May 30, 2024

Anatomy of respiratory organs and functions

Anatomy of respiratory organs and functions

Anatomy

The respiratory system is a complex network of organs and tissues responsible for the exchange of oxygen and carbon dioxide in the body. It includes the following anatomical structures:

Nose and Nasal Cavity:

The respiratory process begins with the nose, which is the primary entrance for air. The nasal cavity is a hollow space behind the nose lined with mucous membranes that help warm, moisten, and filter the incoming air.

Pharynx:

The pharynx, or throat, is a muscular tube located behind the nasal cavity and mouth. It serves as a passage for both air and food.

Larynx:

The larynx, or voice box, is a structure located in the throat that contains the vocal cords. It plays a crucial role in speech production and preventing food and liquid from entering the airway.

Trachea:

The trachea, or windpipe, is a flexible tube that connects the larynx to the bronchi. It is lined with ciliated cells and mucus-producing glands that help trap and remove foreign particles.

Bronchi:

The trachea branches into two bronchi, one leading to each lung. The bronchi further divide into smaller bronchioles, forming a branching network within the lungs.

Lungs:

The lungs are a pair of large, spongy organs located in the chest cavity. They are responsible for the exchange of oxygen and carbon dioxide. The right lung has three lobes, while the left lung has two lobes to accommodate the heart.

Alveoli:

Within the lungs, the bronchioles end in tiny air sacs called alveoli. These grape-like structures are surrounded by a network of blood vessels and are the sites of gas exchange. Oxygen from the inhaled air diffuses into the bloodstream, while carbon dioxide moves from the bloodstream into the alveoli to be exhaled.

Diaphragm:

The diaphragm is a dome-shaped muscle located at the base of the chest cavity. It plays a crucial role in breathing by contracting and relaxing, causing changes in lung volume and air pressure.

Pleura:

The pleura are thin, double-layered membranes that surround each lung. The outer layer, called the parietal pleura, lines the chest cavity, while the inner layer, known as the visceral pleura, covers the lungs. The pleura produce a lubricating fluid that allows the lungs to move smoothly during breathing.

These organs work together to facilitate the process of respiration, allowing the exchange of oxygen and carbon dioxide between the body and the external environment.

Functions:

The respiratory organs play a crucial role in the process of respiration, which involves the exchange of oxygen and carbon dioxide between the body and the environment. Here are the main functions of the respiratory organs:

Lungs:

The lungs are the primary respiratory organs and are responsible for the exchange of gases. They receive oxygen-rich air during inhalation and facilitate the transfer of oxygen into the bloodstream while removing carbon dioxide from the bloodstream and expelling it during exhalation.

Trachea:

The trachea, also known as the windpipe, is a tube-like structure that connects the larynx (voice box) to the bronchi. It serves as a pathway for the passage of air to and from the lungs. The trachea is lined with tiny hair-like structures called cilia, which help to filter and remove foreign particles and mucus.

Bronchi and Bronchioles:

The bronchi are two branches that emerge from the lower end of the trachea and further divide into smaller tubes called bronchioles. These structures serve as conduits for the transportation of air to and from the lungs. The bronchioles eventually lead to tiny air sacs called alveoli.

Alveoli:

Alveoli are small, grape-like sacs located at the ends of the bronchioles within the lungs. They are the sites where the actual gas exchange occurs. Oxygen from inhaled air diffuses across the thin walls of the alveoli into the bloodstream, while carbon dioxide diffuses from the bloodstream into the alveoli to be expelled during exhalation.

Diaphragm:

The diaphragm is a dome-shaped muscle located below the lungs that separates the chest cavity from the abdominal cavity. It plays a crucial role in the process of breathing by contracting and relaxing. When the diaphragm contracts, it moves downward, increasing the volume of the chest cavity and causing inhalation. Relaxation of the diaphragm results in exhalation.

Respiratory Muscles:

In addition to the diaphragm, other muscles such as the intercostal muscles between the ribs also contribute to the breathing process. These muscles help expand or contract the chest cavity, assisting in inhalation and exhalation.

Nasal Cavity and Pharynx:

The nasal cavity and pharynx serve as the entry points for air during inhalation. The nasal cavity helps filter, warm, and moisten the inhaled air, while the pharynx acts as a common passage for both air and food, directing them to their respective destinations (air to the trachea and food to the esophagus).

Overall, the respiratory organs work together to facilitate the exchange of gases, ensuring the supply of oxygen to the body’s cells and the removal of carbon dioxide, a waste product of cellular respiration.

Suggested readings:

First Year Pharm D Subjects Syllabus, Notes, PDF Books, MCQ

1.1Human Anatomy and Physiology
1.2Pharmaceutics
1.3Medicinal  Biochemistry
1.4Pharmaceutical Organic Chemistry
1.5Pharmaceutical Inorganic Chemistry
1.6Remedial Mathematics/ Biology