What Part of the Brain Controls Breathing?

During normal quiet breathing, respiratory muscles are controlled by the medulla in the brainstem and during voluntary and behavioral breathing, respiratory muscles are controlled by the motor cortex in the frontal lobe [1].

The medulla oblongata is situated in the lower part of the brainstem where it has autonomic (involuntary) functions such as the control of breathing, heart rate, blood pressure, and sleep-wake cycle.

The motor cortex is found in the posterior part of the frontal lobe and unlike the medulla, it has functions in the control of voluntary movements.

1. What Muscles Control Breathing?

The lungs have no muscles and breathing is controlled by the following muscles:

• Diaphragm
• Intercostal Muscles
• Abdominal Muscles
• Face, Mouth, and Pharynx Muscles
• Neck Muscles

1.1. Diaphragm

The diaphragm is a dome-shaped muscle separating the thoracic cavity from the abdominal cavity. It is the most important muscle used during inhalation (inspiration).

The diaphragm contraction increases the volume of the thoracic cavity leading to the expansion of the lungs.

It is made of muscle fibers that originate from the surrounding structure and that converge in the middle forming the central cordon.

1.2. Intercostal Muscles

Intercostal muscles are muscles situated between the ribs and that allow help to raise the rib cage during inhalation.

1.3. Abdominal Muscles

The abdominal muscles are mainly used during physical activity to push out air through increasing abdominal pressure which presses the diaphragm against the lungs.

1.4. Face, Mouth, and Pharynx Muscles

These muscles control the air passage through the upper respiratory tract.

1.5. Neck Muscles

The neck muscles include the anterior scalene, the middle scalene, and the posterior scalene. They are called accessory respiratory muscles that help elevate the rib cage during breathing.

2. What Are the 7 Organs of the Respiratory System?

The organs of the respiratory system are mainly divided into organs of the upper respiratory tract, including the nose, mouth, sinuses, pharynx, and larynx, and organs of the lower respiratory tract, including the trachea, the bronchi, the bronchioles, and lungs.

2.1. Nose and Mouth

The nose and mouth allow the passage of air from the outside to the inside of the body.

2.2. Sinuses

The sinuses control the temperature and humidity of the air we breathe.

2.3. Pharynx (Throat)

The air coming from the mouth and the nose travels through the pharynx before reaching the trachea in the lower part of the respiratory tract.

2.4. Larynx

The larynx is situated below the pharynx and is involved in the production of sounds while we breathe but also protects the trachea from food aspiration.

2.5. Trachea

The trachea is a tube made of cartilage that connects the larynx to the lungs and allows the passage of the air.

2.6. Bronchi

Bronchi are tubes that branch from the trachea into left and right primary bronchi which in turn also branch into secondary bronchi.

2.7. Bronchioles

Bronchioles are branches that originate from the bronchi and that connect with the lung alveoli.

2.8. Lungs

The lungs are made of two lobes in the left lung and 3 lobes in the right lung. They are made of air sacs known as alveoli that allow the exchange of oxygen and carbon dioxide with the blood capillaries in proximity.

3. What Are the Most Common Respiratory Disorders?

3.1. Asthma

Asthma is a chronic inflammatory disease of the airways caused by a strong response of the body’s immune system to a substance in the airway (Allergen).

It manifests with symptoms such as cough, wheezing, shortness of breath, and chest tightness, which can evolve into more severe symptoms associated with an asthma attack.

3.2. Pneumonia

Pneumonia is an inflammation of the lungs caused by a bacterial, viral, or fungal infection resulting in the accumulation of fluids or pus in the alveoli.

The most common bacterial pneumonia is caused by Streptococcus pneumoniae, while viral pneumonia is mostly caused by influenza virus (Flu virus) and rhinovirus 9common cold virus), and fungal pneumonia by Pneumocystis jirovecii.

It manifests with symptoms such as fever, chills, chest pain, shortness of breath, and wet coughs.

3.3. Bronchitis

Bronchitis is an inflammation of the bronchi that can be caused by viral infections resulting in acute bronchitis lasting up to 3 weeks. If bronchitis lasts for more than 3 months and comes back several times for at least 2 years in a row, the bronchitis is classified as chronic.

Bronchitis manifests with symptoms such as hacking cough with phlegm (clear, yellowish, or greenish), sore throat, tiredness, and headache.

3.4. COPD

COPD or chronic obstructive pulmonary disease is a progressive disease caused by the irritation of pulmonary airways associated with chronic exposure to cigarette smoke, polluted air, or chemical fumes.

It manifests with symptoms such as difficulty breathing, persistent wheezing, cough with phlegm, and recurrent chest infections.

3.5. Cystic Fibrosis

Cystic Fibrosis is a genetic disorder caused by mutations in the gene coding for a protein known as cystic fibrosis transmembrane receptor (CFTR) involved in the production of mucus in the lung airways.

It manifests with symptoms such as difficulty breathing, persistent wheezing, cough with phlegm, and recurrent chest infections.

Although it mostly affects the lungs, cystic fibrosis can also affect other organs such as the kidneys, the liver, pancreas, and gut.

3.6. Tuberculosis

Tuberculosis (TB) is a bacterial infection that mainly targets the lung (pulmonary tuberculosis) but can also affect another part of the body such as the neck, urogenital system, and central nervous system.

It is caused by Mycobacterium tuberculosis and manifests with symptoms such as fatigue, fever, sweating, chills, loss of appetite, and chest pain.

3.7. Lung Cancer

Lung cancer is a group of cancers characterized by uncontrollable division of lung cells caused by genetic mutations of tumor suppressor genes or the activation of genes that promote cancer (oncogenes).

Mutations in these genes are due to genetics or carcinogens (cancer-inducing substances) such as smoking, air pollution, and asbestos.

Lung cancer manifests with symptoms such as cough with the presence of blood and that lasts for more than 2-3 weeks, difficulty breathing, recurrent chest infections, lasting tiredness, chest pain, finger clubbing, difficulty swallowing, and loss of appetite and weight.

3.8. Emphysema

Emphysema is a disease affecting the alveoli causing their damage and replacement with spongy lung parenchyma. It can be caused by smoking or air pollution.

It manifests with symptoms such as shortness of breath, wheezing, coughing.

Conclusion

Breathing is controlled involuntarily by the medulla oblongata and voluntarily by the motor cortex; however, the execution of the breathing depends on the different organs and muscles of the respiratory system. Damages that affect any of these components result in disorders or diseases that interfere with normal breathing.