Podcast
Questions and Answers
What is the primary function of the oropharynx?
What is the primary function of the oropharynx?
Which structure acts as a passage for both food and air during swallowing?
Which structure acts as a passage for both food and air during swallowing?
Which cartilage is NOT part of the larynx?
Which cartilage is NOT part of the larynx?
Where does gas exchange primarily occur in the respiratory system?
Where does gas exchange primarily occur in the respiratory system?
Signup and view all the answers
Which structure conducts air into the lungs and has progressive branching?
Which structure conducts air into the lungs and has progressive branching?
Signup and view all the answers
What is a key feature of bronchioles?
What is a key feature of bronchioles?
Signup and view all the answers
What is the role of cilia in the bronchioles?
What is the role of cilia in the bronchioles?
Signup and view all the answers
Which type of bronchioles leads directly to the alveolar ducts?
Which type of bronchioles leads directly to the alveolar ducts?
Signup and view all the answers
What is the primary function of the lungs?
What is the primary function of the lungs?
Signup and view all the answers
Which of the following best describes the pleural cavity?
Which of the following best describes the pleural cavity?
Signup and view all the answers
How does oxygen travel from the alveoli into the bloodstream?
How does oxygen travel from the alveoli into the bloodstream?
Signup and view all the answers
What does the pulmonary artery carry to the lungs?
What does the pulmonary artery carry to the lungs?
Signup and view all the answers
What structure allows space for the heart within the left lung?
What structure allows space for the heart within the left lung?
Signup and view all the answers
Which nervous system plays a role in controlling airway dilation and constriction in the lungs?
Which nervous system plays a role in controlling airway dilation and constriction in the lungs?
Signup and view all the answers
What is the role of erythrocytes in pulmonary circulation?
What is the role of erythrocytes in pulmonary circulation?
Signup and view all the answers
Which statement about lung lobes is true?
Which statement about lung lobes is true?
Signup and view all the answers
What is the function of the pulmonary capillary network?
What is the function of the pulmonary capillary network?
Signup and view all the answers
Which muscle group primarily assists in each inhalation?
Which muscle group primarily assists in each inhalation?
Signup and view all the answers
What describes the structure of the hilum in the lungs?
What describes the structure of the hilum in the lungs?
Signup and view all the answers
During exhalation, which of the following occurs?
During exhalation, which of the following occurs?
Signup and view all the answers
How are the intercostal muscles organized?
How are the intercostal muscles organized?
Signup and view all the answers
What happens to the chest cavity during inhalation?
What happens to the chest cavity during inhalation?
Signup and view all the answers
What distinguishes the left hilum from the right hilum?
What distinguishes the left hilum from the right hilum?
Signup and view all the answers
What is the primary blood supply to the intercostal muscles?
What is the primary blood supply to the intercostal muscles?
Signup and view all the answers
Study Notes
Oxygen and Carbon Dioxide Exchange
- Oxygen (O2) diffuses through a single cell in an alveoli, followed by a single cell in a capillary to enter the bloodstream.
- At the same time, Carbon Dioxide (CO2) is released from the capillary to the alveoli and then exhaled.
Pleural Cavity and Membranes
- The pleural cavity is a fluid-filled space between the two pulmonary pleurae.
- The outer pleura (parietal) is attached to the chest (thoracic) wall.
- The inner pleura (visceral) covers the lungs and adjoining structures including blood vessels, bronchi, and nerves.
- The pleural cavity is considered a potential space because the two pleurae adhere to each other through a serous thin film (in normal conditions).
Anatomy of the Lungs
- The right lung consists of three lobes: superior, middle, and inferior.
- The left lung consists of two lobes: superior and inferior.
- A bronchopulmonary segment is a division of a lobe, and each lobe houses bronchopulmonary segments.
- Each segment receives air from its own tertiary bronchus and is supplied with blood by its own artery.
- A pulmonary lobule is a subdivision formed as the bronchi branch into bronchioles.
- Each lobule receives its own bronchiole that has multiple branches.
- An interlobular septum is a wall composed of connective tissue, separating the lobules.
Cardiac Notch
- The indentation seen on the left lung allows space for the heart.
Blood Supply to the Lungs
- The blood supply to the lungs plays an important role in gas exchange and serves as a transport system for gases throughout the body.
- Deoxygenated blood travels to the lungs where erythrocytes pick up oxygen to transport to body tissues.
- The pulmonary artery carries deoxygenated blood to the alveoli.
- One arteriole and one venule supply and drain one pulmonary lobule.
- As they near the alveoli, the pulmonary arteries become the pulmonary capillary network.
Alveoli
- The pulmonary capillary network consists of tiny vessels with very thin walls.
- This capillary network branches and follows the bronchioles and the structure of the alveoli.
- At this point, the capillary wall meets the alveolar wall creating the respiratory membrane.
- Once the blood is oxygenated, it drains from the alveoli by way of multiple pulmonary veins, which exit the lungs through the hilum.
Hilum
- The hilum is a wedge-shaped area on the central portion of each lung where the bronchi, arteries, veins, and nerves enter and exit the lungs.
- Both the right and left hilum are similar in size, but the left hilum is usually slightly higher in the chest than the right.
Intercostal Muscles
- The intercostal muscles are a group of muscles situated in the ribs.
- There are three layers that assist in the breathing process: external, internal, and innermost.
- They are innervated by the intercostal nerves, and blood supply is from the intercostal artery and vein.
Thoracic (Rib) Cage
- The thoracic cage surrounds and protects the heart and lungs.
- It is made up of 12 thoracic vertebrae, 24 ribs plus the sternum.
- The first seven ribs are attached to the sternum by costal cartilage.
- Of the remaining five, three have costal cartilage connected to the cartilage above and the last two floating ribs are connected by their cartilage to muscles in the abdominal wall.
Inhalation
- The diaphragm relaxes, the lungs expand.
- The innermost intercostal muscles relax while the external intercostal muscles contract, causing the chest cavity to expand.
- This expansion allows the lungs to fill with air due to the negative pressure created by the extra space.
- As air fills the lungs, gases are exchanged and it’s time to exhale.
Exhalation
- The chest cavity must become smaller.
- During exhalation, the diaphragm contracts (moves upwards), the external intercostal muscles relax, and the internal intercostal muscles contract (pulling the ribs downward).
- This causes the chest cavity to decrease in volume, which increases the pressure in the lungs, forcing air out.
Oropharynx
- The oropharynx is part of the pharynx.
- It is important that the oropharynx and associated structures prevent food or liquids from entering the lungs.
- If this happens, choking may ensue, potentially with fatal consequences.
Laryngopharynx
- The laryngopharynx is lined by stratified squamous epithelium.
- It works as a passage for food and air.
- During swallowing, the entry of air temporarily stops allowing the food to pass safely to the esophagus. This prevents food from entering our respiratory tract and from choking the trachea (windpipe).
Larynx
- The larynx allows air to pass through it while keeping food and drink from blocking the airway.
- It contains the vocal folds that produce the sounds of speech and singing.
- It is also known as the “voice box”.
- The larynx consists of:
- The thyroid cartilage (Adam's apple) - hyaline cartilage - The cricoid cartilage - hyaline cartilage - The epiglottis - elastic cartilage
Bronchi
- The bronchi conduct air into the lungs.
- The right and left bronchus branch into smaller secondary and tertiary branches which then branch into smaller tubes known as bronchioles.
- No gas exchange takes place in the bronchi.
- Contain progressively less cartilage and more smooth muscle.
Bronchioles
- No cartilage present: smooth muscle dominates.
- Progressing down the bronchioles, the muscle and connective tissue begin to disappear, and a single layer of epithelial cells remains: alveoli.
- The function of the Bronchioles is to deliver air to the network of millions of alveoli.
- There are three types of bronchioles:
- Lobular (these are the passages that first enter the lungs).
- Terminal (smaller passages in each lung).
- Respiratory (leading on from terminal branches that lead to alveolar ducts).
Cilia
- The lobular and terminal branches are often referred to as the dead space because no air exchange takes place in these passages.
- The bronchioles are tiny: 0.3–1 mm in diameter.
- The walls of the bronchioles are lined with finger-like projections known as cilia.
- The function of the cilia is to remove debris and microbes.
Alveoli
- Millions of alveoli….If stretched end to end they would cover a tennis court!
- Air exchange takes place here.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fascinating processes of oxygen and carbon dioxide exchange in the lungs. This quiz covers the anatomy of the lungs, including the pleural cavity and its membranes. Test your knowledge on the structure and function of the respiratory system.
