hhhahha Flashcards
respiratory system
the group of organs that provides living things with oxygen from outside the body and disposes of waste products such as carbon dioxide
respiration
all of the processes involved in bringing oxygen into the body, making it available to each cell, and eliminating carbon dioxide as waste
inspiration
the action
of drawing oxygen-rich
air into the lungs
expiration
the action
of releasing waste air
from the lungs
gas exchange
the transfer of oxygen from inhaled air into the blood, and of carbon dioxide from the blood into the lungs; it is the primary function of the lungs
breathing
Breathing is the process by which air enters and leaves the lungs.
ventilation
the process of drawing, or pumping, an oxygen- containing medium over a respiratory surface
diffusion gradient
describes the relationship in which a dissolved substance moves from a region of high concentration to a region of low concentration
dissolving
the process where a solute in gaseous, liquid, or solid phase dissolves in a solvent to form a solution.
carbon dioxide
A colorless, odorless gas. It is a waste product made by the body. Carbon dioxide travels in the blood from the body’s tissues to the lungs. Breathing out clears carbon dioxide from the lungs.
oxygen
A colorless, odorless gas. It is needed for animal and plant life. Oxygen that is breathed in enters the blood from the lungs and travels to the tissues.
gaseous
relating to or having the characteristics of a gas.
aqueous
of, relating to, or resembling water An aqueous solution is a solution in which the solvent is water.
External respiration
also known as breathing, involves both bringing air into the lungs (inhalation) and releasing air to the atmosphere (exhalation)
internal respiration
The first is the exchange of gasses between the bloodstream and the tissues. The second is the process of cellular respiration, from which cells utilize oxygen to perform basic metabolic functions.
cellular respiration
A chemical process in which oxygen is used to make energy from carbohydrates (sugars).
Q: What is the main function of the respiratory system?
A: The main function of the respiratory system is to ensure that oxygen is brought into the body and made available to each cell that needs it, and that carbon dioxide can leave each cell and be removed from the body.
Q: Why do cells need a continual supply of oxygen?
A: Cells need a continual supply of oxygen to carry out cellular respiration. Oxygen is required as a reactant in the process of breaking down glucose molecules to release energy. Without oxygen, cells cannot efficiently generate the energy needed for their functioning.
Q: What happens during cellular respiration?
A: During cellular respiration, glucose molecules are broken down in the presence of oxygen to release energy. The energy is stored in the form of ATP (adenosine triphosphate), which is the primary energy currency of cells. As a byproduct, carbon dioxide is produced and transported out of the cells to be eliminated from the body.
vQ: How does the respiratory system support cellular respiration?
A: The respiratory system supports cellular respiration by bringing oxygen into the body through inhalation. Oxygen is then transported to cells via the bloodstream, where it can participate in cellular respiration. Simultaneously, carbon dioxide, which is a waste product of cellular respiration, is carried back to the lungs and eliminated from the body through exhalation.
Q: What is the role of respiration in the overall process?
A: Respiration is the general term used to describe the overall process of oxygen intake, transport to cells, cellular respiration, and the removal of carbon dioxide from the body. It encompasses the functions of the respiratory system in ensuring that oxygen reaches cells and carbon dioxide is expelled, allowing for the efficient production of energy through cellular respiration.
Q: What are the two basic processes involved in breathing?
A: The two basic processes involved in breathing are inspiration (inhaling or breathing in) and expiration (exhaling or breathing out).
Q: What is the purpose of inspiration?
A: The purpose of inspiration is to move air from outside the body into the lungs inside the body.
Q: What is the purpose of expiration?
A: The purpose of expiration is to move air from the lungs back to the outside of the body.
Q: What structures are involved in the process of inspiration?
A: The process of inspiration involves the use of specialized structures such as the diaphragm and intercostal muscles.
The diaphragm contracts and moves downward, while the intercostal muscles between the ribs contract, causing the ribcage to expand. These actions increase the volume of the chest cavity and create a negative pressure, drawing air into the lungs.
Q: What structures are involved in the process of expiration?
A: The process of expiration involves the relaxation of the diaphragm and intercostal muscles. The diaphragm moves upward, and the intercostal muscles relax, causing the ribcage to decrease in volume. This decrease in volume increases the pressure in the chest cavity, forcing air out of the lungs.
Q: How do the specialized structures facilitate breathing?
A: The diaphragm and intercostal muscles work together to create changes in the volume and pressure of the chest cavity during inspiration and expiration. These changes in volume and pressure allow for the movement of air into and out of the lungs, enabling the process of breathing.
Q: What is breathing?
A: Breathing is the process by which air enters and leaves the lungs.
Q: What is external respiration?
A: External respiration refers to the exchange of oxygen and carbon dioxide between the inside of the lungs and the blood. It occurs in the alveoli, which are tiny air sacs in the lungs where oxygen from inhaled air diffuses into the bloodstream, and carbon dioxide from the blood diffuses into the alveoli to be exhaled.
Q: What is internal respiration?
A: Internal respiration is the exchange of oxygen and carbon dioxide between the blood and the body’s tissue cells.
It takes place in the capillaries, where oxygen diffuses from the bloodstream into the cells, and carbon dioxide produced by cellular respiration moves from the cells into the bloodstream to be carried away.
Q: How does external respiration occur?
A: During external respiration, oxygen-rich air is inhaled into the lungs, where it reaches the alveoli. In the alveoli, oxygen diffuses across the thin walls of the air sacs and into the surrounding capillaries, binding to hemoglobin in red blood cells. At the same time, carbon dioxide, which is dissolved in the blood, diffuses from the capillaries into the alveoli to be exhaled.
Q: How does internal respiration occur?
A: In internal respiration, oxygenated blood is carried by arteries to the body’s tissues.
In the capillaries, oxygen diffuses out of the blood and enters the cells, where it is used for cellular respiration. At the same time, carbon dioxide, a waste product of cellular respiration, diffuses out of the cells into the capillaries and is transported back to the lungs for elimination during expiration.
Q: What is the significance of external and internal respiration?
A: External respiration ensures that oxygen from the inhaled air enters the bloodstream and is available for cellular respiration, while carbon dioxide is removed from the blood and expelled from the body
Internal respiration allows oxygen to be delivered to the body’s cells and carbon dioxide to be carried away, ensuring proper cellular function and maintaining homeostasis in the body.
Q: What is the second stage of respiration?
A: The second stage of respiration is external respiration, which involves the exchange of oxygen and carbon dioxide between the inspired air inside the lungs and the blood.
Q: What is the primary function of external respiration?
A: The primary function of external respiration is gas exchange. It delivers oxygen from the lungs to the blood and eliminates carbon dioxide from the blood to the lungs.
Q: What is gas exchange in the context of respiration?
A: Gas exchange refers to the process of delivering oxygen from the lungs to the blood and removing carbon dioxide from the blood to the lungs. It occurs during external respiration and is vital for maintaining proper oxygen supply and eliminating waste carbon dioxide.
Q: What is the third stage of respiration?
A: The third stage of respiration is internal respiration, which involves the exchange of oxygen and carbon dioxide between the blood and the body’s tissue cells.
Q: What is the purpose of internal respiration?
A: The purpose of internal respiration is to facilitate the exchange of oxygen from the blood into the body’s tissue cells, where it is utilized for cellular respiration. Simultaneously, carbon dioxide, produced as a waste product of cellular respiration, is exchanged from the tissue cells into the blood for removal.
Q: What is the fourth stage of human respiration?
A: The fourth and final stage of human respiration is cellular respiration. It refers to the series of energy-releasing chemical reactions that occur within the cells.
Q: What is the significance of cellular respiration?
A: Cellular respiration is crucial as it serves as the sole means of providing energy for all cellular activities. It is through cellular respiration that cells break down glucose molecules, releasing energy that can be utilized by the cell for various functions and processes.
Q: What are the two main requirements for respiration?
Sufficiently large respiratory surface area for the exchange of gases (oxygen and carbon dioxide) to occur quickly enough to meet the body’s needs.
Respiration must take place in a moist environment to ensure that oxygen and carbon dioxide can be dissolved in water.
Q: Why is a large respiratory surface area necessary for respiration?
A: A large respiratory surface area is necessary to facilitate the efficient exchange of oxygen and carbon dioxide between the organism and its environment. It allows for a greater surface area available for diffusion, enabling a higher rate of gas exchange to meet the body’s oxygen requirements and remove waste carbon dioxide.
Q: Why is a moist environment important for respiration?
A: A moist environment is important for respiration because oxygen and carbon dioxide need to be dissolved in water for efficient exchange. Moist surfaces help in maintaining the necessary conditions for gas exchange, as gases readily dissolve in water. Moisture also prevents the respiratory surface from drying out, ensuring its functionality.
Q: What happens when respiration occurs in a dry environment?
A: When respiration occurs in a dry environment, the respiratory surfaces may dry out, leading to impaired gas exchange. Dry surfaces hinder the dissolution of gases, making it difficult for oxygen to be absorbed and carbon dioxide to be released. This can negatively affect the organism’s respiratory efficiency and overall function.
Q: How do organisms meet the requirement of a large respiratory surface area?
A: Organisms have adapted various structures to increase their respiratory surface area. For example, humans have lungs with numerous alveoli, which provide a vast surface area for gas exchange.
In other organisms, such as fish, gills provide a large surface area for oxygen uptake from water. Additionally, insects have a network of tiny tubes called tracheae that extend throughout their bodies, allowing for efficient gas exchange.
Q: How is a moist environment maintained for respiration in different organisms?
A: Different organisms employ different mechanisms to maintain a moist environment for respiration. In mammals, the respiratory surfaces, such as the lungs, are protected within a moist mucous lining. In aquatic organisms like fish, respiration occurs in water, which naturally provides a moist environment. Insects have spiracles on their body surface that can open and close, helping to regulate moisture levels during respiration. Overall, the adaptations of each organism ensure the presence of moisture for effective gas exchange.
Q: How do some animals exchange gases without using lungs?
A: Some animals exchange gases through their outer body surface, gills, or trachea instead of using the lungs. These structures serve as respiratory surfaces where gas exchange takes place.
Q: What are gills?
A: Gills are specialized respiratory organs found in aquatic animals such as fish. They are filamentous or plate-like structures rich in bloodvessels. Gills extract oxygen from water, allowing fish to respire efficiently underwater.
Q: What is the function of trachea in respiration?
A: The trachea is a tube-like structure found in insects and some other terrestrial arthropods. It serves as a respiratory organ and carries air directly to and from the tissues. The trachea branches into smaller tubes called tracheae, which deliver oxygen to individual cells.
Q: How are gases transported to and from cells in the body?
A: The circulatory system is responsible for transporting gases to and from the cells of an animal’s body. Oxygen, obtained through respiration, is carried by red blood cells in the bloodstream to the cells. Carbon dioxide, a waste product of cellular respiration, is transported back to the lungs or respiratory organs to be eliminated from the body.
Q: What is ventilation in the context of respiration?
A: Ventilation refers to the process of moving an oxygen-containing medium, such as air or water, over the respiratory surface of an organism. It is a mechanism used by organisms to increase the efficiency of respiration. Ventilation ensures a continuous supply of fresh oxygen and the removal of carbon dioxide from the respiratory surface.
Q: How does ventilation enhance the efficiency of respiration?
A: Ventilation enhances the efficiency of respiration by maintaining a constant flow of oxygen-containing medium (air or water) over the respiratory surface. This continuous movement ensures a high rate of oxygen uptake and carbon dioxide removal, maximizing the efficiency of gas exchange. Ventilation helps replenish the oxygen supply and prevent the buildup of waste gases, promoting effective respiration in organisms.
Q: How do animals like earthworms exchange gases without specialized organs?
A: Animals like earthworms use their entire outer skin as a respiratory surface for gas exchange. Oxygen diffuses into a network of thin-walled capillaries just below the skin, while carbon dioxide diffuses out through the skin.
Q: What is the advantage of using the outer skin as a respiratory surface?
A: Using the outer skin as a respiratory surface allows for a direct exchange of gases with the environment. It eliminates the need for specialized respiratory organs, making respiration more efficient. This adaptation is particularly beneficial for animals like earthworms that lack lungs or gills.
Q: How does oxygen enter and carbon dioxide exit the earthworm’s body through its skin?
A: Oxygen enters the earthworm’s body through its outer skin by diffusion. The thin-walled capillaries just below the skin carry oxygenated blood, allowing oxygen to diffuse into the bloodstream. Simultaneously, carbon dioxide, a waste product of cellular respiration, diffuses out of the capillaries and through the skin, being released into the surrounding environment.
Q: Why do animals that breathe through their skin need to live in damp places or water?
A: Animals that breathe through their skin, such as earthworms and some amphibians, require a moist environment. Moisture is essential to keep their respiratory surface (skin surface) moist, which aids in the dissolution of gases for efficient gas exchange. Living in damp places or water helps prevent the skin from drying out, ensuring the continuation of effective respiration.
Q: How do amphibians use their skin for respiration?
A: Amphibians are known as “skin breathers” because they can exchange gases through their skin. Oxygen from the environment diffuses through the moist skin and into the bloodstream, while carbon dioxide produced by cellular respiration diffuses out of the bloodstream and through the skin for elimination. Amphibians also have lungs for respiration, but their skin contributes significantly to gas exchange, especially when they are submerged in water or in damp environments.
Q: How do fish and aquatic invertebrates exchange gases?
A: Fish and many aquatic invertebrates, such as clams, mussels, crayfish, and crabs, exchange gases through gills.
Q: What are gills?
A: Gills are specialized respiratory organs found in fish and various aquatic invertebrates. They are extensions or folds in the body surface that increase the surface area available for gas exchange.
Q: How do gills facilitate gas exchange?
A: Gills provide a large surface area for gas exchange. Oxygen from the water diffuses across the gill surfaces and enters the surrounding capillaries, where it binds to hemoglobin and is transported throughout the organism’s body. At the same time, carbon dioxide produced by cellular respiration diffuses out of the capillaries and into the water, where it is released into the external environment.
Q: Why do aquatic animals not have a problem keeping their respiratory surfaces moist?
A: Aquatic animals do not have a problem keeping their respiratory surfaces moist because they are surrounded by water. Water naturally keeps the gills moist, ensuring efficient gas exchange. The moisture in the aquatic environment prevents the gills from drying out and facilitates the dissolution of gases necessary for respiration.
Q: How does oxygen enter and carbon dioxide exit the bloodstream in aquatic animals with gills?
A: In aquatic animals with gills, oxygen enters the bloodstream through the gill surfaces. Oxygen-rich water flows over the gills, and oxygen molecules diffuse from the water into the capillaries of the gills, where they bind to hemoglobin in red blood cells. Carbon dioxide, produced as a waste product of cellular respiration, diffuses out of the capillaries and into the water, where it is carried away by the water currents, allowing for efficient gas exchange.
Q: How do insects exchange gases?
A: Insects exchange gases through a tracheal system, which consists of branching respiratory tubes called tracheae.
Q: What are tracheae in insects?
A: Tracheae are internal tubes in insects that form the respiratory system. They branch out extensively, delivering air directly to the body cells.
Q: What is the role of spiracles in the respiratory system of insects?
A: Spiracles are small openings or pores located on the body surface of insects. They serve as the entry and exit points for gases in the respiratory system. Oxygen enters the insect’s body through the spiracles, and carbon dioxide diffuses out of the body through these openings.
Q: How does gas exchange occur in the tracheal system of insects?
A: Oxygen enters the insect’s body through the spiracles and diffuses into the tracheae, the branching respiratory tubes. The tracheae directly deliver oxygen to the body cells, allowing for efficient gas exchange. At the same time, carbon dioxide, produced as a waste product of cellular respiration, diffuses out of the cells and moves in the opposite direction, exiting the body through the spiracles.
Q: Is the circulatory system involved in oxygen transport in insects?
A: No, in insects, the circulatory system is not directly involved in transporting oxygen. Since gas exchange occurs directly with the body cells through the tracheal system, oxygen is delivered to the cells without the need for the circulatory system. The tracheal system acts as a network of tubes that directly supply oxygen to individual cells, eliminating the need for oxygen transport through the bloodstream as seen in vertebrates.
Q: Which animals use lungs as their respiratory organs?
A: Mammals, birds, reptiles, and most amphibians use lungs as their respiratory organs.
Q: What is the structure of the internal respiratory system in animals with lungs?
A: The internal respiratory system in animals with lungs consists of a trachea (or windpipe) that branches into lungs.
Q: What are the lungs?
A: Lungs are sac-like structures in the respiratory system of mammals, birds, reptiles, and most amphibians. They are lined with a moist epithelium and are responsible for gas exchange.
Q: How does gas exchange occur in the lungs?
A: Oxygen diffuses across the moist epithelium of the lungs into the surrounding capillaries. From there, it binds to hemoglobin in red blood cells and is transported throughout the body. Simultaneously, carbon dioxide, produced by cellular respiration, diffuses out of the capillaries and into the lungs, where it is then eliminated into the external environment.
Q: How does the structure of the lungs facilitate gas exchange?
A: The lining of the lungs contains folds that increase the surface area available for diffusion. These folds, called alveoli in mammals, increase the efficiency of gas exchange by providing a larger surface area for oxygen to diffuse into the bloodstream and for carbon dioxide to diffuse out of the bloodstream. The moist epithelium of the lungs helps dissolve gases and facilitate their exchange.
Q: What is the direction of gas diffusion in the lungs?
A: Oxygen diffuses across the epithelium of the lungs into the capillaries, entering the bloodstream. On the other hand, carbon dioxide diffuses from the capillaries into the lungs, where it is then expelled into the external environment during expiration.
Q: How do aquatic organisms, such as fish, exchange gases?
A: Aquatic organisms, including fish, lobsters, clams, and mollusks, exchange gases through their gills.
Q: What are gills in aquatic organisms?
A: Gills are specialized respiratory organs found in aquatic organisms. They are physical adaptations that enable gas exchange in aquatic environments.
Q: How do fish use their gills for gas exchange?
A: Fish ventilate or pump water over their gills by taking it in through their mouths. As water flows across the gills, dissolved oxygen in the water diffuses into the surrounding capillaries, entering the fish’s bloodstream. At the same time, carbon dioxide produced by cellular respiration diffuses from the blood, across the gill tissue, into the water. The carbon dioxide is carried out of the fish’s body when the water passes out through the gill openings.
Q: What is the function of the counter-current exchange mechanism in fish gills?
A: The counter-current exchange mechanism is an adaptation used by fish for efficient gas exchange. In this mechanism, blood flows through the gills in the opposite direction to the flow of oxygen-containing water. This setup creates a diffusion gradient, where oxygen molecules move from a region of high concentration (water) to a region of low concentration (blood). By maintaining the opposite flow of blood and water, the diffusional gradient of oxygen remains high, maximizing the efficiency of oxygen uptake by the fish’s respiratory system.
Q: Why is the counter-current exchange mechanism important for gas exchange in fish gills?
A: The counter-current exchange mechanism is crucial for maximizing oxygen uptake in fish gills. By having blood flow in the opposite direction to the flow of water, the concentration gradient of oxygen is maintained along the entire length of the gill surface. This allows for efficient diffusion of oxygen from the water into the blood, ensuring that fish can extract as much oxygen as possible from their aquatic environment.
Q: What is the role of the respiratory system in air-breathing vertebrates?
A: The respiratory system in air-breathing vertebrates provides a passageway for air to move from outside the body to inside the body, where gas exchange occurs. It facilitates the exchange of oxygen and carbon dioxide between the lungs and the bloodstream.
Q: How is breathing controlled in air-breathing vertebrates?
A: Breathing in air-breathing vertebrates is controlled by the respiratory control center in the brain. This control center coordinates breathing movements and regulates the breathing rate. It also monitors the volume of air in the lungs and the levels of gases, such as oxygen and carbon dioxide, in the blood.
Q: What are the structures involved in controlling air pressure inside the lungs?
A: The muscular diaphragm and the rib muscles are involved in controlling air pressure inside the lungs.
Q: What is the diaphragm?
A: The diaphragm is a dome-shaped layer of muscle located between the thoracic cavity (region of the lungs) and the abdominal cavity (region of the stomach and liver). It plays a crucial role in breathing by contracting and relaxing to change the volume of the thoracic cavity, allowing for inhalation and exhalation.
Q: What are rib muscles or intercostal muscles?
A: Rib muscles, also known as intercostal muscles, are located between the ribs and along the inside surface of the rib cage. These muscles play a role in breathing by assisting the diaphragm in expanding and contracting the chest cavity during inhalation and exhalation. They help in the movement of the ribs, allowing for changes in lung volume and air pressure.
Q: How do the diaphragm and intercostal muscles work together to move air into and out of the lungs?
A: The diaphragm and intercostal muscles work together to facilitate inhalation and exhalation, allowing air to move into and out of the lungs. During inhalation, the external intercostal muscles and diaphragm contract. The diaphragm moves downward, while the intercostal muscles expand the rib cage upward and outward. These actions increase the volume of the chest cavity, reducing air pressure within it. This decrease in air pressure causes the lungs to expand, and air rushes in from the external environment. During exhalation, the diaphragm and intercostal muscles relax, reducing the volume of the chest cavity. This increases the air pressure within the lungs, causing air to move out of the lungs and into the lower-pressure environment outside the body.
Q: How does inhalation occur and what happens to air pressure during this process?
A: Inhalation begins when the external intercostal muscles and diaphragm contract. The diaphragm moves downward, expanding the chest cavity upward and outward. This increase in volume decreases the air pressure within the thoracic cavity. The decrease in air pressure causes air to rush into the lungs from the external environment. When the volume of the chest cavity increases, the molecules of gas (air) become farther apart, exerting less outward pressure and resulting in lower air pressure within the thoracic cavity.
Q: How does exhalation occur and what happens to air pressure during this process?
A: Exhalation begins when the diaphragm and intercostal muscles relax. This reduces the volume of the chest cavity, increasing the air pressure within the lungs. As a result, air moves from the lungs to the lower-pressure environment outside the body. The relaxation of the diaphragm and intercostal muscles leads to a decrease in the volume of the lungs, causing the air pressure inside the lungs to be higher than the air pressure outside the body. Air moves from the area of higher pressure (lungs) to the area of lower pressure (outside the body) during exhalation.
Q: How does the expansion and contraction of the lungs contribute to inhalation and exhalation?
A: During inhalation, as the volume of the chest cavity increases, the walls of the lungs are drawn outward into the chest cavity, causing the lungs to expand. This expansion leads to a decrease in air pressure within the lungs, allowing air to rush in from the external environment. During exhalation, as the volume of the chest cavity decreases, the volume of the lungs also decreases. This increases the air pressure within the lungs, causing air to move out of the lungs and into the lower-pressure environment outside the body. The expansion and contraction of the lungs help facilitate the movement of air during inhalation and exhalation.
Q: How does air enter the respiratory system?
A: Air enters the respiratory system through the nostrils. It can also enter through the mouth, especially during rapid breathing, such as during strenuous exercise.
Q: What happens to the air inside the nasal passages?
A: Inside the nasal passages, the air is warmed, moistened, and cleansed of dust and other small particles. Thin bones called turbinate bones project into the nasal passages, increasing their surface area. A membrane covering the turbinate bones secretes mucus, which moistens the air and traps particles like dust and bacteria. Ciliated cells in the membrane have hair-like projections that move the trapped particles into the nose or throat, where they can be expelled by sneezing or coughing.
Q: How does the secretion of mucus in the nasal passages contribute to air purification?
A: The secretion of mucus in the nasal passages plays a role in air purification. The mucus moistens the air, helping to prevent dryness in the respiratory system. Additionally, the mucus traps particles of dust, bacteria, and other foreign matter present in the inhaled air. Ciliated cells in the membrane with hair-like projections move the trapped particles toward the nose or throat. From there, the particles can be expelled by sneezing or coughing, further contributing to air purification.
Q: What are turbinate bones, and how do they enhance the nasal passages’ function?
A: Turbinate bones are thin bones that project into the nasal passages. They increase the surface area of the nasal chambers. The increased surface area allows for more contact between the inhaled air and the nasal tissues, promoting efficient warming, moistening, and cleansing of the air. The turbinate bones also help to direct the airflow within the nasal passages, optimizing the processes of air conditioning and particle trapping.
Q: How does the dense network of capillaries in the lining of the turbinates contribute to air conditioning?
A: The dense network of capillaries in the lining of the turbinates plays a crucial role in air conditioning. As the warm blood flows through these capillaries, it transfers heat to the nasal passages, warming the inhaled air to body temperature. This helps to protect the delicate structures in the lower respiratory tract from potential damage caused by cold air.
Q: What is the function of the epiglottis in the respiratory system?
A: The epiglottis is a flap-like structure located at the base of the pharynx, behind the tongue. Its primary function is to close the glottis, which is the entrance to the trachea or windpipe. The epiglottis normally remains upright, allowing air to pass freely into the trachea during breathing. However, when we swallow food or liquid, the epiglottis closes over the glottis, preventing the entry of food and liquids into the trachea. This action helps to ensure that food and liquids are directed to the esophagus and do not accidentally enter the respiratory system, which could lead to choking or aspiration into the lungs.
Q: What is the function of the larynx in the respiratory system?
A: The larynx, also known as the voice box, serves multiple functions in the respiratory system. One of its primary functions is sound production in mammals. The vocal cords, which are two folds of membrane located within the larynx, play a crucial role in generating sound. During normal breathing, the vocal cords are held apart, allowing air to pass freely through the larynx. However, when we speak or produce sounds, the vocal cords are brought closer together. When air expelled from the lungs passes through the narrowed opening between the vocal cords, they vibrate, producing sound. The pitch of the sound is determined by the length of the vocal cords, with longer cords producing lower sounds and shorter cords producing higher sounds.
Q: What causes the “breaking” quality in the voice during puberty?
A: During puberty, the vocal cords of males undergo rapid growth. This growth results in a lengthening and thickening of the vocal cords. The changing size and structure of the vocal cords can lead to an irregular vibration pattern, causing a temporary “breaking” or cracking quality in the voice. As the vocal cords continue to develop and mature, the irregularities in vibration diminish, and the voice becomes more stable and characteristic of an adult male voice.
How many lobes does the right lung have in humans?
The right lung has three lobes in humans.
How many lobes does the left lung have in humans?
The left lung has two lobes in humans.
What is the name of the thin, flexible, double-layered sac that surrounds each lung?
The thin, flexible, double-layered sac that surrounds each lung is called the pleural membrane.
What is the function of the pleural membrane?
The pleural membrane helps the layers to slide easily against each other during the movements of breathing.
What is the purpose of the lubricating fluid in the space between the layers of the pleural membrane?
The lubricating fluid in the space between the layers of the pleural membrane allows for smooth movement and reduces friction during breathing.
What is the name of the network of microscopic tubules formed by the subdivision of bronchi?
The network of microscopic tubules formed by the subdivision of bronchi is called bronchioles.
What is found at the end of each bronchiole?
At the end of each bronchiole, there is a grape-like cluster of tiny sacs called alveoli (singular alveolus).
How many alveoli are estimated to be present in an average-size adult human lung?
An estimated 500 million alveoli are present in an average-size adult human lung.
What surrounds each alveolus?
Each alveolus is surrounded by a network of fine capillaries.
What is the thickness of the walls of the alveoli and the capillaries?
The walls of the alveoli and the capillaries are only one cell thick.
What happens across the thin membranes of the alveoli and capillaries?
Across the thin membranes of the alveoli and capillaries, the respiratory system and the circulatory system interact, with oxygen diffusing into the blood and carbon dioxide diffusing into the lungs.
What happens during external respiration in terms of gas exchange?
During external respiration, gases diffuse through the thin walls of the alveoli and capillaries. Oxygen diffuses out of the alveoli into the blood in the capillaries, while carbon dioxide diffuses from the blood in the capillaries into the alveoli.
Why does oxygen diffuse out of the alveoli into the blood in the capillaries?
The air in the alveoli has a higher concentration of oxygen than the blood in the capillaries next to the lungs. This concentration gradient causes oxygen to diffuse into the blood.
Why does carbon dioxide diffuse into the alveoli from the capillaries?
The blood in the capillaries has a higher concentration of carbon dioxide than the air in the alveoli. This is because the blood returning from the body tissue cells carries carbon dioxide. As a result, carbon dioxide diffuses from the capillaries into the alveoli.
What happens to the carbon dioxide after it diffuses into the alveoli?
The carbon dioxide that diffuses into the alveoli is exhaled into the air during the process of breathing.
What enables gases to easily diffuse through the cell membranes of the alveoli and capillaries?
The thin walls of the alveoli and capillaries allow gases to readily diffuse through their cell membranes, facilitating efficient gas exchange during external respiration.
How is oxygen (O2) transported in the bloodstream during respiration?
During respiration, about 99 percent of oxygen that reaches cells is carried by hemoglobin, a protein present in red blood cells. The remaining 1 percent of oxygen is dissolved in the watery blood plasma.
What happens to carbon dioxide (CO2) during respiration?
When carbon dioxide leaves the tissue cells, it diffuses into the capillaries and enters the red blood cells. Approximately 23 percent of carbon dioxide is carried in the blood by hemoglobin, while the remaining 77 percent is carried in the blood fluids.
Where does the exchange of gases occur for oxygen and carbon dioxide during respiration?
The exchange of gases occurs in the alveoli of the lungs. Oxygen diffuses from the air in the alveoli into the bloodstream, while carbon dioxide diffuses from the bloodstream into the air in the alveoli to be exhaled.
What is the role of hemoglobin in the transport of oxygen and carbon dioxide?
Hemoglobin plays a crucial role in the transport of oxygen and carbon dioxide. It binds with oxygen in the lungs, forming oxyhemoglobin, which is then carried to the tissues. In the case of carbon dioxide, hemoglobin can also bind with it and carry it from the tissues to the lungs for exhalation.
What percentage of oxygen and carbon dioxide is carried by hemoglobin in the blood?
Approximately 99 percent of oxygen is carried by hemoglobin, while about 23 percent of carbon dioxide is carried by hemoglobin. The majority of carbon dioxide (77 percent) is carried in the blood fluids.
