Respiratory Muscles: Types, Characteristics And Functions When Breathing
Breathing is one of the basic processes carried out by our body, and one of the most fundamental to survive.
Every time we inhale we introduce oxygen into our body, which allows the cells in our body to survive. In turn, with each exhalation we expel waste such as CO2, something that allows us to cleanse the body of the remains of cellular activity.
But the act of breathing, although semi-conscious (it can be voluntarily controlled although it is usually carried out unconsciously), requires a series of muscular movements to be produced. And there are multiple breathing muscles that are mobilized for this. Throughout this article Let’s see what the breathing muscles are both the most relevant and others that, although less essential, also have a role in the process.
Below we will see the main and most relevant muscles that participate and allow the respiratory process. Although there are many ways to classify them into different categories, this time we are going to divide them into four main groups.
1. Diaphragm
The diaphragm is one of the main and most important respiratory muscles, as well as being among the best known.
Is about a relatively large cylindrical muscle, with a dome also formed by tendon tissue and it is located below the lungs and ribs.
This muscle, which separates the torso from the abdomen, is key in both the inspiration and experiential processes. When it contracts, it moves the viscera downward, leaving space and elevating the thoracic cavity in such a way that it allows the lungs to expand.
2. Intercostal muscles
The second large group of muscles that are essential for breathing are the intercostals, which They allow the displacement of the thoracic cage which in turn enables lung expansion We can find two types of intercostal muscle.
Muscle that covers the internal area of the ribs and is the most important muscle subgroup when it comes to allowing breathing. It is essential when it comes to being able to inspire since they are what open the rib cage and allow lung expansion.
2.2. internal intercostal
The internal intercostal muscles have a predominantly exhalation function: their contraction causes the ribs to go down, returning to its initial position
3. Abdominal muscles
The abdominal muscles are a series of muscles located in the abdomen that actively participate in the respiratory process. Technically they are not so essential when it comes to maintaining unconscious breathing, but they actively participate in voluntary expiration.
3.1. internal obliques
These muscles They are located in the anterior and lateral part of the abdomen and they are especially relevant when it comes to allowing consciously controlled breathing. It allows the chest to flex, causing the diaphragm to stretch and facilitating inspiration. It also allows expiration to occur by moving the belly wall inward.
3.2. External obliques
The external obliques are the outermost muscles that we have anteriorly and laterally, and can be seen around the rectus abdominis. These muscles perform similar functions to those of the internal obliques, promoting inspiration and participating in forced or voluntary expiration
3.3. rectus abdominis muscle
One of the abdominal muscles whose movement is most visible during breathing, it is divided into various intersections separated by connective tissue and extends from the pubis to the lower part of the rib cage. Along with the oblique muscles, They pull the lower ribs down and facilitate expiration Allows you to compress the lower part of the chest.
The transverse muscle can be found attached to the internal oblique. It is the muscle located deepest between the widths of the abdomen , and runs from the spine to the linea alba and from the ribs (it is inserted into ribs seven to twelve). It contributes to compressing the abdominal viscera and the lower part of the chest, and participates in voluntary breathing both in inspiration and especially in expiration.
4. Accessory muscles
Within the group of accessory muscles we include the set of muscles that, although they are not primarily responsible for respiratory movement, do play a relevant role in its occurrence. We will include muscles that could be considered part of the rest of the groups, but that are not so fundamental.
Similar to the abdominals, they are generally mobilized during forced respiratory movement, and especially in situations such as when there are breathing difficulties, coughs or intense physical exercise Below we will see some of the best known, although there are many others involved to a greater or lesser extent in the respiratory process.
4.1. Scalenes: anterior, middle and posterior
The scalene muscles are a set of three muscles (anterior, middle and posterior scalene) located at the level of the neck and beginning of the torso. They go from the cervical vertebrae to the first two ribs and participate in breathing by helping to elevate the first two ribs, facilitating voluntary inhalation.
4.2. Sternocleidomastoid
Also located in the neck, although in the anterolateral part. It contributes to elevating and dilating the rib cage with its contraction, facilitating the pumping movement and being something that can facilitate voluntary inhalation in cases of extreme need
Sternal retraction is usually used in emergency situations, and in fact it is sometimes a sign of respiratory problems.
4.3. Trapeze
The trapezius are muscles that join the shoulder, the spine, the scapula and the skull, linking these areas and allowing, for example, the shoulders to remain in the same position when carrying weight. It consists of three parts: upper, middle and lower. They participate in the voluntary inhalation movement, by elevating the rib cage when it contracts.
4.4. pectoralis major
Located in the thorax and forming one of the most visible and powerful parts of the pectoral muscles, this muscle is also one of the accessories in breathing. Allows mechanical inspiration, since when the rib cage contracts it rises
4.5. pectoralis minor
Located behind the pectoralis major, this muscle helps elevate and rotate the scapula away from the ribs. This allows and facilitates deep and voluntary inhalation.
4.6. Serratus muscles
Divided into major, anterior and posterior, the serratus muscles, which are found in the posterior thoracic part of the body and contribute to voluntary inspiration. Also participate in deep breathing with great efforts.
4.7. Supracostal muscles
These are a dozen small muscles that They are located between the ribs, and they help raise them when they contract and retract them when they relax They participate in both inspiration and expiration.
