The human respiratory system is a marvel of biological engineering, essential for sustaining life by facilitating the exchange of oxygen and carbon dioxide between the body and the environment. At the center of this intricate system are the lungs, remarkable organs responsible for the vital process of respiration.
Understanding the anatomy and function of the human lungs and respiratory system is crucial for comprehending how our bodies obtain oxygen and remove waste gases.
In this comprehensive guide, we delve into the definition and processes of the human lungs and respiratory system.
From exploring the anatomical structures involved to unraveling the physiological mechanisms at play, we aim to provide a clear and insightful overview of this fundamental aspect of human biology.
Join us as we embark on a journey through the intricacies of respiration, shedding light on the remarkable workings of the lungs and respiratory system.
What is Human Respiratory System?
Respiration, also known as breathing, can be defined as the process of taking in oxygen and releasing carbon dioxide while utilizing the energy within the body.
When humans breathe, it means there is a process of oxygen entering the body and carbon dioxide being released from the body. The exchange between oxygen and carbon dioxide occurs within the human blood. Humans with normal respiration are characterized by breathing 12-20 times per minute.
In breathing, humans generally require 300 liters of oxygen per day. If someone is engaged in heavy work such as exercise, their oxygen requirements increase many times over. The amount of oxygen taken depends on the type of activity performed, body size, and the type of food consumed.
Typically, individuals engaged in strenuous activities will take in more oxygen than those engaged in light activities. Individuals with larger bodies also require more oxygen. Additionally, individuals who frequently consume meat will require more oxygen than those who consume more vegetables or are vegetarian.
In normal lungs, the volume of air can reach 4500 cc. This capacity is commonly known as total lung capacity. During the breathing process, the vital capacity of air used is only up to 3500 cc. Vital capacity is the maximum amount of air that can be exhaled by humans after their lungs are filled. So where does the remaining 1000 cc go? The remaining 1000 cc is residual air that cannot be used. This residual air fills the lung as residual volume.
Breathing is an automatic process that occurs within the human body, even when we are asleep. Breathing is divided into two types: external respiration and internal respiration. External respiration is where air exchange occurs within the alveoli with the blood in the capillaries. Internal respiration is where respiration occurs between the blood in the capillaries and all cells within the body.
The amount of air that enters and leaves the body with each breath is called respiratory rate. Respiratory rate in humans is influenced by several factors, including age, gender, body temperature, body position, and activity. As age increases, respiratory rate decreases. Additionally, males have a higher respiratory rate than females because the oxygen demand and carbon dioxide production in male bodies are higher than in female bodies.
4 Type of Human Breathing
Humans can perform four types of breathing:
- Eupnea: Eupnea occurs during rest and does not require cognitive thought from the individual. Also known as quiet breathing, it involves the contraction of the diaphragm and external intercostal muscles.
- Diaphragmatic Breathing: This type of breathing requires diaphragm contraction. Diaphragmatic breathing is also known as abdominal or deep breathing.
- Costal Breathing: Costal breathing involves the contraction of intercostal muscles. It is also referred to as shallow breathing.
- Hyperventilation: Hyperventilation is forced breathing that includes muscle contractions during both inspiration and expiration, including the diaphragm, intercostal muscles, and accessory muscles.
Humans breathe using respiratory organs consisting of the nose, pharynx, trachea, bronchi, bronchioles, and lungs.
Parts of the Human Respiratory System
Here are the structures of the respiratory system in humans that you need to know:
Nose (nasal cavity)
The nose is the entry point for air into the respiratory system. Additionally, it functions to filter, clean, and moisturize the incoming air.
Fine hair cells in the nose help to trap dust particles and microorganisms that can harm the respiratory tract with the help of mucus.
Pharynx (throat)
The throat or pharynx is the air and food passage that serves as the meeting point between the respiratory and digestive tracts.
This part allows you to direct air into the respiratory tract and food into the digestive tract.
Larynx (voice box)
The part of the respiratory system that contains the vocal cords is called the larynx. Its function is to produce sound through the vibration of the vocal cords as air passes through them.
Additionally, the larynx also acts as an air valve that helps prevent food and fluids from entering the respiratory tract. Also, learn 4 Effective Ways to Have a Good Respiratory System.
Trachea (windpipe)
This airway connects the larynx (voice box) to the bronchi, which enter the lungs. The trachea has cartilage rings lining its walls.
These cartilage rings support the structure of the trachea during inspiration. This keeps the airway open so that airflow remains smooth.
Bronchi
Bronchi are the branches of the trachea that enter the lungs. These airways then branch into smaller bronchioles.
Bronchi and bronchioles carry air into the lungs. They are also equipped with fine hairs and mucus that function to clean the air of foreign particles.
Lungs
The main organs in the respiratory system responsible for gas exchange are the lungs.
Inside them, oxygen from the air is taken up by the blood, and carbon dioxide produced by the body is expelled into the air when we exhale.
Alveoli
This part consists of small sacs in the lungs where the exchange of oxygen and carbon dioxide occurs. The walls of the alveoli are thin and lined with blood capillaries.
This allows oxygen from the air to enter the blood and carbon dioxide to exit the blood into the air.
Read More How to Keep Your Respiratory System Healthy
Respiratory System Functioning
The functioning of the human respiratory system is a complex process involving several stages. Here are the stages of the process:
1. Inspiration (Inhalation)
When someone breathes, nerve impulses in the brain cause respiratory muscles, such as the diaphragm and intercostal muscles, to contract. This contraction results in an increase in the volume of the chest cavity.
The decrease in air pressure in the lungs causes air to flow into the lungs through the nose or mouth. During inspiration, oxygen enters the respiratory system.
2. Oxygen Transport
The oxygen that enters the lungs is carried by the blood through the pulmonary blood vessels, which then travel to the heart.
Blood containing oxygen is pumped by the heart to the entire body through the circulatory system.
3. Gas Exchange in the Alveoli
In the lungs, oxygen carried by the blood enters the alveoli, small sacs that line the walls of the lungs.
On the walls of these alveoli, gas exchange occurs between the oxygen in the alveoli and the blood in the blood capillaries lining the alveoli.
Oxygen diffuses into the blood, while carbon dioxide, which is a byproduct of cell metabolism, diffuses out of the blood into the alveoli.
4. Expiration (Exhalation)
After oxygen is absorbed by the blood, carbon dioxide carried by the blood will return to the lungs.
Nerve impulses from the brain cause respiratory muscles to relax, reducing the volume of the chest cavity and increasing pressure within the lungs.
This process forces carbon dioxide out of the lungs and into the nose or mouth, allowing us to exhale it through the process of expiration.
5. Carbon Dioxide Transport
Carbon dioxide that exits the lungs will be carried by the blood and transported back to the heart.
Blood containing carbon dioxide is pumped by the heart to the lungs, where carbon dioxide can be released through the gas exchange process in the alveoli when we exhale.
Function of the Human Respiratory System
The organs of the human respiratory system function to intake air containing oxygen and exhale it in the form of carbon dioxide and water vapor.
In addition to breathing, the human respiratory system also serves the function of producing sound. Here are some functions of the human respiratory system:
1. Inhalation and exhalation or breathing
In the lungs, air is inhaled through the nasal and oral cavities. It will then move through the pharynx, larynx, and trachea before reaching the lungs. Subsequently, air will be exhaled out and flow through the same pathway.
When inhaling air, the diaphragm and rib bones are lifted. As lung volume increases, air pressure decreases, allowing air to enter. When exhaling, muscles relax, the lungs become smaller, and air is expelled.
2. Gas exchange between the Lungs & Blood Flow
In the lungs, there will be an exchange between oxygen and carbon dioxide waste. This process is called external respiration and occurs in the alveoli.
The inhaled oxygen will bind to hemoglobin molecules in red blood cells and pumped through the bloodstream.
3. Gas exchange between the bloodstream and tissues within the body
The bloodstream will deliver oxygen to body cells and remove carbon dioxide waste.
This process is called internal respiration. In this process, red blood cells will carry oxygen absorbed from the lungs to the entire body through blood vessels.
4. Sound Production
Air vibrating the vocal cords will create sound. This sound is formed by structures in the upper respiratory tract. During breathing, air will flow from the lungs to the voice box.
When humans speak, muscles in the larynx will move the arytenoid cartilage, which in turn will push the vocal cords.
Large vibrations on the vocal cords will produce high-pitched sounds. Meanwhile, small vibrations will produce low-pitched sounds.
5. Smelling
The smelling process begins with olfactory fibers lining the nasal cavity. When air enters the nasal cavity, chemical substances in the air will activate nerve receptor systems.
This stimulus will send signals to the brain. These signals will move, and from there humans can recognize smells.
Conclusion
In summary, the human lungs and respiratory system play crucial roles in the body’s functions. The respiratory system facilitates the intake of oxygen and the removal of carbon dioxide through a complex process involving various organs such as the nose, pharynx, trachea, bronchi, bronchioles, and lungs.
This process includes inhalation and exhalation, gas exchange between the lungs and bloodstream, as well as between the bloodstream and body tissues. Additionally, the respiratory system contributes to sound production and the sense of smell.
Understanding the structure and function of the human respiratory system is essential for maintaining overall health and well-being.
