Respiratory System

Which represents the correct order of airflow in the lungs?

After air reaches the trachea, it travels through the bronchi, which branch into bronchioles before reaching the alveolar region of the lungs.

What happens when the diaphragm moves down?

Air is drawn into the lungs.The diaphragm is a muscle that plays a large role in breathing. It is found at the base of the lungs and spreads across the bottom of the rib cage, forming the chest cavity. The human body has two lungs that vary in size and weight. The right lung, which is larger and heavier, has three lobes. The left lung has two lobes.

Which describes pulmonary ventilation?

Air movement into and out of the lungs

What structure plays a role in air conduction?

Air-conducting portion: Air is delivered to the lungs. This region consists of the upper and lower respiratory tract—specifically, the larynx, trachea, bronchi, and bronchioles. Gas exchange portion: Gas exchange takes place between the air and the blood. This portion includes the lungs, alveoli, and capillaries.

Which body system plays a direct role in supplying oxygen to cells and eliminating carbon dioxide from cells?

Although the respiratory system ensures blood contains enough oxygen to be delivered to cells in the body, the cardiovascular system plays a direct role in supplying that oxygen to the cells.

Which forms a network around the alveoli to facilitate gas exchange?

Capillaries are small blood vessels. The walls of the alveoli share a membrane with the capillaries. This allows oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream. Oxygen from the air enters the body through the respiratory system. But the cardiovascular system circulates oxygen throughout the body via the blood. Gas exchange portion: Gas exchange takes place between the air and the blood. This portion includes the lungs, alveoli, and capillaries. The rib cage surrounds the lungs and the heart, it is vital in providing a bony protection for these vital organs. In the lungs, the bronchi branch into bronchioles before reaching tiny air sacs in the lung called alveoli. Gas exchange occurs in the alveolar region. Epithelial cells are cells that come from surfaces in the body, such as your skin, blood vessels, urinary tract, or organs. These cells act as a barrier between the inside and outside of your body, and protect it from viruses.

Which substance determines a person's blood pH level?

Carbon dioxide

What happens as the diaphragm relaxes?

Carbon dioxide is removed from the body.

What happens during internal respiration?

External respiration occurs between the lungs and blood. When a person inhales, alveoli fill with oxygen through diffusion. Oxygen content is much higher than carbon dioxide levels. While in the alveoli region, blood becomes oxygen-rich. Once oxygenated, the blood leaves the lungs and travels through the left side of the heart, where it is pumped into circulation. Internal respiration occurs between the blood and tissues. Once blood enters circulation, it reaches the capillaries. Oxygen diffuses through the capillaries into the cells. Carbon dioxide diffuses from the cells into the capillaries. Because carbon dioxide content is higher than oxygen content in blood at this point, it is called oxygen-poor blood. This oxygen-poor blood travels to the right side of the heart. It moves through the pulmonary circuit, where external respiration begins.

What process begins with red blood cells giving up oxygen to other cells in the body?

Internal respiration occurs between the blood and tissues. Once blood enters circulation, it reaches the capillaries. Oxygen diffuses through the capillaries into the cells. Carbon dioxide diffuses from the cells into the capillaries. Because carbon dioxide content is higher than oxygen content in blood at this point, it is called oxygen-poor blood. This oxygen-poor blood travels to the right side of the heart. It moves through the pulmonary circuit, where external respiration begins.

What structure channels food to the esophagus and air to the trachea?

Just below the pharynx is the larynx, or voice box. It channels air to the trachea and pushes food past the epiglottis, which covers the trachea during swallowing to prevent food from entering the lungs. Once food passes the epiglottis, it moves toward the esophagus. In the lungs, the bronchi branch into bronchioles before reaching tiny air sacs in the lung called alveoli. Gas exchange occurs in the alveolar region. Capillaries are small blood vessels. The walls of the alveoli share a membrane with the capillaries. This allows oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream. Oxygen from the air enters the body through the respiratory system. But the cardiovascular system circulates oxygen throughout the body via the blood. Gas exchange portion: Gas exchange takes place between the air and the blood. This portion includes the lungs, alveoli, and capillaries. Lungs are the primary organs of the respiratory system. The human body has two lungs that vary in size and weight. The right lung, which is larger and heavier, has three lobes. The left lung has two lobes.

Which describes the correct order of structures in the upper respiratory tract?

Nasal cavity, pharynx, larynx

Which organ, not belonging to the respiratory system, plays a direct role in external respiration?

Oxygen from the air enters the body through the respiratory system. But the cardiovascular system circulates oxygen throughout the body via the blood.

Which statement is true regarding gas concentration of blood leaving the left side of the heart?

Oxygen levels are high.

What process does the respiratory system use to facilitate gas exchange in and out of the lungs?

Pulmonary ventilation is the act of breathing, or respiration. The respiratory system uses this process to bring air into and out of the lungs. Refer to the following summary of respiration: Step 1. Air moves in and out of the lungs, which is called pulmonary ventilation. Step 2. Gases are exchanged between air and blood in the lungs by diffusion. Step 3. Gases are transported by circulation of the blood, with help from the heart. Step 4. Gases are exchanged by diffusion between blood and tissues throughout the body.

What structure is directly involved in gas exchange?

The alveolus is a tiny air sac found in the lung. Its primary function is to help the respiratory system perform gas exchange.

What structure changes shape during the mechanics of breathing?

The diaphragm is a muscle that plays a large role in breathing and is the primary muscle of inspiration. It is found at the base of the lungs and spreads across the bottom of the rib cage, forming the chest cavity. This dome shaped structure flattens when it contracts. The rib cage moves outward, allowing outside air to be drawn into the lungs. During relaxation, the diaphragm returns to its dome shape and the rib cage moves back to its natural position. This causes the chest cavity to push air out of the lungs. In the lungs, the bronchi branch into bronchioles before reaching tiny air sacs in the lung called alveoli. Gas exchange occurs in the alveolar region. The nasal cavity opens to the nose. The nose and nasal cavity warm and moisten air as a person breathes. As a defensive mechanism, tiny nose hairs and mucus produced by the epithelial mucosa cells in the nose help prevent particles in the air from entering the lungs. Behind the nasal cavity is the pharynx. Both food and air pass through this long tube.

Where are the vocal cords located?

The larynx is also referred to as the voice box because the vocal cords are housed there.

Which organ uses hairs to filter out particles that try to enter the lungs?

The nasal cavity opens to the nose. The nose and nasal cavity warm and moisten air as a person breathes. As a defensive mechanism, tiny nose hairs and mucus produced by the epithelial mucosa cells in the nose help prevent particles in the air from entering the lungs.

What is the function of the pharynx?

The pharynx is found right behind the nasal cavity. It is a passageway through which food and air flow.

Systemic circulation

The pulmonary vein pushes oxygenated blood into the left atrium. As the atrium relaxes, oxygenated blood drains into the left ventricle through the mitral valve. The left ventricle pumps oxygenated blood to the aorta. Blood travels through the arteries and arterioles before reaching the capillaries that surround the tissues.

Which body system works with the respiratory system to aid in blood pH regulation?

The respiratory system works closely with both the cardiovascular and nervous systems to maintain blood gas and pH homeostasis. The body must regulate blood pH levels. When there is too much carbon dioxide in the blood, it is acidic (that is, its pH value is too low). If there is not enough carbon dioxide in the blood, it will be too alkaline (its pH value will be too high).

The lungs have different sizes because of

The right lung is located under the rib cage, while the left lung is near the heart. Because of their anatomical positions, the lungs are different sizes.

How many lobes comprise the right lung?

The right lung is slightly larger and heavier than the left lung because it is comprised of three lobes. The left lung has two lobes.

After the trachea, the first branch that leads toward the lungs is the

The trachea, *bronchus*, and lungs belong to the lower respiratory tract. When air reaches the trachea, or windpipe, it travels down a long tube that branches into bronchi. The bronchi enter the lungs. As shown in the image, the bronchi branch into bronchioles before reaching tiny air sacs in the lung called alveoli. Gas exchange occurs in the alveolar region. Behind the nasal cavity is the pharynx. Both food and air pass through this long tube. Just below the pharynx is the larynx, or voice box. It channels air to the trachea and pushes food past the epiglottis, which covers the trachea during swallowing to prevent food from entering the lungs.

A person is diagnosed as having acidosis, a condition in which the blood pH is below 7.45. What does the doctor most likely conclude?

Too much carbon dioxide is found in the blood.

Pulmonary circulation

Two major veins, the Superior Vena Cava and the Inferior Vena Cava, brings deoxygenated blood from the upper and lower half of the body. Deoxygenated blood is pooled into the right atrium and then sent into the right ventricle through the tricuspid valve, which prevents blood from flowing backward. The right ventricle contracts, causing the blood to be pushed through the pulmonary valve into the pulmonary artery. Deoxygenated blood becomes oxygenated in the lungs. Oxygenated blood returns from the lungs to the left atrium through the pulmonary veins.

The diaphragm is found

at the base of the lungs.

As air rushes out of the lungs, the

diaphragm relaxes

Oxygen-rich blood is blood that

flows into systemic circulation.Systemic circulation The pulmonary vein pushes oxygenated blood into the left atrium. As the atrium relaxes, oxygenated blood drains into the left ventricle through the mitral valve. The left ventricle pumps oxygenated blood to the aorta. Blood travels through the arteries and arterioles before reaching the capillaries that surround the tissues.

Directly after diffusion occurs in the lungs,

gases are transported by blood into circulation. External respiration occurs between the lungs and blood. When a person inhales, alveoli fill with oxygen through diffusion. Oxygen content is much higher than carbon dioxide levels. While in the alveoli region, blood becomes oxygen-rich. Once oxygenated, the blood leaves the lungs and travels through the left side of the heart, where it is pumped into circulation. Internal respiration occurs between the blood and tissues. Once blood enters circulation, it reaches the capillaries. Oxygen diffuses through the capillaries into the cells. Carbon dioxide diffuses from the cells into the capillaries. Because carbon dioxide content is higher than oxygen content in blood at this point, it is called oxygen-poor blood. This oxygen-poor blood travels to the right side of the heart. It moves through the pulmonary circuit, where external respiration begins.

The oxygen concentration in blood that returns from systemic circulation is

less than the oxygen concentration in the tissues.

A characteristic of alveoli is that they are

tiny air sacs where gas exchange occurs.

Which organ branches off into the bronchi?

trachea

Why is it important to secrete mucous from epithelial cells?

Epithelial mucosal cells that line the nose secrete mucous as a defense mechanism to prevent particles from entering the lungs.