Difference Between Alveoli and Alveolar Sac (With Table)

Our bodies are made up of a variety of intricate components. Animals, like plants, have a root system and a shoot system, as well as a digestive system, respiratory system, heart, lymphatic system, neurological system, bone, reproductive system, integument, and other organs that keep our bodies working and in proper balance. Our respiratory system assists us in taking in and exhaling air. Amphibians, such as frogs, breathe through their skin, while fish breathe through their gills, both of which are comparable to mammals in that they have breathing systems. Our respiratory system comprises several different parts, including the nose, mouth, pharynx, trachea, and lungs, among other things.

Alveoli vs Alveolar Sac

The main difference between alveoli and the alveolar sac is that the alveoli are the terminal end of our respiratory system tract connected to the alveolar tubes. On the other hand, the alveolar sac is an air gap within the alveolar duct (also known as the alveolar duct space). It happens in the lungs, which have two or more alveoli open into the air. Alveoli surround it. The epithelium lines the inside of the tube.

There are two alveolar ducts connected to it, and it is similar to a thin-walled sphere where the most significant gas exchange occurs. Each human lung has at least 700 million alveoli, which is significant.

The alveolar sac, also known as the pulmonary alveolus, is a sort of air sac or air space in the shape of a hollow sphere found in the lungs’ cavity. It is also known as the pulmonary alveolus. The primary objective of these air spaces is to provide adequate space for gas exchange at the maximum possible efficiency rate. Carbon dioxide and oxygen are the most prevalent of these gases. The pulmonary alveolus is the term used in Latin to refer to the alveolar sac.

Comparison Table Between Alveoli and Alveolar Sac

Parameters of ComparisonAlveoliAlveolar Sac
DefinitionLocated at the end of our respiratory system’s tract, the alveoli are connected to the alveolar tubes by the alveolar lines.The alveolar sac, also known as the pulmonary alveolus, is a sort of air sac or air space in the shape of a hollow sphere found in the lungs’ cavity.
NumberIt is estimated that approximately 700 million alveoli are present in the lungs.Approximately 5-6 alveolar sacs are present, each of which contains a cluster of alveoli that open.
FunctionWhen it comes to gas exchange, the alveoli are primarily responsible for transporting carbon dioxide from the body’s tissues to the lungs while also transporting oxygen from the blood to the body’s cells.The primary objective of these air spaces is to provide adequate space for gas exchange at the maximum possible efficiency rate. Carbon dioxide and oxygen are the most prevalent of these gases.
Composed ofA large portion of the alveoli comprises epithelial layers and the extracellular matrix formed by capillaries.This is the last part of our respiratory system that connects to the alveolar tubes. Alveoli
Biological nameThe term “pulmonary alveolus” refers to the alveoli in the lungs.A more scientific word for alveolar sacs is Sacculi Alveolares, which means “alveolar sacs.”

What is Alveoli?

There are two alveolar ducts connected to it, and it is similar to a thin-walled sphere where the most significant gas exchange occurs. Each human lung has at least 700 million alveoli, which is significant.

The alveolar sac is a pocket of air that forms when two or more alveoli open simultaneously. Each alveolus is separated from the others by a shared wall known as the interalveolar septum (interalveolar septum). This wall primarily serves as a gap for gas exchange in type 1 alveolar cells, which is the most common form (simple squamous epithelium).

Fibroblasts are responsible for producing reticular and elastic fibers in the body. Type 2 alveolar cells release alveolar fluid, which helps to keep the respiratory surface moist by retaining moisture. Macrophages are immune cells that prevent foreign particles from entering the body and eliminating them once they do.

We breathe through our alveoli, responsible for filtering the air we take in. Inside our lungs, this primarily serves to extract oxygen from carbon dioxide. Alveoli are highly minute in size. However, they are found in great numbers throughout the body.

What is Alveolar Sac?

Each lung contains many bronchioles, which are present throughout the body. Typically, a bronchiole separates into two or more respiratory bronchioles, each with alveoli attached to it. Each of these has alveolar ducts and other alveoli attached to it. Each alveolar duct is connected to a circle of vacuoles containing alveoli and atria that the body has already formed.

It is also known as Sacculi Alveolar. The primary objective of these air gaps is to exchange gas at the most significant possible rate. Carbon dioxide and oxygen are the most prevalent of these gases. The alveolar sac is referred to by its scientific name, the Sacculi Alveolar.

The alveoli in the lungs are organized into pocket-like structures that extend into the respiratory bronchioles present in their lumen. It is quite elongated, and the alveolar tubules grow progressively alveolar with branching that is further lined with alveoli as they progress down the organ’s length. Each bronchiole has anywhere from two to eleven tubules. Each duct opens into an alveolar sac, a collection of alveoli in its own right. The number of ducts ranges between 5 and 6.

Main Differences Between Alveoli and Alveolar Sac

  1. The alveoli are primarily formed of epithelial layers and the extracellular matrix of capillaries. In contrast, the alveolar sac is a sort of space that forms the distal end of the alveolar ducts and is composed of epithelial layers and the extracellular matrix of capillaries.
  2. Alveoli are mainly composed of collagen and elastic fibers, whereas the alveolar sac is a collection of alveoli that communicate between them.
  3. When it comes to gas exchange, the alveoli are primarily responsible for transporting carbon dioxide from the body’s tissues to the lungs while also transporting oxygen from the blood to the body’s cells. On the other hand, the alveolar sac provides room for this procedure to occur and is where the entire process is finished.
  4. Pneumatic alveoli are pulmonary alveoli, while alveolar sacs are referred to as Sacculi Alveolares in the scientific community.
  5. Alveoli make up approximately 700 million of the lungs’ total alveoli, while the number of alveolar sacs, which clusters of alveoli open, is approximately 5-6 million.

Conclusion

This means that both alveoli and alveolar sac are respiratory system components that reside within the lungs. In contrast, they are not alike. End of the respiratory tract in lungs; alveolar sac is a pouch-like structure that denotes airspace. In addition, their roles are distinct from one another. By transporting carbon dioxide out of the bloodstream and delivering it to the lungs, alveoli play an essential role in the body’s gas exchange system. This procedure is finished in the alveolar sac, which serves as where this occurs. A more significant number of alveoli than alveolar sacs are present in a given body.

References

  1. https://journals.physiology.org/doi/pdf/10.1152/jappl.1974.37.2.249
  2. https://www.tandfonline.com/doi/abs/10.3109/08958371003749939