Lung Anatomy, Physiology, and Health

Healthy Beings Staff
Sep 23, 2021 9:03:21 AM

Lung Anatomy

Respiratory-system-and-alveoli-anatomy Your lungs are within your thorax to either side of your heart and on top of the diaphragm. The left lung has two lobes and is a little smaller than the right to accommodate the heart. The right lung has three lobes.

A pleura, which is a fluid-filled membrane that also lines the inside of chest cavity wall, encases each lung. Its purpose is to allow the lungs to slide easily on the inside of the chest wall as you breathe. The tension that is created by the pleura keeps the lungs inflated.

Our respiratory system begins at the mouth and nose and goes into the trachea, which is directly behind the esophagus. To prevent food and liquid from getting into the lungs, we have a piece of cartilage called the epiglottis that is depressed during swallowing to cover the opening of the trachea.

The trachea branches into the left and right bronchus which enter the lungs and branch again into lobar bronchi, one supplying each lobe. The bronchi continue to branch into segmental bronchi, which supply air to smaller sections of each lobe. Each segmental bronchi continue on to branch into many bronchioles and ends at terminal bronchioles. The terminal bronchioles have tiny air sacs at the end called alveoli where gas exchange occurs.

Lung Physiology

Air enters through the nose and mouth and travels through the trachea to the bronchus and ends up at the alveoli in the terminal bronchioles. The terminal bronchioles are very thin so that gas can easily pass through them into the capillary network that surrounds each alveolus. This is where the oxygen transfer from the air into the capillary network surrounding each alveolus occurs. This is a passive process because gases naturally move from high concentration to low concentration. The atmosphere and the air inhaled have a higher concentration of oxygen than the blood in the alveolar capillaries, so oxygen moves into the blood to be transported to the rest of the body. The expiration of CO2 happens in the exact opposite order. CO2 from the blood goes into the alveoli and travels up the respiratory chain and out into the atmosphere.

Alveolar-gas-exchange-oxygen-and-carbon-dioxide

To move air into the lungs, the diaphragm flattens by contracting; this creates a mild vacuum in the lungs, drawing the air in. While resting, the diaphragm is the only muscle necessary to breathe. Once we move, we need more air. The muscles between the ribs (intercostal muscles) expand the ribs and increase lung volume even more. To breathe out, these muscles relax, which increases the pressure in the chest cavity, pushing the air out. During abnormal breathing, as in exercising, more muscles are at work, including neck, abdominal, and additional intercostal muscles to get even deeper breaths.

Lung Damage and What to do About it

Lungs are incredible organs; however, they are not immune to damage. Several factors can contribute to difficulty breathing.

Scarring along the airways or alveoli - Chemical damage such as smoke inhalation or prolonged infections like bronchitis or pneumonia can cause this. The scarring in the alveoli makes them thicker and less elastic, so gases cannot pass through easily.
Rib injuries–If the ribs are not moving normally, then the lungs cannot fully expand, limiting breathing.
Changes with age–for the most part, these things are preventable
Alveoli can lose their shape and become less elastic.
The diaphragm can, over time, become weaker, decreasing the ability to inhale and exhale. This change will only be significant when exercising.
Decreased sensitivity of the nerves that sense foreign particles in airways. This will cause them to build up in the lungs and damage the lung tissue.
Weaker immune system increasing vulnerability to infections like influenza (the flu) and pneumonia.

(https://www.lung.org/blog/your-aging-lungs)

There are several ways to protect your lungs:

Take deep breaths–when you breathe deep regularly, it helps to keep the alveoli open and improve lung capacity.
Don't smoke–Smoking causes scarring in alveoli
Avoid air pollution–Indoor and outdoor air pollutants can damage your lungs. Secondhand smoke, outdoor air pollution, chemicals in the home and workplace, and radon all can cause or worsen lung disease. There are several websites that show air quality in your area.
Exercise–Regular exercise can help keep chest muscles strong and the rib joints moving well.
Avoid weight gain–Abdominal fat can impede the diaphragm's ability to expand the lungs fully. A combination of both healthy eating and exercise will double the benefit to your lungs.
Get up–Being sedentary, especially lying in bed too long, allows mucus and fluid to settle in your lungs, which can harm lung capacity.
Take enough antioxidants–Increased free radicals from pollution or from your own cell’s energy production can cause cell damage in the lungs if they exceed your antioxidant levels.
Omega-3 fatty acids can decrease inflammation. Omega-3 fatty acids can be found in supplements or from food sources such as flaxseed, soybeans, canola oil, walnuts, and cold-water fatty fish. Decreasing inflammation in the lungs prevents scarring and improves elasticity of alveoli.
Vitamin D and E have been found to improve lung function in some patients.
Add eucalyptus oil to your humidifier. Eucalyptus encourages the air passages to open wide.