Sternum (Breastbone)

The sternum, also called the breastbone, is a key bone in our skeleton. It sits in the middle of our chest. This flat, long bone protects our heart, lungs, and big blood vessels.

The sternum is a big part of the rib cage. It connects to the clavicles and the first seven pairs of ribs.

Knowing about the sternum’s anatomy and functions is important. This article covers its structure, location, how it connects, and its importance in health. By learning about this central chest bone, we can better understand its role in our bodies.

What is the Sternum?

The sternum, also known as the breastbone, is a key part of the skeletal system. It helps protect the chest and its vital organs. Knowing where the sternum is and what it does is important for understanding the human body.

Definition of the Sternum

The sternum is a flat bone in the chest. It has three parts: the manubrium, the body, and the xiphoid process. It connects to the ribs, forming the front of the ribcage structure.

Location of the Sternum in the Body

The sternum is in the middle of the chest. It goes from the neck to the upper belly. It meets the clavicles at the top and the ribs on the sides.

The sternum’s central location in the skeletal system gives stability and protection. It helps keep the heart and lungs safe. Its strong connections with the ribs and clavicles make the ribcage structure strong.

Anatomy of the Sternum

The sternum, or breastbone, is a flat bone in the chest’s center. It protects vital organs and helps muscles and bones attach. Let’s explore the sternum’s anatomy.

Parts of the Sternum

The sternum has three main parts:

Sternal Angle and Jugular Notch

The sternal angle is a landmark where the manubrium meets the body of the sternum. It’s at the second rib level and helps find other structures. Above the manubrium is the jugular notch, a depression between the clavicles.

Articulations with Other Bones

The sternum connects with several bones in the chest:

• The clavicles join the manubrium at the sternoclavicular joints.
• The costal cartilages of the first through seventh ribs attach to the manubrium and body of the sternum.

These connections make the chest wall strong yet flexible. They protect internal organs and help with breathing.

Sternum (Breastbone): The Central Bone of the Chest

The sternum, also known as the breastbone, is the central bone of the chest. It’s a flat, long bone that makes up the front part of the thoracic cage. The sternum sits in the middle of the anterior thoracic wall. It connects with the clavicles and the first seven pairs of ribs’ costal cartilages.

The sternum is key for a strong chest framework. It holds muscles and ligaments in place. Here are some muscles that attach to it:

The sternum also protects vital organs like the heart and lungs. Its strong structure, along with the ribs and vertebrae, makes a safe space for these organs.

The sternum’s central spot and connections help with breathing. When we inhale, the ribs and sternum move up and out. This lets the lungs expand and fill with air.

Functions of the Sternum

The sternum, or breastbone, is a flat bone in the chest’s center. It has key roles in the body. It protects the heart and lungs, helps muscles and ligaments attach, and aids breathing by expanding the chest.

Protection of Vital Organs

The sternum’s main job is to protect the heart and lungs. It acts as a shield, keeping these vital organs safe from harm. Its strong structure and chest location help prevent injuries to the heart and lungs.

Attachment Point for Muscles and Ligaments

The sternum is a key spot for muscles and ligaments in the chest and neck. The pectoralis major, a big chest muscle, attaches here. The sternocleidomastoid muscle, which helps move the head and neck, also attaches to the sternum. These connections help with movement and stability in the upper body.

Role in Breathing and Chest Expansion

The sternum is vital for breathing by allowing the chest to expand when we inhale. When we breathe in, muscles attached to the sternum contract. This makes the chest cavity bigger, pulling air into the lungs. The sternum’s flexibility and connection with the ribs make breathing efficient.

Development and Ossification of the Sternum

The sternum, or breastbone, goes through a cool process during fetal growth and early childhood. It starts as separate bones that join together to form a solid chest bone. This process is key for the sternum’s growth and protection.

At first, the sternum has many areas where bones start to form. The top part, called the manubrium, grows from one area. The middle part, or gladiolus, grows from several areas that line up.

As the child gets older, these areas grow and join together. This usually happens during puberty and is done by early adulthood. The lowest part, the xiphoid process, might stay a bit soft until later in life.

Not every sternum develops the same way. Sometimes, extra areas form or parts don’t join right. This can cause issues like sternal clefts or a bifid sternum.

Knowing how the sternum develops is important for doctors. It helps them spot any problems that need attention.

Common Sternal Conditions and Injuries

The sternum, or breastbone, is a strong bone that protects the heart, lungs, and major blood vessels. But, it can get hurt or have problems. Common issues include breastbone fractures, birth defects, and problems with the sternoclavicular joint.

Sternal Fractures

A breastbone fracture is a break in the sternum, usually from a hard hit to the chest. Car accidents, sports injuries, and falls often cause these fractures. Symptoms include chest pain, swelling, and trouble breathing.

Treatment usually involves managing pain, resting, and sometimes surgery for serious cases.

Pectus Excavatum and Pectus Carinatum

Pectus excavatum, or sunken chest, and pectus carinatum, or pigeon chest, are birth defects. Pectus excavatum makes the chest look sunken, while pectus carinatum makes it look like a pigeon’s chest. These can affect how you look and breathe.

Treatment can be bracing or surgery, depending on how bad it is.

Sternoclavicular Joint Disorders

The sternoclavicular joint connects the sternum to the collarbone. Disorders here can cause pain, swelling, and limited arm movement. A sternoclavicular dislocation is when the joint is out of place, often from trauma.

Treatment may include closed reduction, immobilization, or surgery for severe cases. Arthritis can also affect this joint, leading to pain and stiffness.

Sternal Anomalies and Variations

Some people are born with congenital sternal defects or sternal malformations. These happen during fetal development. They can cause the breastbone to have different shapes. Two common examples are the sternal foramen and the bifid sternum.

Sternal Foramen

A sternal foramen is a small hole in the sternum. It usually appears in the lower part of the sternum. This defect is often found by chance during tests or autopsies.

Having a sternal foramen doesn’t usually cause problems. But, doctors need to know about it when they do procedures on the sternum.

Sternal Clefts and Bifid Sternum

A bifid sternum, or cleft sternum, is a rare birth defect. It happens when the sternum doesn’t join together right. This creates a gap or cleft in the breastbone.

The size of this gap can vary. It can be just a small notch or a big split that goes up to the manubrium.

Most of the time, a bifid sternum doesn’t cause big health problems. But, it can sometimes be linked to other heart or chest wall defects. If it’s very bad, surgery might be needed to protect the organs and make the chest wall stronger.

Clinical Significance of the Sternum

The sternum is key in many medical procedures. It’s vital for doctors to know about it. Two main procedures involve the sternum: bone marrow aspiration and open-heart surgery.

Sternal Puncture and Bone Marrow Aspiration

A bone marrow biopsy is a test that gets bone marrow from the sternum. It’s done by putting a needle into the sternum’s marrow. This helps doctors find blood disorders and cancers.

The sternum is chosen for this test because it’s easy to reach and has a lot of marrow. The procedure is done under local anesthesia and is usually okay for patients.

Sternotomy in Cardiac Surgery

In heart surgery, the sternum is very important. It lets doctors get to the heart and big blood vessels. A median sternotomy, a vertical cut in the sternum, is the most common way to do this.

During this surgery, the surgeon cuts through skin, muscle, and tissue to get to the sternum. They then split the sternum with a special saw. After fixing the heart, the sternum is put back together with wires or plates, and the cut is closed.

The sternum’s special shape and location are very important in medicine. Knowing about the sternum helps doctors give better care and results.

The Sternum in Relation to the Ribcage and Thoracic Cavity

The sternum, or breastbone, is key in the thoracic skeleton. It connects to the ribs and forms the front part of the ribcage. This strong bone protects the heart, lungs, and major blood vessels in the chest.

The sternum links with the first seven pairs of ribs through costal cartilages. This setup is strong yet flexible. It lets the chest expand and contract with breathing. At the same time, it guards the delicate organs inside.

The sternum’s central spot and strong build are vital for the thoracic cavity’s protection. It acts as a shield, absorbing and spreading out impact forces. This helps protect the heart, lungs, and other vital structures from injury.

The sternum also plays a big role in attaching muscles. The pectoralis major and sternocleidomastoid muscles attach here. These muscles help keep the thoracic skeleton stable and functional. They enable various upper body movements and help maintain good posture.

Conclusion

The sternum, or breastbone, is key to our body’s structure. It protects our heart and lungs from harm. It also helps our upper body move by attaching to muscles and ligaments.

We’ve looked at the sternum’s anatomy, growth, and how it affects our health. Knowing about the sternum helps doctors treat injuries and conditions. It’s also important for surgeries and medical tests.

In short, the sternum is vital for our chest’s health. Learning about it helps us appreciate our body’s design. As we learn more, we can improve care and outcomes for patients.