Anatomy | The Sternum, Rib Cage, & Vertebrae

Summary

In this video, Kevin from Catalyst University provides an in-depth overview of the anatomy of the sternum, ribcage, and vertebrae. He explains the structure of the sternum, including its three parts: the manubrium, body, and xiphoid process, and how it functions to protect the heart. The 12 pairs of ribs are also discussed, categorized into true, false, and floating ribs. The video then covers the basic anatomy of the vertebrae, highlighting the differences between cervical, thoracic, and lumbar vertebrae, and introducing the special cervical vertebrae, C1 (Atlas) and C2 (Axis). The sacrum and coccyx are briefly explained at the end.

Takeaways

• 😀 The sternum is made up of three parts: the manubrium (top), body (middle), and xiphoid process (bottom).
• 😀 The primary function of the sternum is to protect the heart, while the ribs protect the lungs.
• 😀 Humans have 12 pairs of ribs, with the first 7 pairs being true ribs (vertebral sternal), which connect directly to the sternum.
• 😀 Ribs 8-10 are false ribs (vertebral chondral), which connect to the sternum via cartilage from rib 7.
• 😀 The last two pairs of ribs (11-12) are called floating ribs (vertebral ribs) and do not connect to the sternum or cartilage.
• 😀 All ribs connect to the vertebrae via the superior costal facet on the vertebrae's body and the transverse process.
• 😀 Vertebral column consists of cervical (7), thoracic (12), and lumbar (5) vertebrae, each serving different functions in support and mobility.
• 😀 Cervical vertebrae have the smallest bodies, with bifid spinous processes and transverse foramen (holes for arteries).
• 😀 Special cervical vertebrae C1 (Atlas) supports the skull and allows nodding motion, while C2 (Axis) allows head rotation.
• 😀 The sacrum is made up of 5 fused vertebrae and the coccyx consists of 2-4 fused vertebrae, which are remnants of the tailbone.

Q & A

What are the three parts of the sternum, and what are their functions?

The sternum has three parts: the manubrium (top), the body (middle), and the xiphoid process (bottom). The sternum protects vital organs, particularly the heart, while the ribs primarily protect the lungs.

How many pairs of ribs are there, and what distinguishes the types of ribs?

There are 12 pairs of ribs. The first 7 pairs are called vertebral sternal ribs, which connect directly to the sternum. Ribs 8-10 are vertebral chondral ribs, which connect to the sternum through cartilage. Ribs 11-12 are vertebral (floating) ribs, which do not connect to the sternum or cartilage.

What is the main difference between true and false ribs?

True ribs (1-7) connect directly to the sternum, while false ribs (8-12) do not connect directly to the sternum. False ribs include both vertebral chondral and floating ribs.

What are the anatomical features common to all vertebrae?

All vertebrae share several features: a body (vertebral body), spinous process, transverse processes, a vertebral foramen (where the spinal cord passes through), and superior and inferior articular processes.

What are the differences between cervical, thoracic, and lumbar vertebrae?

Cervical vertebrae have the smallest bodies and bifid spinous processes. Thoracic vertebrae are larger with spinous processes pointing downward and ribs attaching. Lumbar vertebrae have the largest bodies and more prominent transverse processes.

How does the structure of the cervical vertebrae help identify them?

Cervical vertebrae can be identified by their small bodies, bifid spinous processes, and the presence of two holes called transverse foramina through which arteries pass.

What is the function of the intervertebral disc?

The intervertebral disc, made of fibrocartilage, absorbs shock and protects the vertebrae by preventing them from rubbing against each other. It also helps with flexibility in the spine.

What is a herniated disc, and what causes it?

A herniated disc occurs when the intervertebral disc ruptures or shifts, potentially causing pain, reduced range of motion, and nerve compression due to vertebral bodies rubbing against each other.

What are the roles of C1 (Atlas) and C2 (Axis) vertebrae?

C1 (Atlas) supports the skull and allows nodding of the head (yes motion), while C2 (Axis) allows rotation of the head (no motion) through the odontoid process (dens).

What are the sacrum and coccyx, and what are their features?

The sacrum is made of five fused vertebrae that do not fully fuse until around age 18-30. The coccyx is the remnant of the tailbone and consists of 2-4 fused vertebrae. Both are part of the pelvic region and help in supporting the weight of the upper body.