane/gliding motion. diarthroidal. mnemonic: Super Duper Pooper

Typical Rib (Posterior View)

the lower inside margin of each rib (costal groove) protects an: 1. artery 2. vein 3. nerve therefore, rib injuries are painful and subject to substantial hemorrhage

Describe the appearance of the first 7 (true) ribs

the ribs get longer as they descend from the first pair to the seventh pair.

at what level does the 2nd costocartilage articulate with the sternum?

the sternal angle (T4 + T5)

What is the palpable prominence where the lower end of the manubrium joins the superior end of the sternal body?

the sternal angle / manubriosternal joint