Rectus abdominis muscle

You have muscles on your tummy. Many people call them "abs."

These muscles run down the front of your belly. They are split into small parts by bands of tissue. When you tense these muscles, they bulge out. This can look like a six-pack.

These muscles help you move. They help you do a crunch. They also help you breathe out hard.

They help keep your inside parts in place. They also help when you lift heavy things. These muscles are very important for your body.

You have a pair of long, flat muscles on your belly. Most people call them "abs." These muscles are the rectus abdominis. They run from your ribs down to your pubic bone. A band of tissue called the linea alba sits in the middle. It keeps the two muscles separate.

Small bands of tissue cross the muscle. We call these tendinous intersections. They divide the muscle into smaller parts. When you tense your abs, they bulge between these bands. This can make a "six-pack" look.

These muscles do many jobs. They help you flex your spine. This is how you do a crunch. They also help you breathe out hard. The muscles help keep your inside organs in place. They also help you lift heavy weights.

Sometimes, you can hurt these muscles. This is called a strain. It happens if the muscle stretches too far. This can tear the tiny fibers in the muscle. Most strains are small, but some can be serious.

The rectus abdominis is a pair of long, flat muscles on the front of your belly. Many people call these muscles "abs." Some even call them a "six-pack" when they are very visible. These muscles are very important for how your body moves. They help you stay upright and keep your internal organs in place. Without them, many daily tasks would be much harder to do. They are part of your skeletal muscle system, which means they help move your bones.

These muscles work in a very specific way. Each muscle runs from your ribs down to your pubic bone. A band of tough tissue called the linea alba sits right in the middle. This band keeps the two muscles separate from each other. Small bands called tendinous intersections cross the muscle like little bridges. These intersections divide the muscle into several smaller parts or "bellies." When you tense your muscles, they bulge out between these bands.

Your muscles need energy and care to work well. Blood flows to the rectus abdominis from many different sources. The inferior epigastric artery and vein supply the lower part of the muscle. The superior epigastric artery helps supply the top part. Small arteries from your ribs also help provide blood. Nerves called thoraco-abdominal nerves tell the muscles when to move. These nerves come from the T7 to T11 intercostal nerves. This constant supply of blood and signals keeps the muscles healthy.

There are many interesting facts about the size of these muscles. A typical muscle is about 10 mm thick. However, some athletes can have muscles that are 20 mm thick. The volume of the muscle is also different for different people. Non-active people usually have a volume of around 300 cm3. Athletes often have a larger volume of about 500 cm3. These numbers show how much the muscles can change with use.

These muscles help you with many common movements. They allow you to flex your spine, which is what happens during a crunch. They also help you breathe out forcefully after you exercise. They help create pressure inside your belly when you lift heavy weights. This pressure is also used during childbirth. Sometimes, people can get a muscle strain if they stretch too far. This happens when the tiny fibers in the muscle tear. Most of the time, these tears are very small and microscopic.

The rectus abdominis is a pair of segmented skeletal muscles located on the ventral aspect of the abdomen. Most people know these muscles by their informal names, such as the "abs" or a "six-pack." These muscles are vital for maintaining posture and supporting many bodily functions. They are contained within a protective layer called the rectus sheath. This sheath is made from the aponeuroses, or flat sheets of connective tissue, of the lateral abdominal muscles.

To understand how the muscle is built, we must look at its specific boundaries and divisions. The muscle extends from the xiphoid process and the costal cartilages of the 5th to 7th ribs at the top. At the bottom, it attaches to the pubic symphysis, the pubic crest, and the pubic tubercle. The two sides of the muscle are separated at the midline by a dense band of connective tissue called the linea alba. On the outer edges, the linea semilunaris defines the lateral margins. Each muscle is also divided into smaller parts called muscle bellies by bands of connective tissue known as tendinous intersections.

When the rectus abdominis performs a task, its physical structure changes. For example, tensing the muscle causes it to expand between each tendinous intersection. This muscle is a primary driver for flexing the lumbar spine, which is the movement used during a crunch. It can also move the pelvis toward the rib cage, a movement called a posterior pelvic tilt. This occurs during exercises like a leg-hip raise when the rib cage is held fixed. If neither the ribs nor the pelvis are fixed, the muscle can bring both parts together simultaneously.

The muscle requires a complex system of blood and nerves to function. The blood supply comes from several arterial sources. The inferior epigastric artery and vein run upward on the posterior surface to serve the lower muscle. The superior epigastric artery, which comes from the internal thoracic artery, supplies the upper portion. Additionally, the lower six intercostal arteries provide small segmental contributions. To control movement, the muscle is innervated by thoraco-abdominal nerves. These are continuations of the T7-T11 intercostal nerves that pierce the rectus sheath.

Physical measurements of the rectus abdominis vary based on an individual's activity level. The muscle is typically around 10 mm thick in most people. However, some athletes can possess a rectus abdominis that is up to 20 mm thick. The total volume of the muscle also changes with training. In non-active individuals, the typical volume is approximately 300 cm3. In contrast, athletes often have a larger volume of around 500 cm3.

Beyond movement, the rectus abdominis plays a role in internal bodily processes. It assists with breathing, specifically during forceful exhalation. This is necessary after intense exercise or during conditions like emphysema. The muscle also helps maintain intra-abdominal pressure. This pressure is important when lifting heavy weights or during childbirth, also known as parturition. It also helps keep the internal organs intact within the abdominal cavity.

Sometimes, the muscle can suffer from injuries or medical conditions. An abdominal muscle strain, or a "pulled muscle," happens when the muscle is stretched too far. This causes the muscle fibers to tear. While many tears are microscopic, severe injuries can cause the muscle to rupture from its attachment. Another condition is a rectus sheath hematoma, which is an accumulation of blood within the sheath. This can be caused by a muscular tear or the rupture of an epigastric artery. Factors like trauma, abdominal surgery, pregnancy, or the use of anticoagulant medications can contribute to these issues.