Human Biology Lecture 16

The correct answer is Nasal Cavity because it is the interior area of the nose. The nasal cavity is a hollow space in the nose that is lined with mucous membranes and cilia. It serves as a passage for air to enter the respiratory system, where it is warmed, humidified, and filtered before reaching the lungs. The nasal cavity also contains olfactory receptors that allow for the sense of smell.

The given options are different parts of the respiratory system. The pharynx is a part of the throat that connects the nasal cavity and the larynx. It serves as a passage for both air and food, as well as playing a role in sound production. Therefore, the correct answer is Pharynx.

The epiglottis is a flap of cartilage located at the base of the tongue. Its main function is to prevent food and liquid from entering the trachea during swallowing. When we swallow, the epiglottis closes over the opening of the trachea, directing the food and liquid down the esophagus and into the stomach. This helps to prevent choking and ensures that food and liquid go into the digestive system rather than the respiratory system.

The epiglottis is a flap of tissue located at the base of the tongue. Its main function is to cover the tracheal opening, or windpipe, when food is swallowed. This prevents food and liquids from entering the airway and going into the lungs, which could lead to choking or aspiration. The epiglottis acts as a protective mechanism, ensuring that food goes down the esophagus and into the stomach, while air goes into the lungs.

The ribs are the correct answer because they support the chest wall and provide protection for the heart, lungs, and other organs in the chest. The ribs form a cage-like structure around the chest, providing stability and support. They also help to protect the vital organs from external injuries and impacts.

The respiratory center is the area of the brain that controls breathing. It is responsible for regulating the rate and depth of breathing, ensuring that the body receives an adequate supply of oxygen and removes carbon dioxide. This area receives input from sensors in the body that detect levels of oxygen and carbon dioxide, as well as pH levels in the blood. Based on this information, the respiratory center sends signals to the muscles involved in breathing, coordinating the inhalation and exhalation process.

The lungs are the two organs responsible for extracting oxygen from inhaled air and expelling carbon dioxide in exhaled air. They are vital for the process of respiration, where oxygen is taken in by the body and carbon dioxide is removed. The lungs contain millions of tiny air sacs called alveoli, which are surrounded by capillaries. Oxygen from the air enters the alveoli and is then transported into the bloodstream, while carbon dioxide from the bloodstream is released into the alveoli to be exhaled. Therefore, the lungs play a crucial role in the exchange of gases in the body.

The given correct answer is "Ribs". Ribs are bones that are attached to the spine and the central portion of the breastbone. They form the ribcage, which protects the organs in the chest, such as the heart and lungs. Ribs also provide support and structure to the chest and help with the process of breathing.

The diaphragm is a dome-shaped muscle that separates the chest cavity from the abdominal cavity. It is often compared to a parachute due to its shape, as it is wider in the center and tapers towards the edges. This shape allows the diaphragm to contract and flatten when we inhale, creating more space in the chest cavity and allowing the lungs to expand and fill with air.

The esophagus is the tube that carries food from the mouth to the stomach. It is a muscular tube that contracts and relaxes to push the food down into the stomach through a process called peristalsis. The trachea, on the other hand, is the tube that carries air from the mouth and nose to the lungs. Therefore, the correct answer is esophagus.

The trachea, also known as the windpipe, is a tube-like structure that connects the larynx (voice box) to the bronchi of the lungs. It is responsible for allowing air to pass in and out of the lungs during breathing. The trachea is made up of rings of cartilage that provide support and prevent collapse. It is lined with ciliated cells and mucus-producing cells, which help to trap and remove foreign particles and keep the airways clean. The trachea plays a crucial role in the respiratory system and is essential for proper breathing.

During inhalation, the diaphragm contracts and flattens out. The diaphragm is a dome-shaped muscle located at the base of the lungs. When it contracts, it moves downward and flattens out, causing the volume of the thoracic cavity to increase. This creates a pressure difference between the lungs and the outside air, allowing air to flow into the lungs.

The trachea is the tube through which air passes from the nose to the lungs. It is a part of the respiratory system and is commonly known as the windpipe. The trachea is located in the neck and chest and connects the larynx (voice box) to the bronchi (tubes that lead to the lungs). It is made up of cartilage rings that help to keep the airway open and prevent it from collapsing.

The statement is true because oxygen is required by cells for various metabolic processes. Oxygen is transported through the bloodstream and delivered to cells where it can be used for energy production. Therefore, it is correct to say that oxygen enters the cells because the concentration of oxygen is higher in the blood compared to the cells.

The opposite of the Bohr effect occurs in the lungs. The Bohr effect refers to the phenomenon where an increase in carbon dioxide levels in the blood causes a decrease in the affinity of hemoglobin for oxygen, allowing for easier oxygen release to tissues. In the lungs, however, oxygen levels are high and carbon dioxide levels are low, leading to a higher affinity of hemoglobin for oxygen and facilitating oxygen uptake. This opposite effect in the lungs is crucial for efficient gas exchange and oxygenation of the blood.

The nasal cavity is lined with a sticky mucous membrane and contains tiny, surface hairs called cilia. These structures play a crucial role in the respiratory system by trapping dust, bacteria, and other foreign particles that are inhaled. The sticky mucous membrane helps to moisten and warm the air as it enters the nasal cavity, while the cilia help to move the trapped particles towards the throat where they can be swallowed or coughed out. Overall, the nasal cavity serves as a filter and humidifier for the air we breathe.

The correct answer is intercostal muscles. The intercostal muscles are thin sheets of muscles located between each rib. They play a crucial role in the process of breathing by expanding when air is inhaled and contracting when air is exhaled. These muscles help to increase and decrease the size of the chest cavity, allowing for the movement of air in and out of the lungs.

Both oxygen and carbon dioxide move by diffusion. Diffusion is the process by which particles move from an area of higher concentration to an area of lower concentration. In the case of oxygen, it moves from the lungs, where its concentration is higher, to the bloodstream, where its concentration is lower. On the other hand, carbon dioxide moves from the bloodstream, where its concentration is higher, to the lungs, where its concentration is lower, to be exhaled. Therefore, both gases undergo diffusion to reach their respective destinations in the body.

The statement is true because hemoglobin is a protein made up of four peptide chains that work together to facilitate the binding and release of oxygen. This cooperative behavior allows hemoglobin to efficiently transport oxygen throughout the body.

Carbonic acid is the correct answer because it is responsible for making the blood acidic around the tissues. This occurs because carbon dioxide, which is produced in the tissues, reacts with water to form carbonic acid.

Carbonic anhydrase is an enzyme that catalyzes the conversion of carbon dioxide and water into carbonic acid, which then dissociates into bicarbonate ions and protons. This enzyme is crucial in maintaining the acid-base balance in the body. Red blood cells contain a high concentration of carbonic anhydrase, which allows for the rapid exchange of carbon dioxide and oxygen during respiration. This enzyme helps in the transportation of carbon dioxide from the tissues to the lungs, where it can be expelled from the body. Therefore, the correct answer is red blood cells.

The diaphragm is a dome-shaped muscle located beneath the lungs that separates the chest cavity from the abdominal cavity. It plays a crucial role in respiration by contracting and relaxing to help with the inhalation and exhalation of air. When the diaphragm contracts, it flattens and moves downward, increasing the volume of the chest cavity and allowing the lungs to expand. This creates a pressure difference that draws air into the lungs. Conversely, when the diaphragm relaxes, it moves back up, decreasing the volume of the chest cavity and causing air to be expelled from the lungs. Therefore, the diaphragm is responsible for separating and controlling the movement of air between the chest and abdominal cavities.

The pharynx is the correct answer because it is the area shared by the digestive and respiratory systems. It is a muscular tube located behind the nasal cavity, mouth, and larynx. It serves as a passageway for both air and food, allowing air to travel to the lungs and food to enter the esophagus.

The pharynx is located at the back of the oral cavity, making it the correct answer. The pharynx is a muscular tube that connects the nasal cavity and mouth to the esophagus and larynx. It serves as a passage for both air and food, and plays a crucial role in the respiratory and digestive systems.

The Bohr effect refers to the phenomenon where hemoglobin's affinity for oxygen changes depending on the acidity of the blood. When the blood is less acidic, hemoglobin binds more easily to oxygen, allowing for oxygen uptake in the lungs. On the other hand, when the blood becomes more acidic, hemoglobin unbinds more easily from oxygen, facilitating oxygen release to the tissues. This effect is crucial for efficient oxygen transport and delivery in the body.

The given statement "This is supported by rings of cartilage" suggests that the structure being referred to requires support from rings of cartilage. The trachea is a tube-like structure in the respiratory system that connects the larynx to the bronchi and is responsible for allowing air to pass in and out of the lungs. It is supported by C-shaped rings of cartilage that prevent its collapse and maintain its shape, making it the correct answer.

Carbon dioxide is carried in the blood attached to hemoglobin in small amounts and primarily by reacting with water. This means that a small portion of carbon dioxide molecules bind to hemoglobin molecules, while the majority of carbon dioxide molecules dissolve in the blood plasma and react with water to form carbonic acid. This reaction allows carbon dioxide to be transported throughout the body and eventually eliminated through respiration.

The bronchi are the two main air passages into the lungs. They branch off from the trachea and lead to the lungs, where they further divide into smaller airways called bronchioles. The bronchi are responsible for carrying air in and out of the lungs, allowing for the exchange of oxygen and carbon dioxide. The other options listed, such as the nasal cavity, pharynx, and respiratory center, are not the main air passages into the lungs, making the bronchi the correct answer.

The diaphragm is the main muscle used for breathing. It is a dome-shaped muscle located at the base of the lungs. When we inhale, the diaphragm contracts and moves downward, creating more space in the chest cavity and allowing the lungs to expand and fill with air. When we exhale, the diaphragm relaxes and moves upward, pushing the air out of the lungs. The diaphragm plays a crucial role in the process of respiration and is responsible for the majority of the work involved in breathing.

Gas exchange occurs from the alveoli into or out of the blood. This process involves the diffusion of gases, such as oxygen and carbon dioxide, across the thin walls of the alveoli and the surrounding capillaries. Oxygen from the alveoli diffuses into the bloodstream, where it binds to hemoglobin in red blood cells for transport to tissues. At the same time, carbon dioxide, a waste product of cellular respiration, diffuses from the bloodstream into the alveoli to be exhaled. Gas exchange is essential for maintaining proper oxygen levels in the body and removing carbon dioxide, allowing for efficient respiration.

Frogs are an example of animals that breathe by positive pressure breathing. Unlike humans who use negative pressure breathing, frogs force air into their lungs by creating a positive pressure in their mouth and throat. When a frog closes its nostrils and mouth, it lowers the floor of its mouth, which pushes air into its lungs. This type of breathing is necessary for frogs as they live both in water and on land, and positive pressure breathing allows them to inflate their lungs while keeping their mouth and nostrils closed underwater.

Carbon anhydrase is an enzyme that plays a crucial role in catalyzing the reaction between carbon dioxide and water in the lungs. By speeding up this reaction, carbon anhydrase helps to convert carbon dioxide into bicarbonate ions, which can then be transported through the bloodstream for elimination or used in other physiological processes. Without carbon anhydrase, this reaction would occur much more slowly, hindering the efficient exchange of gases in the lungs and potentially impacting overall respiratory function.

Hemoglobin is a protein found in red blood cells that binds to oxygen and carries it throughout the body. Oxygen is transported in the blood by binding to hemoglobin, forming oxyhemoglobin. Carbon dioxide, on the other hand, is primarily transported in the blood as bicarbonate ions. Therefore, the correct answer is oxygen, as it is carried in the blood by hemoglobin.

Carbon dioxide is in high concentration in the lung blood compared to the atmosphere. When blood reaches the lungs, carbon dioxide diffuses from the blood into the alveoli, which are tiny air sacs in the lungs. This process allows for the removal of carbon dioxide from the body during exhalation. Oxygen, on the other hand, is in higher concentration in the atmosphere compared to the lung blood. It diffuses from the alveoli into the blood, providing oxygen to the body's cells. Therefore, the correct answer is Carbon Dioxide.

During inhalation, the ribs move up and out due to muscular contraction. This is because the diaphragm, a large dome-shaped muscle located at the base of the lungs, contracts and flattens out. Simultaneously, the external intercostal muscles between the ribs contract, causing the ribs to move upwards and outwards. These actions increase the volume of the thoracic cavity, creating a negative pressure that allows air to rush into the lungs.

Alveoli are tiny air sacs in the lungs that are one layer thick and in close contact with capillaries. This close proximity allows for efficient gas exchange between the air in the alveoli and the blood in the capillaries. Oxygen from the inhaled air diffuses across the thin alveolar walls into the bloodstream, while carbon dioxide, a waste product, diffuses from the bloodstream into the alveoli to be exhaled. This arrangement maximizes the surface area available for gas exchange and ensures that oxygen can be efficiently delivered to the body's tissues.

The formation of carbonic acid, which occurs when carbon dioxide dissolves in water, acts as a stimulus for the increase in breathing rate. This is because carbonic acid is a byproduct of cellular respiration and needs to be eliminated from the body. To achieve this, the body increases the breathing rate, allowing more carbon dioxide to be exhaled and maintaining the balance of gases in the bloodstream.

Oxygen is in low concentration in the lungs compared to the atmosphere because it is constantly being used by the body for various metabolic processes. When we inhale, oxygen enters the lungs and diffuses into the bloodstream through the thin walls of the alveoli. From there, it is transported to the body's tissues where it is utilized for cellular respiration. On the other hand, carbon dioxide, which is produced as a waste product of cellular respiration, is in higher concentration in the lungs and is exhaled out of the body. Therefore, the correct answer is oxygen.

The term "lumen" refers to the central cavity or opening of a tubular structure, such as the trachea. In this context, it is explaining that within the lumen of the trachea, the cells lining its surface possess cilia. Cilia are hair-like structures that help in moving mucus and foreign particles out of the respiratory system.

The explanation for the answer "False" is that carbon dioxide is actually high in the blood and low in the cells. During cellular respiration, carbon dioxide is produced as a waste product and diffuses out of the cells into the bloodstream. From there, it is transported to the lungs where it can be exhaled. Therefore, the statement in the question is incorrect.

Ciliated cells are specialized cells found in the trachea that have hair-like structures called cilia on their surface. These cilia beat in coordinated motions, creating a wave-like movement that helps to move mucus upward in the trachea. This upward movement of mucus is important for clearing out any foreign particles, such as dust or pathogens, that may have been inhaled. Therefore, ciliated cells play a crucial role in maintaining the health and function of the respiratory system.

During inhalation, the diaphragm contracts and moves downward, while the intercostal muscles between the ribs contract, causing the ribcage to expand. This expansion creates more space in the cavity around the lungs, known as the thoracic cavity. As a result, the pressure within the thoracic cavity decreases. This decrease in pressure allows air to flow into the lungs, filling them with oxygen. Exhalation involves the relaxation of the diaphragm and intercostal muscles, which causes the thoracic cavity to decrease in size and increases the pressure. Therefore, the correct answer is "cavity" as it refers to the space around the lungs that expands and contracts during the inhalation and exhalation processes.

Frogs use a process called positive pressure breathing, where they take a mouthful of air, close their nostrils, and push the air into their lungs using the muscles in their mouth. This is different from humans and other mammals, who use negative pressure breathing, where the lungs expand and fill with air as the diaphragm and chest muscles contract. Positive pressure breathing allows frogs to force air into their lungs, enabling them to breathe effectively both on land and in water.

The respiratory rate is controlled by the acidity of the blood. When the blood becomes too acidic, the body increases the respiratory rate to remove excess carbon dioxide and restore the pH balance. On the other hand, when the blood becomes too alkaline, the respiratory rate decreases to retain carbon dioxide and maintain the acid-base balance. This regulation of respiratory rate helps to maintain homeostasis and ensure proper oxygenation of the body's tissues.

This answer is correct because oxygen is a molecule that consists of two oxygen atoms bonded together. It does not contain any peptides or iron. Carbon dioxide, on the other hand, is a molecule that consists of one carbon atom bonded to two oxygen atoms. Therefore, the correct answer is oxygen.

The opening to the trachea is in front of the opening to the esophagus (to the stomach).

Negative pressure breathing refers to the mechanism by which air is drawn into the lungs. In this process, the diaphragm and intercostal muscles contract, causing the volume of the thoracic cavity to increase. This increase in volume leads to a decrease in pressure within the thoracic cavity, creating a pressure gradient between the atmosphere and the lungs. As a result, air from the higher pressure atmosphere rushes into the lower pressure thoracic cavity, allowing for inhalation.

Carbonic acid plays a crucial role in the Bohr effect, which is the phenomenon where hemoglobin releases oxygen near the tissues. When carbon dioxide levels increase in the tissues, it diffuses into red blood cells and reacts with water to form carbonic acid. This reaction is catalyzed by an enzyme called carbonic anhydrase. Carbonic acid then dissociates into hydrogen ions and bicarbonate ions. The increase in hydrogen ions causes a decrease in pH, which weakens the bond between hemoglobin and oxygen, allowing oxygen to be released to the tissues. Therefore, carbonic acid helps in unloading oxygen from hemoglobin near the tissues.

The mucus produced by the ciliated cells acts as a sticky barrier that traps particles, such as dust and bacteria, preventing them from entering the lung alveoli. The cilia then move the mucus and trapped particles upward towards the throat, where they can be coughed out or swallowed. This mechanism helps to protect the delicate lung alveoli, which are responsible for gas exchange, from potential damage or infection caused by foreign particles.

Negative pressure breathing refers to the process by which air is drawn into the lungs due to a decrease in pressure within the chest cavity. During inhalation, the diaphragm and intercostal muscles contract, causing the chest cavity to expand. This expansion leads to a decrease in pressure within the lungs, creating a pressure gradient between the lungs and the atmosphere. As a result, air is pushed into the lungs from the higher pressure outside, allowing for inhalation to occur.